Physical factors influencing the oviposition behaviour of European grapevine moths Lobesia botrana and Eupoecilia ambiguella

Abstract

Uncovering the entire process of oviposition could enable the development of innovative pest control strategies. The European grapevine moth Lobesia botrana as well as the European grape berry moth Eupoecilia ambiguella are serious insect pests, which still threaten viticulture in many parts of the world. By creating an artificial semiochemical emitting surface, in form of a card, we tried to develop an egg-monitoring tool for the oviposition of these two species in vineyards. The idea was to create a decision support system that facilitates timing and necessity of insecticide treatments.This article deals exclusively with the initial step towards the development of this tool: the influence of physical factors (colour, shape or texture) of a surface on the oviposition behaviour of L. botrana and E. ambiguella under laboratory conditions. The acceptance of different artificial substrates as oviposition site was analysed exclusive of volatile organic compounds emitted by a host plant. We investigated particular colours of the surface, which could be a visual stimulus to trigger the oviposition of both species. Apparently, the colour green, the texture of the material and the light conditions turned out to be highly important stimuli for oviposition. K E Y W O R D Sattraction, colour, shape, tactile responses, texture

Do Grapholita funebrana Infestation Rely on Specific Plum Fruit Features?

“…In Argyrotaenia montezumae (Walsingham), a higher number of eggs per female was laid on green, blue, and yellow substrates than on transparent and pink ones [68]. The shape of the oviposition site can influence selection in Choristoneura fumiferana (Clemens) [69], whereas in laboratory tests, L. botrana and E. ambiguella females preferentially laid eggs on spherical surfaces [33,70].…”

“…In organic plum orchards, good fruit protection can be achieved by alternating a low number of spinosad applications and mineral oil applications, despite the short period of effectiveness typical of spinosad [27].In other tortricid species, the effect of the cultivar in the oviposition choice has been assessed in field studies for Lobesia botrana (Denis and Schiffermüller), Eupoecilia ambiguella (Hübner) Grapholita molesta (Busck), and Cydia pomonella (L.) [28][29][30][31]. In laboratory tests, preference for different apple cultivar was demonstrated for C. pomonella [32], whereas the influence of fruit characteristics like shape, size, texture and colour on L. botrana and E. ambiguella have been studied [33]. Moreover, differences in L. botrana performance (larval development time, fecundity, egg size and egg hatchability) due to grape cultivar have been investigated [34][35][36].The oviposition behaviour of lepidopterans and the selection of an egg-laying site depends upon the multimodal integration of sensory cues in the host location and selection processes.…”

Tracking Short-Range Attraction and Oviposition of European Grapevine Moths Affected by Volatile Organic Compounds in a Four-Chamber Olfactometer

“…Grapevine moths do not require the stimulus of a natural plant to accept surfaces for oviposition [25,32,40]. L. botrana is essentially nocturnal and mating flight is initiated during night, while oviposition starts with sunset and lasts until night.…”

“…In contrast, E. ambiguella is flight active during dawn and egg laying was observed at noon until night [7,42]. Hence, any visual component in host-seeking behavior, which is known to play a key role in some insects that are active by day [43] is assumed to be less significant, at least for L. botrana [25,32]. Therefore, response to volatile plant odors and fruit surface condition are probably the most likely mechanisms for Lepidoptera species like E. ambiguella and L. botrana for locating suitable host plants for reproduction [21,24,26,27,30,[44][45][46].…”

“…Moths used in the bioassays were taken from an insect culture established at Julius Kühn-Institut, Siebeldingen, Germany. They were reared according to Markheiser et al [32] on a semi-artificial diet. Pupae were separated by sex [12], individually transferred into 15 mL falcon tubes (VWR International GmbH, Darmstadt, Germany) and closed using a moisturized cellulose-plug.…”