Wasp-associated factors can induce physiological suppression and promote coexistence during multiple parasitism

Issue Date

10-2017

Abstract

Resource sharing or exclusion of parasitoids within a host during multiparasitism may depend on their similar life-history traits and strategies. Conflict in the possession of a host may lead to displacement of inferior species through physical attack and/or physiological suppression. However, mechanisms of physiological suppression during multiparasitism remain equivocal. In the present study, we investigated the influence of wasp regulatory factors (virus-like particles, polydnaviruses, and venoms) on the development of competing endoparasitoids Meteorus pulchricornis (Wesmael), Cotesia kariyai (Watanabe) and Cotesia ruficrus (Haliday) in their common host Mythimna separata (Walker). We found that the virus-like particles alone (or with venom) of M. pulchricornis were deleterious to the development of two gregarious parasitoids. Similarly, polydnaviruses plus venom of C. kariyai had toxic effects on solitary M. pulchricornis eggs and immature larvae, although they were not harmful to C. ruficrus. The two gregarious species were able to coexist mainly through the expression of regulatory factors and both could successfully survive from multiparasitized host. The presence of C. kariyai polydnaviruses and venom facilitated C. ruficrus after oviposition in L5 host increasing the rate of successful parasitism from 9-62%. This suggests that the two gregarious parasitoids exhibit strong phylogenetic affinity, favoring their coexistence and success in multiparasitized host. Different protein bands from hemolymph of parasitized host larvae were also observed, suggesting dissimilarity in nutritional requirements of each parasitoid species.

Source or Periodical Title

The Philippine Entomologist

ISSN

0048-3753

Volume

31

Issue

2

Page

149

Document Type

Article

Frequency

semi-annually

Language

English

En – AGROVOC descriptors

MYTHIMNA SEPARATA; MYTHIMNA; METEORUS; COTESIA; POLYDNAVIRUS; PARASITOIDS; PARASITISM; ENDOPARASITES; HOSTS; HOST PARASITE RELATIONS; BIOLOGICAL CONTROL

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