As an alternative to antihelminthic drugs, we are exploiting vaccination to control infections with the abomasal nematode Ostertagia ostertagi in cattle. Our focus for vaccine targets is excretory-secretory (ES) products of this parasite. One of the most abundant antigens in larval and adult Ostertagia ES products is a protein homologous to nematode polyprotein allergens. We found that the Oste...

UHAZY, L. S., and J. C. HOLMES. 1971. Helminths of the Rocky Mountain bighorn sheep in Western Canada. Can. J. Zool. 49: 507-512. Thirty-six Rocky Mountain bighorn sheep (Ovis c. canadensis), 33 from four areas in Alberta and 3 from Kootenay National Park, British Columbia, were examined for helminths. Data from these exammations were supplemented by examination of 462 fecal samples from the sa...

Assessments were made of the influence of several microclimatic variables on the availability of third-stage larvae of Ostertagia ostertagi, on pasture herbage. Variables most closely related to recovery of larvae from the lower herbage samples were: maximum air, mat and dung temperatures. Recovery of larvae from the upper portion of the herbage was closely correlated with dung temperature, sam...

Two experiments were carried out during summer and winter conditions to determine if Dictyocaulus vivipams infective larvae could survive on pasture during these seasons in Louisiana. Pairs of tracer calves were grazed in August and September on a pasture that was heavily contaminated in May and then left free of cattle during June-July. These tracers were not infected with D. vivipams, indicat...

We investigated interactions between the generalist predator Orius insidiosus (Say) (Heteroptera: Anthocoridae) and two species of thrips prey, Frankliniella bispinosa (Morgan) and Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), and interspecific differences in morphology and behavior between these prey species that could contribute to differences in predation by O. insidiosus ...

Understanding the geographic range and growth of species is essential for effective land management in a landscape affected by anthropogenic activity and climate change. Climate change is expected to alter the distribution and growth of many tree species in eastern North America, including northern white cedar (Thuja occidentalis L.). This research examined the effects of climate on radial grow...

The taxonomic status of B. terricola Kirby and B. occidentalis Greene has long been questioned. However recent COI gene sequence data suggests that B. occidentalis and B. terricola do represent good biological species. In this paper we test the hypothesis that B. terricola and B. occidentalis are conspecific by using independent morphometric and genetic (RAPD) data. For comparison we also analy...

The western flower thrips, Frankliniella occidentalis (Pergande), and the sweetpotato whitefly, Bemisia tabaci (Gennadius), are both invasive insect pests and are present in most of the same agricultural crops without a clear dominance of either species. Here, intra- and interspecific competition in B. tabaci and F. occidentalis was determined under controlled experiments. The results showed th...

It has been shown that many insects have Enterobacteriaceae bacteria in their gut system. The western flower thrips, Frankliniella occidentalis Pergande [Thysanoptera: Thripidae], has a symbiotic relation with Erwinia species gut bacteria. To determine if other Thripidae species have similar bacterial symbionts, the onion thrips, Thrips tabaci, was studied because, like F. occidentalis, it is p...