Common volatiles are major attractants for neonate larvae of the specialist flea beetle Altica koreana (Coleoptera: Chrysomelidae)

Abstract

Olfactory stimuli play an important role in the host searching of larval phytophagous insects. Previous studies indicate that larvae that have to find feeding sites after hatching are generally attracted to host volatiles. However, there are few studies on the olfactory responses of neonate larvae to host volatiles in cases when those larvae hatched on the host plant. In the present study, we determined the olfactory responses of neonate larvae of the specialist flea beetle, Altica koreana Ogloblin, to host and six non-host plants, using a static-air "arena." Larvae responded significantly to the host plant Potentilla chinensis Ser. and five of six non-host plants, compared to the control. Larvae did not prefer the host plant over the non-host plants (except Artemisia sp.) when offered a choice. Additionally, odours of a non-host plant, which were unattractive to neonate larvae, may have masked the attractive odour of the host plant. These results indicate that common volatiles can play a major role in attracting larvae of this specialist to plants, but attraction to such odours may not be the major mechanism of host choice.

Oviposition, larval preference, and larval performance in two polyphagous species: does the larva know best?

“…For example, Ascia monuste (Godart) larvae often perform large‐range migrations of more than 5 m in response to food shortage (Barros‐Bellanda & Zucoloto, ), and Manduca sexta L. larvae perform such large‐range migrations that the effects of oviposition site choice are minor in individual performance (Potter et al., ). Xue & Yang () categorized four egg‐laying strategies that imply larval mobility: (1) larvae that hatch on the foliage and have to search for the fruits of their host plant; (2) larvae that hatch on the soil surface and have to dig in the soil searching for belowground tissue of the host plant; (3) larvae that hatch on dry left‐over material from the previous growing season and have to search for fresh tissue; and (4) highly mobile larvae that search for host plants after the unselective female laid the eggs on any plant. A fifth case occurs when selective adults’ preferences are negatively related to larval preferences, females choose to oviposit on non‐preferred or unsuitable larval host species, and consequently larvae must move to an appropriate host (Foster & Howard, ).…”

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

“…assulta ovipositing females in our study. Supersensitive host selection response of adult females in parallel with insensitive response of conspecific larvae has also been demonstrated in several specialist herbivores [ 19 – 21 ].…”

Genetic analysis of feeding preference in two related species of Altica (Coleoptera: Chrysomelidae: Alticinae)

“…Larval feeding preference has important fitness consequences, because the feeding site selection of larvae is not only governed by females, but also by the larvae themselves in many phytophagous insects ( Janz & Nylin, 1997;Foster & Howard, 1999 ). However, in some other specialists, nutrition available to larvae and exposure to the elements is determined by female oviposition ( Mayhew, 1997;Xue & Yang, 2008 ). The larval feeding preference may then be comparatively unimportant in these cases, whereas the adult feeding preference carries more significance.…”