ABSTRACT

Texas High Plains cotton losses due to beet armyworms have increased greatly over the last ten years. This study is being conducted to determine the influence of cotton planting date window (timely vs. late) and level of pigweed infestation (pigweed-infested vs. non-infested) on beet armyworm population abundance in Texas High Plains cotton. Planting window and level of pigweed infestation both contributed to differences in seasonal beet armyworm activity. Significantly higher numbers of beet armyworm larvae were observed in the timely (10 May) planted cotton than in the late (14 June) planted cotton, with seasonal averages of 2579 and 1676 larvae per acre in the May and June planted cotton, respectively. Pigweed-infested cotton was observed to have a seasonal average of 3240 larvae per acre compared with a significantly lower count of 1015 larvae per acre in the clean-tilled non-infested cotton. Preliminary results suggest that cotton fields infested with a preferred wild host, such as pigweed, could have an increased risk for beet armyworm colonization.