Efficacy of Aphicides on Cotton Aphids, Aphis Gossypii, and Their Natural Enemies

The cotton aphid, Aphis gossypii, has the potential to cause detrimental losses to a cotton crop. The use of chemical control is the most common choice of farmers to eliminate not only the cotton aphid but many other arthropod pests as well.  Some commonly used insecticides may only worsen an aphid outbreak by removing aphid predator species and allowing an aphid population to dramatically increase.  The objective of this study was to observe the mortality effects of various insecticides on the larvae of the ladybeetle, Hippodamia convergens, a natural enemy to the cotton aphid. Carbine, Centric, Intruder, and Transform were used in an assay study at standard label rates.  Each insecticide was tested indirectly vs. directly on the ladybeetle larvae.  The efficacy of Centric, Intruder, Transform, and Cruiser on the cotton aphid, as well as their effects on the natural enemy population, was examined in a field study.  Significant differences were observed between the various spray treatments and the numbers of beneficial insects present.  Plots treated with Transform displayed satisfactory aphid control and contained the highest numbers of beneficial insects.