Research on the biology, morphology and control of the Nantucket pine tip moth
Young, James Daniel
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The Nantucket pine tip moth (NPTM) is a major pest of several economically important southern pines. Annually, a small percentage of overwintering NPTM emerge prior to the first generation. It had been assumed that only males emerged during this period. I found that females also have the potential to emerge during this period and can lay viable eggs, but in numbers too low to require management. To quantify and predict the fecundity of the NPTM, field-collected pupae were measured and allowed to complete development. Adults were then dissected to quantify the contents of the ovaries. I found that the average female has 38 mature and 92 immature oöcytes. Additionally, pupal weight was found to be directly correlated to fecundity. A morphological study of the male and female reproductive systems was conducted to redescribe the structures using current terminology. Illustrations and descriptions to show the organs and how they attach to the cuticle were provided. The description of NPTM pupae was revised and expanded upon to include new characters. Detailed illustrations were made of male and female pupae to depict the position of each character. Finally I studied how the first three generations of NPTM in the Georgia Coastal Plain affect the growth (stem volume) of loblolly pines. For this study 2,000 1/0 seedlings and 2,000 trees entering their second growing season were subjected to 1 of 5 treatments. The treatments involved the individual control of the first three generations, a positive control which received 4 insecticide applications per year and a negative control that was unsprayed. I found that controlling only the first generation of NPTM during the first and second growing seasons results in trees that are approximately 30% larger then the negative control.