Insect Science (2019) 26, 341-350

Tolulope Morawo and Henry Fadamiro (2019)
The role of herbivore- and plant-related experiences in intraspecific host preference of a relatively specialized parasitoid
Insect Science 26 (2), 341-350
Abstract: Parasitoids use odor cues from infested plants and herbivore hosts to locate their hosts. Specialist parasitoids of generalist herbivores are predicted to rely more on herbivore-derived cues than plant-derived cues. Microplitis croceipes (Cresson) (Hymenoptera: Braconidae) is a relatively specialized larval endoparasitoid of Heliothis virescens (F.) (Lepidoptera: Noctuidae), which is a generalist herbivore on several crops including cotton and soybean. Using M. croceipes/H. virescens as a model system, we tested the following predictions about specialist parasitoids of generalist herbivores: (i) naive parasitoids will show innate responses to herbivore-emitted kairomones, regardless of host plant identity and (ii) herbivore-related experience will have a greater influence on intraspecific oviposition preference than plant-related experience. Inexperienced (naive) female M. croceipes did not discriminate between cotton-fed and soybean-fed H. virescens in oviposition choice tests, supporting our first prediction. Oviposition experience alone with either host group influenced subsequent oviposition preference while experience with infested plants alone did not elicit preference in M. croceipes, supporting our second prediction. Furthermore, associative learning of oviposition with host-damaged plants facilitated host location. Interestingly, naive parasitoids attacked more soybean-fed than cotton-fed host larvae in two-choice tests when a background of host-infested cotton odor was supplied, and vice versa. This suggests that plant volatiles may have created an olfactory contrast effect. We discussed ecological significance of the results and concluded that both plant- and herbivore-related experiences play important role in parasitoid host foraging.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Tolulope Morawo, Henry Y. Fadamiro

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Heliothis virescens	Soybean (Glycine max)
	Heliothis virescens	Cotton (Gossypium)
Glabromicroplitis croceipes (parasitoid)	Heliothis virescens	Soybean (Glycine max)
Glabromicroplitis croceipes (parasitoid)	Heliothis virescens	Cotton (Gossypium)