Theses and Dissertations

Date of Award

5-2018

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

First Advisor

Dr. Alexis E. Racelis

Second Advisor

Dr. Mohammed Farooqui

Third Advisor

Dr. Yonghong Zhang

Abstract

Biological control, or the use of natural enemies for pest management, may the best long-term option for managing the invasive Arundo donax , a noxious weed dominating riparian habitats globally and along the Rio Grande River. This work reports on the progress and potential of two arundo biological control agents permitted for release in Texas and Mexico. The arundo wasp, Tetramesa romana, released in 2009, is having significant impacts as reported from various field locations around the world, described here using standard exit hole counts. The highest density levels were found in Texas (introduced range) compared to relatively low populations in the native range (ave. exit holes = 79.98, p = 0.001 and 4.81, p = 0.001 respectively). Lasioptera donacis, the arundo leaf miner, is currently permitted for release in North America. Field research was conducted in the native range of L. donacis (Greece) to evaluate the biotic and abiotic factors that influence population density. Lasioptera donacis feeding damage was documented on 40.4 and 67.8 % of dead and decaying leaf sheaths respectively across all sites. Lasioptera donacis was active in all locations including highly disturbed sites, but showed a slight preference for sites near running freshwater sources (R = -0.514, p = 0.001) and lower densities adjacent to salt water sources (R = 0.463, p = 0.001). The environmental preferences of L. donacis in Europe signal strong potential for impact in the U.S. where A. donax is invasive.

Comments

Copyright 2018 Madeline Marshall. All Rights Reserved.

https://www.proquest.com/dissertations-theses/progress-potential-two-biological-control-agents/docview/2097271903/se-2?accountid=7119

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