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Injury metabolism in an insect, Rhodnius prolixus
r. Insect Physiol., 1970, Vol. 16, pp.
INJURY
1579to 1585. Pergomon
Press. Printed in Great Britain
METABOLISM IN AN INSECT, RHODNIUS PROLIXUS A. Y. K. OKASHA”
Department of Zoology, University of Assiut, U.A.R. (Received
21 December
1969; revised 9 February
1970)
Abstract-Injury of Rhodnius larvae, in which growth and development are arrested by decapitation 1 day after feeding, results in an increase in the rate of oxygen consumption to levels characteristic of fed larvae in which these processes are not interfered with. This increase occurs in the period 2 to 5 days after wounding. Thereafter, the respiratory rate gradually starts to decline. However, if intact larvae are injured 12 days after feeding and the respiratory rate measured 6 days later, there is no detectable increase in the respiratory rate. The significance of this discrepancy in reaction to wounding is discussed.
INTRODUCTION BASED on convincing cytological evidence, WIGGLE~WORTH(1937, 1954, 1957) put forward the theory that there are striking similarities between the ‘wound hormones’ and the moulting hormone. Since then several investigators have extended this theory and it is now established that although the injury factor might be produced locally, it nevertheless affects the metabolism of the whole insect (SCHNEIDERMANand WILLIAMS, 1953, 1954; TELFER and WILLIAMS, 1960; STEVENSON and WYATT, 1962; SKINNER,1963 ; SHAPPIRIOand HARVEY,1965). The rate of oxygen consumption of a diapausing Cecropia pupa rises rapidly following injury (SUSSMAN,1952; SCHNEIDERMAN and WILLIAMS, 1953) and this elevated rate of respiration persists for a few days before it slowly returns to the pre-injury level (SCHNEIDERMAN and WILLIAMS, 1954). MECCA(1960) on the other hand, working on the non-diapausing pupae of the southern armyworm Prodenia eridania, reported that the rate of oxygen consumption of injured insects is not measurably different from the uninjured controls when compared daily during the period between pupation and adult emergence (true pupal instar + pharate adults). She suggested that although injury with a fine needle has no effect, yet it is possible that larger injury will elevate respiration. Mecca also mentioned that her results agree with Schneider-man’s unpublished findings on Galleria. The present investigation compares the effects of injury on the general metabolism of the same insect in different developmental states, in an attempt to understand the apparent contradiction of the above-mentioned examples.
* Present address: School of Biological Sciences, University of East Anglia,,Norwich NOR 88C. 1579
1580
A. Y. K. OKA~HA
MATERIALS AND METHODS A culture of Rhodnius was maintained at 28°C as described by OKA~HA(1968a). Decapitation was performed by cutting through the neck and sealing the wound by a mixture of wax and resin heated to just above the melting point. The injury consisted of a cuticular incision; a longitudinal slit was made with a sharp scalpel in the third or fourth abdominal tergite and sealed with the wax-resin mixture. The cut passed through the integument and care was taken not to injure the internal organs. The methods of measuring and calculating the rate of oxygen uptake of individual insects are those described by OKASHA(19686). All the insects were kept at 28°C and the respiratory rate was measured at this temperature. RESULTS Effect of injury on respiration of larvae decapitated 1 day after feeding
Fourth instar larvae were fed and 24 hr later they were decapitated, i.e. before the critical period for growth and development (WIGGLESWORTH,1934). The insects were allowed to recover from decapitation for 12 days (for the course of oxygen consumption of such decapitated larvae see OKASHA,1968b). The insects were then injured and their oxygen consumption was measured daily from the day of injury onwards. Insects from the same batch, fed and decapitated at the same time but with no abdominal cuticular injury, served as controls. The results of this experiment are represented in Fig. 1. Since the maximum rate of respiration attained after injury differed from one individual to another within the small number of insects used in this experiment, the changes in respiration of individual insects are also shown (Table 1). The results of this experiment indicate quite clearly that injury results in an increase in the respiratory rate; about a twofold increase is attained by 2 to 5 days after injury. This is followed by a gradual decrease; by 8 days after wounding when the experiment was terminated, the metabolic rate was still higher than that of the same insects on the day of injury. In the control group, however, the respiratory rate remained more or less constant after a slight initial decrease. It is of some interest to note that a comparison of the level of respiration of both the experimental and control insects on the day of injury shows that the wounded insects did not exhibit an elevated respiratory rate although the measurements lasted for 6 hr after injury. This is in contrast with the results of HARVEYand WILLIAMS(1961) who found that oxygen uptake reaches a twofold increase in the diapausing Cecropia pupae 2 hr after injury. The same result was obtained when this was tested using adult insects. Adult males were fed and 24 hr later their oxygen consumption was measured for 1 hr. Then they were immediately wounded and their rate of respiration was recorded until 6 hr after injury. Control insects were used from the same batch. The results of this experiment are illustrated in Fig. 2 which shows that there is no detectable increase in respiration during the first 6 hr that follow wounding. It could be argued, however, that a recently fed adult Rhodnius
INJURY
METABOLISM
IN
AN
1581
INSECT
IS’-
17 -
./
i: %
15-
t s: .e \ N n;
3
./‘\. \
3
.\.
/
.A.
13-
E s I” II -
9I I
I
I
0
I
1
I
2
4
6
8
Days
after
injury
FIG. 1. Effect of injury on the rate of oxygen consumption at 28°C in fourth instar larvae decapitated 1 day after feeding and injured 12 days later. Each point represents the mean of four insects and the same insects were used throughout.
i .E .
6
“E E
3O-
f
Injury I -I
0
I
I
I
l-2
2-3
3-4
Time,
I 4-5
1 5-6
hr
FIG. 2. The rate of oxygen consumption at 28°C of adult males just before injury and during the first 6 hr after injury. Each point represents the mean of five insects.
10.9 12.8 IS-9 15-o 7.4 10.5 11.9 8.2
9.2 14.5 14.7 14.1 7.4 IO.2 13.9 9.1
8.3 11.2 7.2 10.0 7.0 13.0 15.9 9.5
1 2 3 4 5 6 7 8
Injured
Controls
7.8 9.8 13,2 8.0
17.9 20.8 14.2 13.9
17.8 15.1 15.9 14.3 8.5 9-8 13-o 8.1
4 days
3 days
8.4 8-3 1 l-9 8.2
7.8 8.7 11.7 8.0
15.4 16.7 12-s 13.2
8 days
oxygen uptake in
8.4 8.6 11.7 8-l
16.4 17.9 12.9 13.6
16.9 20.7 12-8 17.0 17.2 21.2 13.6 18.3 8-2 8.5 12.5 8.2
7 days
6 days
5 days
Insects were decapitated 1 day after feeding and injured 12 days after decapitation, mn?/insect per hr. The means of these figures are those represented in Fig. I.
2 days
1 day
INSTAR LARVAE AT 28°C
Time after injury
OF INJURY ON RESPIRATION OF FOURTH
OdaY
I-EFFECT
No.
Treatment
TABLE
INJURY METABOLISM IN AN INSECT
1583
is in a physiological state which is not comparable with that of a diapausing pupa or that of a Rhodnius larva decapitated 24 l-n-after feeding (see Discussion).
E#ect of injury on respiration offed intact larvae Fifth instar larvae were fed and 12 days later, one-half of the insects was wounded, while the other half served as controls. The oxygen consumption of both groups was measured at 6 days after injury, a time when the respiratory rate of injured larvae would be expected to be around its maximum, if injury had been affecting it. The results of this experiment are shown in Table 2. TABLE%-EFFECT OFINJURYON THERESPIRATION OFFIFTHINSTAR LARVAE AT 28°C
Treatment
No. of insects
Injured Intact
7 7
Oxygen uptake (rnn?OJinsect per hr) f standard error 32.9 L!Y 2.3 31.1 f 1.3
Insects were injured 12 days after feeding and their respiration was measured 6 days after injury. From this Table it can be seen that the injury metabolism in an insect which is undergoing growth and development cannot be induced or, more precisely, is not reflected in an increase in its respiratory rate. DISCUSSION That injury of a
Rhodnius larva decapitated 1 day after feeding is associated
with an increase in the respiratory rate, thus raising the latter to a level which approximately parallels that of a normal fed larva in the same instar (see OKASHA, 1968b), agrees fairly well with the results of previous authors working on diapausing pupae (SUSSMAN, 1952; and WILLIAMS, 1961).
SCHNEIDERMANand WILLIAMS, 1953, 1954; HARVEY
This elevated rate of general metabolism was found to be
associated with, or perhaps can be regarded as a reflection of, a prompt increase in the rate of protein synthesis as judged by an increase in the rate of incorporation of amino acids into haemolymph proteins (TELFER and WILLIAMS, 1960) or into the fat body proteins (STEVENSONand WYATT, 1962), or by an increase in the activity of oxidative enzymes (SHAPPIRIOand HARVEY, 1965). In contrast to what happens in response to injury in the decapitated larva, wounding does not result in any increase in the general metabolic rate of the larva in which growth and development are proceeding normally. It must be remembered here that both the rate of respiration and that of protein synthesis increase during growth and development under the influence of the moulting hormone (for review see WIGGLESWORTH,1964). That being the case, it seems reasonable that injury does not raise the metabolic level of an insect whose metabolism is already at a high
1584
A. Y. K.
OKASHA
level, although the local repair of the wound takes place together with the physiological and cytological changes necessary for the formation of a new cuticle in the wounded area. SHAPIRO(1968), f or example, reported that in Galleria mellonella larvae there is a significant increase in the number of circulating haemocytes/mma a day after wounding. Recently ARKING and SHAAYA(1969), h owever, showed that the injection of ecdysone into 6- and 8-day-old larvae of Calliphora stimulated the rate of incorporation of i4C-leucine into fat body proteins, when the larvae already have circulating natural ecdysone, though not at its maximum. The view presented here is not a new one. In Cecropia pupae, HARVEYand WILLIAMS (1961) suggested that injury raises metabolism to the level of a nondiapausing pupa by disrupting the conservative mechanism by which the diapausing insect keeps its metabolism at a low level, the ‘maintenance metabolism’. These authors postulated that it would be impossible to elevate the metabolism of a non-diapausing insect by injury. A similar suggestion was put forward to explain the short survival of a full-grown larva of Lymantria after removing the brain when compared with that of the unhatched larva. In the former, a mechanism which is required for reducing the metabolism to the low level characteristic of diapause is lacking (LEES, 1955). The experiments reported here give an experimental proof to the hypothesis of HARVEYand WILLIAMS (1961). Furthermore, these experiments strongly suggest that the failure of MECCA(1960) to induce an elevated respiratory rate in Prodenia pupae following injury is not due to the small size of the wound, but is due to the injured pupae not being in a diapausing state.
REFERENCES R. and SHAAYAE. (1969) Effect of ecdysone on protein synthesis in the larval fat body of Calliphora. J. Insect Physiol. 15,287-296.
ARKINC
HARVEYW. and WILLIAMSC. M. (1961) The injury metabolism of the Cecropia silkworm-I. Biological amplification of the effects of localized injury. J. Insect Physiol. 7, 81-99. LEES A. D. (1955) The Physiology of Diapause in Arthropods. Cambridge University Press, * London. MECCA C. E. (1960) Lack of elevated respiration in injured pupae of the southern army worm, Prod&a eria’ania (Lepidoptera). Ann. ent. Sot. Am. 53, 849-850. OKASHAA. Y. K. (1968a) Effects of sub-lethal high temperature on an insect, Rhodnius prolixus (St&l.)-I. Induction of delayed moulting and defects. J. exp. Biol. 48,455-463. OKASHAA. Y. K. (1968b) Changes in the respiratory metabolism of Rhodnius prolixus as induced by temperature. J. Insect Physiol. 14,1621-1634. SCHNEIDERMAN H. A. and WILLIAMSC. M. (1953) The physiology of insect diapause-VII. The respiratory metabolism of the Cecropia silkworm during diapause and development. Biol. Bull., Woods Hole 105,320-334. SCHNEIDERMAN H. A. and WILLIAMS C. M. (1954) The physiology of insect diapause_IX. The cytochrome oxidase system in relation to the diapause and development of the Cecropia silkworm. Biol. Bull., Woods Hole 106,238-252. SHAPIROM. (1968) Changes in the haemocyte population of the wax moth, Galleria mellonella, during wound healing. J. Insect Physiol. 14,1725-1733.
INJURYMETABOLISM IN AN INSECT
1585
SHAPPIRIOD. G. and HARVEYW. R. (1965) The injury metabolism of the Cecropia silkworm -11. Injury-induced alterations in oxidative enzyme systems and respiratory metabolism of the pupal wing epidermis. J. Insect Physiol. 11,305-327. SKINNERD. M. (1963) Incorporation of labelled valine into the proteins of the Cecropia silkworm. Biol. Bull., Woods Hole 125,16.5-176. IncorporaSTEVENSON E. and WYATT G. R. (1962) Th e metabolism of silk moth tissues-I. tion of leucine into protein. Archs Biochem. Biophys. 99, 65-71. SUSSMANA. S. (1952) Tyrosinase and the respiration of pupae of Platysamia cecropia L. Biol. Bull., Woods Hole 102, 39-47. TELFER W. H. and WILLIAMS C. M. (1960) The effects of diapause, development, and injury on the incorporation of radioactive glycine into the blood proteins of the Cecropia silkworm. J. Insect Physiol. 5,61-72. WIGGLESWORTH V. B. (1934) The physiology of ecdysis in Rhodnius prolixus (Hemiptera)II. Factors controlling moulting and metamorphosis. Quart. J. micr. Sci. 77, 191-222. WIGGLESWORTH V. B. (1937) W ound healing in an insect (Rhodnius prolixus, Hemiptera). J. exp. Biol. 14,364-381. WIGGLESWORTH V. B. (1954) The Physiology of Insect Metamorphosis. Cambridge University Press, London. WIGGLESWORTH V. B. (1957) The action of growth hormones in insects. Symp. Sot. exp. Biol. 11, 204-227. WIGGLESWORTH V. B. (1964) The hormonal regulation of growth and reproduction in insects. Adv. Insect Physiol. 2, 247-336.
INJURY
1579to 1585. Pergomon
Press. Printed in Great Britain
METABOLISM IN AN INSECT, RHODNIUS PROLIXUS A. Y. K. OKASHA”
Department of Zoology, University of Assiut, U.A.R. (Received
21 December
1969; revised 9 February
1970)
Abstract-Injury of Rhodnius larvae, in which growth and development are arrested by decapitation 1 day after feeding, results in an increase in the rate of oxygen consumption to levels characteristic of fed larvae in which these processes are not interfered with. This increase occurs in the period 2 to 5 days after wounding. Thereafter, the respiratory rate gradually starts to decline. However, if intact larvae are injured 12 days after feeding and the respiratory rate measured 6 days later, there is no detectable increase in the respiratory rate. The significance of this discrepancy in reaction to wounding is discussed.
INTRODUCTION BASED on convincing cytological evidence, WIGGLE~WORTH(1937, 1954, 1957) put forward the theory that there are striking similarities between the ‘wound hormones’ and the moulting hormone. Since then several investigators have extended this theory and it is now established that although the injury factor might be produced locally, it nevertheless affects the metabolism of the whole insect (SCHNEIDERMANand WILLIAMS, 1953, 1954; TELFER and WILLIAMS, 1960; STEVENSON and WYATT, 1962; SKINNER,1963 ; SHAPPIRIOand HARVEY,1965). The rate of oxygen consumption of a diapausing Cecropia pupa rises rapidly following injury (SUSSMAN,1952; SCHNEIDERMAN and WILLIAMS, 1953) and this elevated rate of respiration persists for a few days before it slowly returns to the pre-injury level (SCHNEIDERMAN and WILLIAMS, 1954). MECCA(1960) on the other hand, working on the non-diapausing pupae of the southern armyworm Prodenia eridania, reported that the rate of oxygen consumption of injured insects is not measurably different from the uninjured controls when compared daily during the period between pupation and adult emergence (true pupal instar + pharate adults). She suggested that although injury with a fine needle has no effect, yet it is possible that larger injury will elevate respiration. Mecca also mentioned that her results agree with Schneider-man’s unpublished findings on Galleria. The present investigation compares the effects of injury on the general metabolism of the same insect in different developmental states, in an attempt to understand the apparent contradiction of the above-mentioned examples.
* Present address: School of Biological Sciences, University of East Anglia,,Norwich NOR 88C. 1579
1580
A. Y. K. OKA~HA
MATERIALS AND METHODS A culture of Rhodnius was maintained at 28°C as described by OKA~HA(1968a). Decapitation was performed by cutting through the neck and sealing the wound by a mixture of wax and resin heated to just above the melting point. The injury consisted of a cuticular incision; a longitudinal slit was made with a sharp scalpel in the third or fourth abdominal tergite and sealed with the wax-resin mixture. The cut passed through the integument and care was taken not to injure the internal organs. The methods of measuring and calculating the rate of oxygen uptake of individual insects are those described by OKASHA(19686). All the insects were kept at 28°C and the respiratory rate was measured at this temperature. RESULTS Effect of injury on respiration of larvae decapitated 1 day after feeding
Fourth instar larvae were fed and 24 hr later they were decapitated, i.e. before the critical period for growth and development (WIGGLESWORTH,1934). The insects were allowed to recover from decapitation for 12 days (for the course of oxygen consumption of such decapitated larvae see OKASHA,1968b). The insects were then injured and their oxygen consumption was measured daily from the day of injury onwards. Insects from the same batch, fed and decapitated at the same time but with no abdominal cuticular injury, served as controls. The results of this experiment are represented in Fig. 1. Since the maximum rate of respiration attained after injury differed from one individual to another within the small number of insects used in this experiment, the changes in respiration of individual insects are also shown (Table 1). The results of this experiment indicate quite clearly that injury results in an increase in the respiratory rate; about a twofold increase is attained by 2 to 5 days after injury. This is followed by a gradual decrease; by 8 days after wounding when the experiment was terminated, the metabolic rate was still higher than that of the same insects on the day of injury. In the control group, however, the respiratory rate remained more or less constant after a slight initial decrease. It is of some interest to note that a comparison of the level of respiration of both the experimental and control insects on the day of injury shows that the wounded insects did not exhibit an elevated respiratory rate although the measurements lasted for 6 hr after injury. This is in contrast with the results of HARVEYand WILLIAMS(1961) who found that oxygen uptake reaches a twofold increase in the diapausing Cecropia pupae 2 hr after injury. The same result was obtained when this was tested using adult insects. Adult males were fed and 24 hr later their oxygen consumption was measured for 1 hr. Then they were immediately wounded and their rate of respiration was recorded until 6 hr after injury. Control insects were used from the same batch. The results of this experiment are illustrated in Fig. 2 which shows that there is no detectable increase in respiration during the first 6 hr that follow wounding. It could be argued, however, that a recently fed adult Rhodnius
INJURY
METABOLISM
IN
AN
1581
INSECT
IS’-
17 -
./
i: %
15-
t s: .e \ N n;
3
./‘\. \
3
.\.
/
.A.
13-
E s I” II -
9I I
I
I
0
I
1
I
2
4
6
8
Days
after
injury
FIG. 1. Effect of injury on the rate of oxygen consumption at 28°C in fourth instar larvae decapitated 1 day after feeding and injured 12 days later. Each point represents the mean of four insects and the same insects were used throughout.
i .E .
6
“E E
3O-
f
Injury I -I
0
I
I
I
l-2
2-3
3-4
Time,
I 4-5
1 5-6
hr
FIG. 2. The rate of oxygen consumption at 28°C of adult males just before injury and during the first 6 hr after injury. Each point represents the mean of five insects.
10.9 12.8 IS-9 15-o 7.4 10.5 11.9 8.2
9.2 14.5 14.7 14.1 7.4 IO.2 13.9 9.1
8.3 11.2 7.2 10.0 7.0 13.0 15.9 9.5
1 2 3 4 5 6 7 8
Injured
Controls
7.8 9.8 13,2 8.0
17.9 20.8 14.2 13.9
17.8 15.1 15.9 14.3 8.5 9-8 13-o 8.1
4 days
3 days
8.4 8-3 1 l-9 8.2
7.8 8.7 11.7 8.0
15.4 16.7 12-s 13.2
8 days
oxygen uptake in
8.4 8.6 11.7 8-l
16.4 17.9 12.9 13.6
16.9 20.7 12-8 17.0 17.2 21.2 13.6 18.3 8-2 8.5 12.5 8.2
7 days
6 days
5 days
Insects were decapitated 1 day after feeding and injured 12 days after decapitation, mn?/insect per hr. The means of these figures are those represented in Fig. I.
2 days
1 day
INSTAR LARVAE AT 28°C
Time after injury
OF INJURY ON RESPIRATION OF FOURTH
OdaY
I-EFFECT
No.
Treatment
TABLE
INJURY METABOLISM IN AN INSECT
1583
is in a physiological state which is not comparable with that of a diapausing pupa or that of a Rhodnius larva decapitated 24 l-n-after feeding (see Discussion).
E#ect of injury on respiration offed intact larvae Fifth instar larvae were fed and 12 days later, one-half of the insects was wounded, while the other half served as controls. The oxygen consumption of both groups was measured at 6 days after injury, a time when the respiratory rate of injured larvae would be expected to be around its maximum, if injury had been affecting it. The results of this experiment are shown in Table 2. TABLE%-EFFECT OFINJURYON THERESPIRATION OFFIFTHINSTAR LARVAE AT 28°C
Treatment
No. of insects
Injured Intact
7 7
Oxygen uptake (rnn?OJinsect per hr) f standard error 32.9 L!Y 2.3 31.1 f 1.3
Insects were injured 12 days after feeding and their respiration was measured 6 days after injury. From this Table it can be seen that the injury metabolism in an insect which is undergoing growth and development cannot be induced or, more precisely, is not reflected in an increase in its respiratory rate. DISCUSSION That injury of a
Rhodnius larva decapitated 1 day after feeding is associated
with an increase in the respiratory rate, thus raising the latter to a level which approximately parallels that of a normal fed larva in the same instar (see OKASHA, 1968b), agrees fairly well with the results of previous authors working on diapausing pupae (SUSSMAN, 1952; and WILLIAMS, 1961).
SCHNEIDERMANand WILLIAMS, 1953, 1954; HARVEY
This elevated rate of general metabolism was found to be
associated with, or perhaps can be regarded as a reflection of, a prompt increase in the rate of protein synthesis as judged by an increase in the rate of incorporation of amino acids into haemolymph proteins (TELFER and WILLIAMS, 1960) or into the fat body proteins (STEVENSONand WYATT, 1962), or by an increase in the activity of oxidative enzymes (SHAPPIRIOand HARVEY, 1965). In contrast to what happens in response to injury in the decapitated larva, wounding does not result in any increase in the general metabolic rate of the larva in which growth and development are proceeding normally. It must be remembered here that both the rate of respiration and that of protein synthesis increase during growth and development under the influence of the moulting hormone (for review see WIGGLESWORTH,1964). That being the case, it seems reasonable that injury does not raise the metabolic level of an insect whose metabolism is already at a high
1584
A. Y. K.
OKASHA
level, although the local repair of the wound takes place together with the physiological and cytological changes necessary for the formation of a new cuticle in the wounded area. SHAPIRO(1968), f or example, reported that in Galleria mellonella larvae there is a significant increase in the number of circulating haemocytes/mma a day after wounding. Recently ARKING and SHAAYA(1969), h owever, showed that the injection of ecdysone into 6- and 8-day-old larvae of Calliphora stimulated the rate of incorporation of i4C-leucine into fat body proteins, when the larvae already have circulating natural ecdysone, though not at its maximum. The view presented here is not a new one. In Cecropia pupae, HARVEYand WILLIAMS (1961) suggested that injury raises metabolism to the level of a nondiapausing pupa by disrupting the conservative mechanism by which the diapausing insect keeps its metabolism at a low level, the ‘maintenance metabolism’. These authors postulated that it would be impossible to elevate the metabolism of a non-diapausing insect by injury. A similar suggestion was put forward to explain the short survival of a full-grown larva of Lymantria after removing the brain when compared with that of the unhatched larva. In the former, a mechanism which is required for reducing the metabolism to the low level characteristic of diapause is lacking (LEES, 1955). The experiments reported here give an experimental proof to the hypothesis of HARVEYand WILLIAMS (1961). Furthermore, these experiments strongly suggest that the failure of MECCA(1960) to induce an elevated respiratory rate in Prodenia pupae following injury is not due to the small size of the wound, but is due to the injured pupae not being in a diapausing state.
REFERENCES R. and SHAAYAE. (1969) Effect of ecdysone on protein synthesis in the larval fat body of Calliphora. J. Insect Physiol. 15,287-296.
ARKINC
HARVEYW. and WILLIAMSC. M. (1961) The injury metabolism of the Cecropia silkworm-I. Biological amplification of the effects of localized injury. J. Insect Physiol. 7, 81-99. LEES A. D. (1955) The Physiology of Diapause in Arthropods. Cambridge University Press, * London. MECCA C. E. (1960) Lack of elevated respiration in injured pupae of the southern army worm, Prod&a eria’ania (Lepidoptera). Ann. ent. Sot. Am. 53, 849-850. OKASHAA. Y. K. (1968a) Effects of sub-lethal high temperature on an insect, Rhodnius prolixus (St&l.)-I. Induction of delayed moulting and defects. J. exp. Biol. 48,455-463. OKASHAA. Y. K. (1968b) Changes in the respiratory metabolism of Rhodnius prolixus as induced by temperature. J. Insect Physiol. 14,1621-1634. SCHNEIDERMAN H. A. and WILLIAMSC. M. (1953) The physiology of insect diapause-VII. The respiratory metabolism of the Cecropia silkworm during diapause and development. Biol. Bull., Woods Hole 105,320-334. SCHNEIDERMAN H. A. and WILLIAMS C. M. (1954) The physiology of insect diapause_IX. The cytochrome oxidase system in relation to the diapause and development of the Cecropia silkworm. Biol. Bull., Woods Hole 106,238-252. SHAPIROM. (1968) Changes in the haemocyte population of the wax moth, Galleria mellonella, during wound healing. J. Insect Physiol. 14,1725-1733.
INJURYMETABOLISM IN AN INSECT
1585
SHAPPIRIOD. G. and HARVEYW. R. (1965) The injury metabolism of the Cecropia silkworm -11. Injury-induced alterations in oxidative enzyme systems and respiratory metabolism of the pupal wing epidermis. J. Insect Physiol. 11,305-327. SKINNERD. M. (1963) Incorporation of labelled valine into the proteins of the Cecropia silkworm. Biol. Bull., Woods Hole 125,16.5-176. IncorporaSTEVENSON E. and WYATT G. R. (1962) Th e metabolism of silk moth tissues-I. tion of leucine into protein. Archs Biochem. Biophys. 99, 65-71. SUSSMANA. S. (1952) Tyrosinase and the respiration of pupae of Platysamia cecropia L. Biol. Bull., Woods Hole 102, 39-47. TELFER W. H. and WILLIAMS C. M. (1960) The effects of diapause, development, and injury on the incorporation of radioactive glycine into the blood proteins of the Cecropia silkworm. J. Insect Physiol. 5,61-72. WIGGLESWORTH V. B. (1934) The physiology of ecdysis in Rhodnius prolixus (Hemiptera)II. Factors controlling moulting and metamorphosis. Quart. J. micr. Sci. 77, 191-222. WIGGLESWORTH V. B. (1937) W ound healing in an insect (Rhodnius prolixus, Hemiptera). J. exp. Biol. 14,364-381. WIGGLESWORTH V. B. (1954) The Physiology of Insect Metamorphosis. Cambridge University Press, London. WIGGLESWORTH V. B. (1957) The action of growth hormones in insects. Symp. Sot. exp. Biol. 11, 204-227. WIGGLESWORTH V. B. (1964) The hormonal regulation of growth and reproduction in insects. Adv. Insect Physiol. 2, 247-336.