| dc.description |
The biology of Anisota senatoria J. E. Smith (Lepidoptera: Saturniidae) was examined through ecological studies of within-tree distribution and dispersion, and the influence of a tree growth regulator on development and survival. Biological characteristics examined egg mass size and development, pheromone attraction, response to blacklight traps, adult emergence, laboratory development, pupal mortality and comparison of first versus second generation development time, fecundity and amount of infestation. Within-tree distribution of life stages showed significant differences between low (1.7-3.6 min height), middle (3.7-5.5 m) and high (5.6-7.6 m) strata. Dispersion indices generated from Taylor’s power law showed aggregation was greatest among early instars, followed by third instars and late instars. A fixed level precision sampling plan was developed based on the number of eggs and early instars present in low strata. The tree growth regulator paclobutrazol significantly reduced Q. Phellos L., willow oak, growth, especially one and two years posttreatment. One year posttreatment, paclobutrazol treatments significantly slowed development and decreased survival of early instars, but the opposite relationship was found with late instars.
Behavior studies showed that increased A. senatoria survival occurred with increased group size. Laboratory and field experiments revealed critical group sizes for survival of 1-3 larvae and between 25-50 larvae.
Anisota senatoria defoliation impact and frass were measured. Growth and root starch were significantly reduced with increased defoliation in Quercus palustris Muench., pin oak, but Q. phellos root starch was not reduced. Reduction in starch content in Q. palustris may have been related to additional stress factors. Landscape fabrics were a reliable sampling method for frass. Frass was used as a method for differentiating larval instars and predicted defoliatioonf Q. palustris.
An integrated pest management (IPM) program was developed that included information on native parasites, host plant preference, a citizen survey, and aesthetic indicators. Four egg parasite species including an Aprostocetus new species, five larval parasites and eight hyperparasites were collected. Host plant preference experiments indicated that Q. alba L., white oak, was least preferred by A. senatoria. A citizen survey provided a framework for designing an IPM program. Monitoring and establishing an aesthetic injury level of 25% defoliation decreased pesticide volume without an attendant increase in damage. The number of egg masses (threshold) that caused 25% defoliation ranged from one to nine. |
|