Results of a two year study of colonization of two introduced trees, Quercus acutissima and Castanea crenata, by leaf-mining insects are described in Chapter I. More species of miners completed larval development on Q. acutissima, which has more local native congeners than does C. crenata. However, all miners found on Q. acutissima (subgenus Lepidobalanus) are found on native red oaks (subgenus Erythrobalanus). Leaf-miner density and survivorship were higher on C. crenata than on Q. acutissima, although most of these differences are attributable to two species. Parasitism rates for these species and all miners analyzed together were lower on C. crenata than on Q. acutissima. For some species, reduced parasitism on C. crenata was partially offset by increased predation. Successful colonization of C. crenata by at least one dominant miner may be related to the higher nitrogen content of this host. / In Chapter II, I tested the hypothesis that a significant amount of larval leaf-miner mortality on water oak, Quercus nigra, results from nutritional inadequacy of the host tree. I altered phytochemistry of water oaks with urea- and ammonium-nitrate-fertilization and drought stress. Survivorship of all leaf miners together, and of several dominant species analyzed separately, increased on fertilized trees. Generally, miners responded more to urea-fertilization of trees than to ammonium-nitrate-fertilization. Higher survivorship on fertilized trees was associated with reduced predation. Enhanced larval leaf-miner survivorship correlated with increased densities in 1981, but not in 1980. Leaf-miner survivorship and density increased on drought-stressed trees in both years. / Larvae of two bivoltine species of leaf miners feed only on young, second-flush leaves of their host trees in north Florida. In Chapter III, I show that first-generation larval densities of these species on 30 water oaks is positively correlated with amount of secondary leaf production in 1980 and 1981. During this study, five trees abscised their leaves and reflushed new ones at atypical times of the growing season. Densities of the phenologically specialized miners increased dramatically on these trees only when refoliation coincided with emergence of ovipositing adults. / Source: Dissertation Abstracts International, Volume: 43-06, Section: B, page: 1719. / Thesis (Ph.D.)--The Florida State University, 1982.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_74861 |
| Contributors | AUERBACH, MICHAEL JEFF., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 170 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
Page generated in 0.0016 seconds