Efficacy of ground spray application of bait sprays with malathion or spinosad on Mexican fruit fly (Diptera: Tephritidae) in Texas citrus

An important component in the Mexican fruit fly, Anastrepha ludens (Loew) (Diptera: Tephritidae), eradication program is bait spray application to knock down localized A. ludens infestations enhancing the sterile to wild fly ratio and increasing the effectiveness of the sterile insect release program. Efficacy tests were conducted using spray equipment that applies ultralow application rates of malathion NU-LURE or GF-120 spinosad by ground into citrus. Trapit Dome traps located in fields treated with malathion NU-LURE and GF-120 spinosad high rate caught significantly fewer flies than the control in all replications. Treatments reduced the Mexican fruit fly populations by 99.1 and 92.5% with malathion and 98.2 and 89.9% with GF-120 spinosad high rate. Traps in plots with lower rates of GF-120 reduced fly populations by 76.3 and 74.3% in winter and summer test, respectively. There was no indication of fly repulsion from either malathion or GF-120 spinosad during this test. The bait spray option using ground spray equipment to apply ultra-low rates of either malathion NU-LURE or GF-120 spinosad high rate is a viable cost effective treatment method to treat small acreages for A. ludens. For organic growers, the ground spray equipment is effective in applying GF-120 spinosad at the labeled rates.