| Title: | Host-Induced Plant Volatiles Mediate Ability of the Parasitoid Microplitis croceipes to Discriminate Between Unparasitized and Parasitized Heliothis virescens Larvae and Avoid Superparasitism |
| Author(s): | Kafle BD; Morawo T; Fadamiro H; |
| Address: | "Department of Entomology & Plant Pathology, Auburn University, Auburn, AL, 36849, USA. Indian River Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Fort Pierce, FL, 34945, USA. Department of Entomology & Plant Pathology, Auburn University, Auburn, AL, 36849, USA. fadamhy@auburn.edu" |
| DOI: | 10.1007/s10886-020-01218-x |
| ISSN/ISBN: | 1573-1561 (Electronic) 0098-0331 (Linking) |
| Abstract: | "In solitary endoparasitoids, oviposition in a host previously parasitized by a conspecific (superparasitism) leads to intraspecific competition, resulting in the elimination of all but one parasitoid offspring. Therefore, avoidance of parasitized hosts presents a strong selective advantage for such parasitoid species. Parasitoids use herbivore-induced plant volatiles (HIPVs) to find their hosts. In this study, we evaluated the ability of Microplitis croceipes (Hymenoptera: Braconidae) to discriminate between unparasitized and parasitized Heliothis virescens (Lepidoptera: Noctuidae) larvae using cotton plant odors as cues. A combination of behavioral and analytical techniques were used to test two hypotheses: (i) parasitoids will show preference for plant odors induced by unparasitized hosts over odors induced by parasitized hosts, and (ii) the parasitism status of herbivores affects HIPV emission in plants. Heliothis virescens larvae were parasitized for varying durations (0, 2 and 6-days after parasitism (DAP)). In four-choice olfactometer bioassays, female M. croceipes showed greater attraction to plant odors induced by unparasitized hosts compared to plant odors induced by parasitized hosts (2 and 6-DAP). Comparative gas chromatography-mass spectrometry analyses of cotton volatiles indicated reduced emission of 10 out of 21 identified compounds from plants infested by parasitized hosts compared with plants infested by unparasitized hosts. The results suggest that changes in plant volatile emission due to the parasitism status of infesting herbivores affect recruitment of parasitoids. Avoidance of superparasitism using plant odors optimizes host foraging in M. croceipes, and this strategy may be widespread in solitary parasitoid species" |
| Keywords: | Animals Gas Chromatography-Mass Spectrometry Gossypium/chemistry/*parasitology Herbivory *Host-Parasite Interactions Larva/drug effects/growth & development Lepidoptera/drug effects/*growth & development Oviposition Volatile Organic Compounds/analysis/*ph; |
| Notes: | "MedlineKafle, Basu D Morawo, Tolulope Fadamiro, Henry eng 2020/09/27 J Chem Ecol. 2020 Oct; 46(10):967-977. doi: 10.1007/s10886-020-01218-x. Epub 2020 Sep 26" |
