THE HIGHER CLASSIFICATION OF THE ORDER EMBIOPTERA: A CLADISTIC ANALYSIS

Cladistics (1996) 12:41–64

THE HIGHER CLASSIFICATION OF THE ORDER EMBIOPTERA: A CLADISTIC ANALYSIS Claudia A. Szumik Department of Entomology, American Museum of Natural History, Central Park West at 79th Street, New York, 10024, U.S.A. and CONICET, Facultad de Ciencias Naturales e Instituto Miguel Lillo, Miguel Lillo 205, 4000 S.M. de Tucuma´n, Argentina Received for publication 24 April 1994; accepted 24 July 1995 Abstract — A matrix of 41 Embiid taxa (representing the 8 formally recognized families of the Order) and 36 characters were cladistically analysed as a first attempt for understanding the higher classification of the Order Embioptera. The resulting trees were rooted with Clothodidae as the sister group of the other Embioptera. The results suggest that the current classification contains several artificial groups. With the rooting used, only Anisembiidae and Australembiidae are monophyletic. Embiidae is polyphyletic, as Australembiidae+ Notoligotomidae, Enveja (incertae sedis) and Oligotomidae+Teratembiidae appear within Embiidae, and the “embiid” Microembia appears within Notoligotomidae. Oligotomidae is paraphyletic in terms of Teratembiidae. Four of the genera included in the analysis are paraphyletic: Mesembia, Chelicerca (in terms of Dactylocerca and Pelorembia), Aposthonia (in terms of Oligotoma), and Metoligotoma (in terms of Australembia). Pelorembia and Dactylocerca are synonymized with Chelicerca.  1996 The Willi Hennig Society

Introduction The insect order Embioptera is a monophyletic group defined by several morphological and behavioral characters. The most striking apomorphy of these subsocial insects is their ability to produce silk in all instars from unicellular glands in the swollen first basitarsus (Barth, 1954; Alberti et al., 1976; Nagashima et al., 1991) and to use it to construct tunnels under bark, stones or soil. Other synapomorphies of the order are the prognathous head, presence of a gula, absence of ocelli, poorly developed compound eyes, three segmented tarsi, thickened hind femora, bisegmented cerci, secondary intromittent organs, ovipositor absent and wingless females (Hennig, 1981). In a cladistic analysis of insect orders (Wheeler et al., in prep.), Embioptera appeared as sister group of the Plecoptera by virtue of sharing tarsal plantulae, reduced phalomeres, a trocantin-episternal sulcus, separate coxopleuron and premental lobes. Most publications on the systematics of the order Embioptera are descriptions of new species and new records. Of all published research on this group, only three papers (Davis, 1938, 1940b; Ross, 1970) refer to their higher classification. Two of these contributions (Davis, 1938, 1940b) were based on systematic analyses, which, interestingly, used methods closely resembling parsimony methods used today. Davis (1938) chose 21 terminal taxa as representatives of the main lineages of Embioptera. He used seven multistate characters, coding the characters with numbers and the states with letters. Based on the distribution of character states observed in his representative taxa, he proposed a scheme (Fig. 1) that had 0748-3007/96/010041+24/$18.00/0

 1996 The Willi Hennig Society

Fig. 1. Tree of Davis (reproduced with permission from Proc. Linn. Soc. N.S.W. (1938) 65: 265, fig. 120).

42 C. A. SZUMIK

ORDER EMBIOPTERA: A CLADISTIC ANALYSIS

43

“been drawn up in the simplest possible way; convergence has not been invoked unless the opposite course does violence to any known facts.” (1938:266). Davis indicated on his cladogram all the changes (even the homoplastic ones), thereby allowing a complete reconstruction of his data set (Appendix 3). Although Davis included some terminal taxa at the nodes of the tree, he pointed out that that was not to be interpreted as a proposal of actual ancestry, but instead, “implied that the hypothetical ancestor resembled the existing form named—at least for those characters here dealt with—and that the existing type has changed little in these characters from this ancestor.” (1938:262). In a subsequent analysis, the same author (Davis, 1940b), using 55 taxa and 15 characters, presented four trees (each for a different geographic area), but this time specifying only the changes between hypothetical ancestors and terminal taxa. Ross (1970) proposed an entirely new classification. He divided the order into 4 subgroups and 14 families and rejected all previous classifications on the following grounds (1970:164): “No attempts will be made at this time to discuss the history of Embioptera classification. . . The great number of new species and higher categories known to the writer make all old classifications obsolete”. It is true that, after Davis’ work, the number of described genera and species of embiids greatly increased (mostly thanks to Ross’ excellent contributions). However, the discovery of new taxa is certainly not in itself a reason to refute any previous classification, particularly when the evidence cited in support for some of the groups in the new classification is weak. This lack of justification is extreme in several cases. For example, all information given by Ross for his new “Suborder B” (said to include Enveja bequaerti and undescribed species from Africa) is that it includes “. . . very large, often colorful embiids with distinctive features in almost every structure” (1970:169). A new “Family C” is proposed, but no information for the constituent genera and species is given, except that they are undescribed, they live in Peru´ and Colombia, and they have been discovered recently (1970:168). Previous work by Davis and Ross on the higher classification of Embioptera invites, for different reasons, a reanalysis of the problem. In the case of Davis’ work, it is tempting to examine to what extent results obtained in one of the first papers using cladistic techniques would hold 50 years later. In the case of Ross’ work, it is interesting to see to what extent a deep general knowledge of the group is sufficient in itself to erect groups which, given the lack of explicit justification and methodology, appear to be based on no more than intuition.

Methods and Materials CLADISTIC ANALYSIS Hennig86 (Farris, 1988) was used to calculate most parsimonious tree(s) under equal weights for all characters, with the commands mh* bb*. However, as argued by Farris (1969, 1983) and most recently by Goloboff (1993a), cladistic analysis depends on the weights assigned to the characters. Therefore, the program Pee-Wee (Goloboff, 1993b) was used to weight the characters and calculate tree(s) that give the highest weight for the characters. The quantity to be maximized is referred to as the “fit” of the characters, as the weight of a character is a function

44

C. A. SZUMIK

of its homoplasy or fit to a tree; the fit for each character is measured as a concave function of its number of extra steps (see Goloboff, 1993a, for justification and discussion). In this analysis, the concavity value of Pee-Wee was set at 5 and all characters were given a prior weight of 10. Character fits were then calculated as 50/5+R+ES, where R is the number of steps implied by polymorphisms in terminal taxa and ES is the number of extra steps on the tree. The total fit of all the characters is reported as rescaled fit (expressed as percentage) and was calculated using the formula 1−(max.fit−fit)/(max.fit−min.fit) (this formula is analogous to that of the retention index; see Goloboff’s 1993b documentation). Among all possible trees, the tree(s) with the highest total fit are chosen. The command mult* was used to search trees of highest fit, performing 50 replications of a random addition sequence Wagner tree each followed by tree bisection reconnection branch-swapping. The command jump* was used in an attempt to find additional fittest trees, swapping in trees suboptimal by a fit difference of up to 0·2. To compare the results with previous classifications the commands force, max/ and cmp of Pee-Wee were used. Force was used to define groups to be constrained for monophyly and max/ to search the fittest trees containing those groups. Then, cmp was used to check the difference in steps and fit of each character between the constrained and the best-fitting tree(s). To give some notion of how strong the support is for each clade in the tree, the commands swap, mv and cmp were used; these commands used in combination find the differences in fit and length when a clade or taxon is moved to another part of the cladogram. The program Clados (Nixon, 1992) was used to produce tree diagrams. Ambiguous optimizations were not considered as support for any clade (i.e. the ambiguous- option of Pee-Wee was used). The consensus tree does not show a single most parsimonious optimization, but instead those synapomorphies shared by 500 dichotomous parsimonious resolutions. This was accomplished with the command apo of Pee-Wee (Goloboff, 1993b), which can be used to find change common to sets of trees. Many more dichotomous parsimonious resolutions exist; these 500 were arbitrarily chosen. TAXA EXAMINED The trees were rooted with Clothodidae as the sister group to all other Embioptera, following the concepts of rooting and polarity most recently described in Nixon and Carpenter (1993). Clothodidae has been ‘’defined” (Davis, 1938, 1940b; Ross, 1970, 1984) as the family comprising the “simplest” Embioptera. All other embiids differ from clothodids and are united into a monophyletic group by being medium to small in size, having weak and incomplete wing venation, modified head and thoracic structures and asymmetrical male terminalia. The trees were rooted arbitrarily on Clothoda with Clothodidae as paraphyletic, but the root might as well have been placed on Antipaluria or Clothodidae. To make an analysis of the higher classification, one should include representatives of the different groups used by Davis and Ross. However, six of the 14 families mentioned by Ross (1970) are made up exclusively of undescribed genera and species. Ross claimed (1970:158) that the “. . . species and other details [would] be treated in a series of regional monographs . . .”, but more than 20 years later those

ORDER EMBIOPTERA: A CLADISTIC ANALYSIS

45

species still remain undescribed. Obviously, those presumed new families could not be included in this analysis. A matrix with 41 species in 32 genera and eight families was assembled (Table 1; see Appendix 1 for a complete list of specimens and vouchers). Each species used was chosen because it has a character combination corresponding to a taxon used in the classifications of Davis and Ross. To insure that no significant character combinations were excluded from the analysis, 51 other species were examined (see Appendix 2). CHARACTERS Characters 0, 4, 5, 7, 9, 23 and 24 were used by Davis (1938 and 1940b), and characters 2, 11, 13, 14, 15, 20 and 22 by Davis (1940b). The following abbreviations are used in the description of the characters. Wings: Rs, radial section; R1 , first radial; Ma, anterior medial vein; Mp, posterior medial vein; Cu, cubittal vein. Terminalia: Ep, epiproct; Lpp, left paraproct; H, hypandrium or ninth abdominal sternite; Hp, process of the hypandrium; LC1, basal segment of the left cercus; LC2, apical segment of the left cercus; RC1, basal segment of the right cercus; RC2, apical segment of the right cercus; 10T, tenth abdominal tergite; 10L, left hemitergite of the tenth abdominal tergite; 10R, right hemitergite of the tenth abdominal tergite. (0) Middle bladder of the hind basitarsus: 0, present; 1, absent. (1) Shape and chaetotaxy of the hind basitarsus: 0, broad and long with many setae on the ventral surface; 1, narrow and long with few setae on the ventral surface; 2, broad and short with few setae on the ventral surface. (2) Size of the male hind basitarsus middle bladder: 0, large; 1, small. (3) Female genital plate (Fig. 2): 0, central plate separated from lateral plates (Fig. 2a); 1, central plate partially fused to the lateral plates (Fig. 2b); 2, central plate fused to the lateral plates and differentiated from them on the posterior margin (Fig. 2c). Stefani (1953a) first described the subgenital plate (8th sternite) and made dissections in some species of Embia and Haploembia (Stefani, 1953a,b,c, 1955). Because his work suggested that this character could differentiate taxa, the female genitalia was examined for all taxa included here (if females were available). (4) Wings, Ma vein: 0, forked; 1, unforked. (5) Wings, Cu vein: 0, forked: 1, unforked. (6) Unions on the wing base between Rs+Ma and Mp with R1 and Cu veins (Fig. 3). 0, Rs+Ma and Mp fork together from Cu, a cross-vein present between Rs+Ma and R 1 (Fig. 3a); 1, Rs+Ma and Mp start separately from R1 and Cu (Fig. 3b); 2, Rs+Ma and Mp start fused from R1 and Cu (Fig. 3c). (7) Wings: 0, present; 1, absent. Apterism occurs in all families of the order; it can occur within a genus, a species, or even a population (Davis, 1938; Ross, 1984). Those species with both winged and wingless males (Anisembia texana, Chelicerca wheeleri and Notoligotoma nitens) were scored here as winged. (8) Mandibles (Fig. 4): 0, incisor and molar areas robust with many teeth without any space between them (Fig. 4a); 1, incisor area conspicuous, three teeth on the left mandible, two on the right, molar area with two or more teeth with a space between these areas (Fig. 4b); 2, incisor area with the same number of teeth as in 1, but sharper and located on the tip of the mandibles, molar area with few

Clothoda Antipaluria Archembia Conicerembia Dinembia Donaconethis Embia Machadoembia Metembia Microembia Neorhagadochir Pachylembia Pararhagadochir Parembia Pseudembia Scelembia Enveja Australembia M. convergens M. ingens A. borneensis A. glauerti Haploembia Oligotoma Teratembia Anisembia Bulbocerca C. dampfi C. davisi C. jaliscoa C. maxima C. wheeleri Dactylocerca M. catemacoa M. chamulae M. venosa Pelorembia Stenembia N. hardyi N. nitens Ptilocerembia

0 0 0 0 0 1 1 1 0 1 0 0 0 0 0 0 0 1 0 0 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1

0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 1 0 1 1 2 1 1 1 1 1 1 1 2 2 2 0 1 0 0 0

1 0 0 1 0 1 — — — 0 — 1 0 1 0 1 1 0 — 0 0 — — 0 — — — — — — — — — — — — — — — 0 0 —

2 2 2 1 1 1 — 1 1 1 — 2 1 2 — 1 1 — 0 — 0 2 2 — 2 2 2 — 2 2 2 2 2 2 2 2 2 2 2 — — —

3 0 0 0 0 0 0 0 0 0 0 0 — 0 0 0 0 0 — — — 1 1 — 1 0 1 — 1 1 — 1 1 1 1 1 1 — 1 1 1 0

4 0 0 1 1 1 1 1 1 1 1 1 — 1 1 1 1 1 — — — 1 1 — 1 1 1 — 1 1 — 1 1 1 1 1 1 — 1 1 1 1

5 0 1 1 2 1 — 0 0 0 2 1 — 1 1 0 1 1 — — — 2 2 — 2 2 1 — 1 1 — 1 1 1 1 1 1 — 1 1 1 1

6 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 1 1 0 0 1 0 0 0 1 0 0 1 0 0 0 0 0 0 1 0 0 0 0

7 1 1 2 1 1 1 1 1 1 3 2 2 2 1 1 2 6 0 0 0 3 3 6 3 3 4 4 5 5 4 5 5 4 5 5 5 0 5 1 3 3

0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 3 3 3 0 0 0 0 0 2 2 3 1 3 2 3 3 2 0 3 1 0 2 2 2

8 9 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 1 1 0 1 1 0 1 1 1

1 0 0 0 1 0 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1

1 — — 1 — 0 0 1 1 0 1 — — 1 2 0 1 2 0 0 0 — — — — — 1 1 1 1 1 1 1 1 1 1 1 1 — 1 0 1

2 — — 1 — 0 0 1 1 0 1 — — 1 1 1 1 1 1 1 1 — — — — — 1 1 1 1 1 1 1 1 1 1 1 1 — 1 1 1

3 0 0 1 1 1 1 1 1 1 1 0 0 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1

4 0 0 0 0 1 1 0 0 1 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

6 7 0 0 0 0 0 0 1 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

9 0 1 4 4 3 4 3 4 3 4 4 4 4 4 3 4 4 3 3 3 5 5 5 5 5 1 2 2 2 2 2 2 2 1 1 1 1 1 4 4 4

2 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1

1 — — 0 0 1 1 1 1 1 0 0 0 0 1 1 0 0 2 2 2 0 0 0 0 0 — — — — — — — — — — — — — 0 0 0

2 — 0 2 2 5 5 2 2 2 1 2 2 5 2 5 5 1 1 5 2 3 4 3 3 4 1 1 4 4 4 4 4 4 1 1 2 4 1 2 2 4

3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

4 5 — 0 2 4 2 2 2 2 2 2 4 1 4 2 2 2 3 1 2 1 3 3 2 3 3 1 1 3 3 3 3 3 3 1 1 1 3 1 2 2 2

Table 1 Data matrix. Character numbers and coding correspond to those indicated in the text

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1 0 0 0 0

6

8

9

3 0 1

0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 1 0 1 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 0 0 1 1 0 0 1 1 0 0 0 0 0 0 1 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 — — — — 0 0 0 0 0 0 0 0 0 0 0 — — — — 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 — 0 0 — 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 1 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2 3

5

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 1 0 1 0 0 0 0 0 0 1 0 1 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

4

46 C. A. SZUMIK

ORDER EMBIOPTERA: A CLADISTIC ANALYSIS

2a

47

2b

2c Fig. 2.

Female genital plate. (a) Australembia incompta; (b) Archembia sp.; (c) Antipaluria caribbeana.

R1 Rs+ Ma Mp Cu 3a Fig. 3.

3b

3c

Wing base unions. (a) Pseudembia truncata; (b) Mesembia venosa; (c) Oligotoma saundersii.

rounded teeth (Fig. 4c); 3, incisor area same as 2, but molar area with a conspicuous, sharp tooth (Fig. 4d); 4, ncisor area with 2 teeth on the left mandible, and one on the right, molar area same as 3 (Fig. 4e); 5, incisor area with one tooth on each mandible, molar area same as 3 (Fig. 4f); 6, mandibles curves, on each tip many rounded teeth incisor and molar area not differentiated (Fig. 4g). A great variety of shapes are exhibited by the mandibles. Some of those shapes are clearly distinct and easily identifiable (for example, states 3, 4 and 5). However, the distinction between some other states (e.g. 0, 1 and 2) is more difficult and some taxa could perhaps be scored differently for this character. This is the case for Parembia persica, Metembia ferox and Machadoembia angolica which were scored as having state 1, but might be scored state 2 as well. (9) Apical left cercus (LC2) (Fig. 5): 0, normal (Fig. 5a); 1, reduced (Fig. 5b); 2, fused to the basal segment but conspicuous (Fig. 5c); 3, fused and not distinguishable from basal segment (Fig. 5d). The form of the LC2 is variable in Anisembiidae. Chelicerca has species with states 1, 2 or 3, and the genus Mesembia includes species with states 0, 2 or 3. For both of these genera, several species (representing the variation in this character) were included in the matrix (Table 1). (10) Apical right cercus (RC2): 0, normal; 1, reduced. (11) Basal left cercus (LC1), macrosetae: 0, absent; 1, present. (12) LC1, macrosetae distribution: 0, on apical and basal area; 1, on apical area

48

C. A. SZUMIK I M

4a

4b

4d

4c

4e

4f

4g

Fig. 4. Mandibles. (a) Australembia incompta; (b) Dinembia ferruginea; (c) Machadoembia angolica; (d) Microembia rugosifrons; (e) Anisembia texana; (f) Chelicerca wheeleri; (g) Haploembia.

5a

5b

5c

5d

Fig. 5. Left cercus. (a) Aposthonia borneensis; (b) Microembia rugosifrons; (c) Mesembia catemacoa; (d) Chelicerca jaliscoa.

only; 2, on basal area only. Dactylocerca flavicollis and Chelicerca jaliscoa have some middle-basal macrosetae (Fig. 5d), and therefore could have state 0 (instead of 1, as scored here). Other taxa with state 0, however, have many more macrosetae in the basal area. (13) LC1, macrosetae size: 0, large; 1, small. (14) LC1, apical nodule: 0, absent; 1, present. (15) LC1, basal nodule: 0, absent; 1, present. (16) LC1, basal and lateral process: 0, absent; 1, present. (17) LC1, base: 0, narrow; 1, broad. (18) LC1, inner side: 0, not depressed; 1, depressed. (19) RC1, shape: 0, normal; 1, reduced to a broad base. (20) Tenth abdominal tergite (10T) (Fig. 6): 0, only one sclerotized plate (Fig. 6a); 1, two plates (10L and 10R) more or less fused to each other on the basal half (Fig. 6b); 2, 10L and 10R with irregular inner margins and with a central membranous area between both plates (Fig. 6c); 3, 10L and 10R with well-differentiated

ORDER EMBIOPTERA: A CLADISTIC ANALYSIS

6a

49

6b

6d

6c

6e

6f

Fig. 6. Tenth abdominal tergire. (a) Clothoda longicauda; (b) Stenembia perenensis; (c) Chelicerca jaliscoa; (d) Metembia ferox; (c) Scelembia malkini; (f) Oligotoma saundersii.

7a

7b

7c

7d

7e

7f

Fig. 7. Process of the left hemitergite of the tenth abdominal tergite. (a) Antipaluria caribbeana; (b) Australembia incompta; (c) Machadoembia angolica; (d) Aposthonia sp; (e) Chelicerca jaliscoa; (f) Pararhagadochir trachelia.

inner margins and fused on the base with a sclerotized band (Fig. 6d); 4, two plates, 10R with a membranous basal area and sclerotized basal band present (Fig. 6e); 5, 10R apical half not fused with the rest of the tergite (Fig. 6f). (21) 10R, second process: 0, absent; 1, present. (22) 10R, second process form: 0, rod-like, very sclerotized; 1, lateral flap not extended over the 10L, more or less sclerotized; 2, lateral flap extended over the 10L, sclerotized. (23) 10L, process (Fig. 7): unsclerotized lobe (Fig. 7a); 1, more or less sclerotized lobe (Fig. 7b); 2, sclerotized flat hook (Fig. 7c); 3, more or less sclerotized twisted oval leaf (Fig. 7d); 4, inner and outer margins differentiated in hook and membranous portions, fused to each other (Fig. 7e); 5, same as 4 but partially or totally separated (Fig. 7f). Some species of Oligotoma (not included in the matrix) have state 4; the only species of Oligotoma included (O. saundersii) has state 3. An extra step was therefore added to this character.

50

C. A. SZUMIK

(24) 10R, first process: 0, unsclerotized lobe; 1, sclerotized lobe; 2, sclerotized sharp hook; 3, sclerotized lobe with a small thorn on the dorsal surface; 4, same as 3, but with a long spine instead of the small thorn. (25) H and Hp: 0, Hp fused to H; 1, Hp separated of H. (26) Sclerotized hook on the posterior area of the Hp: 0, absent; 1, present. (27) Hp, denticles: 0, absent; 1, present. (28) Posterior side of the Lpp turned on the right as a flat hook: 0, absent; 1, present. The genus Pararhagadochir is polymorphic for this character because some species do not have a flat hook in the Lpp. Therefore, 1 extra step was added to this character. (29) Lpp, nodule: 0, absent; 1, present. In Embia and Pseudembia the nodule can be present or absent; two extra steps were added. (30) Lpp, denticles: 0, absent; 1, present. (31) Lpp, sclerotized spine: 0, absent; 1, present. Species of Embia may either have or lack this spine; 1 extra step was added. (32) Ep denticles: 0, absent; 1, present. (33) Lpp reduced to a long sclerotized spine: 0, absent; 1, present. (34) Length of the Hp and H: 0, Hp short, minor than H; 1, Hp longer (longer than H). (35) Hp: 0, rectangular; 1, circular. Results Pee-Wee produced three trees of maximum fit (378·84 [58%]), 132 steps long. Two of those trees differ only in the partial resolution of the group formed by Chelicerca davisi+C. dampfi+C. jaliscoa+Dactylocerca; the third is the same as the strict consensus of the three. All of the characters require the same number of steps on the three trees; the different resolutions result only from ambiguities in optimizations. The discussion will use as reference the strict consensus (Fig. 8). The black boxes indicate only unambiguous synapomorphies, common to 500 dichotomous parsimonious resolutions (see Methods section), and the white boxes indicate synapomorphies present in only some of the resolutions. Only those changes occurring in all trees are considered to be synapomorphies of the groups, but those occurring in some of the trees might become unambiguous if future evidence allows further resolution of the cladogram (i.e. forbid some of the possible resolutions!). The three trees of highest fit found with Pee-Wee are not among the 2275 (bb* overflow; length=131, CI=45, RI=74) found by Hennig86 with all characters equally weighted and non-additive (they are one step longer). The strict consensus of those 2275 trees is almost totally unresolved, but each of its groups is also present in the consensus of the three Pee-Wee trees. The groups in common are: Neorhagadochir+Pachylembia, Aposthonia borneensis+Oligotoma, Australembia+Metoligotoma convergens+M. ingens, Archembia+(Pararhagadochir+Scelembia), Chelicerca davisi+C. dampfi+(C. jaliscoa+Dactylocerca). Discussion Anisembiidae—This is one of only two families which are monophyletic in the present analysis. The group is characterized by the absence of middle bladder

ORDER EMBIOPTERA: A CLADISTIC ANALYSIS

51

Fig. 8. Consensus of the three fittest trees. CLO, Clothodidae; ANI, Anisembiidae; EMB, Embiidae; OLI, Oligotomidae; TER, Teratembiidae; NOT, Notoligotomidae; AUS, Australembiidae; INC, incertae sedis. Black hashes indicate unambiguous synapomorphies occurring in all of 500 dichotomous parsimonious resolutions and white hashes indicate synapomorphies occurring in only some.

(char. 0), Ma vein unforked (char. 4), and mandibles with incisor and molar area with only one tooth (char. 8). Two of the three trees obtained in the present analysis differ in the partial resolution the group formed by Chelicerca davisi+C. dampfi+C. jaliscoa+Dactylocerca, the

52

C. A. SZUMIK

third tree is identical to the consensus tree of the other two. These two partial resolutions are based on two possible optimizations of the highly homoplastic character 8 (mandibles). One of the trees groups C. davisi and C. dampfi by having an incisor and molar area with one tooth (state 5), the other groups C. jaliscoa and Dactylocerca by having one and two teeth on the right and left incisor (state 4). If char. 12, of dubious scoring for Dactylocerca flavicollis and C. jaliscoa was scored as having state 0 in those taxa, the results would remain unchanged (with state 0 appearing as a synapomorphy of those two taxa). The genus Chelicerca appears as paraphyletic; some of its species are more closely related to Pelorembia (sharing a hook on the Hp [char. 26]) and others to Dactylocerca (sharing the presence of denticles on the Hp [char. 27] and the hypandrial shape [char. 35]). Two species of Chelicerca not included in the present analysis (C. grandis and C. callani) have plesiomorphic states for those three characters; given their character combinations it is likely that those species, if included, would appear as sister group of the other species of Chelicera+Dactylocerca+Pelorembia.

Table 2 Character statistics, according to the trees with fit 278.84 Character 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

Steps (E.S.)

Weight

CI

RI

6 (5) 7 (5) 3 (2) 4 (2) 3 (2) 1 (0) 6 (4) 6 (5) 13 (7) 9 (6) 2 (1) 2 (1) 5 (3) 2 (1) 3 (2) 3 (2) 2 (1) 1 (0) 1 (0) 1 (0) 8 (3) 1 (0) 2 (0) 16 (11) 9 (5) 1 (0) 1 (0) 1 (0) 1 (0) 3 (2) 1 (0) 3 (2) 2 (1) 1 (0) 1 (0) 1 (0)

5·00 5·00 7·14 7·14 7·14 10·00 5·55 5·00 4·16 4·54 8·33 8·33 6·25 8·33 7·14 7·14 8·33 10·00 10·00 10·00 6·25 10·00 10·00 2·94 5·00 10·00 10·00 10·00 10·00 5·55 10·00 6·25 8·33 10·00 10·00 10·00

16 28 33 50 33 100 33 16 40 33 50 50 40 50 33 33 50 100 100 100 62 100 100 31 44 100 100 100 100 33 100 33 50 100 100 100

70 68 60 77 85 100 55 28 70 60 94 90 62 50 60 50 0 100 100 100 86 100 100 52 76 100 100 100 100 66 100 33 50 100 100 100

Ross, 1970

Oligotomidae monophyletic

Notoligotomidae monophyletic

Embiidae monophyletic

Anisembiidae monophyletic

Tree

Length diff. 6

4 3 6 18

Fit diff.

−8·18

−6·21

−1·13

−3·44

−19·77 1(1,0·55); 23(1,0·18) 31(1,0·89)

13(1,1·67); 14(1,1·19)

13(1,1·67); 14(1,1·19); 23(1,0·18)

23(3,0·39); 31(1,0·89)

1(2,1·25); 8(2,0·84); 13(1,1·67);

Characters with better fit

0(2,0·84); 2(1,0·89); 8(1,0·24); 9(1,0·38); 10(3,2·78); 11(1,1·10); 12(1,0·70); 14(1, 0·89); 18(1,1·67); 20(1,0·7); 21(1,1·67); 24(1,0·46); 26(1,1·67); 27(1,1·67); 28(1,1·67); 29(1,0·55); 33(1,1·67); 35(1,1·67)

0(2,0·84); 1(1,0·46); 2(1,0·89); 11(1,1·19); 12(1,0·70); 29(1,0·55); 33(1,1·67)

0(2,0·84); 2(1,0·89); 11(1,1·19); 12(1,0·70); 29(1,0·55)

0(2,0·89); 4(1,0·89); 10(1,1·19); 11(1,1·19); 12(1,0·70); 18(1,1·67); 20(1,0·70); 29(1,0·55)

2(1,0·89); 9(1,0·38); 10(1,1·19); 11(2,2·08); 14(1,1·19); 23(1,0·18) 12(1,0·70); 21(1,1·67); 24(2,0·84) 26(1,1·67); 27(1,1·67); 29(1,0·55); 35(1,1·67)

Characters with worse fit

Table 3 Fit difference between the fittest tree and trees having the groups indicated as monophyletic. For the difference in fit in individual characters, the numbers in parentheses indicate (step difference, fit difference)

ORDER EMBIOPTERA: A CLADISTIC ANALYSIS 53

54

C. A. SZUMIK

Pelorembia was created for a single species with highly modified head, mandibles and terminalia, but those characters are autapomorphies and this species and Dactylocerca are both within the Chelicerca clade. Ross was aware of the paraphyly of Chelicerca in terms of Pelorembia and Dactylocerca: “In spite of the simplicity of the terminalia, the affinities of the genus [Pelorembia] appear to be with the wheeleri group of Chelicerca . . . Dactylocerca appears to be derived from the davisi group of Chelicerca. Some species of these genera could almost be assigned to either, but the bulk of Dactylocerca are clearly generically distinct.” (1984:41, 38). Chelicerca must now be considered to be the senior synonym of Pelorembia and Dactylocerca. Constraining the monophyly of all anisembiid genera implies an additional six steps, saving steps in 5 characters and sacrificing them in 11 (Table 3). Oligotomidae+Teratembiidae—Both families share the 10R apical half not fused with the rest of the tergite (char. 20, state 5) and the Hp prolonged and curved (char. 34). Haploembia is the sister group of the other Oligotomidae and Teratembiidae (here represented only by Teratembia), which share the absence of a bladder (char. 0) and a narrow and long basitarsus with few setae (char. 1). Both characters are quite homoplastic; the loss of the middle bladder, in particular, occurs repeatedly in the order. A third shared character is the lobe with a sharp thorn on the dorsal surface of 10R (char. 24), a state also found in some anisembiids. Davis (1940b:536) listed a series of characters shared by Oligotomidae and Teratembiidae but was still of the opinion that they were not closely related. Ross (1970) grouped Oligotomidae+Teratembiidae in his “suborder C”, although he did not explain the basis for this action. Aposthonia was synonymized with Oligotoma by Davis (1940b). In 1951, Ross treated Aposthonia as a subgenus of Oligotoma, but later as a genus (1963; discussing some Australian species of Aposthonia). The present results suggest that Aposthonia is paraphyletic. The character linking it to Oligotoma is the Ma unforked (char. 4), a state found also in Anisembiidae and Notoligotoma. A. borneensis and O. saundersii share the shape of the Lpp (char. 34), but this character is actually absent in some Aposthonia. The generic limits made by Ross for these genera seem to have been based, not on morphological characters, but only on the assumption that the species of India would fit in Oligotoma, and those of Australia and the Pacific in Aposthonia. The actual limits between the two genera (which include, in total, 34 species) seem more complex than suggested by this simple geographic delimitation and constitute a problem exceeding the scope of this paper. Constraining the monophyly of Oligotomidae and its genera implies a total increase of 8 steps (shorter for 2 characters and longer for 7; Table 3). Notoligotomidae+Australembiide—Notoligotomidae was one of the families most studied by Davis (1936a,b, 1938, 1940a, 1942a,b, 1944a,b) and he included Notoligotoma, Ptilocerembia, Embonycha, Burmitembia and Metoligotoma in it. In 1963, Ross made several significant changes to the composition of Notoligotomidae. He removed Embonycha and gave it familial status, providing a typically gradistic justification: “Although Embonycha appears to have developed from the same stock as Notoligotoma, it seems sufficiently differentiated to justify a separate family” (1963:123). Burmitembia was also removed from the family, but it was not explicitly placed elsewhere, so it has been treated as incertae sedis. Metoligotoma was also removed and included with Australembia in the newly erected family Australembii-

ORDER EMBIOPTERA: A CLADISTIC ANALYSIS

55

dae. As a result of the changes made by Ross, the family Notoligotomidae eventually contained only three species and two genera, Ptilocerembia roepkei, Notoligotoma hardyi and Notoligotoma nitens. In his 1963 paper, Ross listed the characters supporting his view that Australembiidae is not related to any other group of Embioptera. It is obvious that Australembiidae is a monophyletic group (since it is supported by numerous, almost nonhomoplastic characters), but it is no less obvious that (unless it is the sister group of all other Embioptera, a hypothesis easily rejected by numerous characters) it must be more closely related to some Embioptera than to others. The problem is which one. According to Ross (1970) Australembiidae is the only family in his “suborder B”, and Notoligotomidae belongs to the suborder “Embioptera”, together with Embiidae, Clothodidae and Anisembiidae. In the best fit trees presented here, however, Notoligotomidae and Australembiidae are grouped by having the LC2 fused to the LC1 but conspicuous (char. 9) and by the reduced RC2 (char. 10). Both characters are also found in some anisembiids. Notoligotomidae, as defined by Ross, is paraphyletic because Ptilocerembia is more closely related to Microembia Ross (Embiidae) than to Notoligotoma (Fig. 8). Ptilocerembia and Microembia are grouped by having no middle bladder (char. 0). Constraining the monophyly of Notoligotomidae increases the tree length by three steps. The fit decreases only slightly, but only three characters are favored (while five have a worse fit). Microembia (Embiidae) is a genus with a complex character combination and important autapomorphies. Ross (1944) did not make his reasons for including the genus in Embiidae explicit, but it can be assumed that it was because of its forked Ma, because that is the only character shared with embiids (and teratembiids). The absence of the middle bladder (char. 0), the type of mandibles (char. 8) and the form of the 10T (char. 20) relate this genus to Teratembiidae. The absence of the middle bladder and the type of genitalia (char. 10, 23, 24) relate it to some Anisembiidae. Other possible placements of Microembia included as sister group of either Notoligotoma or Australembiidae, or Australembiidae+Notoligotomidae, but all of these imply a decrease in fit as small as 0·46 (adding a step in char. 0). Embiidae—As currently delimited, the Embiidae is one of the largest families in the order, with representatives in all continents except Australia. In the trees of maximum fit, the family appears polyphyletic. Forcing the monophyly of Embiidae (and Ross’ subfamilies) implies eight additional steps and a decrease in fit of 5·56, improving the fit for 4 characters and decreasing it for 10 (Table 3). The Neorhagadochir+Pachylembia clade diverges first from the tree because its members lack a process and denticles in the LC1 separate it from the other Neotropical embiids. The monophyly of Neorhagadochir+Pachylembia is supported by the type of mandible (state 2, char. 8), the exclusive basal broadening of the LC1 (char. 17) and the presence of a nodule and denticles in the Lpp (chars. 29 and 30, present in other embiid genera as well). Conicerembia has some modifications that obscure its possible relationships with other Neotropical embiids, particularly in the shape of the LC1. For example, making Conicerembia the sister group of Teratembia+Oligotomidae implies a decrease in fit of only 0·19, saving one step in char. 6 and adding another in char. 3 (as char. 6 is more homoplastic than 3, the trees that save a step in char. 3 are slightly preferable, even if having the same absolute number of steps).

C. A. SZUMIK

Fig. 9.

Australembiidae

Suborder A

Teratembiidae Oligotomidae

Suborder C

Unnamed family

Suborder B

Anisembiidae

Embiidina

Australembia M. convergens M. ingens Teratembia Haploembia Oligotoma A. borneensis A. glaverti Enveja Anisembia Bulbocerca Dactylocerca Pelorembia Stenembia M. catemacoa M. chamulae M. venosa C. davisi C. dampfi C. jaliscoa C. maxima C. wheeleri Ptilocerembia N. hardyi N. nitens Donaconethis Embia Machadoembia Metembia Parembia Dinembia Pseudembia Conicerembia Microembia Neorhagadochir Pachylembia Parahagadochir Scelembia Archembia Clothoda Antipaluria

Notoligotomidae

Embioptera

Embiinae

Subfamily D

Embiidae

56

Subfamily B Subfamily A Clotodidae

Tree containing all the groups in the classification proposed by Ross (1970).

Two groups of embiid genera appear as sister taxa to Conicerembia, each supported by several synapomorphies (Fig. 8). The relationship between these two groups is not resolved and they are part of a trichotomy, together with Australembiidae+Notoligotomidae. This group is supported by the presence of macrosetae in the LC1 (char. 11), with parallelism in some anisembiids). The resulting trees imply a lot of homoplasy in the mandibles (char. 8). Therefore, this character exerts little influence in the results. Using an alternative scoring for doubtful taxa (the case of Metembia ferox, Machadoembia angolica and Parembia persica, see section on Characters) or even deactivating the character, does not change the results (the alternative scoring would only add to tree length). According to Ross (1970), Enveja belongs in the “Suborder B” (monotypic). Enveja appears here grouped with other African and Asian embiids sharing the presence of macrosetae in the basal part of the LC1 (char. 12). An alternative, only slightly inferior placement for Enveja would be as sister group of Embiidae+ Teratembiidae+Oligotomidae+Australembiidae+Notoligotomidae, with a decrease in fit of only 0·52 (saving one step in characters 14 and 13, and adding it in 11 and 12).

ORDER EMBIOPTERA: A CLADISTIC ANALYSIS

57

The present analysis includes roughly half of the described embiid genera (most of the unrepresented genera are small, highly autapomorphic and containing only one or two species). It is evident that the family Embiidae should be redelimited (as currently saying Embiidae is almost equivalent to saying “non-Anisembiidae and non-Clothodidae”), but such redelimitation requires a more detailed analysis. COMMENTS ON PREVIOUS CLASSIFICATIONS Classification of Ross (1970) Given that Ross did not provide either a matrix or explicit character information to support his groupings, his classification can only be judged by its fit to the present data set. The best-fit trees which contain all of Ross’ groups (Fig. 9) are 22 steps longer than the best-fit unconstrained trees. These trees gives a better for 4 characters, worse for 20, and implies an overall decrease in fit of 23·36 (Table 3). Those results show that Ross’ classification is far from being the most explanatory for the current set of data. Classification of Davis (1938, 1940b) Two types of comparisons are relevant here: first, to what extent Davis was successful in finding the trees which best explain his own data, compared to modern methods of tree-searching with computer programs, and second, to what extent Davis’ results are stable to the addition of new evidence. In his two papers, Davis used 7 (in 1938) and 15 characters (in 1940b) to support his schemes of relationships. All the characters used by Davis in those two analyses were included in the matrix of Table 1. On the basis of the information provided in the tree of Davis (1938, reproduced here in Fig. 1), it is possible to unequivocally assign states for all characters for each of the terminals (see Appendix 3; some of Davis’ 7 characters were recoded in binary form and therefore the matrix contains 11 characters). On the basis of those data, as scored by Davis (1938), Pee-Wee produces eight trees (29 steps long). The tree proposed by Davis is only 3 steps longer, and it agrees with the best fit trees in showing as monophyletic Metoligotoma, Notoligotoma and the species now included in Aposthonia (included by Davis in Oligotoma). In the global analysis based on the complete data set (which includes all of Davis’ characters; Table 1), Aposthonia appears paraphyletic because some species are more closely related to Oligotoma (as already discussed under Oligotomidae). However, it must be noted that Davis did not include any species of Oligotoma sensu Ross in his analysis. Davis’ tree and the global analysis both support the monophyly of Metoligotoma and Notoligotoma, as well as the group formed by Bulbocerca+Anisembia. In 1940b, Davis presented four separate trees, indicating only the putative synapomorphies of the clades. Because not all the homoplastic changes are indicated on the tree it is not possible to reconstruct Davis’ original data. In those trees, the family Anisembiidae, the genera Metoligotoma and Notoligotoma and Anisembia+ Chelicerca (present in the trees of best fit for the complete data set) appear as monophyletic; in most cases, the characters proposed by Davis (1940b) as synapomorphies for those taxa do indeed appear as their synapomorphies in the global analysis. In conclusion, the most interesting aspect of Davis’ classification is that he pro-

58

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posed that Metoligotoma belonged in Notoligotomidae (whereas Ross placed that genus in the Australembiidae) and that Embiidae (considered as a family by Ross) was a polyphyletic group. The evidence presented here clearly supports Davis’ point of view.

Acknowledgements The material used in this analysis was available as a courtesy of Abraham Willink (IFML), Axel O. Bachmann (MACN), Alcide Costa and Ricardo P. da Rocha (MZSP), G. B. Monteith and Robert J. Raven (QM), John E. Rawlins (CMNH), David G. Furth (MCZ), David A. Nickle (USNM), Randall T. Schuh (AMNH), and Edward S. Ross (CAS). James K. Liebherr (Cornell University, Ithaca), Norman I. Platnick (AMNH), Axel O. Bachmann (MACN), Elisa Angrisano (Universidad de Buenos Aires) and Abraham Willink (IFML) provided working space and help at different stages of my research. Axel O. Bachmann, James M. Carpenter, Pablo A. Goloboff, Diana Lipscomb, Arturo Roig Alsina and two anonymous reviewers provided useful comments on different versions of the manuscript. The encouragement by James M. Carpenter was greatly appreciated.

REFERENCES ALBERTI, V. G. AND V. STORCH. 1976. Transmission und Rasterelektronen Mikroskopische Untersuchung der Spinndrusen Von Embien (Embioptera, Insecta). Zool. Anz. 197: 179–186. BARTH, R. 1954. I. Untersuchgen an den Tarsaldrusen von Embolyntha batesi MacLachlan, 1877 (Embioidea). Zoologische Jahrbuecher (Anatomie) 74: 172–188. DAVIS, C. 1936a. Studies in Australian Embioptera. Part I: Systematics. Proc. Linn. Soc. N.S.W. 61: 229–253. DAVIS, C. 1936b. Studies in Australian Embioptera. Part II: Further notes on systematics. Proc. Linn. Soc. N.S.W. 61 254–258. DAVIS, C. 1938. Studies in Australian Embioptera. Part III: Revision of the genus Metoligotoma, with descriptions of new species, and other notes on the family Oligotomidae. Proc. Linn. Soc. N.S.W. 63: 226–272. DAVIS, C. 1940a. Studies in Australian Embioptera. Part IV: Supplementary taxonomic notes. Proc. Linn. Soc. N.S.W. 65: 155–160. DAVIS, C. 1940b. Taxonomic notes of the Order Embioptera. Part XX: The distribution and comparative morphology of the Order Embioptera. Proc. Linn. Soc. N.S.W. 65: 533–542. DAVIS, C. 1942a. Studies in Australian Embioptera. Part V. Geographical variation in Metoligotoma reducta Davis. Proc. Linn. Soc. N.S.W. 67: 331–334. DAVIS, C. 1942b. Studies in Australian Embioptera. Part VI. Records of the genus Metoligotoma from Victoria. Proc. Linn. Soc. N.S.W. 68: 65–66. DAVIS, C. 1944a. Revision of the Embioptera of Western Australia. J. R. Soc. West. Aust. 28: 135–147. DAVIS, C. 1944b. Studies in Australian Embioptera. Part VII: New Embioptera from tropical Australia. Proc. Linn. Soc. N.S.W. 69: 16–20. FARRIS, J. S. 1969. A successive approximations approach to character weighting. Syst. Zool. 18: 374–385. FARRIS, J. S. 1983. The logical basis of phylogenetic analysis. In: N. Platnick and V. Funk (eds) Advances in Cladistics 2. Proceedings of the Second Meeting of the Willi Hennig Society. Columbia Univ. Press, New York, pp. 7–36. FARRIS, J. S. 1988. Hennig86. Vers. 1.5. Port Jefferson Station, New York.

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GOLOBOFF, P. A. 1993a. Estimating character weights during tree search. Cladistics 9: 83–91. GOLOBOFF, P. A. 1993b. Pee-Wee. Vers. 2.15. San Miguel de Tucuma´n, Argentina. HENNIG, W. 1981. Insect Phylogeny. In: A. C. Pont. (ed.), Chichester (Eng.), New York, 514 pp. NAGASHIMA, T., N. NIWA, S. OKAJIMA AND T. NONAKA. 1991. Ultrastructure of silk gland of webspinner Oligotoma japonica (Insecta: Embioptera). Cytologia (Tokyo) 56: 679–685. NIXON, K. C. 1992. Clads. Vers. 1.2. Trumansburg, New York. NIXON, K. C. AND J. M. CARPENTER. 1993. On outgroups. Cladistics 9: 413–426. ROSS, E. S. 1944. A revision of the Embioptera or web-spinners, of the New World. Proc. U.S. Nat. Mus. 94: 401–504. ROSS, E. S. 1951. A new species of Embioptera from Oceania. Proc. Hawaii. Entomol. Soc. 14: 307–310. ROSS, E. S. 1963. The families of Australian Embioptera, with descriptions of a new family, genus and species. Wasmann J. Biol. 21: 121–136. ROSS, E. S. 1970. Biosystematics of the Embioptera. Annu. Rev. Entomol. 15: 157–172. ROSS, E. S. 1984. A classification of the Embiidina of Mexico with descriptions of new taxa. Occas. Pap. Calif. Acad. Sci. 140: 1–56. ROSS, E. S. 1987. Studies in the insect order Embiidina: A revision of the family Clothodidae. Proc. Calif. Acad. Sci. 45: 9–34. STEFANI, R. 1953a. La fisiologia dell’ accopiamento in Haploembia solieri Ramb. (Embioptt. Oligotomidae). Atti. Accad. naz. Lincei Rc., Rome, 15: 211–216. STEFANI, R. 1953b. Un particolare modo de accopiamento negli Insetti Embiotteri. Atti. Accad. naz. Lincei Rc., Rome 15: 544–549. STEFANI, R. 1953c. Nuovi Embiotteri della Sardegna. Boll. Soc. Entomol. Ital., Genoa 83: 84–98. STEFANI, R. 1955. Revisione del genere Haploembia Verth. e descrizione di una nuova species (Haploembia palaui n. sp.) (Embioptera: Oligotomidae). Boll. Soc. Entomol. Ital., Genoa 85: 110–120.

Appendix 1 Species used for the cladistic analysis (including material examined, where corresponding, using the following acronyms for Institutions: USNM, National Museum of Natural History, Washington; AMNH, The American Museum of Natural History, New York; CMNH, Carnegie Museum of Natural History, Pittsburgh; MCZ, Museum of Comparative Zoology, Cambridge; CAS, California Academy of Sciences, San Francisco; MACN, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Buenos Aires; IFML, Instituto y Fundacio´n Miguel Lillo, Tucuma´n; MZSP, Museu de Zoologia, Sa˜o Paulo; QM, Queensland Museum, South Brisbane). Those species for which no specimens were seen were scored on the basis of published data. CLOTHODIDAE Antipaluria caribbeana Ross, 1987 Venezuela; Topoparatypes USNM. Clothoda longicauda Ross, 1987 Peru´; Topoparatypes USNM. EMBIIDAE Archembia sp. Peru´; AMNH. Conicerembia tepicensis Ross, 1984 Me´xico; Paratypes USNM.

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Dinembia ferruginea Davis, 1939 Congo; Holotype MCZ. Donaconethis abyssinica Enderlein, 1909 Africa (no specimens seen). Embia savignyi Westwood, 1837 Egypt; USNM. Machadoembia angolica Ross, 1952 Angola; Paratypes MCZ, USNM. Metembia ferrox Davis, 1939 India; Holotype MCZ, specimens USNM. Microembia rugosifrons Ross, 1944 Peru´; Holotype and Paratypes USNM. Neorhagadochir salvini (MacLachlan, 1877) El Salvador and Honduras; USNM. Pachylembia unicincta Ross, 1984 Me´xico; Paratypes USNM. Pararhagadochir balteata Ross, 1972 Brazil; Paratypes USNM. Parembia persica (McLachlan, 1877) India (no specimens seen). Pseudembia truncata Davis, 1939 India; Holotype MCZ. Scelembia malkini (Ross, 1952) Angola; Paratype MCZ. INCERTAE SEDIS Enveja bequaerti Nava´s, 1914 Congo; CAS. AUSTRALEMBIIDAE Australembia incompta Ross, 1963 Queensland, Australia; Topoparatypes USNM. Metoligotoma convergens Davis, 1938 New South Wales, Australia; QM. M. ingens Davis, 1936 ACT, Australia; MCZ. OLIGOTOMIDAE Aposthonia borneensis (Hagen, 1885) Java and Thailand; MCZ, USNM. A. glauerti (Davis, 1936) West Australia (no specimens seen). Haploembia sp. Turkey; USNM. Oligotoma saundersii (Westwood, 1837) India; AMNH, CMNH, MZSP, MCZ, USNM. TERATEMBIIDAE Teratembia geniculata Krauss, 1911 Argentina; IFML, MACN.

ORDER EMBIOPTERA: A CLADISTIC ANALYSIS

ANISEMBIIDAE Anisembia texana (Melander, 1902) Me´xico; USA, AMNH, MCZ, USNM. Bulbocerca sini (Chamberlin, 1923) Me´xico (no specimens seen). Chelicerca dampfi Ross, 1944 Me´xico (no specimens seen). C. davisi (Ross, 1940) USA; USNM. C. jaliscoa Ross, 1984 Me´xico; Paratypes USNM. C. maxima Ross, 1984 Me´xico (no specimens seen). C. wheeleri (Melander, 1902) Me´xico; Holotype MCZ. Dactylocerca flavicollis Ross, 1984 Me´xico; Paratypes USNM. Mesembia catemacoa Ross, 1984 Me´xico; Paratypes USNM. M. chamulae Ross, 1984 Me´xico; Paratypes USNM. M. venosa (Banks, 1924) Cuba; Holotype MCZ. Pelorembia tumidiceps Ross, 1984 Me´xico, Paratypes USNM. Stenembia perenensis Ross, 1972 Peru´, Paratypes USNM. NOTOLIGOTOMIDAE Notoligotoma hardyi (Friederichs, 1914) West Australia (no specimens seen). N. nitens Davis, 1936 New South Wales, Australia; MCZ. Ptilocerembia sp. Java; CAS. Appendix 2 Additional material examined. CLOTHODIDAE Antipaluria aequicercata (Enderlein, 1912) Colombia; USNM. A. marginata Ross, 1987 Colombia; Paratype USNM. A. panamensis Ross, 1987 Panama´; Paratypes USNM. A. silvestris Ross, 1987 Venezuela; USNM.

61

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A. urichi (de Saussure, 1896) Trinidad; USNM. Chromatoclothoda aurata Ross, 1987 Peru´; Paratypes USNM. C. elegantula Ross, 1987 Brazil; Paratypes USNM. Clothoda nobilis (Gerstaecker, 1888) Brazil; USNM. EMBIIDAE Archembia lacombea Ross, 1971 Brazil; Paratypes USNM. Archembia sp. Brazil; MZSP, USNM. Brachypterembia moreliensis Ross, 1984 Me´xico; Paratypes USNM. Embia mauritanica Lucas, 1849 Iraq; USNM. E. ramburi Rimsky Korsacov, 1905 France; USNM. Embia sp. Spain; MCZ, USNM. Pachylembia chapalae Ross, 1984 Me´xico; Paratypes USNM. P. taxcoensis Ross, 1984 Me´xico; Paratypes USNM. Pararhagadochir christae Ross, 1972 Brazil; Paratypes USNM. P. confusa Ross, 1944 Paraguay; Paratypes and specimens MCZ. P. trinitatis (de Saussure, 1896) Trinidad; MCZ, USNM. P. birabeni (Nava´s, 1918) Argentina; IFML, MACN. P. trachelia (Nava´ s, 1915) Argentina; IFML, MACN. Pseudembia flava (Ross, 1943) India; Holotype MCZ. P. immsi (Davis, 1939) India; Holotype MCZ. AUSTRALEMBIIDAE Metoligotoma reducta subtropica Davis, 1942 New South Wales, Australia; QM. Metoligotoma sp. New South Wales, Australia; QM. OLIGOTOMIDAE Aposthonia ceylonica (Enderlein, 1912)

ORDER EMBIOPTERA: A CLADISTIC ANALYSIS

Thailand, Sri Lanka, India; MCZ, USNM. A. indica (Davis, 1940) India; MCZ, USNM. Aposthonia sp. New South Wales, Australia; QM. Oligotoma falcis Ross, 1943 India; Paratype MCZ. O. humbertiana (de Saussure, 1896) Sri Lanka; USNM. O. japonica Okajima, 1926 Japan; MCZ. O. nigra Hagen, 1866 Me´xico, USA; AMNH, USNM. Oligotoma sp. Queensland, Australia; QM. TERATEMBIIDAE Diradius erba Szumik, 1991 Argentina; Holotype and Paratypes MACN. D. lobatus (Ross, 1944) USA; Paratypes USNM. D. pallidus Ross, 1984 Me´xico; Paratypes USNM. D. plaumanni (Ross, 1944) Brazil; Paratypes MZSP, USNM. Diradius sp. Panama´, AMNH. Oligembia capensis Ross, 1984 Me´xico; Paratype USNM. O. hubbardi (Hagen, 1885) USA; AMNH, USNM. O. melanura Ross, 1944 USA; Paratypes USNM, specimens AMNH. O. mini Szumik, 1991 Argentina; Holotype and Paratypes MACN. O. versicolor Ross, 1972 Brazil; Paratype USNM. Oligembia sp. Peru´; AMNH. Teratembia banksi (Davis, 1939) Paraguay; MCZ. ANISEMBIIDAE Chelicerca galapagensis Ross, 1966 Galapagos; Paratypes USNM. C. grandis (Ross, 1944) Colombia; USNM. Dactylocerca ashworthi Ross, 1984 USA; Paratypes USNM.

63

64

C. A. SZUMIK

D. multispiculata Ross, 1984 Me´xico; Paratypes USNM. D. rubra (Ross, 1940) USA; Paratypes USNM, specimens AMNH. Mesembia aequalis Ross, 1944 Brazil; Paratypes MZSP. M. hospes (Myers, 1928) Cuba; Holotype and specimens MCZ, USNM. Stenembia exigua Ross, 1972 Brazil; Paratype USNM.

Appendix 3 Matrix according to Davis’ tree (1938:265, Fig. 120), 22 taxa and 11 characters:

Ancestral type Clothoda nobilis Donaconethis abyssinica Embia sabulosa E. major Rhagadochir flavicollis Ptilocerembia roepkei Haploembia solieri Monotylota ramburi Anisembia texana A. sini A. heymonsi Notoligotoma hardyi N. nitens Metoligotoma convergens M. pugionifer M. pentanesiana Oligotoma vosselieri O. gurneyi subclavata O. g. gurneyi O. tillyardi O. glauerti

0

1

2

3

4

5

6

7

8

9

0

0 1 0 1 1 1 1 3 3 4 3 2 2 4 3 3 3 2 2 4 2 2

0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1

0 0 0 0 1 0 0 1 0 0 0 0 1 1 1 1 1 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 1 1 0 0 0 0 0

0 0 1 1 1 1 2 1 1 2 2 1 2 2 1 1 1 1 1 1 1 1

0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0

0 0 1 1 1 2 1 1 1 1 1 1 1 1 2 1 2 1 1 1 2 1

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 1 0 1

0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2

0 0 0 0 0 0 1 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0