Record Details
Insect enemies of Dendroctonus pseudotsugae Hopk. : indentification of their immature stages and distribution in standing trees
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Insect enemies of Dendroctonus pseudotsugae Hopk. : indentification of their immature stages and distribution in standing trees |
| Names |
Kline, LeRoy N.
(creator) Rudinsky, Julius A. (advisor) |
| Date Issued | 1963-02-01 (iso8601) |
| Note | Graduation date: 1963 |
| Abstract | The objectives undertaken in this study were: 1) to develop means of identifying the immature stages of the known insect predators and parasites of the Douglas-fir beetle; 2) to investigate the possible distribution, spatially and/or temporal, of the known insect predators and parasites in standing trees infested by the Douglas-fir beetle; and 3) to develop a method of censusing the abundance of such insect enemies either by species or in group of species. Descriptions and illustrations of the immature stages of the predators and parasites of the Douglas-fir beetle in the Intermountain and Pacific Northwest regions are given. A key separating the larvae is also included. Emphasis is placed on the following species: Enoclerus sphegeus Fab., E. lecontei Wolc., Thanasimus undatulus Say, and Temnochila virescens chlorodia Mann. The remaining species, Medetera spp., Lonchaea spp., Coeloides brun-neri Vier., and the pteromalids are treated in a more general manner. Three instars exist for the clerids with five to six for the ostomatid. The distribution data of the predators and parasites is quite variable and contains a large portion of zero classes. The larvae of E. sphegeus and T. virescens are more abundant in the center region of the tree. Number of E. sphegeus larvae decreased somewhat in the latter part of the season. Presumably, this is due to the migration of the mature larvae. T. virescens population increases slightly throughout the season. No conclusions are made concerning T. undatulus as this species is not very abundant. Both groups of flies, Medetera spp. and Lonchaea spp., show a very strong tendency to be aggregated towards the base of the tree throughout the season. Lonchaea larvae are present several weeks later than Medetera larvae. The parasites, C. brunneri and the pteromalids, tend to increase in numbers throughout the summer and are more numerous toward the top of the tree. Regression equations for E. sphegeus and C. brunneri are included. A significant relationship exists between the number of individuals of these species and the variables of height and time of sample, and the Douglas-fir beetle brood. |
| Genre | Thesis/Dissertation |
| Topic | Douglas fir beetle |
| Identifier | http://hdl.handle.net/1957/49228 |
