The two cruciferous plants Thlaspi arvense and Lunaria annua are largely unacceptable to the striped flea beetle, Phyllotreta striolata, which normally feeds on cruciferous plants. Results suggest that these plants contain chemical compounds that act as feeding deterrents to the beetles. Methanol fractions of the leaves of both plants deterred feeding when added to the surface of acceptable radish leaves. An alkaloid fraction of Lunaria annua was, surprisingly, not deterrent. Evidence suggests that saponins in both Lunaria annua and Thlaspi arvense may be a major reason for the low acceptability of these plants as food for Phyllotreta striolata. Commercial saponins are highly deterrent at concentrations of 0.05% and above.

Research on operational use of Bacillus thuringiensis 3a3b against spruce budworm, Choristoneura fumijerana (Clem.), led to the development of a concentrated B. thuringiensis formulation containing the required potency of 20 B.I.U. of B. thuringiensis in a final volume of 4.7 l./ha (Smirnoff 1978). Aerial operational applications of this formulation were highly effective against the spruce budworm and resulted in acceptable foliage protection (Smirnoff 1979, 1980a). However, it is felt that B. thuringiensis will be used extensively against C. fumiferana only when its cost is lowered to that of chemical insecticides. heref fore, several B. thuringiensis + chitinase formulations were developed leading to an even more concentrated B. thuringiensis formulation, which we call Futura, in which the required 20 B.I.U./ha is applied in a final volume of 2.5 l./ha. We describe the composition of Futura and discuss the bacteriological and physical qualities of the formulations and its efficacy.

In a previous investigation on the effects of sublethal doses of fenitrothion (O,O-dimethyl-O-(3-methyl-4-nitrophenyl)phosphorothioateo)n the tobacco hornworm, Manduca sexta (L.), it was found that the treated larvae developed asynchronously, required more time to reach the pupal stage, and had larger bodyweights than the control larvae (Stewart and Philogène 1983). Regressive moults, faster pupal development, and shorter longevity of the adults were also observed. The impact of sublethal doses of insecticides on subsequent generations of insects has, however, received limited attention. We now present experimental evidence that the progeny of treated insects can also show some of the characteristics described above, an observation that may have significant consequences in the field.

The northern corn rootworm, Diabrotica longicornis (Say), is a recent pest of corn in southern Québec (Guibord 1976). Little is known of local quantitative temperature relationships, although such information could have important practical applications in developing a pest management program.

The object of this study was to determine the threshold temperature and thermal constant for egg development and eclosion, and to relate soil and air temperatures to the phenology of egg hatch in the field under Qutbec corn-growing conditions.

Eurasian water milfoil, Myriophyllum spicatum Linnaeus, was introduced into eastern North America late in the nineteenth century. It has spread and developed into a major aquatic weed in many areas of the United states and Canada (Aiken et al. 1979; Reed 1977). In British Columbia, it was first observed in the Vernon Arm of Okanagan Lake in 1970 and had spread to all major 1,akes in the Okanagan Valley by 1976 (Newroth 1979).

The effectiveness of several commercially available sunlight screens in protecting Bacillus thuringiensis Berliner (B.t.) against inactivation by solar irradiation was assessed in the laboratory and field. Spore viability and residual insecticidal activity of B.t. were rapidly reduced by solar radiation in the range of 300 to 400 nm wavelength. The addition of ultraviolet absorbers, Uvinul DS49 and Erio Acid Red, to a Thuricide spray formulation prolonged the insecticidal residual activity on coniferous trees, resulting in greater effectiveness against the spruce budworm, Choristoneura fumiferana (Clem.), compared with a formulation lacking these protectants.

Members of the pulcher–undulatus species group of Hydroporus Clairville (sensu Fall 1923) were rearranged as follows by Wolfe and Matta (1981): (1) H. pulcher LeConte and 12 other species (each with a bifurcate aedeagal apex) were assigned to the subgenus Heterosternuta E. Strand; (2) H. pilatei Fall and H. triangularis Fall were revised and assigned to a new genus, Falloporus; (3) and the remaining approximately 35 species were placed in the subgenus Neoporus Guignot.

In the first generation brown mite, Bryobia rubrioculus (Scheuten), on apple inhabits the wood as well as the leaves. To eliminate sampling the wood, which is very tedious and time consuming, equations were developed to describe the total population of immature stages and adults from observations of the number of mites on the leaves alone.

Attempts to develop artificial diets for the Colorado potato beetle, Leptinotarsa decemlineata (Say), have had limited success (Hsiao 1972; Krzymanska and Zwolinska-Sniatalowa 1980). Consequently, all available rearing methods require the use of fresh potato foliage (e.g., de Wilde 1957) and large greenhouse space over an extended period of time. We needed a rearing method that could produce batches of beetles < 1 week old and with synchronized emergence (± 3 days) from a small laboratory colony of < 100 pairs of adults. One method might have been to induce adult diapause and break it whenever sufficient numbers had accumulated for testing. Unfortunately, this method requires mature adults that have fed for 1–2 weeks. not her procedure used in rearing a number of insect species uses a period of low temperature storage. For example, 2nd instar Choristoneura fumiferana (Clem.) can be stored at 1°C for 4–8 months (Grisdale 1970). Wegorek (1959) suggested that the hatching of eggs of L. decemlineata could similarly be delayed by placing them at relatively low temperatures. Wegorek observed that the incubation period of the eggs in Poland could take < 8 days in warm weather but last as long as 19 days in periods of cool weather when the temperature fell below 15°C. The feasibility of using this temperature dependence for incubation in our rearing program was investigated.

Corn lodging due to bent or broken stalks results mostly from feeding by the European corn borer, Ostrinia nubilalis (Hübner), and from stalk rot infections. Stalk rot of corn (Zea mays L.) is caused in southwestern Ontario mainly by Gibberella zeae (Schw.) Petch (Fusarium graminearum Schwabe), which attacks roots during the summer and invades the bases of the stems as the plants mature (Gates and Mortimore 1972). Several studies in the U.S.A. reported an association between the rot and the borer. Christensen and Schneider (1950) recorded severest stalk rot with highest borer infestation and found that inbred lines usually free from rot became susceptible when infested by the borer. Chiang and Wilcoxson (1961) reported a higher incidence of rot in plants artificially inoculated with Fusarium graminearum and borer larvae than in those inoculated with F. graminearum alone. A recent study in Iowa (Jarvis et al. 1982) showed that the greatest stalk rot damage occurred in high borer infestations. Carson and Hooker (1981), however, were unable to relate the incidence and severity of rot to corn borer infestation. In their 3-year study, the least rot occurred in the year of severest borer infestation. Since observations in corn fields in southwestern Ontario also indicated that there might not be a direct relationship between severity of stalk rot and severity of corn borer infestation, further studies were undertaken.

Western false hemlock looper, Nepytia freemani Munroe, is a cyclical pest in British Columbia which defoliates mainly Douglas-fir, Pseudotsugata menziesii (Mirb.) Franco, often near residential areas. Outbreaks were recorded from 1947 to 1949, 1963 to 1964, and 1972 to 1976; the current outbreak started in 1980 and, in 1982, covered 1,100 ha near Tappen, Canoe, Enderby, and Carquile (Ferris and Woensdregt 1983).

The pea aphid, Acyrthosiphon pisurn (Harris), is a serious pest of alfalfa (Medicago sativa L.) and is known to reduce the cold-hardiness of seedling alfalfa (Harper and Freyman 1979). To determine whether or not pea aphids also reduce cold-hardiness in older alfalfa, plants were grown in the field for 1, 2, or 3 years, then tested for cold-hardiness under controlled conditions of infestation, hardening, and freezing.