Kentucky State University
Lady Beetle and Green Lacewing Populations in Organic, Conventional and Genetically Engineered Sweet Corn
Institution
Kentucky State University
Faculty Advisor/ Mentor
John Sedlacek; Karen Friley
Abstract
In sweet corn, lady beetles and green lacewings, Crysoperla carnea, prey upon the eggs and small larvae of corn earworm, Helicoverpa zea; European corn borer, Ostrinia nubilalis; southwestern corn borer, Diatreae grandiosella; and fall armyworm, Spodoptera frugiperda. Concerns regarding negative impacts on beneficial insects and biodiversity in conventionally sprayed and genetically engineered (Bt) crops have been raised. Thus, the objective of this research was to determine lady beetle species composition and abundance and green lacewing abundance in sweet corn using these cropping methods. Sweet corn was grown in 2006 and 2007 using organic, conventional, and genetically engineered production practices. Yellow sticky traps 232 cm2 in area were used to capture flying insects at tassel and silk height during anthesis. Eight sticky traps were placed within the middle row of the center subplot in each plot. Sticky traps were replaced weekly for three weeks. In both years, pink lady beetle, Coleomegilla maculata, was the most abundant lady beetle caught followed by the Asian multicolored lady beetle, Harmonia axyridis. Spotless lady beetle, Cycloneda munda; mildew eating lady beetle, Psyllobora vigintimaculata; seven-spotted lady beetle, Coccinella septempunctata; parenthesis lady beetle, Hippodamia parenthesis; variegated lady beetle, Hippodamia variegata; convergent lady beetle, Hippodamia convergens; and green lacewing, were captured in low numbers. Greater numbers of pink lady beetle, Asian lady beetle, seven spotted lady beetle and spotless lady beetle were found in organic than conventional or Bt sweet corn plots.
Lady Beetle and Green Lacewing Populations in Organic, Conventional and Genetically Engineered Sweet Corn
In sweet corn, lady beetles and green lacewings, Crysoperla carnea, prey upon the eggs and small larvae of corn earworm, Helicoverpa zea; European corn borer, Ostrinia nubilalis; southwestern corn borer, Diatreae grandiosella; and fall armyworm, Spodoptera frugiperda. Concerns regarding negative impacts on beneficial insects and biodiversity in conventionally sprayed and genetically engineered (Bt) crops have been raised. Thus, the objective of this research was to determine lady beetle species composition and abundance and green lacewing abundance in sweet corn using these cropping methods. Sweet corn was grown in 2006 and 2007 using organic, conventional, and genetically engineered production practices. Yellow sticky traps 232 cm2 in area were used to capture flying insects at tassel and silk height during anthesis. Eight sticky traps were placed within the middle row of the center subplot in each plot. Sticky traps were replaced weekly for three weeks. In both years, pink lady beetle, Coleomegilla maculata, was the most abundant lady beetle caught followed by the Asian multicolored lady beetle, Harmonia axyridis. Spotless lady beetle, Cycloneda munda; mildew eating lady beetle, Psyllobora vigintimaculata; seven-spotted lady beetle, Coccinella septempunctata; parenthesis lady beetle, Hippodamia parenthesis; variegated lady beetle, Hippodamia variegata; convergent lady beetle, Hippodamia convergens; and green lacewing, were captured in low numbers. Greater numbers of pink lady beetle, Asian lady beetle, seven spotted lady beetle and spotless lady beetle were found in organic than conventional or Bt sweet corn plots.