THE EFFECTS OF COVER CROPS AS INSECTARY PLANTS ON INSECT NATURAL ENEMIES AND THEIR POTENTIAL FOR CONSERVATION BIOLOGICAL CONTROL
Open Access
- Author:
- Hinds, Jermaine L
- Graduate Program:
- Entomology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- August 22, 2017
- Committee Members:
- Mary Barbercheck, Dissertation Advisor/Co-Advisor
Mary Barbercheck, Committee Chair/Co-Chair
Kelli Hoover, Committee Member
John Frazier Tooker, Committee Member
David A Mortensen, Outside Member - Keywords:
- conservation biological control
insectary
natural enemy - Abstract:
- Agronomic cropping systems are often highly disturbed, lacking alternative resources for natural enemies critical for suppressing pests. Under these conditions, natural enemy survival and biological control potential may be reduced. As a conservation biological control approach, insectary plants may be introduced to provide supplemental nectar, pollen, and habitat to improve the performance and survival of natural enemies. However, natural enemies exhibit preferences toward specific flowering plants. Furthermore, different plant species may provide different resources. Therefore diverse insectary mixtures may be deliberately designed to more effectively support targeted natural enemies. I established buckwheat, Fagopyrum esculentum, and cowpea, Vigna unguiculata, in monocultures and mixtures adjacent to corn, Zea mays, to test the effects of insectary provisioning on the natural enemy community, predator dispersal between cover and cash crops, and potential for pest suppression. To measure these effects, I used sweep net sampling, protein-based mark-recapture and sentinel prey. Results suggest that predator abundance increases with increasing density of inflorescences and extrafloral nectaries. Coleomegilla maculata and Orius insidiosus, two key generalist predators, as well as crab spiders (Thomisidae) were more abundant in buckwheat monoculture and buckwheat-cowpea mixture treatments than in the cowpea monoculture. Recovered protein-marked C. maculata and O. insidiosus indicated migration between the insectary border and corn, as well as predation on sentinel prey. Despite higher predator abundance and confirmed predator dispersal, sentinel egg predation, while high, did not differ between treatments. Landscape factors may play a greater role than field-scale management in influencing predator dynamics at this site.