Submission Date


Document Type

Paper- Restricted to Campus Access



Faculty Mentor

Cory Straub

Student Contributor

Gabriella Altmire


Presented during the 20th Annual Summer Fellows Symposium, July 20, 2018 at Ursinus College.

Project Description

Agroecosystems have lower plant species richness and are more vulnerable to pest outbreaks when compared to natural ecosystems. These pest outbreaks lead to the use of insecticides which can have negative effects on both humans and the surrounding ecosystems. Understanding how plant diversity changes interactions between plants and insects may lead to improvements in pest management. It has been shown that increasing plant species richness in alfalfa by adding an orchardgrass intercrop decreases the abundance of the potato leafhoppers and limits the amount of damage done by these insects. This study expands on this work by evaluating the effects of plant diversity on insect pests of both legumes and grasses in a forage agroecosystem. Two species were of specific interest, the grass pest Trigonotylus caelestialium and the legume pest Acyrthosiphon pisum. Tall fescue, orchardgrass, alfalfa, and white clover were planted to create treatments with one, two, or four plant species. Each plot was sweep sampled once a week for four weeks. After processing the sweep samples, we will test the hypothesis that increasing plant diversity reduces the focal pest populations, and that mixtures with four plant species provide even stronger pest control than mixtures with two plant species.


Available to Ursinus community only.