Date of Award

5-19-2013

Document Type

Honors Thesis

Department

Environmental Studies

First Advisor

Carol Loeffler

Language

English

Abstract

Increasing human health concerns, predicted growth of insect populations due to global warming, and increasing prevalence of pesticide resistance in insects have led to a recent surge of interest in alternatives to traditional, broad-spectrum chemical pesticides. One proposed alternative is the modification of agricultural landscapes to create habitat for beneficial insects, natural predators and parasites of pest insects. During the 2011-2012 academic year the Dickinson College Organic Farm created a series of six hubs, small ponds surrounded with native, flowering vegetation to attract and shelter insect predators and parasites. In order to assess the effectiveness of these hub habitats, a variety of tests were implemented including: comparison of families of insects found in hub vegetation with those targeted in planting; plotting of parasitized and non-parasitized tomato hornworms in tomato fields adjacent to ponds; and a series of transects, consisting of sweep net sampling, pitfall, and sticky traps, to determine the influence of ponds on spatial distribution of insects. Testing of hub vegetation showed goldenrod and cosmos to attract the greatest diversity and density of beneficial insects. Mapping of parasitized tomato hornworms showed no significant correlation (F>0.05) between distance from hub ponds and the presence of parasitic wasps. Results from cluster analysis, Shannon-Weaver Diversity index, and linear regressions of transect data do not suggest a pattern. From this research, it appears that further research and modifications will be necessary in order for these ponds to become an effective means of pest control.

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