Differential attraction of parasitoids in relation to specificity of kairomones from herbivores and their by‐products

Abstract

Infochemicals are used by foraging parasitoids in the host selection process from habitat preference until host recognition. Kairomones from the herbivore host plays a vital role in the attraction of parasitoids, particularly in the micro‐habitat. Parasitoids are specifically attracted to their respective herbivore species even when different herbivores are present on the same plant. Chemicals emitted from different stages of host (eggs, larvae, pupae, adult), host by‐products (e.g., frass, exuviae, mandibular gland secretions, defense secretions etc.), or intra‐specific infochemicals (pheromones) can be main signals for the parasitoids. Parasitoids can differentiate between host and non‐host, between different hosts and host stages by perceiving specific volatile and contact kairomones from the host itself, host along with its by‐product, by‐products alone or intra‐specific infochemicals; of which frass (by‐product) and intra‐specific infochemicals are the most reported ones. Adult and larval parasitoids have been reported to be attracted to kairomones of their target stage or byproduct of their host. Pupal parasitoids have been found to utilize kairomones from the preceding host stage while egg parasitoids are known to exploit a variety of host infochemicals, for example, either from eggs themselves or other non‐target host stages, especially adults and adult‐related by‐products. The kairomonal chemicals identified so far include various groups, but mainly hydrocarbons. A high degree of host specificity and host acceptance is important for the parasitoids as any mistake may result in the loss of fitness.

Comparative GC-EAD Responses of A Specialist (Microplitis croceipes) and A Generalist (Cotesia marginiventris) Parasitoid to Cotton Volatiles Induced by Two Caterpillar Species

“…Additionally, unknown minor compounds as well as hostspecific volatiles also may play a role in differentiation of different host-plant complexes. Further discrimination may be mediated at short range by host contact kairomones (which are typically of relatively lower volatility), such as host feces (Loke and Ashley 1984;Dmoch et al 1985;Afsheen et al 2008) and caterpillar chemical footprints on infested plants (Rostas and Wölfling 2009). Future behavioral studies are necessary to confirm whether or not the ability of M. croceipes to distinguish between plants damaged by its host and non-host caterpillars (Rosé et al 1997), is in fact mediated by the subtle quantitative differences in volatile blends recorded in this study.…”

Modifications of the Chemical Profile of Hosts after Parasitism Allow Parasitoid Females to Assess the Time Elapsed Since the First Attack

“…Semio-chemicals are known to play a crucial role in host localization in parasitoids (Afsheen et al 2008). Host cues can have many different origins such as oviposition markers (Kumazaki et al 2000;Onodera et al 2002), chemical residues left by adult hosts on the substrate (Colazza et al 1999(Colazza et al , 2007Peri et al 2006), chemicals originally from host feces (Meiners et al 1997;Steidle et al 2003;Steiner et al 2007;Inoue and Endo 2008), or possibly even carbon dioxide (Hilker and McNeil 2008).…”

Kairomones for Increasing the Biological Control Efficiency of Insect Natural Enemies

“…Among the different by-products, frass is the most commonly reported source for parasitoids. Many insect natural enemies use frass kairomone to find their hosts, as frass consists of volatile and contact kairomones acting as a strong kairomone source for the respective parasitoid (Afseen et al 2008). The female Cotesia marginiventris (Cresson) responded positively to the materials derived from the fall armyworm (FAW) larvae, Spodoptera frugiperda (J. E. Smith), more intensely to the frass (Loke and Ashley 1984).…”