Location: Areawide Pest Management Research
Title: Almond, pigweed, and melon pollen retention in the boll weevil (Coleoptera: Curculionidae) Authors
Submitted to: Palynology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 11, 2007
Publication Date: January 15, 2007
Citation: Jones, G.D., Greenberg, S.M., Eischen, F.A. 2007. Almond, pigweed, and melon pollen retention in the boll weevil (Coleoptera: Curculionidae). Palynology. 31:81-93. Interpretive Summary: Boll weevils remain an important economic pest where they have not been eradicated by the Boll Weevil Eradication Program. In the Lower Rio Grande Valley of Texas, weevils are active year-round even during cotton-free periods. This research indicated that pollen is readily eaten and retained longer by overwintering weevils than previously reported. This research is a first step in examining the longevity of weevils fed pollen. Boll Weevil Eradication Programs will benefit from these findings through increased knowledge of pest survival and feeding behavior between cotton-growing seasons.
Technical Abstract: The boll weevil (Anthonomus grandis Boheman) remains a devastating insect pest on cotton (Gossypium hirsutum C. Linnaeus) particularly where it has not been eradicated. Identifying and understanding the survival of boll weevils during overwintering periods when cotton is not available is important in designing programs and controlling this insect pest especially in areas where boll weevils are active year-round. Many non-malvaceous taxa have been listed as possible adult food sources. The purpose of this research was to determine if the pollen from three non-malvaceous taxa, almond [Prunus dulcis (Mill.) D.A. Webb], pigweed (Amaranthus sp.), and melon (C. melo C. Linnaeus subsp. melo) could be used as food sources for overwintering boll weevils, in the Lower Rio Grande Valley of Texas, where weevils are active year round and during cotton free periods. In addition, we wanted to determine the retention of those pollen types in the boll weevil gut. More weevils (84%) contained almond pollen when they had additional water than those (30%) that did not have additional water. Almond pollen was found in 100% of the examined weevils after 72 hours and in 80% after 96 hours. Pigweed and melon pollen were never found after 48 hours. Over all, almond pollen was found in more weevils (96%) than pigweed (40%) or melon (12%). In addition, a greater number of almond pollen grains (539) were found than pigweed (41) or melon (21). This research shows that these types of pollen were consumed and could play a part in the survival of overwintering weevils. However, more research is needed to examine the nutritional value of these and other pollen grains for overwintering boll weevil survival, and to determine the length of time weevils can survive on these pollen types.