Studies were conducted to evaluate the ability of six commercially available species of Trichogramma to parasitize eggs of tomato pinworm (TPW), Keiferia lycopersicella (Walsingham), and their potential use for biological control of TPW eggs. Of the six species, Trichogramma pretiosum Riley and Trichogramma brassicae Bezdenk parasitized the most TPW eggs (40–50%). Further studies assessed the effectiveness of T. pretiosum and T. brassicae as biological control agents for TPW eggs under controlled environmental conditions which simulated conditions that could be found during the greenhouse crop production season. Trichogramma pretiosum caused significantly higher mortality of TPW eggs than did T. brassicae at all parasitoid to host egg (P:H) ratios. Mortality caused by host feeding and stinging increased significantly with increasing P:H ratios for both species. Parasitism by T. pretiosum on TPW eggs was reduced significantly and mortality caused by feeding and stinging increased significantly at 28 °C, compared with those at 20 and 25 °C. No differences were found in parasitoid-induced mortality when T. pretiosum were offered 1-, 2-, or 3-day-old TPW eggs, but parasitoid-induced mortality was reduced significantly when parasitoids were offered 4- and 5-day-old TPW eggs. Based on these trials, a P:H ratio of between 1:1 and 10:1 is recommended for inundative releases of T. pretiosum for control of TPW on greenhouse tomatoes.

The field attractivity of (E,Z)-2,13-octadecadienyl acetate (E,Z-2,13-18:OAc) (30 μg loaded on red rubber tubing) alone or in combination with (E,Z)-3,13-octadecadienyl acetate (E,Z-3,13-18:OAc) (0.9 μg added) towards the male currant borer, Synanthedon tipuliformis Cl., (Lepidoptora: Sesiidae), was compared in British Columbia (B.C.) and in Quebec (Canada) by means of trapping trial. The binary mixture attracted males in significantly higher numbers into sticky traps than E,Z-13-18:OAc alone [17.0 male captures/trap/inspection versus 1.7 in Langley (B.C.), 32.7 versus 11.9 in De Roche (B.C.), and 5.3 versus 0.2 in Ile d’Orleans (Que.), respectively]. These results suggest that the Canadian currant borer populations belong to the same strain as those in Europe and New Zealand, with E,Z-3,13-18:OAc remaining an important attractant-synergistic component.

Gilbert and Raworth (1996) propose a general theory to explain the effects of temperature on the development and growth rates of insects. The theory is evolutionary rather than physiological. They propose that insects are selected for a high rate of increase (i.e., rapid growth and large size) in spring, and for rapid development in summer. They claim that these selection pressures explain five “puzzles:” (1) the linearity of the relationship between development rate and temperature, (2) a reduction in the genetic variation of development rate at high temperature (i.e., average midsummer temperature), (3) a reduction in the genetic variation of growth rate at low temperature (i.e., average spring temperature), (4) slow development at the time of emergence after overwintering, and (5) a greater reduction in development rate than growth rate at low temperature.

Intraguild predation, a common interaction among arthropods (Polis et al. 1989), has been investigated recently in aphidophages (Rosenheim et al. 1993; Lucas et al. 1998). Sessile stages of coccinellids, gall midges, and lacewings (eggs, moulting individuals, and pupae) were shown to be highly vulnerable to intraguild predators (Lucas et al. 1998). Several defensive mechanisms have already been described for eggs of aphidophages, including chemical protection (Eisner et al. 1996), structural protection (Canard and Duelli 1984), and behavioural avoidance through the selection by females of protected oviposition sites (E. Lucas, and J. Brodeur, unpublished data).

Effects of photoperiod, time of year, temperature, and an insect growth regulator (fenoxycarb) on ovarian development rate in overwintering pear psylla, Cacopsylla pyricola (Foerster), were determined. Winterform pear psylla were collected from the field at intervals between October and February, and reared at 20 °C and one of three treatments: short-day photoperiod, long-day photoperiod, or short-day photoperiod + fenoxycarb. Insects were then dissected at intervals to score ovarian development. Baseline scores (i.e., ovarian development in the field on date of collection) increased very slowly between October and February. By mid-February, only about 20% of insects in the field were categorized as having postdiapause status based upon ovarian development. In the laboratory, time required for insects to reach postdiapause status decreased between the October and February collection dates. Number of days necessary for 50% of the long-day insects to reach postdiapause status was approximately 2 weeks in October, 6 days in December, and < 2 days in February. Short-day insects also required fewer than 2 days in February, but required > 2 weeks in the October and December samples. Our results suggested that insects collected in January and February had completed diapause but that ovarian development was subsequently prevented in the field by low temperatures. Fenoxycarb caused rapid ovarian development even in October-collected insects; rate of development was only slightly more rapid in the February-treated psylla.

Pandeleteius florivorus sp.nov. is described from specimens feeding on the flowers of Piptadenia leucoxylon Barneby et Grimes (Mimosaceae) in Venezuela. Additional distribution records and a revised key to the species of the Pandeleteius biseriatus (Kirsch) species-group are given.

Males of Eucosma gloriola Heinrich (Lepidoptera: Tortricidae) were caught in pheromone traps for about 5 weeks from 17 May to 21 June in 1996 in three 6-year-old plantations of jack pine, Pinus banksiana Lamb. (Pinaceae), located near Ramsey, Ontario. Peak flight occurred during the first week of June. Pheromone trap catch was greatest about 1 h before and after sunset (2130 hours EDT). Moth flight began when all jack pine pollen cones and vegetative shoots were still under bud scales, and when flights were nearly completed the pollen cones had completed shedding pollen and needle pairs were visible on the new shoots. Pheromone traps placed near the top of trees caught the most males, suggesting that males search for females at tree-top level and that some visual or chemical cue(s) of the host tree may enhance the response of males to pheromone-baited traps.

During a study on the parasitoids of the imported cabbageworm, Artogeia rapae (L.) (Lepidoptera: Pieridae), undertaken in 1993 and 1994, we recovered Cotesia rubecula (Marshall) (Hymenoptera: Braconidae) for the first time in Quebec, Canada. Samples were taken from pesticide-free plots of cabbage, broccoli, and Brussels sprouts located at Ste-Clotilde (45°09′N, 73°41′W) and L'Acadie, Quebec (45°18′N, 73°21′W), as described by Godin and Boivin (1998). In addition, survival of diapausing C. rubecula was evaluated after a 5-month incubation at 4°C (Godin 1997). Both A. rapae and C. rubecula are introduced species and originate most likely from Europe (Richards 1940). Artogeia rapae was discovered in 1860 in Quebec (Harcourt 1963), and C. rubecula was first reported in 1963 in British Columbia (Wilkinson 1966).

In the laboratory a proprietary, neem-based insecticide formulation (NBI) was evaluated as a potential pest management tool for the western cherry fruit fly, Rhagoletis indifferens Curran (WCFF). NBI was tested for its potential effects on survival and development of juvenile WCFF. Incorporation of NBI into an artificial larval diet resulted in a decrease in the formation of pupae and subsequent adult emergence. Late third instar larvae exposed to NBI in sand were able to form puparia; however, the numbers of adults and pupae developing inside the puparia were decreased at concentrations as low as 0.05% NBI. Well-timed root drenches with NBI could control R. indifferens by disrupting pupation. Applied in this manner, NBI may provide cherry orchardists with an effective, new control tactic.

Feeding damage by the crucifer flea beetle, Phyllotreta cruciferae (Goeze), was assessed on 51 accessions of false flax, Camelina sativa L., and compared with damage to seven other crucifer species. Three experiments were conducted on seedlings in laboratory arenas infested with field-collected beetles. Feeding damage was estimated visually at daily intervals for up to 7 days. Natural infestation of false flax and other crucifers was observed in the field. Flea beetles fed little (0–10% consumption) on cotyledons or true leaves of any of the false flax accessions, and fed more (59–100% consumption) on the other crucifers. Flea beetles were observed sitting on false flax in the field, sometimes in high numbers, but they did not feed. In the laboratory, beetles eventually fed on cotyledons and leaves and once feeding was initiated, it tended to continue. Resistance in false flax may result from the absence of cues that initiate feeding, rather than a feeding deterrent. The high level of resistance in false flax would likely be economically beneficial if this species is developed as an oilseed crop. False flax could also be useful experimentally for identifying the cues that attract flea beetles to plants and stimulate their feeding.

Pieris rapae (L.) (Lepidoptera: Pieridae) is endemic in the Canary Islands, presumably since Roman times. Average temperatures at sea level on Tenerife and La Gomera range from 17°C at midwinter to 25°C in summer. If the argument of Gilbert and Raworth (1996) is correct, we might expect the development threshold of P. rapae in the Canaries to be 17°C, much higher than the 10°C observed elsewhere: Cambridge, U.K.; Cordoba, Spain; Pompei, Italy; Montpellier, France; Vancouver, Canada; and Canberra, Australia (Gilbert 1988).

Green lacewings (Neuroptera: Chrysopidae) are commercially available augmentative biological control agents. Despite centuries of recognition as beneficial insects (Darwin 1800), scant information can be found describing what lacewing larvae prey upon in the field when several different prey species are present (New 1975). I assessed the types of prey that Chrysoperla plorabunda (Fitch) larvae consume when they are released on peas, Pisum sativum L. (Fabaceae), in western Washington. In 1997, two field assistants and I made observations at three sites: the Rent's Due Ranch (RDR: 48°14′N, 122°22′W), an organic farm located just outside Stanwood, Washington, and two research farms (Sumner: 47°11′N, 122°13′W; and Fife: 47°12′N, 122°20′W) in the Washington State University extension station system. Planting dates differed among these sites; at RDR, peas were planted in the spring, whereas we planted peas at the Sumner and Fife farms in June and July, respectively. Despite this and other differences, the peas at each site harbor similar insect communities (unpublished data).

Sphaerularia bombi Dufour is an internal nematode parasite of bumble bee queens in North America and Europe. Infection functionally castrates the bee. Here we document the prevalence and intensity of S. bombi infections in seven species of Bombus and three species of Psithyrus on Cape Breton Island, Nova Scotia, Canada. We found dramatic variation in prevalences among Bombus spp., and some evidence that prevalence increased as the nesting season progressed. Also, we report S. bombi in the bumble bee nest parasite Psithyrus insularis (Smith), the first record for the genus in North America.

The crucifer flea beetle, Phyllotreta cruciferae (Goeze), feeds primarily on plants in the Brassicaceae (Cruciferae) (Feeny et al. 1970). Introduced from Europe, it is now a widespread pest of canola, Brassica napus L. and Brassica rapa L., in North America (Lamb and Turnock 1982; Weiss et al. 1991). Before canola occupied so much crop land in western Canada, flea beetles were present and presumably fed mostly on wild crucifers. These native and weedy crucifers are potential sources of resistance genes that might be transferred to canola. We examine feeding preferences of flea beetles among nine wild crucifers (Table 1) to determine which, if any, are avoided. The suitability of these plants has already been examined for another crucifer-feeding chrysomelid, the red turnip beetle, Entomoscelis americana Brown (Gerber and Obadofin 1981; Gerber 1984), and the feeding responses of the beetles are compared.

During their reproductive period, white pine weevils, Pissodes strobi Peck., remain on susceptible Sitka spruce trees, Picea sitchensis (Bong) Carr., that are suitable for their reproduction and progeny development. Weevils depart from resistant Sitka spruce trees, where weevil reproduction is inhibited or blocked by resistance (Sahota et al. 1994). This resistance appears to work by interfering with the juvenile hormone (JH) system of the weevil (Sahota et al. 1994; Leal et al. 1997). In our experiments to investigate whether or not interference with JH could also account for the weevils' domicile at susceptible trees and their departure from resistant trees (see Sahota et al. 1994), we routinely treat weevils with hormones and study their flight behaviour in the laboratory and field.

Queenless, caged, newly emerged worker bees (Apis mellifera L.) were fed honey, 22 and 40% pollen in honey, and 22 and 40% royal jelly in honey for 14 days. Workers fed royal jelly, pollen, and honey had large, medium, and small ovaries, respectively. Royal jelly had higher nutritive value for workers’ ovarian development than did pollen, possibly because royal jelly is predigested by nurse bees and easily used by adult and larval bees. These results suggest that nurse bees could mediate workers’ ovarian development in colonies via trophallactic exchange of royal jelly. Six levels of royal jelly in honey, 0, 20, 40, 60, 80, and 100% (royal jelly without honey), were tested for their effects on workers’ ovarian development and mortality for 10 days. High levels of royal jelly increased ovarian development, but also increased worker mortality. All caged bees treated with 100% royal jelly died within 3 days. When workers were incubated at 20, 27, and 34 °C for 10 days, only bees at 34 °C developed ovaries. These findings suggest that nurse bees functioning as units which digest pollen and produce royal jelly may feed some potentially egg-laying workers in a brood chamber with royal jelly when a queen is lost in a colony. Feeding workers a diet of 50% royal jelly in honey and incubating at 34 °C for 10 days is recommended for tests of ovarian development.

The eastern spruce budwonn, Choristoneuva fumiferana (Clem.) (Lepidoptera: Tortricidae), is subject to a variety of naturally occurring infectious diseases including nuclear polyhedrosis virus (NPV), granulosis virus (GV), cytoplasmic virus (CPV), and entomopox virus (EPV), of which the most intensively studied is NPV (CfMNPV) (Cunningham 1985). If CfMNPV is ever to be deemed an effective and economical alternative to chemical pesticides for spruce budworm control, additional research is required.

Water stress, especially wilting, can increase the susceptibility of plants to herbivory by insects (Holtzer et al. 1988). Insects as diverse as locusts and leaf-cutting ants prefer wilted foliage (Bernays and Lewis 1986; Vasconcelos and Cherrett 1996). Palaniswamy et al. (1997) observed that the crucifer flea beetle, Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae), fed on excised and wilted foliage of Thlaspi arvense L. (Cruciferae) but not on intact and turgid foliage. If water stress can make unpalatable plants more palatable, identifying robust resistance to pests such as flea beetles will be difficult. The purpose of this study was to determine whether wilting affects feeding by the crucifer flea beetle and in particular if wilting differentially affects feeding on preferred and nonpreferred plants.

A detailed description and illustrations of the larva of Remartinia secreta (Calvert) are provided. The main features that distinguish the larva of this species are dark brown coloration; prementum 0.25 times longer than its widest part, with a dorsal row of small spiniform setae close to the lateral margins; length of the lateral spine on abdominal segment six 0.4–0.5 mm; lateral valvae of female gonapophyses shorter than central ones; and female epiproct longer than cerci. Larvae were found living in a lagoon densely covered by aquatic phanerogams such as Eichhornia sp. (Pontedereaceae) and Typha sp. (Thyphaceae). Larva of R. secreta is compared to that of Remartinia luteipennis florida (Hagen), its only sympatric congener.

Ctenolepisma (C.) electrans sp.n., from the Dominican amber, is described and compared with the closest living species. The new taxon is the only Lepismatidae known so far in the Dominican Republic amber and corresponds to the only known fossil Ctenolepisma.