Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 3, 2007
Publication Date: N/A
Interpretive Summary: We evaluated the ComboLure™ (25-mg grandlure + 30-mg eugenol + 90-mg dichlorvos, an extended-release lure (25-mg grandlure + 30-mg eugenol + 60-mg dichorvos kill-strip), and an extended-release lure with no dichlorvos for boll weevil captures in South Texas during February-March of 2005 and March-April of 2006. Boll weevil numbers were higher on 5 out of ten trapping weeks for the extended-lure with no dichlorvos, and never significantly lower than the extended-lure with dichlorvos used separately or when combined with the lure dispenser. Using dichlorvos in the boll weevil trap did not affect the ratio of males to females caught in the trap. There was no advantage of using dichlorvos with the pheromone regardless of how it was presented in the boll weevil trap.
Technical Abstract: Boll weevil traps baited with a ComboLure™ (25-mg grandlure + 30-mg eugenol + 90-mg dichlorvos (DDVP)), an extended-release lure (25-mg grandlure + 30-mg eugenol + 60-mg DDVP kill-strip), and extended-release lure with no DDVP were evaluated for boll weevil, Anthonomus grandis grandis Bohemia, captures in South Texas during February-March of 2005 and March-April of 2006. The traps were serviced once a week for 5 consecutive weeks using the same methodology as active boll weevil eradication programs. Mean captured boll weevils from extended-release lures with no DDVP were significantly higher in five of ten trapping weeks when compared to captures of the ComboLure™ and extended-lure used with a 60 mg DDVP kill strip. Weekly mortality of boll weevils captured in the field study was similar for the ComboLure™ (72.6 % ± 4.7) and extended-lure + DDVP (73.5 % ± 4.0), and both were significantly higher than the extended-lure (32.8 % ± 5.0) with no DDVP. The presence or absence of DDVP did not significantly affect the sex ratio of field captured boll weevils. We found no functional reasoning for using DDVP in large scale trapping of boll weevils regardless of the formulation or presentation in the trap. We conducted 2 additional trapping evaluations following the 2005 and 2006 studies, but the numbers of boll weevils captured were too low for statistical comparisons, indicating that boll weevil eradication is reducing populations in the Rio Grande Valley of Texas.