Term of Award

Summer 1997

Degree Name

Master of Science in Biology

Document Type and Release Option

Thesis (restricted to Georgia Southern)

Committee Chair

Daniel V. Hagan

Committee Member 1

Frank E. French

Committee Member 2

Donald J. Drapalik

Abstract

Seasonal abundance and distribution of Nantucket pine tip moths and their parasites were examined during a 13 - month period (June 1996 - June 1997) at three elevations on loblolly pines in the Coastal Plain (Bulloch and Effingham Counties) of Georgia. Trees were sampled in nine plots of loblolly pine of varied silvicultural treatments and ages, ranging from trees planted in 1992 to 1995.

A total of 1,374 pine tip moths was collected, 832 in the top, 422 in the middle, and 120 in the bottom third of the trees. Differences in number of pine tip moths found between the three tree levels were significant.

A two-fold increase in the number of parasites was found in larvae or pupae of pine tip moth infested shoots in the top of the tree, when compared to the middle or bottom of the tree.

Ten species of parasitic wasp (Hymenoptera) and one species of parasitic fly (Diptera) were found. The dipteran was Lixophaga mediocris (Tachinidae), and was found 77.3% in the top, 18.5% in the middle, and 4.1% in the bottom third of the trees. Significantly more L. mediocris were in the top third of the trees.

Three Braconidae (Hymenoptera) were found. Braeon variabilis, Apanteles petrovae and Macrocentrus ancylivorus. Of the B. variabilis found, 66.6% were in the top, 16.7% in the middle, and 16.7% in the bottom third of the trees. The specimen of A. petrovae was found in the top of one of the trees. Of the M. ancylivorus found, 71% were in the top, 25.8% in the middle, and 3.2% in the bottom third of the trees. No significant differences were found between the number of M. ancylivorus in any level of the trees.

Two Chalcididae were found, Conura side and Haltichella rhyacioniae. Of the C. side found, 53.3% were in the top, 46.7% in the middle, and none in the bottom third of the trees. No significant differences were found in the number of C. side between any level of the tree. Of the H. rhyacioniae found, 63.6% were in the top, 36.4% in the middle, and none in the bottom third of the trees. Differences in the number of H. rhyacioniae between any level of the tree were not significant.

Three Eulophidae were identified, Hyssopus rhyacioniae, Sympiesis stigmatipennis and a species of Horismenus. Hyssopus rhyacioniae found were 66.5% in the top, 27.5% in the middle, and 6% in the bottom third of the trees. Significant differences were found in the number of H. rhyacioniae at all three levels. The S. stigmatipennis found were 41.9% in the top, 53.5% in the middle, and 4.6% in the bottom third of the trees. Differences in the number of S. stigmatipennis were not significant at any of the three levels. All Horismenus sp. were found in the middle third of the trees.

Eupelmis cyaniceps in the family Eupelmidae was collected. The E. cyaniceps found were 58.9% in the top, 35.3% in the middle third, and 5.8% in the bottom of the trees. Significantly more E. cyaniceps were found in the top level of the trees.

One species from the family Eurytomidae was collected, Eurytoma pini. The E. pini found were 43.9% in the top, 45.5% in the middle, and 10.6% in the bottom third of the trees. Differences in the number of E. pini between the middle, and bottom third were not significant.

One Ichneumonidae was collected, Itoplectus conquisitor. The I. conquisitor found were 62.5% in the top, 37.5% in the middle and none in the bottom third of the trees.

Insect associates were also collected by sweep nets in five plots of loblolly pines. Thirteen orders and 122 families were identified. Trophic levels included herbivores, parasites, predators and scavengers. Most taxa were herbivores, followed by predators, scavengers and parasites. No significant differences were found between the number of families in each plot.

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