Effect of insecticides on immature and mature stages of <i>Encarsia citrina</i>, an armoured scale parasitoid

Abstract

Laboratory bioassays were conducted to determine the effect of Bacillus thuringiensis, diazinon, diofenolan and lufenuron on preimaginal and/or adult stages of Encarsia citrina, a key parasitoid of the armoured scale insects infesting kiwifruit. Bioassays were conducted by dipping potatoes, which were infested with second instar greedy scale (Hemiberlesia rapax) parasitised by E. citrina, in insecticide solutions, or caging adult parasitoids in treated Petri dishes. Of the insecticides tested, diazinon had the highest level of toxicity to the adult parasitoids. The need to change to insecticides with low or nil toxicity to scale parasitoids for increased biological control in 'Kiwigreen' is discussed.

Effect of ground cover vegetation on the abundance and diversity of beneficial arthropods in citrus orchards

“…Direct or indirect effects upon the diversity and abundance of natural enemies might have resulted from the insecticide applications, despite a small number of chemical interventions with relatively selective pesticides was carried out. Lufenuron was reported to have no effect on the wasp parasitoid Encarsia citrina (Thomson et al, 1996) but was classified as harmful for the larvae of the green lacewing Chrysoperla externa (Bueno & Freitas, 2004). Abamectin was considered to be innocuous for the larvae of C. externa (Bueno & Freitas, 2004).…”

Integrated pest management in the global arena

“…This equates to a reduction of 100 t of pesticide per annum. This has had a positive impact on orchard biodiversity and has created opportunities for greater use of biological controls (Thomson et al, 1996;Thomson, 1997). In regions where kiwifruit orchards and urban settlements have to coexist, this reduction in insecticide use has also alleviated the potential for conflict between the two communities.…”