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

• Published in: Journal of economic entomology 1999-02, Vol.92 (1), p.130-139
• Main Authors: HARDEE, D. D, JONES, G. D, ADAMS, L. C
• Format: Article
• Language: English
• Subjects: Anthonomus grandis; Biological and medical sciences; Curculionidae; Fundamental and applied biological sciences. Psychology; Phytopathology. Animal pests. Plant and forest protection; Protozoa. Invertebrates; Records, symptoms, damages, economic importance, population surveys
• ISSN: 0022-0493; 1938-291X
• DOI: 10.1093/jee/92.1.130

More boll weevils, Anthonomus grandis Boheman, were captured after 20 May in 1995-1997 in grandlure-baited traps 1-5 km from cotton in Washington County, MS, than in traps near cotton. Even though few weevils were trapped from first bloom to mature boll (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 cotton. This suggested that competition from male weevils feeding in cotton as well as cotton odors may have masked late-season overwintering emergence. These results further suggested that overwintered weevils continue to emerge 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 June 1996 were only 5% of those trapped during the same period in 1995. However, numbers captured from 18 August to 28 December 1996 equalled those for the same period in 1995, which showed the powerful ability of the boll weevil to rebuild from low numbers in a single season. Boll weevils responding to traps were slightly >50% females before July 1, increased to almost 100% females in midseason, and declined to slightly >50% females again in late season. Over 5,000 boll 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), Cheno-am (Chenopodiaceae and Amaranthaceae, goosefoot, and pigweed), Fagaceae (oak), Malvaceae (mallow), and Poaceae (grass) families. These results indicated that noncotton hosts were potentially important in survival of boll weevils throughout the year but not a factor in reproduction, because boll weevils have been found to reproduce only on cotton in the Mississippi Delta.