, Volume 92, Issue 9, pp 435–439 | Cite as

Cannibalistic feeding of larval Trichogramma carverae parasitoids in moth eggs

  • Leeane M. Heslin
  • David J. MerrittEmail author
Short Communication


Wasps of the genus Trichogramma parasitise the eggs of Lepidoptera. They may deposit one or many eggs in each host. Survival is high at low density but reaches a plateau as density increases. To reveal the mechanism by which excess larvae die we chose a lepidopteran host that has flattened, transparent eggs and used video microscopy to record novel feeding behaviours and interactions of larval Trichogramma carverae (Oatman and Pinto) at different densities. Single larvae show a rapid food ingestion phase, followed by a period of extensive saliva release. Ultimately the host egg is completely consumed. The larva then extracts excess moisture from the egg, providing a dry environment for pupation. When multiple larvae are present, the initial scramble for food results in the larvae consuming all of the egg contents early in development. All larvae survive if there is sufficient food for all to reach a threshold developmental stage. If not, physical proximity results in attack and consumption of others, continuing until the surviving larvae reach the threshold stage beyond which attacks seem to be no longer effective. The number of larvae remaining at the end of rapid ingestion dictates how many will survive to emerge as adults.


Physical Attack Developmental Threshold Single Larva Light Brown Apple Moth Urate Cell 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Financial support came from an Australian Research Council SPIRT Grant C00107081. L. Heslin is the recipient of an ARC APAI award. We thank Molly Hunter and Gimme Walter for their comments on the manuscript, Dan Papacek (Bugs for Bugs, Mundubbera, Queensland) for supplying T. carverae, Nancy Cunningham (South Australian Research and Development Industry) and Queensland Department of Primary Industries for supplying moths. The experiments comply with the current laws of Australia.

Supplementary material

S1. Development of a single T. carverae larva inside an E. postvittana host egg. Individual frames were captured at 10 minute intervals.

S2. Development of multiple T. carverae larva inside an E. postvittana host egg. Five larvae hatch but only two develop to the prepupal stage. Individual frames were captured at 10 minute intervals. Single frames from the movie are depicted in Figure 3. (1.2 mb)
S3. Development of T. carverae larvae within a heavily parasitised E. postvittana host egg. Larvae are numbered in accord with the fate diagram of Figure 2C in the text. Single frames from the movie are used in Figure 4. Individual frames were captured at 10 minute intervals. The gaps in the movie are due to the loss of some frames during filming.
114_2005_15_MOESM4_ESM.pdf (333 kb)
Development of T. carverae larvae within a heavily parasitised E. postvittana host egg. Larvae are numbered in accord with the fate diagram of Figure 2C. Numerals in top right corner denote time after hatching (h). a. The full complement of larvae is numbered. b. Larva 10 is consuming larva 15 (arrow indicates mouth). c. Larva 2 is consuming larva 10, and 1 is consuming 14. d, e. Four larvae (1-4) occupy most of the host egg. f. Urate cells are visible in the four surviving larvae (arrows). Scale: 100 μm.


  1. Boivin G, van Baaren J (2000) The role of larval aggression and mobility in the transition between solitary and gregarious development in parasitoid wasps. Ecol Lett 3:469–474CrossRefGoogle Scholar
  2. Hutchison WD, Moratorio M, Martin JM (1990) Morphology and biology of Trichogrammatoidea bactrae (Hymenoptera: Trichogrammatidae), imported from Australia as a parasitoid of pink bollworm (Lepidoptera: Gelechiidae) eggs. Ann Entomol Soc Am 83:46–54Google Scholar
  3. Klomp H, Teerink BJ (1967) The significance of oviposition rates in the egg parasite, Trichogramma embryophagum. Arch Neerl Zool 17:350–375CrossRefGoogle Scholar
  4. Klomp H, Teerink BJ (1978) The elimination of supernumerary larvae of the gregarious egg parasitoid Trichogramma embryophagum (Hymenoptera: Trichogrammatidae) in eggs of the host Ephestia kuehniella (Lepidptera: Pyralidae). Entomophaga 23:153–159CrossRefGoogle Scholar
  5. Liu WH, Xie ZN, Xiao GF, Zhou YF, Yang DHO, Li LY (1979) Rearing of the Trichogramma dendrolimi in artificial diets. Acta Phytophyl Sinica 6:17–24Google Scholar
  6. Olson DM, Andow DA (1998) Larval crowding and adult nutrition effects on longevity and fecundity of female Trichogramma nubilale Ertle and Davis (Hymenoptera: Trichogrammatidae). Environ Entomol 27:508–514Google Scholar
  7. Pak GA, Oatman ER (1982) Biology of Trichogramma brevicapillum. Ent Exp Appl 32:61–67Google Scholar
  8. Salt G (1934) Experimental studies in insect parasitism. II. Superparasitism. Proc R Soc Lond B Biol Sci 114:455–476CrossRefGoogle Scholar
  9. Salt G (1936) Experimental studies in insect parasitism. IV. The effect of superparasitism on populations of Trichogramma evenescens. Proc R Soc Lond B Biol Sci 116:363–375Google Scholar
  10. Schieferdecker H (1969) Der gregarparasitismus von Trichogramma. Beitr Entomol 19:507–521Google Scholar
  11. Strand MR, Vinson SB (1985) In vitro culture of Trichogramma pretiosum on an artificial medium. Ent Exp Appl 39:203–209CrossRefGoogle Scholar
  12. Volkoff AN, Daumal J, Barry P, Francois MC, Hawlitzky N, Rossi MM (1995) Development of Trichogramma cacoeciae Marchal (Hymenoptera: Trichogrammatidae): Timetable and evidence for a single larval instar. Int J Insect Morphol Embryol 24:459–466CrossRefGoogle Scholar
  13. Waage JK, Godfray HCJ (1985) Reproductive strategies and population ecology of insect parasitoids. In: Sibly RM, Smith RH (eds) Behavioural ecology: ecological consequences of adaptive behaviour. Blackwell Scientific Publications, Oxford, pp 449–470Google Scholar
  14. Waage JK, Ng SM (1984) The reproductive strategy of a parasitic wasp. I. Optimal progeny and sex allocation in Trichogramma evanescens. J Anim Ecol 53:401–415CrossRefGoogle Scholar
  15. Wu ZX, Cohen AC, Nordlund DA (2000) The feeding behaviour of Trichogramma brassicae: new evidence for selective ingestion of solid food. Ent Exp Appl 96:1–8CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.School of Integrative BiologyThe University of QueenslandBrisbaneAustralia

Personalised recommendations