Tetrastichus julis (Walker), a European larval endoparasite of the cereal leaf beetle, Oulema melanopus (L), has become widely established in southern Ontario. In 1975, rates of parasitism in 14 counties varied from 15% in the east to 95% in the west Dispersal into Ontario was natural and is attributed to extensive colonization of the parasitoid in Michigan and other parts of the U.S. midwest. Reasons for its success in Ontario are suggested.

Special techniques are necessary to study the morphology of complex chitinous structures such as insect mouthparts. Many of the details are beyond the resolution of light microscopy, and the methods of conventional electron microscopy do not include the efficient production of serial sections for reconstruction. Although the scanning electron microscope (SEM) permits detailed observation of 3-dimensional surfaces, it cannot see internal surfaces and under complex folds, nor can it readily show the thickness of solid structures. To study the details of the stylet tips of the bug Rhodnius prolixus (Stål) several techniques were tried. Initially, specimens had been embedded in paraffin wax, sectioned, dewaxed, and prepared for the scanning electron microscope. Because of difficulties in sectioning the hard stylets and poor preservation of fine structure, this method was abandoned in favour of one using thick sections (2 μm) of material embedded in a mixture of Epon and Araldite.

The bertha armyworm, Mamestra configurata Wlk., is a periodic pest of rape in western Canada. After a massive outbreak of the species during 1971 and 1972, investigations on the insect were intensified in many laboratories. A technique for rearing the larvae on a semi-defined diet was developed by our Winnipeg-based group and has been used successfully to rear 21 consecutive generations of M. configurata in the laboratory (Bucher and Bracken 1976). Our current culture originated from a few pupae field-collected in Alberta and has been carried through 21 generations without addition of new stock.