A review of insect adaptations for resistance to cold and for life-cycle timing reveals the complexity of the adaptations and their relationships to features of the environment. Cold hardiness is a complex and dynamic state that differs widely among species. Surviving cold depends on habitat choice, relationships with ice and water, and synthesis of a variety of cryoprotectant molecules. Many aspects are time-dependent and are integrated with other factors such as taxonomic affinity, resource availability, natural enemies, and diapause. Timing adaptations reflect the fact that all environments change over many different time frames, from days to thousands of years. Environments differ in severity and in the extent, nature, variability, and predictability of change, as well as in how reliably cues indicate probable conditions in the future. These differences are reflected by a wide range of insect life-cycle systems, life-cycle delays, levels of responsiveness to various environmental signals, genetic systems, and circadian responses. In particular, the degree of environmental change, its predictability on different time frames, and whether it can be monitored effectively dictate the balance between fixed and flexible timing responses. These same environmental features have to be characterized to understand cold hardiness, but this has not yet been done. Therefore, the following key questions must be answered in order to put cold hardiness into the necessary ecological context: How much do conditions change? How consistent is the change? How reliable are environmental signals?

The distribution, spread, and adaptations of the 81 alien heteropterous species recorded in Canada are summarized. Sixty-nine species had eastern introductions and 47 had western introductions; 35 were introduced separately on both coasts. Most of the alien species are mirids of European origin. Several of these alien mirids have adapted and become pests of fruit and other agricultural crops, and some have become useful predators. Only 3 have adapted and spread across the whole country.

Melanism in the sulphur butterfly Colias nastes Boisduval was quantified and related to their ability to remain active under cool or cloudy conditions and to their risk of predation. Darker individuals were more active, moved greater distances, and disappeared from the population at a greater rate. Disappearance of darker individuals was not due to greater predation. Light-coloured individuals suffered greater predation than dark individuals, but only at higher elevations. The broad geographical pattern of increased melanism in Arctic and alpine Colias butterflies is likely a response to the consistent pattern of cooler temperatures in these habitats rather than local variation in predation pressure.

Although the extreme winter conditions of Arctic habitats are considered to be important determinants of the faunal composition of Arctic regions, the overwintering biology of most Arctic insects is unknown. A significant proportion of the insect fauna at high latitudes are hymenopterans, yet little information is available on their overwintering strategies. In this study I examined the overwintering strategies of willow gall-forming and catkin-feeding nematine sawflies and their parasitoids. All sawfly species overwintered as prepupae, were freezing-tolerant, and survived exposure to −50 °C. Freezing at high subzero temperatures was initiated by ice nucleators associated with the posterior hind gut wall. Heterogeneity of overwintering habitats with respect to temperature was not a determinant of the overwintering success of these Arctic sawflies. Divergent overwintering mechanisms were evident in the sawfly parasitoid taxa. Endoparasitoid larvae, like their sawfly hosts, were freezing-tolerant. Freezing of immature, feeding endoparasitoid larvae occurred at the freezing point of the host prepupa and was a consequence of the inoculation of the endoparasitoids' fluid compartments by ice crystals growing in the host hemolymph. Peculiarities in the structure of the endoparasitoid larval gut suggest that the site of nucleation is across the gut wall. Outside their hosts, however, endoparasitoid larvae can supercool extensively, and their tolerance of extremely low temperatures is similar to that of their hosts. Overwintering strategies adopted by the ectoparasitoids were also diverse, with both freezing-tolerant and freezing-intolerant species present in the parasitoid community. Freezing-intolerant species could not survive winter temperatures in the field in the absence of an insulating layer of snow.

This paper is a tribute to Dr. R.A. Ring upon his retirement. During the past 12 years (1993–2005), an emerging canopy research program has established a wealth of baseline information on the structure and functioning of temperate rain forest canopy arthropod communities. Studies from research sites on Vancouver Island, British Columbia, have shown that ancient temperate rain forest canopy ecosystems contain a largely undescribed fauna that is specific to habitat features found only in these canopies. In particular, diverse assemblages of free-living mites have been shown to dominate conifer species and canopy microhabitats. For example, oribatid mites are the dominant arthropod fauna on branches, branches with attached lichens, and suspended soil accumulations. Species composition differs significantly between the ground and the canopy at both the family and the species level. Arboreal specificity may be due to intrinsic variation in habitat quality, habitat architecture, patchiness, and (or) resource availability. The prevalent patterns of habitat specialization, low vagility, and restricted distribution displayed by a large percentage of the resident canopy microarthropods are features often associated with forest ecoregions that have enjoyed relatively stable conditions for long periods of time, as have the ancient forests on Vancouver Island. Investigators in the “one-Ring lab” continue to document the diversity and abundance of canopy arthropods of temperate forests in British Columbia. In particular, studies are concerned with defining the organizing principles that elicit community patterns associated with the various levels of complexity in arboreal communities. Our long-term goal is to provide a greater degree of predictability when addressing temperate forest diversity issues. To meet the stated goals of sustainable forest management and retention of biodiversity, an extensive plan of ecological research that features arthropods is needed. This plan, fostered by Dr. Ring, should have as a priority the inventory and cataloguing of species assemblages and should address dynamic processes such as organismal dispersal and the effects of habitat loss and fragmentation on arthropods in ancient forests.

Cast exuviae from final-instar larvae of four species of hymenopterous parasitoids of Dendroctonus rufipennis (Kirby, 1837) were examined for diagnostic characters. The head capsules of Bracon tenuis Muesebeck and Walkley, 1951, Coeloides rufovariegatus (Provancher, 1880), Roptrocerus xylophagorum (Ratzeburg, 1844), and Dinotiscus dendroctoni (Ashmead, 1894) each displayed unique combinations of characters allowing discrimination among species. Head capsules are illustrated, and a key to species is presented.

During a survey of frog-biting corethrellid midges in Costa Rica, we collected 79 female Uranotaenia lowii Theobald, mosquitoes known to bite frogs, from seven lowland localities using the recorded calls of a frog. The calls of male barking tree frogs, Hyla gratiosa LeConte, were repeated about once per second, lasted about 0.15 s, and had a fundamental frequency near 450 Hz. We suggest that this frequency is within the range of acoustic sensitivity of the female mosquito antennae. Males of several families of Nematocera use sound to detect flying females of their own species, but we believe ours is the first observation of female mosquitoes being attracted by the sound of a host.

Protein-rich pea flour is an antifeedant and a repellent and is toxic to the rice weevil, Sitophilus oryzae (L.), but its mode of action is not known. Results showed that protein-rich pea flour had no fumigant effect on adult survival or offspring production of S. oryzae. In a contact experiment, immobilized weevils were fed every other day and had their abdomens brushed with protein-rich pea flour or wheat flour on the alternate days. Insects treated with protein-rich pea flour had an average longevity of 9.6 days, which was significantly shorter than that for insects treated with wheat flour (11.3 days) or brushed controls (17.6 days). These results suggest that toxins from the protein-rich pea flour may be able to penetrate the insect cuticle. Midguts from weevils fed protein-rich pea flour, a pea flour extract, or a mixture of pea peptides contained numerous bubbles. Midgut tissues in these treated adults were injured, as shown by dual staining with the fluorescent dyes calcein AM and propidium iodide. The volume of the bubbles increased rapidly when insects were fed protein-rich pea flour or pea flour extract. There were no bubbles found in the midguts of S. oryzae that fed on wheat kernels or wheat flour.

Alate aphids were sampled in five fields of commercial blueberry, Vaccinium corymbosum L. (Ericaceae), during 2001 and 2002 using yellow tile, green tile, and Tremclad® yellow water traps. Eighty-seven species were identified among a total of 7722 alatae. Several of the species are known virus vectors, including Aphis fabae Scopoli, Brachycaudus helichrysi (Kaltenbach), Hyalopterus pruni (Geoffroy), Hyperomyzus lactucae (L.), Myzus persicae (Sulzer), Rhopalosiphoninus staphyleae (Koch), and Rhopalosiphum padi (L.). The number of species caught varied with year, and the number of species and the total number of alatae varied with field, trap colour, and season. More species were caught in 2001 than in 2002, in yellow than in green traps, and in the summer than in the spring or the autumn, and more alatae were caught in Tremclad® yellow traps than in yellow or green tile traps, and in the autumn than in the spring or the summer. However, numerous interactions limit generalizations. Analyses of the data for individual species revealed similar patterns and interactions. The effects of year, field, trap colour, and season varied with species. Given nonpersistent virus transmission and the large numbers of alatae caught of species that are known virus vectors, there is considerable potential for spread of Blueberry scorch virus by migrant aphids. Field- or area-specific and season-specific control strategies could be developed once the virus vector status of the different species is known. In addition, given the number of significant interactions observed in the data, there is a need to investigate alternative, generalized approaches to reducing virus transmission rates, such as applying whitewash or kaolin particle film to blueberry leaves.

An oviposition trap recently developed to survey hemlock looper (Lambdina fiscellaria (Guenée)) eggs and consisting of a small strip of white polyurethane foam stapled to the tree bole provides reliable estimates of Telenomus spp. parasitism on hemlock looper eggs. Oviposition traps are a standard tool that never varies. They allow us to avoid the tedious and expensive extraction process used when collecting eggs from branches. This new method can be implemented rapidly in a high number of plots and provides the egg parasitism estimates needed in spring to improve hemlock looper population management.

We investigated the use of wooden boards to sample ground beetles (Coleoptera: Carabidae) and compared their efficacy with that of single pitfall traps and two modified pitfall traps (barrier and grouped traps). Carabid captures and species richness were similar between wooden boards and single pitfall traps, but higher in barrier and grouped traps. Although captures were higher in the modified pitfall traps, no method was consistently superior or capable of capturing all carabid species recorded at our study site. A distinct advantage of wooden boards is their ease of installation and maintenance and the fact that they can be left in remote areas for extended periods of time, eliminating the need to visit areas to open traps (if livetrapping is the desired outcome). These time savings and reduced site disturbance may make wooden boards an alternative to single pitfall traps.