Finding an egg in a haystack: variation in chemical cue use by egg parasitoids of herbivorous insects

Differential effects of plant-beneficial fungi on the attraction of the egg parasitoid Trissolcus basalis in response to Nezara viridula egg deposition

“…Since the setups used for the Y-tube olfactometer assays and headspace sampling were slightly different in our study, and a different set of plants was used in these experiments, this also could have contributed to the discrepancy between our behavioural assays and VOC analysis. Moreover, parasitoids have evolved highly effective mechanisms for detecting subtle variations in the complex blends of VOCs associated with their hosts [ 41 , 76 ]. Additionally, it is well known that insect behaviour is not always influenced by the volatile blend as a whole or the presence and abundance of specific compounds in the blend, but rather depends on the level and ratio of the different compounds [ 18 , 41 , 77 , 78 ].…”

“…Moreover, parasitoids have evolved highly effective mechanisms for detecting subtle variations in the complex blends of VOCs associated with their hosts [ 41 , 76 ]. Additionally, it is well known that insect behaviour is not always influenced by the volatile blend as a whole or the presence and abundance of specific compounds in the blend, but rather depends on the level and ratio of the different compounds [ 18 , 41 , 77 , 78 ]. It must also be noted that minor constituents of the VOC blend are often highly important in natural enemy behaviour, in particular given the highly sensitive olfactory receptor neurons in insect antennae [ 79 ].…”

“…Egg parasitoids are an important group of natural enemies of herbivorous insects as they kill their hosts in the egg stage before plant damage occurs [ 38 , 39 ]. When searching for hosts, egg parasitoids use host-associated cues, especially OIPVs and odours from gravid females [ 21 , 40 , 41 ]. To date, virtually nothing is known about whether the host-seeking behaviour of egg parasitoids can be modulated by plant-associated microbes.…”

The mirid predator Macrolophus basicornis smells and avoids eggs of Tuta absoluta parasitized by Trichogramma pretiosum

“…Numerous studies have shown that herbivore insect oviposition induces plant volatiles (OIPVs) attract egg and larval parasitoids and repel ovipositing herbivores (reviewed by 27,30,31,32 ) Lepidopteran oviposition, including that by T. absoluta, does not cause obvious damage to plants. Nevertheless, egg deposition of several lepidopteran species induces quantitative changes in the plant volatile blends 33 .…”

Dispersal of Optimal Foragers in a Patchy Environment: Simulations with a Mathematical Model and Tests of Predictions in Field Experiments

“…Parasitoid movement among patches takes time (Driessen and 83 Hemerik, 1992), the number of unparasitized hosts in a patch decreases as a result of parasitoid 84 activity (Wajnberg et al, 2000). Although females of some species can use volatile odors to 85 detect distant hosts (Aartsma et al, 2019;Hedstrom et al, 2017;Yong et al, 2007) (reviewed in 86 Godfray, 1994;Greenberg et al, 2023) or competitors (Janssen et al, 1997;Janssen et al, 1995a, 87 b), they are very unlikely to have perfect knowledge of the environment. This probably explains 88 why observations, even in extremely simplified environments, often fail to fit with predictions 89 (Kennedy and Gray, 1993;reviewed in Tregenza et al, 1996).…”