title: Toxicity of imidacloprid-treated spheres to Caribbean fruit fly, Anastrepha suspensa (Diptera: Tephritidae) and its parasitoid Diachasmimorpha longicaudata (Hymenoptera: Braconidae) in the laboratory.
abstract: No-choice cage tests were used to study the toxicity of imidacloprid-treated spheres to Caribbean fruit fly, Anastrepha suspensa (Loew), and its associated parasitoid, Diachasmimorpha longicaudata (Ashmead), in the laboratory. Three imidacloprid sphere treatments (2, 4, and 8% active ingredient [AI] Provado 1.6 F) and an untreated control sphere (no toxicant) were evaluated against A. suspensa. Throughout the observation period (2-72 h), all concentrations of imidacloprid-treated spheres killed significantly more A. suspensa compared with control spheres. After 4 h of exposure to imidacloprid-treated spheres, significantly more A. suspensa were killed on spheres treated with 8% compared with 2% (AI). At 48 and 72 h, there were no significant differences in the mean number of A. suspensa killed at 2, 4, and 8% (AI), potentially indicating that a period of 24 h was sufficient for flies to ingest a lethal dose of the pesticide. Overall, significantly more A. suspensa males were killed after 72 h of exposure to imidacloprid-treated spheres compared with females. For D. longicaudata, only two imidacloprid sphere treatments, 2 and 4% (AI), and an untreated sphere (control) were evaluated for mortality in cage tests. There were no significant differences in mortality of D. longicaudata between the 2 and 4% (AI) imidacloprid-treated spheres. Both rates killed significantly more D. longicaudata compared with the control. However, after 24, 48, and 72 h of exposure to imidacloprid-treated spheres, significantly more D. longicaudata were killed in cages containing 4% compared with 2% (AI) and untreated control spheres. The study demonstrates the potential use of imidacloprid-treated spheres for control of A. suspensa in areas where it may be difficult to apply broad-spectrum insecticides.
authors.affiliation: Department of Entomology and Nematology, Natural Area Dr., University of Florida, Gainesville, FL 32611, USA. oeliburd@mail.ifas.ufl.edu
authors.forename: Oscar E
authors.initials: OE
authors.lastname: Liburd
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Holler
authors.forename: Amy L
authors.initials: AL
authors.lastname: Moses
mesh_terms: D000818:Animals; D005260:Female; D006927:Hymenoptera / Q000187:drug effects; D007093:Imidazoles / Q000008:administration & dosage* / Q000633:toxicity; D007306:Insecticides / Q000008:administration & dosage* / Q000633:toxicity; D008297:Male; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010572:Pest Control, Biological; D010944:Plants; D033621:Tephritidae
chemical_list: D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; C082359:imidacloprid