After about 20 years of wide usage in integrated pest management (IPM) programs on peach in the Niagara Peninsula of Ontario, populations of Oriental fruit moth, Grapholita molesta (Busck), resistant to azinphosmethyl and phosmet have been selected. Resistance, as expressed in first-instar larvae, was only two- to four-fold to azinphosmethyl or phosmet, but up to 45% fruit infestations have been documented in commercial blocks. Resistance to azinphosmethyl was not well expressed in adult Oriental fruit moths. In tests with larvae, cross-resistance occurred to most other organophosphorus insecticides except acephate and chlorpyrifos. Acephate was more toxic to resistant than to susceptible larvae. Resistance was higher (> 100-fold) to the methyl carbamates carbaryl and carbofuran but was approximately fivefold to the carbamoyl oxime methomyl. Cross-resistance to pyrethroids was not observed. Tests with field-collected material, either from crosses on mating trays in the field or from pupae collected in cardboard bands attached to trees, indicated that resistance was widespread across the Niagara production area but that the resistance was not uniformly expressed at all locations. Resistance was expressed in F1 larvae from crosses of susceptible females with field-collected males, indicating that the genetic change in resistant larvae was unlikely the effect of a single recessive gene. Field tests in replicated two-tree plots and in larger (0.25–0.6 ha) plots treated with up to five applications as a season-long control program indicated that neither chlorpyrifos nor acephate were as effective as a pyrethroid (deltamethrin). The sustainability of these IPM programs and potential resistance management strategies are discussed.

No sexual dimorphism in weight was observed at emergence of adult Aleochara bilineata Gyll. (Coleoptera: Staphylinidae). The weight of adults was strongly correlated with the size of the pupa in which the parasitoid developed. Newly emerged adults increased in weight after feeding, and this increase was greater in females than in males, reflecting the beginning of oogenesis. We showed that females invested simultaneously in reproduction and somatic functions the first day following mating. Although males and females showed no significant differences in weight at emergence, the females fed actively upon emergence and weighed significantly more than the males for 30 days after emergence. After that period, most of the eggs has been laid and both male and female weights were similar.

The first North American records for Deraeocoris punctulatus (Fallén), Labopidea artemisiae (Sahlberg), and Labopidea bermani Kerzhner indicate that the species are naturally Holarctic. Lygus rugulipennis Poppius is now considered naturally Holarctic after specimens of Lygus perplexus Stanger from Alaska, Yukon Territory, and Northwest Territories are correctly identified as L. rugulipennis. Additional North American localities for Labopidea discolor (Sahlberg) support the contention that the species is naturally Holarctic. Collections of Orthotylus ochrotrichus Fieber from Royal Oak, British Columbia, and Malacocoris chlorizans Panzer from British Columbia and Washington state suggest that these species are adventive to North America. Diagnoses are provided to distinguish all the taxa from other North American congeners. A key to the northern Nearctic species of Labopidea is given.

All ontogenetic stases of the yew big bud mite, Cecidophyopsis psilaspis (Nalepa), from British Columbia were studied by scanning electron and light microscopy and were compared with an English population of this species. The species was redescribed from the two populations, which were found to be quite similar in general appearance and in most of the morphometric data analyzed. Spermatophores in this species are similar to those observed in other Eriophyoidea. Details of a male spermatophoric organ are described and illustrated for the first time in an eriophyoid mite. Moulting in C. psilaspis is shown to be prodehiscent. The data reported here neither support nor reject the alternative hypothesis that the first active stase is larval versus nymphal. However, to account for the ontogenetic evidence, the first active stase is herein considered larval.

The number and volume of feeding and oviposition holes made by female white pine weevils, Pissodes strobi (Peck), on lateral branches of resistant and susceptible Sitka spruce, Picea sitchensis (Bong.) Carr., were determined. When all possible effects of weevil reproduction on feeding rates were eliminated, by using reproductively noncompetent weevils, there was no significant difference in the number of feeding holes made on the two host types. In addition, the volume of feeding holes was unaffected by host type on day 1. In contrast, when differential reproductive activity was induced by treating weevils with juvenile hormone, and the host factor was eliminated, by using only the susceptible host, higher reproductive activity was accompanied by a significantly larger number of feeding holes. Hormone treatment also led to an increase in the volume of feeding holes in the absence of any influence of host factors. Results are interpreted in relation to the direct effects of host resistance on feeding rates (which determine host acceptability) and the indirect effects of host resistance on feeding rates mediated through the physiology of the weevils (which determine host suitability). Our results show that both the number of feeding holes and their volume are determined primarily through weevil metabolism.

Attempts at using Perillus bioculatus (F.) for control of Colorado potato beetle, Leptinotarsa decemlineata (Say), have been hampered by an incomplete understanding of the predator’s over-wintering biology. This study determined the effects of photoperiod and life stage of prey (Colorado potato beetle) on tendency for adult females to enter reproductive diapause, duration of the preoviposition period, and mortality of females. Perillus bioculatus showed an increasing tendency to enter diapause rather than to initiate reproductive activities as day length decreased. Females that were fed large beetle larvae (mid to late fourth instar) showed a significant increase in the number of individuals entering diapause compared with females that were fed a mix of beetle eggs and small larvae (first to third instar). Probit analysis was used to estimate the photoperiod that caused 50% of females to enter diapause; these estimates were 15L:9D for females feeding on large larvae, and 14.5L:9.5D for females feeding on eggs and small larvae. Females that were fed large larvae also showed a longer preoviposition period and had a slightly significant higher rate of mortality than those fed eggs and small larvae.

The bertha armyworm has been recognized as an agricultural pest in western Canada for more than 85 years, during which time outbreaks have occurred at irregular intervals. The first major outbreak occurred in Saskatchewan in 1944 on the new crop, rapeseed. The development of canola as a major crop led to a dramatic increase in the economic damage caused by the bertha armyworm and resulted in the widespread use of insecticides for control. Discovery of a species-specific pheromone and development of an adult monitoring system in the late 1970s and early 1980s led to a method for providing producers with early warning of potential for crop damage. In parallel, methods for estimating larval populations were developed but are in need of improvement. Refinement of these methods has the potential to provide a more accurate indication of damage risk for producers of canola. Control of bertha armyworm relies heavily on the use of chemical insecticides, emphasizing the need for development of integrated management strategies.

Feeding on leaders of resistant Sitka spruce trees, Picea sitchensis (Bong.) Carr., Led to ovarian regression in white pine weevils, Pissodes strobi Peck., that contained already mature eggs at the time of caging on leaders. Such feeding also led to inhibition or a virtual blockage of ovarian development in weevils that did not contain already mature eggs at the time of caging. Ovarian maturation in such weevils was restored by application of juvenile hormone to female weevils. Effects of three levels of resistance were consistent within the experiments and with the field performance of the tested clones. These results indicate that the effects of resistance were postingestive, i.e., resistance was a form of antibiosis. How antibiosis can cause the weevils to concentrate oviposition on susceptible trees is discussed. Results also provide a means of selecting and ranking resistance of individual spruce trees for tree breeding and reforestation.

Field tests were conducted in an argan forest in Morocco to evaluate the performance of a cylindrical dry trap and food-based synthetic attractant (FA) for monitoring the Mediterranean fruit fly (medfly), Ceratitis capitata (Weidemann). This female-targeted trapping system was compared with Jackson traps baited with trimedlure (TML), a male-targeted trapping system. TML-baited traps attracted significantly more males than FA-baited traps (91.4 ± 13.01 and 5.0 ± 0.75 males, respectively), and the FA-baited traps captured significantly more females than did TML-baited traps (9.3 ± 1.93 and 0.1 ± 0.04 females, respectively). For the first month of the field trial, the ratio of mature females to immature females captured in the FA-baited traps was approximately equal, but more immature females were captured in the second month. FA-baited traps were less specific and captured significantly more nontarget flies than did TML-baited traps.

Diplolepis rosaefolii (Cockerell) induces a lenticular gall on the leaves of various roses across Canada. In Ontario and Quebec, D. rosaefolii is found only on Rosa acicularis Lindl., and its galls are inhabited by eight species of parasitoids, the most common being Chrysocharis pentheus (Walker), Orthopelma luteolator (Gravenhorst), and Eupelmus dryorhizoxeni Ashmead. Parasitoids and the inquiline Periclistus sp. make up 48–62% of gall inhabitants. Here we report a population of D. rosaefolii on the hybrid rugosa shrub rose Thérèse Bugnet in a field of experimental roses in Quebec. Only two species of parasitoids and one specimen of Periclistus sp. were associated with these galls.

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 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.

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.