Potential of Winter Cover Crops to Increase Abundance ofSolenopsis invicta(Hymenoptera: Formicidae) and Other Arthropods in Sugarcane: Table 1

Abstract

A 3-yr study was conducted in Louisiana sugarcane field plots to determine the potential of vegetation management and winter cover crops to enhance abundance of the fire ant, Solenopsis invicta Buren, other arthropods, gastropods, and spring sugarcane density. Treatments included pea, clover, and vetch cultivars, a weed-free herbicide treatment, a vetch with herbicide on the row tops; and a mixed weeds treatment arranged in a randomized complete block design. Compared with similar studies conducted during the summer months, spring collections of arthropods in pitfall traps were very low and few differences in arthropod densities occurred. Neither cover crop cultivar nor biomass substantially influenced arthropod density or cane stand density. Slugs (Limacidae) and earwigs (Dermaptera) were most abundant in mixed weed plots. The highest numbers of carabids in 1994 were found in vetch plots, which tended to have higher biomass than other treatments. Soybean oil-soaked bait cards attracted more ants in clover plots than in the plots with vetch plus herbicide. Compared with previous summer studies, we feel that harsher winter weather and other density independent mortality factors during this study period superseded effects of cover crops, vegetation management and quantity of biomass on arthropod densities during the winter. Although positive impacts of winter cover crops were not detected for the variables measured during the study period these data should not be used to suggest that cover crops do not provide agronomic benefit to farmers.