Oviposition behaviour and patch‐time allocation in two aphid parasitoids exposed to deltamethrin residues

Abstract

Neurotoxic insecticides are widely used for crop protection. One consequence is that changes in behaviour can be expected in surviving beneficial insects because of an impairment of host perception and motor abilities. Under laboratory conditions, we studied the impact of deltamethrin, a pyrethroid, on the oviposition behaviour of two hymenopterous parasitoids of aphids, Aphidius matricariae (Haliday) and Diaeretiella rapae (McIntosh) (Hymenoptera: Braconidae). They both parasitize Myzus persicae (Sulzer) (Homoptera: Aphididae), which is the preferred host of A. matricariae, regardless of the host plant, whereas D. rapae is a major parasitoid of aphids on Cruciferae crops, including M. persicae. After exposure to deltamethrin, the different items of oviposition behaviour and the total time spent on the patch were recorded. The results showed that the patch time allocation by both parasitoid species was not significantly affected by deltamethrin treatment, when compared with the controls. Nor were the frequencies and sequences of behavioural items modified (e.g., frequency of sting). It therefore appeared that the patch use of A. matricariae and D. rapae on new colonies of M. persicae was not disturbed by deltamethrin at the three doses tested. The possibility that parasitoid strains are partially tolerant to deltamethrin is discussed.

Plant characteristics mediated by growing conditions can impact parasitoid’s ability to attack host aphids in winter canola

“…Upon host encounter, eVective detection of the host (e.g. aphid) occurs when 'antennal palpation' follows 'antennal contact' (Desneux et al 2004b) and is based on the physical and chemical cues acting at short range or by contact (Battaglia et al 2000). In our experiment, frequencies of 'antennal palpation' were always equal to or higher than frequencies of 'antennal contact', indicating that parasitoids easily detected M. persicae.…”

“…Although both species diVer in their behavioral responses to M. persicae on canola (Desneux et al 2004b), both appear well-adapted to this speciWc host-plant complex (Wilson and Lambdin 1987;Desneux et al 2005). In contrast, Aphidius ervi Haliday and A. colemani Viereck (Hymenoptera: Braconidae), both parasitoids of M. persicae that are abundant in European agricultural landscapes (Kavallieratos et al 2004;Lumbierres et al 2007), are respectively rarely found and not found at all to attack M. persicae in winter canola (Desneux et al 2006b;Desneux N. unpublished data).…”

Parasitism of the soybean aphid,Aphis glycinesbyBinodoxys communis: the role of aphid defensive behaviour and parasitoid reproductive performance

“…maximum of 5 min or until successful oviposition) (Desneux et al, 2004). We compared these frequencies and the time until oviposition for the various aphid developmental stages using a non-parametric Kruskal-Wallis test.…”

Sublethal Effects of Pyrethroids on Insect Parasitoids: What We Need to Further Know

“…The results obtained by these authors draw attention to the fact that orientation and oviposition behaviours of parasitoids may be disturbed by pyrethroids, depending on the dose, the parasitoid experience and the type of behaviour. Conversely, the oviposition behaviour (both frequencies and behavioural sequences) of D. rapae and A. matricariae (Hymenoptera: Braconidae) on aphid-infested plants and patch-time allocation were not disturbed following exposure to deltamethrin residues (Desneux et al, 2004b), regardless of the dose. According to these authors the unexpected lack of effects after deltamethrin exposure can have two explanations: either the deltamethrin molecules did not alter the functions necessary for host-handling behaviour, or the surviving insects were less susceptible (reflecting differences in parasitoid vigour or in genetically determined susceptibility to pesticides).…”