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A fungal-like organism associated with a wasp (Hymenoptera: Pteromalidae) in Dominican amber
Journal of Invertebrate Pathology 110 (2012) 132–134
Contents lists available at SciVerse ScienceDirect
Journal of Invertebrate Pathology journal homepage: www.elsevier.com/locate/jip
Short Communication
A fungal-like organism associated with a wasp (Hymenoptera: Pteromalidae) in Dominican amber George Poinar Jr. a,⇑, Joseph W. Spatafora b a b
Department of Zoology, Oregon State University, Corvallis, OR 97331-2902, USA Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331-2902, USA
a r t i c l e
i n f o
Article history: Received 22 February 2012 Accepted 23 February 2012 Available online 4 March 2012 Keywords: Dominican Republic Amber Fungal-like organism Pteromalid wasp
a b s t r a c t A fungal-like organism emerging from a parasitic wasp (Hymenoptera: Pteromalidae) in Dominican amber is characterized. The fossil consists of a white sclerotium-like formation in the wasp’s abdomen and a flattened clava-like structure with an ovoid terminus emerging from the sclerotium-like formation. The ovoid terminus bears a protruding elliptical appendix. The fossil, which is characterized by its small size, somatic configuration, pteromalid host and presence in Dominican amber, cannot be placed with assurance in any extant fungal group at this time. Ó 2012 Elsevier Inc. All rights reserved.
1. Introduction
3. Results
Various types of pathogens infect insects and most can be assigned to one of the following groups: viruses, bacteria, protozoa, fungi and nematodes (Steinhaus, 1949; Poinar and Thomas, 1984). Occasionally a pathogen appears that is structurally so aberrant that its affinity is a mystery. This is the case with a fungal-like growth protruding from the side of the abdomen of a parasitic chalcidoid wasp (Pteromalidae) in Dominican amber. Because of the unique morphology of this organism, it is characterized below as an unknown fungal entity.
The fossil organism occurs on the right side of the wasp (length of wasp, 2.5 mm). The left side of the insect is normal and well preserved (Fig. 1A). The organism consists of a white sclerotium-like formation on the wasp’s abdomen and a flattened tan colored, clava-like structure with a tan colored ovoid terminus arising from the sclerotium-like formation (Fig. 1B and C). The sclerotium-like formation is visible as a raised ring surrounding the base of the clava-like structure (Fig. 1B and C). The clava-like structure, which is 250 lm long and 85 lm wide, has an ovoid terminus (Fig. 1C). The wall of the ovoid terminus is composed of parallel rows (occasionally interwoven) of hypha-like cells, 2–3 lm wide. The ovoid terminus, which is 244 lm long and 170 lm wide, bears a protruding tan colored elliptical appendix that is 122 lm long and 42 lm in greatest width. The elliptical appendix bears a series of dark protrusions on the lower surface (Fig. 1D). The tips of protrusions extend 2–3 lm from surface. Two slender filaments, 13–14 lm long, are positioned adjacent to the elliptical appendix (Fig. 1E).
2. Materials and methods The piece of amber containing the specimen originated from mines in the northern mountain range (Cordillera Septentrional) of the Dominican Republic, between the cities of Puerto Plata and Santiago. Amber from this deposit was produced by Hymenaea protera Poinar (Fabaceae). Dating of Dominican amber is controversial, with the youngest proposed age of 20–15 mya based on foraminifera (Iturralde-Vinent and MacPhee, 1996) and the oldest as 45–30 mya based on coccoliths (Cêpek in Schlee, 1990). Most of the amber is secondarily deposited in turbiditic sandstones of the Upper Eocene to Lower Miocene Mamey Group (Draper et al., 1994), so the amber could be older than the Miocene dates. The fossil is deposited in the Poinar amber collection (accession # SY-1-190) maintained at Oregon State University. ⇑ Corresponding author. E-mail address: [email protected] (G. Poinar Jr.). 0022-2011/$ - see front matter Ó 2012 Elsevier Inc. All rights reserved. doi:10.1016/j.jip.2012.02.013
4. Discussion The fossil is characterized by its small size, somatic configuration, pteromalid host and presence in Dominican amber. While it is not possible to assign it to any known pathogen group, some characters (sclerotium-like formation, clava-like structure with an ovoid terminus) resemble those found in the fungal genus Cordyceps (Ascomycota). The latter genus has a wide range of stromatal morphology (filiform, wiry, fibrous, pliant or fleshy).
G. Poinar Jr., J.W. Spatafora / Journal of Invertebrate Pathology 110 (2012) 132–134
133
Fig. 1. Photograph of a pteromalid wasp in amber apparently parasitized by a fungal-like organism. (A) Left side of pteromalid wasp. Bar = 460 lm. (B) Right side of the wasp with clava-like structure emerging from a sclerotium-like formation in the wasp’s abdomen. Arrow shows ovoid terminus attached to the sclerotium-like formation. Bar = 230 lm. (C) Ventral-lateral view of fossil showing the white sclerotium-like formation (W) on the wasp’s abdomen, the protruding clava-like structure (C), the ovoid terminus (T) and the elliptical appendage (A). Bar = 148 lm. (D) Protrusions (arrows) on the lower surface of the elliptical appendix of the fossil. Bar = 26 lm. (E) Two filaments (arrow) adjacent to the elliptical appendix of the fossil. Bar = 65 lm.
The fertile region can be terminal, subterminal, nonterminal, clavate, capitate, globose, elongated, pad-like or cushion-like. However species of Cordyceps are much larger than the fossil, the clava-like structure on the fossil differs from the typical clava type found in Cordyceps spp. and while representatives of Cordyceps spp. infect aculeate Hymenoptera, none have been reported from parasitic wasps (McEwen, 1963; McCoy et al., 1988; Sung et al., 2007). The series of dark protrusions on the lower surface of the elliptical appendix of the fossil are much smaller than Cordyceps perithecia and the adjacent two slender filaments appear too fine to represent asci or ascospores. It is difficult to determine from where these two filaments originated, however no similar structures were found in other portions of the amber piece. Pteromalid wasps parasitize a wide range of insect hosts (Goulet and Huber, 1993). It is unknown whether the infection was acquired in the adult or larval stage of the wasp. The larval stage could have become infected through its host during development. Extant insect pathogens are known to be transferred from diseased hosts to their internal parasites. Virus-like particles in the reproductive system of parasitic braconid wasps are transferred into and infect their hosts (Poinar et al., 1976). The pillbug iridovirus can infect nematode parasites developing in the
hemocoel of the crustaceans (Poinar et al., 1980) and microsporidian pathogens of Lepidoptera can infect developing entomopathogenic nematodes (Veremtchuk and Issi, 1970). The fossil represents an unknown entity from the mid-Tertiary. While we have been unable to find any closely related extant organism, it is possible that due to its minute size and presence in a little studied host group, it has not yet been discovered. Hymenopterists normally examine parasitic wasps after they become entrapped in chemical preservatives. Any internal pathogens would not be able to emerge from the body of wasps under these conditions. Acknowledgments We thank Alex Brown for donating the specimen to the Poinar amber collection, John Huber for the identification of the wasp host and Roberta Poinar for reviewing the manuscript. References Draper, G., Mann, P., Lewis, J.F., 1994. Hispaniola. In: Donovan, S., Jackson, T.A. (Eds.), Caribbean Geology: An Introduction. The University of the West Indies Publishers’ Association, Kingston, Jamaica, pp. 129–150.
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G. Poinar Jr., J.W. Spatafora / Journal of Invertebrate Pathology 110 (2012) 132–134
Goulet, H., Huber, J.T. 1993. Hymenoptera of the World: An Identification Guide to Families. Centre for Land and Biological Resources Research, Ottawa, 668 pp. Iturralde-Vinent, M.A., MacPhee, R.D.E., 1996. Age and paleogeographic origin of Dominican amber. Science 273, 1850–1852. McCoy, C.M., Samson, R.A., Boucies, D.G., 1988. Entomogenous fungi. In: Ignoffo, C. (Ed.), CRC Handbook of Natural Pesticides, vol. 5, pp. 151–243. McEwen, F.L., 1963. Cordyceps infections. In: Steinhaus, E.A. (Ed.), Insect Pathology: An Advanced Treatise, vol. 2. Academic Press, New York, pp. 273–290. Poinar Jr., G.O., Thomas, G.M., 1984. Laboratory Guide to Insect Pathogens and Parasites. Plenum Press, New York. Poinar Jr., G.O., Hess, R.T., Cole, A., 1980. Replication of an iridovirus in a nematode (Mermithidae). Intervirology 14, 316–320.
Poinar Jr., G.O., Hess, R.T., Caltagirone, L.E., 1976. Virus-like particles in the calyx of Phanerotoma glavitestacea (Hymenoptera: Braconidae) and their transfer into host tissues. Acta Zool. 57, 161–165. Schlee, D., 1990. Das Bernstein-Kabinett. Stuttg. Beitr. Naturk. (C). 28, 100. Steinhaus, E.A., 1949. Principles of Insect Pathology. McGraw- Hill Book Co., New York. Sung, Gi-Ho., Hywel-Jones, N.L., Sung, Jae-Mo., Luangsa-ard, J.J., Shrestha, B., Spatafora, J.W., 2007. Phylogenetic classification of Cordyceps and the clavicipitaceous fungi. Stud. Mycol., 57: 5–59. Veremtchuk, G.V., Issi, I.V., 1970. On the development of the microsporidian of insects in the entomopathogenic nematodes Neoaplectana agriotos veremtchuk (Nematodes: Steinernematidae). Parazitologiya 4, 3–8 (in Russian).
Contents lists available at SciVerse ScienceDirect
Journal of Invertebrate Pathology journal homepage: www.elsevier.com/locate/jip
Short Communication
A fungal-like organism associated with a wasp (Hymenoptera: Pteromalidae) in Dominican amber George Poinar Jr. a,⇑, Joseph W. Spatafora b a b
Department of Zoology, Oregon State University, Corvallis, OR 97331-2902, USA Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331-2902, USA
a r t i c l e
i n f o
Article history: Received 22 February 2012 Accepted 23 February 2012 Available online 4 March 2012 Keywords: Dominican Republic Amber Fungal-like organism Pteromalid wasp
a b s t r a c t A fungal-like organism emerging from a parasitic wasp (Hymenoptera: Pteromalidae) in Dominican amber is characterized. The fossil consists of a white sclerotium-like formation in the wasp’s abdomen and a flattened clava-like structure with an ovoid terminus emerging from the sclerotium-like formation. The ovoid terminus bears a protruding elliptical appendix. The fossil, which is characterized by its small size, somatic configuration, pteromalid host and presence in Dominican amber, cannot be placed with assurance in any extant fungal group at this time. Ó 2012 Elsevier Inc. All rights reserved.
1. Introduction
3. Results
Various types of pathogens infect insects and most can be assigned to one of the following groups: viruses, bacteria, protozoa, fungi and nematodes (Steinhaus, 1949; Poinar and Thomas, 1984). Occasionally a pathogen appears that is structurally so aberrant that its affinity is a mystery. This is the case with a fungal-like growth protruding from the side of the abdomen of a parasitic chalcidoid wasp (Pteromalidae) in Dominican amber. Because of the unique morphology of this organism, it is characterized below as an unknown fungal entity.
The fossil organism occurs on the right side of the wasp (length of wasp, 2.5 mm). The left side of the insect is normal and well preserved (Fig. 1A). The organism consists of a white sclerotium-like formation on the wasp’s abdomen and a flattened tan colored, clava-like structure with a tan colored ovoid terminus arising from the sclerotium-like formation (Fig. 1B and C). The sclerotium-like formation is visible as a raised ring surrounding the base of the clava-like structure (Fig. 1B and C). The clava-like structure, which is 250 lm long and 85 lm wide, has an ovoid terminus (Fig. 1C). The wall of the ovoid terminus is composed of parallel rows (occasionally interwoven) of hypha-like cells, 2–3 lm wide. The ovoid terminus, which is 244 lm long and 170 lm wide, bears a protruding tan colored elliptical appendix that is 122 lm long and 42 lm in greatest width. The elliptical appendix bears a series of dark protrusions on the lower surface (Fig. 1D). The tips of protrusions extend 2–3 lm from surface. Two slender filaments, 13–14 lm long, are positioned adjacent to the elliptical appendix (Fig. 1E).
2. Materials and methods The piece of amber containing the specimen originated from mines in the northern mountain range (Cordillera Septentrional) of the Dominican Republic, between the cities of Puerto Plata and Santiago. Amber from this deposit was produced by Hymenaea protera Poinar (Fabaceae). Dating of Dominican amber is controversial, with the youngest proposed age of 20–15 mya based on foraminifera (Iturralde-Vinent and MacPhee, 1996) and the oldest as 45–30 mya based on coccoliths (Cêpek in Schlee, 1990). Most of the amber is secondarily deposited in turbiditic sandstones of the Upper Eocene to Lower Miocene Mamey Group (Draper et al., 1994), so the amber could be older than the Miocene dates. The fossil is deposited in the Poinar amber collection (accession # SY-1-190) maintained at Oregon State University. ⇑ Corresponding author. E-mail address: [email protected] (G. Poinar Jr.). 0022-2011/$ - see front matter Ó 2012 Elsevier Inc. All rights reserved. doi:10.1016/j.jip.2012.02.013
4. Discussion The fossil is characterized by its small size, somatic configuration, pteromalid host and presence in Dominican amber. While it is not possible to assign it to any known pathogen group, some characters (sclerotium-like formation, clava-like structure with an ovoid terminus) resemble those found in the fungal genus Cordyceps (Ascomycota). The latter genus has a wide range of stromatal morphology (filiform, wiry, fibrous, pliant or fleshy).
G. Poinar Jr., J.W. Spatafora / Journal of Invertebrate Pathology 110 (2012) 132–134
133
Fig. 1. Photograph of a pteromalid wasp in amber apparently parasitized by a fungal-like organism. (A) Left side of pteromalid wasp. Bar = 460 lm. (B) Right side of the wasp with clava-like structure emerging from a sclerotium-like formation in the wasp’s abdomen. Arrow shows ovoid terminus attached to the sclerotium-like formation. Bar = 230 lm. (C) Ventral-lateral view of fossil showing the white sclerotium-like formation (W) on the wasp’s abdomen, the protruding clava-like structure (C), the ovoid terminus (T) and the elliptical appendage (A). Bar = 148 lm. (D) Protrusions (arrows) on the lower surface of the elliptical appendix of the fossil. Bar = 26 lm. (E) Two filaments (arrow) adjacent to the elliptical appendix of the fossil. Bar = 65 lm.
The fertile region can be terminal, subterminal, nonterminal, clavate, capitate, globose, elongated, pad-like or cushion-like. However species of Cordyceps are much larger than the fossil, the clava-like structure on the fossil differs from the typical clava type found in Cordyceps spp. and while representatives of Cordyceps spp. infect aculeate Hymenoptera, none have been reported from parasitic wasps (McEwen, 1963; McCoy et al., 1988; Sung et al., 2007). The series of dark protrusions on the lower surface of the elliptical appendix of the fossil are much smaller than Cordyceps perithecia and the adjacent two slender filaments appear too fine to represent asci or ascospores. It is difficult to determine from where these two filaments originated, however no similar structures were found in other portions of the amber piece. Pteromalid wasps parasitize a wide range of insect hosts (Goulet and Huber, 1993). It is unknown whether the infection was acquired in the adult or larval stage of the wasp. The larval stage could have become infected through its host during development. Extant insect pathogens are known to be transferred from diseased hosts to their internal parasites. Virus-like particles in the reproductive system of parasitic braconid wasps are transferred into and infect their hosts (Poinar et al., 1976). The pillbug iridovirus can infect nematode parasites developing in the
hemocoel of the crustaceans (Poinar et al., 1980) and microsporidian pathogens of Lepidoptera can infect developing entomopathogenic nematodes (Veremtchuk and Issi, 1970). The fossil represents an unknown entity from the mid-Tertiary. While we have been unable to find any closely related extant organism, it is possible that due to its minute size and presence in a little studied host group, it has not yet been discovered. Hymenopterists normally examine parasitic wasps after they become entrapped in chemical preservatives. Any internal pathogens would not be able to emerge from the body of wasps under these conditions. Acknowledgments We thank Alex Brown for donating the specimen to the Poinar amber collection, John Huber for the identification of the wasp host and Roberta Poinar for reviewing the manuscript. References Draper, G., Mann, P., Lewis, J.F., 1994. Hispaniola. In: Donovan, S., Jackson, T.A. (Eds.), Caribbean Geology: An Introduction. The University of the West Indies Publishers’ Association, Kingston, Jamaica, pp. 129–150.
134
G. Poinar Jr., J.W. Spatafora / Journal of Invertebrate Pathology 110 (2012) 132–134
Goulet, H., Huber, J.T. 1993. Hymenoptera of the World: An Identification Guide to Families. Centre for Land and Biological Resources Research, Ottawa, 668 pp. Iturralde-Vinent, M.A., MacPhee, R.D.E., 1996. Age and paleogeographic origin of Dominican amber. Science 273, 1850–1852. McCoy, C.M., Samson, R.A., Boucies, D.G., 1988. Entomogenous fungi. In: Ignoffo, C. (Ed.), CRC Handbook of Natural Pesticides, vol. 5, pp. 151–243. McEwen, F.L., 1963. Cordyceps infections. In: Steinhaus, E.A. (Ed.), Insect Pathology: An Advanced Treatise, vol. 2. Academic Press, New York, pp. 273–290. Poinar Jr., G.O., Thomas, G.M., 1984. Laboratory Guide to Insect Pathogens and Parasites. Plenum Press, New York. Poinar Jr., G.O., Hess, R.T., Cole, A., 1980. Replication of an iridovirus in a nematode (Mermithidae). Intervirology 14, 316–320.
Poinar Jr., G.O., Hess, R.T., Caltagirone, L.E., 1976. Virus-like particles in the calyx of Phanerotoma glavitestacea (Hymenoptera: Braconidae) and their transfer into host tissues. Acta Zool. 57, 161–165. Schlee, D., 1990. Das Bernstein-Kabinett. Stuttg. Beitr. Naturk. (C). 28, 100. Steinhaus, E.A., 1949. Principles of Insect Pathology. McGraw- Hill Book Co., New York. Sung, Gi-Ho., Hywel-Jones, N.L., Sung, Jae-Mo., Luangsa-ard, J.J., Shrestha, B., Spatafora, J.W., 2007. Phylogenetic classification of Cordyceps and the clavicipitaceous fungi. Stud. Mycol., 57: 5–59. Veremtchuk, G.V., Issi, I.V., 1970. On the development of the microsporidian of insects in the entomopathogenic nematodes Neoaplectana agriotos veremtchuk (Nematodes: Steinernematidae). Parazitologiya 4, 3–8 (in Russian).