Lady Beetle Composition and Abundance in Sweet Corn Bordered by Pasture, Buckwheat or Sunflower Companion Plantings

Abstract

To determine the effect habitat management/border plantings have on beneficial insect diversity and abundance in agricultural crops, sweet corn, Zea mays L. ‘Garrison®’, was grown in replicated plots on Kentucky State University's Agricultural Research and Demonstration Farm. Each 25 m × 12 m plot was bordered on each length by a 2 m wide border of un-mowed pasture, buckwheat (Fagopyrum esculentum Moench), or dwarf sunflower (Heliathus annuus L. var. ‘Big Smile’). Yellow sticky traps 15 cm × 15 cm were used to capture lady beetles weekly through anthesis. Pink lady beetle, Coleomegilla maculata (DeGeer); Asian lady beetle, Harmonia axyridis (Pallas); spotless lady beetle, Cycloneda munda (Say); and seven spotted lady beetle, Coccinella septempunctata L. were caught in this study. The pink lady beetle was the most abundant species overall in all three borders and in the sweet corn plots with 79% and 94%, respectively. There were greater numbers of pink lady beetles in buckwheat (P < 0.00001) and sunflower (P = 0.0064) borders than pasture borders. However, there were no differences among populations of any of the lady beetle species in any of the sweet corn plots. Pink lady beetles were more numerous in sweet corn bordered by buckwheat (P ≤ 0.05), sunflower (P < 0.0001) and pasture borders (P ≤ 0.03) than in the borders themselves.