Effect of a new insect growth regulator, RO 13-5223, on hymenopterous parasites of scale insects

Abstract

The insect growth regulator, RO 13-5223, applied at concentrations up to 0.1% ai., did not affect the normal development of immature stages of 2 hymenopterous parasites :Metaphycus bartletti Annecke & Mynhardt and Aphytis holoxanthus DeBach, parasitoids of Saissetia oleae (Olivier) and Chrysomphalus aonidum (L.), respectively. Spraying citrus trees at the rate of 7.5 g. a.i./tree had no adverse effect on the activity of the following parasitoids : Aphytis chrysomphali (Mercet) and Compe.riella bifasciata Howard, an ecto-and endoparasite of the California red scale, Aonidiella aurantii MaskeU, respectively ; Aphytis hispanicus (Mercet) and Prospaltella inquirenda Silvestri, an ecto-and endoparasite of the citrus chaff scale, Parlatoria pergandii Comstock, respectively.The wide spread and continuously increasing use of different types of non-selective pesticides in citrus groves in Israel, and elsewhere, disturbs the biological balance and causes outbreaks of insect and mite pests. Unfortunately, only a few selective insecticides are known, among them are mineral oil and various acaricides. The use of mineral oil has been gradually decreasing because of certain agrotechnical difficulties. In an integrated pest management programme one should try to employ selective pesticides or those which have a lesser adverse impact on nontarget organisms. Potentially selective or semi-selective insecticides are insect growth regulators (Franz et al., 1980; Peleg & Gothilf, 1980) which have been subjected to insect control Studies (Stall, 1975 ;Bullock & McCoy, 1978 ;Hoying & Riedel, 1980 ;Retnakaran, 1980 ; Peleg & Gothilf, 1981). Recently I tested a new insect growth regulator (IGR), RO 13-5223, in controlling scale insect pests. It was found (Peleg, 1982) that the chemical could be used to control soft scales, particularly the Florida wax scale, Ceroplastes floridensis Comstock, and the Mediterranean black scale, Saissetia oleae (Olivier). It is therefore of interest to examine the effect of the IGR on beneficial insects. The present work describes the effect of RO 13-5223 treatment on the development of immature stages of 2 hymenopterous parasites in the laboratory, as well as evaluates the impact of field application for soft scales control on the activity of 2 armoured scales parasites. 368 BA. PELEG MATERIALS AND METHODS LABORATORY EXPERIMENTSThe insect growth regulator used was RO 13-5223 [ethyl < 2-(p-phenoxyphenoxy) ethyl > carbamate ] 50 % W.P. (Dr, R. Maag Ltd., Dielsdoff, Switzerland). The chemical was disolved in water to the desired concentrations, and then sprayed with a hand sprayer to full coverage on plant material infested with parasitized scales. All laboratory tests were conducted in a room with ambient temperature of 26 -+ 1 ~ and R~. of 65 -+ 5 %. The parasites, their hosts and the way they were handled were as the following :Metaphycus bartletti Anneeke & Mynhardt (Encyrtidae) is a gregarious endoparasite of the Mediterranean black scale, Saissetia oleae (Coccidae). Potato sprouts, artificially inocula...

Effects of some insect growth regulators on natural enemies of scale insects (Hom.: Coccoidea)

“…in the citrus grove. Fenoxycarb had no adverse effect on three species of Aphytis under laboratory conditions (Peleg, 1983b). It seems that in most cases, buprofezin and the juvenoid insect growth regulators have no appreciable effect on hymenopterous parasites attacking scale insects.…”

Fenoxycarb, a fairly new Insect Growth Regulato: review of its effects on insects

“…only some developmental arrests and a low mortality (15%) are observed. There is no effect for the latter (Peleg. 1983~).…”

“…Charmillot (1989~) reveals the selectivity of fenoxycarb and its innocuity to Hymenopteran parasitoids, that seems excessive because the quoted references are Dorn et al (1981), Peleg (1983~) and De Reede, Groendijk & Wit (1984), previously analysed. The selectivity of fenoxycarb is because beneficials are not present or not at a sensitive stage when treatments take place.…”

Les régulateurs de croissance d'insectes (RCI), mimiques de l'hormone juvénile, en tant que moyen de lutte morphogénétique et ovicide contre les tordeuses des vergers

“…L'application du fenoxycarb au moment de l'intensification du' vol des papillons et de la ponte assure une bonne efficacit6 ovicide pendant environ 4 semaines. (Dora etat., 1981;Peleg, 1983;Galli, 1984;De Reede et aL, 1984). Ces produits se sont 6galement montrrs inoffensifs pour de nombreux prrdateurs tels que Syrphus corollae F., Chrysopa carnea Steph.…”