The influence of insecticide residues on primary parasitoid and hyperparasitoid foraging behaviour in the laboratory

Abstract

The behaviour of Aphidius rhopalosiphi DeStefani-Perez (Hymenoptera: Braconidae) was recorded in laboratory bioassays in the presence and absence of both residues of honeydew from the English grain aphid, Sitobion avenae (F.) and the pyrethroid insecticide, deltamethrin. Insecticide concentrations ranged from the field recommended dose rate (6.25 g ai/ha in 200 l water) to 1/16th of field rate. Parasitoids responded strongly to patches of honeydew on filter papers, however the addition of increasing concentrations of deltamethrin caused increasingly early departure from the honeydew-treated areas. Parasitoids pre-exposed to field concentration residues for between 1 and 20 min showed shorter retention times and abnormal types of behaviour on honeydew-treated patches compared to control wasps. Recovery of 'normal' behaviour patterns occurred over a 12 h period away from the insecticide source. Further laboratory studies examined the foraging of A. rhopalosiphi and one of its associated hyperparasitoids, Dendrocerus carpenteri (Curtis), on mature wheat plants treated with an artificial honeydew solution and deltamethrin. Wasps exposed to deltamethrin residues were observed to spend shorter visit times, to groom more frequently and to rest less frequently than those on insecticide-free plants. Differences were found between the distribution of parasitoids on insecticide-treated and untreated plants, with D. carpenteri showing greater movement down insecticide-treated plants accompanied with an increase in time spent on abaxial leaf surfaces compared to A. rhopalosiphi. The results are discussed in terms of the repellency of deltamethrin and the implications for integrated pest management of differing sub-lethal insecticide effects on primary parasitoid and hyperparasitoid behaviour.

Effects of selective insecticides on host searching and oviposition behavior of Neochrysocharis formosa (Westwood) (Hymenoptera: Eulophidae), a larval parasitoid of the American serpentine leafminer

“…Irving and Wyatt, 1973;Perera, 1982;Jiu and Waage, 1990;Longley and Jepson, 1996;Umoru et al, 1996). However, we did not observe parasitoids attempting to escape from the observation cage during this study.…”

“…However, insecticides such as organophosphates, carbamates, and synthetic pyrethroids are generally highly toxic to biological control agents, due to their broad spectrum of activity (Croft, 1990). Other insecticides that do not appear to kill natural enemies, may also have sub-lethal effects, such as altered behavior, reduced reproduction, and reduced longevity, on natural enemies (Jacobs et al, 1984;Elzen, 1989;Croft, 1990;Longley and Jepson, 1996). In IPM, therefore, it is important to examine the possible disruptive effects of candidate insecticides on beneficial insects, and to determine the insecticides compatible with key biological control agents (Stapel et al, 2000).…”

Pengaruh insektisida deltametrin terhadap perilaku orientasi parasitoid Anagrus nilaparvatae (Pang et Wang) (Hymenoptera: Mymaridae)

“…Konsentrasi dengan metode ini digunakan karena masing-masing nilai konsentrasi pada metode kontak dan oral menunjukkan nilai 95% FL yang tumpang tindih yang menunjukkan tidak berbeda nyata. Metode paparan pestisida dengan aplikasi topikal, oral, residu, atau studi lapangan telah banyak digunakan untuk melihat responsnya terhadap musuh alami (Longley & Jepson 1996;Longley 1999;Desneux et al 2005;Wang et al 2008;Liu et al 2010;Fernandes et al 2010). Masing-masing pendekatan memberikan informasi terhadap dampak pestisida terhadap musuh alami.…”

Lethal and sublethal effects of cypermethrin and methoxyfenozide on the larvae ofRachiplusia nu(Guenee) (Lepidoptera: Noctuidae)

“…Several studies have reported pyrethroid repellence. For example, Longley and Jepson (1996) detected lower percentages of parasitism of Aphidius rhopalosiphi (De Stefani-Perez) (Hymenoptera: Aphidiidae) to aphids previously treated with deltamethrin. In this study, organisms exposed to cypermethrin consumed very little of the treated diet during the first 24 h of testing.…”