The epizootiology of Entomophthora canarjensis Macleod, Tyrrell, & Soper in populations of the woolly pine needle aphid (Schizolachnus piniradiatae (Davidson)) was investigated during a 5-year period in an isolated plantation of red pine (Pinus resinosa Aitj in northern Ontario. Climatic factors...

Six Eurasian species of Carduus thistles (Compositae: Cynareael are troublesome weeds in North America. They are attacked by about 340 species of phytophagous insects, including 71 that are oligophagous on Cynareae. Of these Eurasian insects, 39 were extensively tested for host specificity, and...

The genus Cecidomyia contains 11 species, 8 from North America and 3 from Eurasia. Most are only broadly host specific and occur on many species of pines in North America and also spruce and fir in Europe. The larvae feed on pitch and can cause extensive primary damage. The species are analyzed...