Masters Theses

Date of Award

12-2000

Degree Type

Thesis

Degree Name

Master of Science

Major

Entomology and Plant Pathology

Major Professor

Paris L. Lambdin

Committee Members

Jerome F. Grant, M. L. Pan

Abstract

A study was initiated in May of 1999 to assess the effectiveness of sex pheromone traps in attracting predators of Matsucoccus spp., and evaluate those predators as potential biological control agents for soft-bodied insect pests of southern Appalachian forests. Sixty sticky traps equipped with rubber dispensers saturated with the pheromones were exposed at monthly intervals in mixed pine stands at six sites along an elevation gradient m the Great Smoky Mountains National Park, the University of Tennessee Arboretum, and the Foothills Parkway Captured predators included hemerobiids, anthocorids, and coniopterygids.

A total of 514 hemerobiids were captured during the 1999 and 2000 field seasons, represented by three species Hemerobius stigma Stephens, Sympherobius barberi Banks,and Micromus posticus Walker. Of these, H stigma represented the dominant taxa attracted to the traps. Traps baited with the sex pheromones of M josephi attracted and captured the highest number of individuals (267) compared to M feytaudi (224), M matsumurae (25), and control (1) Captured Hemerobiidae demonstrate a significant preference to the sex pheromone of M josephi and M feytaudi and were most abundant m stands of table mountain pine {Pinus pungens Lamb) on dry, rocky ridges between 914m and 1392m. A significant (p < 0 05) inverse relationship between hemerobiids captured m traps baited with the pheromones of M feytaudi and M josephi occurred in all pine sites, except pine site 2. No significant differences were found between collections of hemerobiids from traps baited with racemic mixtures and natural stereoisomers of Matsucoccus spp. sex pheromones. The analogue of M feytaudi and M josephi was significantly (p < 0.05) less active than the corresponding natural pheromones.

Twenty five adult anthocorids (Elatophilns inimica D. & H.) were captured from pine sites 3, 4, the UT Arboretum, and the Foothills Parkway sites Of these, 14 were captured from pine site 3 m traps baited with the pheromones of M matsumurae, and M feytaudi. The low number of captured E inimica suggests that either the population is small within the area, perhaps due to the lack of substantial numbers of the preferred prey, or that they are not attracted to these pheromones m mass. The collection of this species represents new county and state records, the southernmost distribution recorded for this species, and the first collection of this species m relationship to P pungens.

Thirteen coniopterygids {Coniopteryx sp ) were captured during this study in traps baited with the pheromones of M. feytaudi and M josephi. This is the first record of Coniopteryx sp captured in traps baited with the sex pheromones of Matsucoccus spp., inferring that this predator responds to kairomones to find its prey. Four specimens of M gallicolus were captured at pine site 4 m traps baited with the sex pheromone of M josephi. The capture of M gallicolus males may indicate that this species exhibits cross-attraction to the sex pheromones of other Matsucoccus species. No males of M feytaudi, M josephi, and M matsumurae were captured, inferring that these species are uncommon within the range of these study sites. This implies that the attraction of Hemerobiidae and E. inimica to sex pheromones of different Matsucoccus spp is based on the recognition of key chemical combinations of the pheromones.

The kairomonal attraction of adult hemerobiids and anthocorids to the sex pheromones of Matsucoccus spp may be exploited to enhance biological control programs against exotic adelgid and scale insect pests in forest habitats. Further biological control projects may benefit from the use of the sex pheromones of Matsucoccus spp to identify potential predators and introduce them into forests threatened by Mat^wcoccM^ and other soft- bodied forest pests.

The effects of prey and water on the survivorship and feeding behavior of H stigma larvae were determined to evaluate this predator as a biological control agent. Results demonstrate that a lack of water had no bearing on larval development or behavior of H stigma larvae, as long as suitable prey was present Three female eupelmid adults and 9 unidentified pupae were reared from two-field collected H stigma larvae.

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