Emergence, movement, and host plants of boll weevils (Coleoptera : Curculionidae) in the Delta of Mississippi

More boil weevils, Anthonomus grandis Boheman, were captured after 20 May i n 1995-1997 in grandlure-baited traps 1-5 km from cotton in Washington Coun ty, MS, than in traps near cotton. Even though few weevils were trapped fro m first bloom to mature boil (about 1 July to 18 August), >5 times as many weevils were captured in traps 1-5 km away from cotton than in traps near c otton. This suggested that competition from male weevils feeding in cotton as well as cotton odors may have masked late-season ovenwintering emergence . These results further suggested that overwintered weevils continue to eme rge in low numbers into August, and that considerable movement of weevils ( both overwintering and reproductive) occurred throughout the growing season . Numbers of overwintered weevils trapped from 23 March to 29 lune 1996 wer e only 5% of those trapped during the same period in 1995. Wowever, numbers captured from Ig August to es December 1996 equalled those for the same pe riod in 1995, which showed the powerful ability of the boil weevil to rebui ld from low numbers in a single season. Boil weevils responding to traps we re slightly >50% females before July I, increased to almost 100% females in midseason, and declined to slightly >50% females again in late season. Ove r 5,000 boil weevils were examined in 1996 for pollen grains in the midgut throughout the year, and over 300 plant taxa were identified. A majority of the taxa occurred in the Anacardiaceae (sumac), Asteraceae (sunflower), Ch eno-am (Chenopodiaceae and Amaranthaceae, goosefoot, and pigweed), Fagaceae (oak), Malvaceae (mallow), and Poaceae (grass) families. These results ind icated that noncotton hosts were potentially important in survival of boll weevils throughout the year but not a factor in reproduction, because boil weevils have been found to reproduce only on cotton in the Mississippi Delt a.