Submitted to: Journal of Economic Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/14/2014
Publication Date: 8/20/2014
Citation: Vargas, R.I., Souder, S., Hoffman, K., Dowell, R., Mercogliano, J., Smith, T.R., Hammond, J.H., Davis, B.J., Brodie, M., Dripps, J.E. 2014. Attraction and mortality of Bactrocera dorsalis to STATIC Spinosad ME weathered under operational conditions in California and Florida: A reduced-risk male annihilation treatment. Journal of Economic Entomology. 107(4):1362-1369. Interpretive Summary: Introduction of fruit flies of economic importance into the United States is a constant threat to our Agriculture. Bactrocera dorsalis and the four closely related sibling species, B. papayae, B. carambolae, B. philippinensis and B. invadens are highly polyphagous, invasive and adapts readily to local host conditions. Numerous eradication efforts undertaken by the California Department of Food and Agriculture (CDFA), Florida Department of Agriculture and Consumer Services (FDACS), and U.S. Department of Agriculture (USDA) over the years have allowed for movement of agricultural commodities. However, concerns over use of organophosphate (OP) insecticides in fruit fly eradication and management systems (Min-U-Gel + ME+ naled) has raised serious environmental/human health concerns. Safer alternatives to organophosphate insecticides for fruit fly control have been funded and researched by the U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS). Some of the novel IPM technologies include the use of STATIC Spinosad ME (Dow AgroSciences) a Male Annihilation Treatment (MAT) containing fruit fly lures Methyl Eugenol (ME) that also contained the reduced risk insecticide spinosad. Previous research in Hawaii has shown that STATIC Spinosad ME was an effective fruit fly control method and could replace the current standard of Min-U-Gel + ME + naled(OP). The objective of the present study was to investigate performance of STATIC Spinosad-ME compared to Min-U-Gel + ME + naled, weathered under operational conditions under California and Florida climatic conditions to attract and kill male B.dorsalis in bioassays done in Hawaii. The current study demonstrates general equivalence between STATIC Spinosad ME and Min-U-Gel + ME + naled in terms of attractiveness and toxicity (24 h) to male B.dorsalis weathered in both locations. STATIC Spinosad ME provides a suitable alternative to Min-U-Gel + ME + naled as a MAT option in eradication programs.
Technical Abstract: Studies were conducted in 2013 in Hawaii, USA, to quantify attraction, feeding, and mortality of male oriental fruit flies, Bactrocera dorsalis (Hendel)(Diptera: Tephritidae), to a reduced risk male annihilation treatment(MAT)formulation consisting of an amorphous polymer matrix in combination with methyl eugenol(ME) and spinosad(STATIC Spinosad-ME) compared to the standard treatment of Min-U-Gel-ME with naled(Dibrom). Our approach utilized a behavioral methodology for evaluation of slow-acting reduced-risk insecticides. ME treatments were weathered for 1,7, 14,21, and 28 d under operational conditions in California and Florida and shipped to Hawaii for bioassays. In field tests using bucket traps to attract and capture wild males, and in toxicity studies conducted in 1 meter cages using released males of controlled ages, STATIC Spinosad-ME performed equally as well to the standard formulation of Min-U-Gel-ME with naled for material aged up to 28 d in both California and Florida. In laboratory feeding tests in which individual males were exposed for 5 minutes to the different ME treatments, mortality induced by STATIC Spinosad-ME recorded at 24 h did not differ from mortality caused by Min-U-Gel ME with naled at 1, 7, 14, and 21 d in California and all weathered time periods in Florida. Spinosad has low contact toxicity, and when mixed with an attractant and slow release matrix, offers a reduced-risk alternative for eradication of B. dorsalis and related ME attracted species, without many of the negative effects to humans and non-targets associated with broad-spectrum contact poisons such as naled.