Safflower, Carthamus tinctorius L., is an important drought-tolerant oilseed crop, used for the production of vegetable oil and protein meal. It is one of the few broadleaf crops that can be used for crop rotation in the small grains agroecosystem of the Northern Great Plains. Safflower is currently produced on about 60 000 ha in eastern Montana and northwestern North Dakota and about 10 000 ha in Alberta and Saskatchewan. There is little information available on the pest insect species on safflower in the Northern Great Plains; however, four pest species have been reported from California, including the westem flower thrips (Frankliniella occidentalis (Pergande)), lygus bug (Lygus hesperus Knight), green peach aphid (Myzus persicae (Sulzer)), and the bean aphid (Aphis fabae Scopoli) (Carlson 1966, 1972).

The construction of a simulated-ear-insect-trap (SEIT) for ear-feeding black flies is described. The SEIT, which consists of a styrofoam container with dry ice and a mock sticky ear mounted on a tripod, was developed to capture Simulium jenningsi Malloch and S. vittatum Zett., both widespread pests of livestock. SEIT units set on horse farms within 5 km north of the Potomac River in south-central Maryland, USA (n = 36 samples of 30 min each), consistently captured S. jenningsi and S. vittatum ( and 7.1 per sample, respectively), whereas units set simultaneously on farms > 5 km north of the river (n = 99 samples of 30 min each) captured progressively fewer individuals of both species.

Spruce budworm larvae were bioassayed against Bacillus thuringiensis Berliner to study the effect of temperature on the expression of toxicity. Temperatures between 16 and 28°C did not affect the ultimate level of toxicity (LC50). However, LT50’s increased from 2–8 days at 28°C to 11–20 days at 16°C, depending on concentration of the pathogen. When larvae were force-fed with a single dose, temperature had a similar effect on the time course of mortality without affecting the level of mortality. Feeding inhibition of force-fed larvae commenced immediately after dosing. Larvae that did not recover died without further feeding, even at lower temperatures when death occurred 2–3 weeks after dosing. Recovering larvae resumed feeding after 2 (28°C) to 6 (13°C) days. Recovered larvae took longer to develop and produced lighter pupae than untreated larvae. Our data suggest that temperature-dependent feeding and recovery did not contribute to quicker death at higher temperatures. Expression of the toxin itself appears to depend on temperature, possibly through the influence of temperature on metabolic rate of affected gut cells. Implications of these findings for the efficacy of spruce budworm control operations are discussed.

The large yellow underwing moth, Noctua pronuba (L.), was first recorded as occurring in Canada by Wright and Neil (1983), when a single specimen was taken at a porch light in Halifax, Nova Scotia, 7 July 1979. Since then the species has become prevalent throughout eastern Nova Scotia. In Newfoundland, this moth was first taken at Kilbride in 1984 in a light trap and in subsequent years it was caught in light traps at Goulds and Mt. Pearl (Table 1). A total of 17 moths have been taken in light traps to date, and all but one were males. In the Palearctic, N. pronuba (L.) has been reported from North Africa through western Europe to Finland and Iceland (Wright and Neil 1983).

Bacillus thuringiensis Berliner is registered for control of several defoliating forest insects, including the spruce budworm (Choristoneura fumiferana Clem.), jackpine budworm (C. pinus Freeman), and gypsy moth (Lymantria dispar L.) (Morris et al. 1986). Product labels and user guidelines of several manufacturers recommend application to dry foliage for best results. Efficacy is presumably reduced when foliage is wet from dew or precipitation. Possible causes are lower impaction efficiency of spray droplets on the wet leaf surface (Spillman 1984) and dilution of the active ingredient. I compared the efficacy of B. thuringiensis applied to wet and dry balsam fir foliage (Abies balsamea L.) in a laboratory bioassay with larvae of the spruce budwom, Choristoneura fumiferana.

The symbiosis between bark beetles and microorganisms, mostly fungi, has been investigated and reviewed by Graham (1967) and Whitney (1982). Bark beetles and their habitat fungi have been studied separately but a suitable method for studying them in combined culture is lacking. To study bark beetles in the laboratory, a method for axenic rearing was developed by Bedard (1966), then improved by Whitney and Spanier (1982). Beetle development was retarded or nil without the addition of Brewer's yeast to the diet (H.S. Whitney, Pacific Forest Research Station (PFRC), Victoria, BC, pers. comm.). The inclusion of yeast in the diet precludes studies of symbiosis, such as the role of fungi in beetle nutrition. I describe a method for rearing bark beetles with or without a fungal complement to investigate this symbiosis

Predation on adults of the crucifer flea beetle, Phyllotreta cruciferae (Goeze), by the northern fall field cricket, Gryllus pennsylvanicus Burmeister, was recorded in laboratory tests to identify predators of flea beetles that attack canola and mustard crops. In these tests, four field-collected adult crickets all ate live adult P. icruciferae, as did 15 of 16 lateinstar cricket nymphs. The tests were carried out in 60 by 20 mm disposable plastic Petri dishes, with a stoppered hole to facilitate introduction of flea beetles. A filter paper liner in the bottom of the dish gave the insects a firm footing.

Methods of separating Pissodes strobi (Peck) from its insect associates in leaders of Picea sitchensis (Bong.) Carr. would enable the associates to be returned to the field when infested leaders are routinely clipped to remove P. strobi. We recently demonstrated a method based on the relative lack of cold-hardiness of P. strobi (Hulme et al. 1986). Another method suggested many years ago (e.g. Taylor 1929) is to exploit the different ability of adult insects to crawl through a screen. To our knowledge the efficacy of such a separation has never been demonstrated. We report here an investigation into the ability of these adult insects to crawl through screens having openings of various sizes, with the objective of establishing how completely these insect associates could be separated from P. strobi

The aphidophagous midge, Aphidoletes aphidimyza (Rondani), is a promising biological control agent for aphids in agricultural crops, although its low fecundity has been cited as a disadvantage (Harris 1982; Chambers 1986). In previous studies, fecundity was reported as 70 eggs (Uygun 1971), 100 eggs (Harris 1973), and 6–38 eggs per female (Ushchekov 1975). Recently, Gilkeson and Hill (1986) reported a mean of 156.6 eggs per female from a laboratory line reared under optimum conditions (17-h day, 25°C, ample food supply). These differences in fecundity could be due to variation in genetic makeup, rearing conditions, or larval nutrition, which has been shown to influence adult fecundity (Kuo 1982; Havelka and Růžička 1984). While conducting a project on commercial application of A. aphidimyza, I have recently found that providing a source of drinking water in oviposition cages resulted in higher egg production than has been previously reported.

The Simulium arcticum Malloch sibling (IIS-10.11), which breeds in the Athabasca River (Procunier et al. 1984), is a major pest of cattle in central Alberta (Haufe and Croome 1980). Insecticide treatment of the river is the primary control method with the number of applications per season having increased from one to two treatments since 1978. The timing and number of applications per season are determined from information on larval instar and abundance, which is obtained from an extensive larval monitoring program that is conducted annually from late April to mid-September. Prediction of embryonic development and hatching rates of S. arcticum (IIS-10.11) eggs and when eggs enter diapause would provide for more accurate determination of the timing and number of treatments required each season.

The Colorado potato beetle, Leptinotarsa decemlineata (Say), has a genetic system of great diversity and dynamic nature. This results in an enormous adaptability to a range of habitat conditions. Its genetic diversity is exemplified by the existence of color mutants (Tower 1906; Boiteau 1980, 1985).

In the summer of 1986, a red-body mutant male beetle was found in a potato field on the grounds of the Research Station in Fredericton, N.B., Canada. No other red beetles could be found in spite of frequent monitoring of beetle populations. The specimen retains the normal black maculation throughout but all pale yellow to flavous areas of normal beetles have been replaced by the color red (Scarlet 19/3 of the Royal Horticultural Society Colour Charts, 1942). To the best of my knowledge, this is the first report of a red Colorado potato beetle in Canada. Previously, red potato beetles had only been reported from the semi-desertic area of Toluca, near Mexico City (Tower 1906).

The western flower thrips, Frankliniella occidentalis (Pergande), occurs from sea level to subalpine altitudes in western North America (Bryan and Smith 1956). Until recently, it was assumed that this species was found primarily west of the Rocky Mountains and that Frankliniella tritici (Fitch), the eastern flower thrips, was the dominant flower thrips in both eastern Canada and United States. Beshear (1983) reported F. occidentalis on cotton, peas, beans, and peanuts in Georgia. The following year, in the Niagara Peninsula of Ontario, the tomato spotted wilt virus caused extensive crop losses to greenhousegrown tomatoes and ornamentals. The virus-vector was identified as F. occidentalis (Allen and Broadbent 1986). Previously, F. fusca was the only known vector of tomato spotted wilt virus in Ontario and the eastern provinces (Paliwal 1974, 1976).