Two tephritid flies of European origin have been introduced into North America for biological control of spotted knapweed, Centaurea maculosa Lam., and diffuse knapweed, C. diffusa Lam. One, Urophora affinis Frauenfeld, was released in British Columbia in 1970 and in 5 states, including Montana, in 1973 (Hanis 1980a; Maddox 1979; Story and Anderson 1978). The other, Urophora quadrifasciata (Meigen), was introduced at Ned's Creek, British Columbia but was not released in the United States. The larvae of both flies induce galls (1 larva/gall) in immature knapweed flower heads and thus reduce seed production. Galls of Urophora affinis occur in the flower-head receptacle whereas galls of U. quadrifasciata are in the ovary wall. In contrast with U. affinis, which has only a partial second generation, U. quadrifasciata normally has 2 complete generations per year, induces thinner galls, and attacks more-mature flower heads than does U. affinis (Harris 1980a).

In a previous report (Jansson and Smilowitz 1985), several life statistics of Myzus persicae (Sulzer) were compared on upper and lower leaves of three potato cultivars (Solanum tuberosum tuberosum cvs. Katahdin, Norchip, and Superior). In general, life statistics were similar (p > 0.05) between cultivars. However, certain life statistics (fecundity and intrinsic rate of increase) consistently were greater (p < 0.05) on lower leaves than on upper leaves of each cultivar. In the previous study, we did not include data on age-specific survival or the relationship between fecundity and longevity to support the premise that the population dynamics of M. persicae on potato are related to the physiological age of leaves (i.e. nutritional quality of leaves) (see Jansson and Smilowitz 1985). This information would be useful for developing a model describing the population dynamics of M. persicae. For this reason, we present here data on age-specific survival and the relationship between fecundity and longevity of M. persicae on upper and lower leaves of three Dotato cultivars.

In the course of investigations of the cabbage maggot, Delia radicum (L.) (= brassicae Wiedemann, brassicae Bouché), a pest of canola (rapeseed) in northern Alberta, an epidemic of the parasitic fungus Strongwellsea castrans Batko and Weiser (see Humber 1976) was documented during July 1983. Infected flies (mostly females) can be recognized by the presence of one or more cavities in the abdominal membrane, into which the fungus discharges its spores (conidia). The flies continue to feed (as vital organs are not attacked), but their eggs fail to mature, apparently because of inadequate nutrition. The presence of this fungus as a pathogen of the cabbage maggot in Canada is well known (Nair and McEwen 1973).

The face fly, Musca autumnalis De Geer, overwinters in an imaginal diapause characterized by cessation of reproductive activity and hypertrophy of the fat body (Stoffolano and Matthysse 1967). As in species of mosquitoes that employ a similar overwintering strategy (see Washino 1977), the potential of the face fly to serve as a vector of animal disease agents would be enhanced if flies contact animals prior to hibernation, thus possibly acquiring pathogens that overwinter in the insects. Because little is known about the prehibernation behavior of the face fly, a vector of several parasites of cattle (Branch and Stoffolano 1974; Bech-Neilsen et al. 1982), we here report observations of the physiological condition of face flies captured from cattle during the fall months.

On 2 occasions in August 1983, during the course of a study of the arthropod community associated with collards (Brassica oleracea L. [Cruciferae]) in central New York State, the pentatomid bug Euschistus servus euschistoides (Vollenhoven) was observed feeding on larvae of the imported cabbage butterfly, Pieris rapae (L.). The individuals making the attacks, both adults, were discovered on the upper surface of a collard leaf with 4th-stage caterpillars firmly impaled on their rostra. Both caterpillars appeared lifeless. In 1 case, the P. rapae larva appeared somewhat shrunken, indicating that the bug had probably removed some body fluids from it. Voucher specimens of the bug have been deposited in the Cornell University Insect Collection (lot #1137). This note constitutes another record of predatory behavior exhibited by this nominal phytophage (Esselbaugh 1948; McPherson 1982).

Disruption of mating and of trap capture of spruce budworm, Choristoneura fumiferana (Clem.), has been accomplished in recent years (reviewed in Silk and Kuenen 1984) by disseminating large quantities of the primary components (synthetic) of the female sex pheromone within a forest environment. These components (E)- and (2)-11-tetradecenal (E/Z11-14:Ald) (Sanders and Weatherston 1976) are emitted by virgin female budworm at a 95/5 E/Z ratio (Silk et al. 1980). Unsaturated aldehydes are expensive, tend to polymerize readily (Dunkelblum et al. 1984), and are susceptible to air oxidation and/or photodegradation in the field environment. Analogues, with increased stability and reduced cost, that duplicate the effects of these pheromone components would therefore be of practical value.

The bertha armyworm, Mamestra conjigurata Wlk., is a polyphagous climbing cutworm (Lepidoptera: Noctuidae) that attacks canola (Brassica napus L. and B. campestris L.) in the prairie provinces of Canada. Following the outbreaks of 1971–1974 (Turnock and Philip 1977), sampling methods to determine larval density in the field were developed by researchers in Manitoba, Saskatchewan, and Alberta. The methods were basically similar, using a 3-sided metal frame to outline each 0.5-m2 sample unit, with the long side of the frame (1 m) parallel to the rows of the crop. The differences were in the way in which the plants and soil surface were searched for larvae. In Manitoba, the plants within each sampling unit were shaken by hand, then the soil surface was examined for larvae and earthen lumps and plant debris were moved to expose hidden larvae. In Saskatchewan, the plants were shaken, then cut near the base and discarded before the ground surface and debris were searched. In Alberta, the plants were cut near the base, then shaken over a sheet, and the sheet and ground surface were examined for larvae.

The peach-twig borer, Anarsia lineatella (Zeller), is one of the most important pests of peaches, almonds, and other stone fruits in the western United States (Bailey 1948), with larvae infesting both twigs and fruit. Infested fruit cannot be marketed and twig injury is damaging to young trees because the young worms burrow into the tender terminal growth of the twigs and cause the rapidly growing twigs to wilt. In this way, infestations by the peach-twig borer interfere with development in young orchards (Newcomer 1966).

The spruce coneworm, Dioryctria reniculleloides (Mut. and Mun.), is often associated with the spruce budworm on spruce host trees and sometimes approaches or equals the spruce budworm, Choristoneura fumiferana (Clem.), in numbers (Spies and Dimond 1985). The coneworn is probably~responsiblefo r some of the damage on spruce attributed to the budworm, and with much balsam fir in eastern North America now dead from defoliation or harvested, there is increasing interest in spruce as the major resource to protect.

In a series of papers (Vickery and Nagy 1973; Vickery et al. 1974; Vickery and Kevan 1983), 2 members of the genus Trimerotropis were considered to be subspecies, T. verrruculata verruculata (Kirby) and T. verruculata suffusa Scudder. This relationship was based in part on a statement by Hebard (1929) that 1 was sometimes mistaken for the other where the ranges meet. The former is widespread across the northern part of the continent from Newfoundland to British Columbia and north into the Northwest Territories. The latter is a western taxon, occurring from British Columbia southward into California. Helwig (1955) reported on genetic studies of hybrids between the 2. We made no careful study of the problem, but accepted that production of hybrids indicated a lack of reproductive isolation and therefore considered them as subspecies even though the work of Helwig (1955) indicated that the F, hybrids may be infertile.