Comparative host selection responses of specialist (Helicoverpa assulta) and generalist (Helicoverpa armigera) moths in complex plant environments

Abstract

We tested the behavioral responses of ovipositing females and natal larvae of two sibling species, a generalist Helicoverpa armigera (Hübner) and a specialist Helicoverpa assulta (Guenée), to odor sources emitted from different combinations of six plant species (tobacco, Nicotiana tabacum; hot pepper, Capsicum annuum; tomato, Solanum esculentum; cotton, Gossypium hirsutum; peanut, Arachis hypogaea; maize, Zea mays). Under the conditions of plant materials versus corresponding controls, both stages of both species could find their corresponding host plants. However, H. assulta females and larvae exhibited a supersensitive and an insensitive response, respectively. Under the conditions of tobacco paired with each plant species, H. assulta females exhibited more specialized ovipositional response to tobacco than its sibling. When each plant species were combined with tobacco and tested against tobacco reference, peanut played an opposite role in the two species in their ovipositional responses to tobacco, and cotton can enhance the approaching response of H. armigera larvae when combined with tobacco. It seems that two attractive host plants also can act antagonistically with respect to host selection of the generalist via volatile exchange. Tomato should better be excluded from host list of H. assulta.

Experience-based mediation of feeding and oviposition behaviors in the cotton bollworm: Helicoverpa armigera (Lepidoptera: Noctuidae)

“…armigera were picked out and directly subjected to approaching and feeding response bioassays without further rearing. As a reference, a laboratory colony, originated from pupae provided by Baiyun Industrial Co. Ltd., has been maintained on artificial diet [ 13 ] for successive three generations. To save space, the larvae of the five groups will be abbreviated as “cotton-larvae”, “tobacco-larvae”, “tomato-larvae”, “hot pepper-larvae”, and “naïve larvae”, hereinafter.…”

Nonanal modulates oviposition preference in female Helicoverpa assulta (Lepidoptera: Noctuidae) via the activation of peripheral neurons

“…The insect olfactory system plays an important role in many aspects of insect biology and ecology, including natural enemy avoidance, host preference, mate location and oviposition. 1,2 Insects can perceive odorants such as sex pheromones, 3 aggregation pheromones, 4 alarm pheromones 5 and host-plant volatiles [6][7][8] through their olfactory system. Many proteins are involved in the olfactory system, including odorant-binding proteins (OBPs), 9 odorant receptors (ORs), 10 sensory neuron membrane proteins (SNMPs) 11 and odorant-degrading enzymes (ODEs); 12,13 of these, ORs form the core of odorant detection.…”

“…25 Among the host plants, H. assulta females show a strong oviposition preference for tobacco compared with sunflowers, hot peppers, green peppers, aubergines or tomatoes. 7,26,27 More eggs are found on the leaves than on other parts of the tobacco plant, such as the stems, fruit and flowers. 27 Chemical cues are important in host selection and female egg-laying preferences.…”

“…H. assulta is a serious threat to tobacco and peppers in China 25 . Among the host plants, H. assulta females show a strong oviposition preference for tobacco compared with sunflowers, hot peppers, green peppers, aubergines or tomatoes 7,26,27 . More eggs are found on the leaves than on other parts of the tobacco plant, such as the stems, fruit and flowers 27 .…”

What is the level of fruit infestation by pulp-feeding insects? An overview of their meaning and measurement

“…Host plant selection is critical for development and survival in the next stages of 2015). Generally, the behavioural scheme of adult females shows the following steps: searching, encounter, landing, fruit surface evaluation and host acceptance (Li et al, 2017). The behaviour determines particular traits which promote a successful egg-laying and larval growth (Janz, 2005).…”