Date of Graduation
2001
Document Type
Thesis
Degree Type
MS
Committee Chair
Linda Butler
Abstract
Eighteen 200 ha plots were established in the Monongahela National Forest (MNF), Pocahontas County, West Virginia, and in the George Washington National Forest (GWNF), Augusta County, Virginia. From 1995-1999 Malaise traps and foliage pruning were used to collect Symphyta adults and larvae. During 1997 and 1998, six plots each were aerially treated with nucleopolyhedrosis virus (Gypchek™) and Bacillus thuringiensis var. kurstaki. The remaining six plots were left untreated. Adult Symphyta richness and abundance were studied using Malaise traps. Each plot contained two Malaise traps, located at different elevations, which were monitored from early May through mid-August of 1995 through 1999. The Malaise traps captured a total of 8,434 adults representing 155 species in 49 genera and 8 families. Fifty-two percent of all adults (4,423) were Acordulecera dorsalis Say (Pergidae). The next most abundant species were Pristiphora banksi Marlatt (Tenthredinidae) (12.8%), Pachynematus corniger (Norton) (Tenthredinidae) (4%), Paracharactus rudis (Norton) (Tenthredinidae) (3%), and Taxonus pallipes (Say) (Tenthredinidae) (2%). Differences in species richness and abundance occurred between forests and between years. However, no significant treatment effect was indicated. Larval Symphyta richness and abundance were studied by foliage collection. Foliage pruning of Quercus spp., Carya spp., and Acer spp. produced 11,621 Symphyta larvae representing eight different genera. Sixty-three percent of all larvae (7,373) were Acordulecera. The next most abundant genus was Periclista (2328) which accounted for 20% of the total larvae. Differences in species richness and abundance occurred between forests and between years. However, no significant treatment effect was indicated. Laboratory experiments were also conducted to test the potential lethal effects of Btk on sawfly larvae. One hundred Acordulecera larvae were placed in individual cups. Each larva received either a Btk-treated red oak leaf or a control leaf. The experiment was also done using hickory leaves. The hickory portion of the experiment was repeated one week later. A significant difference occurred between the treatment and non treatment groups (p=0.0001) in survival of larvae.
Recommended Citation
Braud, Rachel Ann, "Diversity, abundance, and the effect of Bacillus thuringiensis var. kurstaki Berliner and Gypchekâ„¢ on larval and adult Symphyta in Virginia and West Virgina." (2001). Graduate Theses, Dissertations, and Problem Reports. 10572.
https://researchrepository.wvu.edu/etd/10572