Bees of the genus Osmia Panzer (Hymenoptera: Megachilidae) are among the contenders to replace honey bees, Apis mellifera L. (Apidae), for pollinating tree-fruit crops. One species, Osmia lignaria Say, has shown great potential in western North America and was recently introduced into Nova Scotia for evaluation as a pollinator of apple, Malus Mill. (Rosaceae). A major component of that study was to develop management options for O. lignaria, including methods of sustaining nesting females following crop flowering to maximize population recovery for pollination in subsequent seasons. The objective of this study was to evaluate bigleaf lupine, Lupinus polyphyllus Lindl. (Fabaceae), as a secondary food plant for nesting female O. lignaria by investigating nesting activity, pollen-use patterns, and fecundity. During 2002–2003, female O. lignaria collected high proportions of apple pollen (>70%) during mid and late flowering; after then, most pollen (>90%) was collected from bigleaf lupine. The flowering period of lupine in Nova Scotia (late May to early July) slightly overlapped that of apple, so there was no scarcity of pollen resources during the life-span of O. lignaria. Most nests typically showed high levels (≤200%) of population growth, but recorded levels varied among nest types and locations. In 2004, nests closer to lupine plots exhibited significantly greater population recovery than nests located farther away (i.e., approximately 600 m). Bigleaf lupine is a suitable plant species for meeting the pollen requirements of nesting populations of O. lignaria following apple flowering, thus promoting the recovery of populations to meet apple pollination requirements in subsequent seasons.

Knowledge of the effects of variables that can influence trapping results should help to optimise efforts in exotic species detection and other surveys. Two vertical trap placements (understorey, canopy) were tested to determine influence of these two heights on captures of Scolytinae (Coleoptera: Curculionidae), Cerambycidae (Coleoptera), and Siricidae (Hymenoptera) using semiochemical-baited multiple-funnel traps. Traps were baited with α-pinene, ethanol, ipsdienol, and ipsenol. A total of 8463 insects from 65 species and one genus were captured during the study. Average species richness, species diversity, abundance, number of unique species, and expected diversity were higher in understorey compared with canopy traps. Jaccard (0.94 ± 0.05) and Sørensen abundance (0.97 ± 0.03) similarity indices suggested highly similar communities sampled at the two trap heights. Dendroctonus valens LeConte, Dryocoetes autographus Ratzeburg, Hylastes opacus Erichson, Orthotomicus caelatus (Eichhoff), Gnathotrichus materiarius (Fitch), Asemum striatum (Linnaeus), Monochamus scutellatus scutellatus (Say), Rhagium inquisitor (Linnaeus), and Xylotrechus sagitattus sagitattus (Germar) were more abundant in understorey traps. In contrast, Ips pini (Say), Pityogenes hopkinsi Swaine, Monochamus carolinensis (Olivier), Acmaeops proteus (Kirby), and Astylopsis sexgutatta (Say) were more abundant in canopy traps. The common practice of trapping in the understorey may be optimal for sampling arboreal insects as part of survey efforts. However, additional species may be found by trapping at other vertical placements.

The effect of temperature on the age-specific fecundity and the survival of apterous and alate virginoparous pea aphid, Acyrthosiphon pisum (Harris), from Kamloops, B.C., was measured. Demographic statistics were estimated for 10.3°, 14.8°, 19.7°, 26.1°, and 27.8°C constant and for fluctuating field temperatures. On a 24-h-day time-scale, temperature and longevity were inversely related in both morphs; total fecundity was highest at average and low constant temperatures. On a physiological time-scale, the intrinsic rate of increase (rm) was insensitive to changes in constant temperature in the range between 10° and 20°C; temperatures above 25°C were detrimental to aphid population growth and survival. Alate virginoparae generally had a longer pre-reproductive period and achieved a lower mean total fecundity than apterae maintained under identical conditions. The usefulness of laboratory measurements for the prediction of population growth under variable field temperatures is discussed. Differences in the reproductive patterns of alate and apterous pea aphids are considered in the context of the r- and K-hypothesis of selection.

Larvae of Leptinotarsa decemlineata (Say) reared on tomato fed longer, consumed more foliage, and had a lower survival rate than when reared on potato, its principal host. On both plants, a direct linear relationship was obtained between food consumption and larval growth. Potato was the more efficient of the two plants in terms of food conversion to body matter. This was reflected by increased weight gain of the larvae and greater pupal size.

Adults from larvae reared on tomato were smaller and less fecund than those from larvae reared on potato. Half of them rejected tomato as food. However, egg-laying increased when they were transferred to potato after 50 days. The present investigation indicates that L. decemlineata can survive and attain maturity on tomato in the absence of its principal host plant. However, when potato is once again available, it is able to increase growth, accelerate development, and achieve a greater reproductive potential.

There is a correlation between the amount of blood ingested by Aedes aegypti (L.) and the trypsin activity (but not the chymotrypsin activity) in the midgut 16 and 24 hr after feeding. Puromycin and Dactinomycin ingested with a blood meal depress the level of midgut trypsin. Trypsin purified from the midguts of A. aegypti fed upon defibrinated blood containing 14C-amino acids contains radioactivity. Midguts from blood-fed mosquitoes did not produce significant amounts of trypsin when dissected from mosquitoes and maintained in a tissue culture medium for up to 50 hr.

Ten species of the larger, primarily aphidophagous, coccinellids were present in peach orchards of the Niagara Peninsula. Adalia bipunctata (L.) and Coccinella trifasciata perplexa Mulsant were the commonest. All were most numerous in the spring while the green peach aphid, Myzus persicae (Sulzer), was present but their population densities were low at all times, apparently because suitable prey was scarce. They were not attracted to dense populations of the European red mite, Panonychus ulmi (Koch), and were of no importance as predators of peach pests.

At least 7 species were bivoltine but the second generation was only partial.

Cultivars of winter wheat, Triticum aestivum L., previously identified as possible sources of resistance to wheat midge, Sitodiplosis mosellana (Géhin), were crossed with spring wheat to produce lines with a spring growth habit and assure synchrony between insect and plant. Many of the lines showed low levels of infestation by wheat midge in the field, and 21 of these were tested for resistance in the laboratory. All test lines exhibited resistance, ranging from 58 to 100% suppression of larvae and 70 to 100% suppression of seed damage, compared with a susceptible line. Larval development was delayed and survival was reduced on all lines. This antibiosis was associated with a hypersensitive reaction in the seed surface. The hypersensitive reaction, or feeding damage by young larvae before they died, reduced the biomass of some infested resistant seeds by 28% compared with over 60% for infested susceptible seeds. Some lines also reduced the level of infestation either through oviposition deterrence or a resistance which prevented newly hatched larvae from establishing on the seed surface. A few lines also reduced the hatching rate of wheat midge eggs. The resistance was equally effective in field trials during two consecutive summers in Manitoba and Saskatchewan, with at least a 20-times difference in the level of infestation between susceptible and resistant wheats. No larvae could develop to maturity on some resistant lines. Large plots of one resistant line produced less than 1% as many larvae as a typical susceptible wheat, and the larvae that did survive produced few, small adults. This resistance is the first documented case of a high level of true resistance to wheat midge in spring wheat, distinct from asynchrony between the insect and susceptible stage of the plant. The antibiosis component of the resistance is currently being incorporated in cultivars suitable for production in western Canada.

The parasite and predator component of within-tree southern pine beetle, Dendroctonus frontalis Zimmermann, mortality was investigated by mechanically excluding insect parasites and predators from the bark surface of naturally infested shortleaf, Pinus echinata Mill., and loblolly, P. taeda L., pines. Mortality caused by insect parasites and predators was determined by comparisons of five treatments that differed only in the duration of natural enemy exclusion. These natural enemies were responsible for 28.04% and 23.85% of the within-tree beetle mortality in 1978 in Arkansas and in 1979 in Georgia, respectively. Natural enemy species that arrived on the tree during the first week following mass attack by beetles caused the greatest amount of mortality.

Predator density was greater than parasite density at both locations. The majority of the predator complex arrived during the first week following mass attack by beetles, while the parasite complex arrived throughout the entire period of beetle brood development.

A linear response was found between the number of southern pine beetle prey and the number of prey destroyed per predator. A mean (± S.E.) of 4.79 ± 0.64 southern pine beetle immatures were destroyed by each individual predator.

The threshold temperature of development, life table, and innate capacity for increase of the twospotted spider mite, Tetranychus urticae Koch, were established from life stage development studies at constant temperatures. The threshold for development was determined to be 10.0°C. The durations in degree-days above 10°C from the beginning of the egg stage to adult for females were 141.3, 152.3, and 139.8; for males 134.2, 144.7, and 135.2 at 15°, 18°, and 21°C, respectively. Life tables were constructed and innate capacity for increase was .069, .156, and .372; net reproduction rate 20.8, 38.4, and 58.1; and mean generation time 44.0, 23.4, and 10.9 at 15°, 18°, and 21°C, respectively.

Under favourable conditions some species of insects and mites complete development very quickly. This paper considers species with a mean minimum generation time of 15 days or less and tabulates developmental data for many sample species. Such species belong chiefly to a limited number of taxa of small size, notably aphids and several families of mites and parasitoid Hymenoptera. Characteristics of these taxa are reviewed. Even in families containing many species with rapid life cycles, normally many other species lack such rapid development. Very short life cycles depend on phylogeny, strain, rapid development in all stages, small size, rich food, and other habitat features including high temperatures. Within this framework, life cycles are accelerated by reducing elements requiring the investment of resources (size, fecundity, longevity, structural complexity), eliminating instars and even life stages, accelerating development (through lower requirements especially of heat, heat gain by adaptations such as basking, and rapid reproduction), and choosing the most suitable habitats and microhabitats from those available. Mean minimum generation times in insects and mites with coincident adaptations of this sort can be as short as 4 days. Notwithstanding the advantages of rapid development in maximizing the intrinsic rate of natural increase (and hence fitness), most species cannot achieve the highest rates of development. They are constrained not only by resources and intrinsic physiological or phylogenetic patterns but also by variability of conditions and seasonality that can be survived only by interpolating delays or resistant stages.

The importance of predators in the natural control of mosquitoes has been suggested by a number of workers. Comprehensive reviews have been presented by Hinman (1934) and Gerberich (1946). The conclusions are open to somequestion, however, since the investigations were confined for the most part to studies in laboratory aquaria. These environments create conditions such as crowding, absence of prey shelter, and lack of alternative prey, which prevent an analysis of predation in terms of field conditions. An accurate assessment of predation in nature requires a technique to identify predators that have consumed prey. This is a report on an attempt to analyse the predator-prey relationships of animals in a natural mosquito pool in a woodland swamp near Chatterton, in Hastings County, Ontario, in April and May, 1953, by means of a radioactive tracer.

Results of the analyses for digestive enzymes in the glands and midguts of five species of ants showed that invertase is usually secreted by the maxillary glands, amylase by the salivary glands, and protease and lipase by the midgut. Lipase was found in the post-pharyngeal glands but observations indicate that it is not associated with the digestion of ingested food. Differences in the activity of the enzymes in different species tended to reflect the feeding habits of the ants.

Populations of the citrus red mite, Panonychus citri (McGregor), reared on “rough lemon” seedlings (Citrus limon (L.) Burm.) in a greenhouse and treated with malathion or permethrin were significantly higher than those on untreated seedlings. Significant increases were demonstrated in age-specific fecundity (mx), mortality corrected mx (lx mx), and net reproductive rate (Ro) values for mites reared in the laboratory on leaves treated with malathion or permethrin when compared with those reared on untreated leaves. Mites reared on oxamyl-treated leaves exhibited significant reductions in age-specific survivorship (% lx), mx, lxmx, and Ro values compared with those reared on untreated leaves. The importance of reproductive stimulation in relation to other causes of pest resurgence is discussed.

Field plot tests during two seasons show that augmentative releases of Perillus bioculatus can control first-generation eggs and larvae of the Colorado potato beetle (CPB) under Quebec short-season conditions. Stinkbugs mass-reared on CPB were introduced manually as 2nd- and 3rd-stage nymphs during spring oviposition of the beetle at densities of one nymph per 50–225 CPB eggs recruited per plant, in 0.025-ha plots. Sampling at intervals of 1–3 days measured predator establishment, CPB egg and larval mortality, and foliage protection level. Direct observations were used to document predator-prey relationships and to determine weather conditions favourable to P. bioculatus.

In the 1 st-year test, with predators released over all plants within plots, CPB control was compared among: (1) stinkbugs alone, (2) the bioinsecticide Bacillus thuringiensis (BT) as Trident™, (3) a combination of both control alternatives, and (4) no protection against the CPB. BT and stinkbugs, both alone and in combination, produced significant control as measured by percentage reductions in prepupal drop to the ground, new adult emergence, and foliage protection. Only treatments involving P. bioculatus reduced CPB egg eclosion which was the key control factor; it is strongly correlated with overall control level.

In the 2nd-year test, predators were released in a central area comprising only 25% of all plants within plots. Predator and CPB egg mass densities were manipulated to produce predator: prey ratios of 0:1, 0:2, 1.5:2, 1.5:1, 3:2, and 3:1, representing average ratios of 0, 1.5,or 3 P. bioculatus per plant, and 1 or 2 CPB egg masses per plant at release time. As expected, central release produced complex interactions between control, and predator and prey densities. High beetle density slowed predator emigration from the centre, more so at low predator density than at high predator density. Predators moved more quickly within the same row than across rows. CPB eggs were destroyed in large numbers in both years but in 1993, final control correlated with larval rather than egg predation. A maximum 80% reduction in prepupal drop to the ground was obtained at the 3:1 predator:prey ratio (1 P. bioculatus:95 CPB eggs recruited per plant).

The results prove the efficacy of P. bioculatus for biological control of first-generation L. decemlineata populations, at densities resulting in approximately 300 eggs laid per plant during spring oviposition in the study area. Despite low natural populations of P. bioculatus and unclear prospects for commercial availability at reasonable cost, it is evident that stinkbug releases have potential as a non-chemical control measure within an IPM program in Quebec potato production.

Mesothoracic skeletomusculature of male and female Eupelminae is described and compared with that of other Eupelmidae, Chalcidoidea, and Hymenoptera. Various external mesopleural features and structural dimorphism between the sexes are explained by differences in muscle form and placement. A set of terms for mesothoracic structure is proposed that is equally applicable to male and female eupelmines and to other chalcidoids. Mechanics of flight and jumping in male eupelmines, and of jumping in females, is also described. The flight mechanism of males is similar to that previously described in other hymenopterans and is structurally independent of the jumping mechanism. Contraction of large mesotergal-mesotrochanteral muscles, originating from the axillae and axillar phragmata, act directly to retract the mesotrochanters into the mesocoxae for jumping. Females have coadapted the flight and jumping mechanisms into a single mechanism to improve jumping greatly. The mesotergal-mesotrochanteral muscles are reduced to slender, tendon-like muscles originating from the anteroventral angle of each lateral axillar surface. Jumping in females results from contraction of large mesopleural-mesotergal muscles that insert into anterolateral processes of the mesoscutum by pads of resilin. The pads are stretched during contraction of the mesopleural-mesotergal muscles and the potential energy thus stored is subsequently released to flex the mesonotum along the transscutal articulation. The first and second axillary sclerites are modified to function as a hinge to control mesonotal flexing for jumping. Flexing the mesonotum rotates the lateral axillar surfaces anteriorly and dorsally, thereby pulling up on the mesotergal-mesotrochanteral muscles and changing a horizontally directed force into a vertical force that is used to retract the mesotrochanters for jumping. A mesothoracic lock mechanism to prevent initial mesonotal flexing is proposed, but is not documented. “Contortion” of female eupelmines is described, and is a consequence of the increased degree of mesonotal flexing required for their jumping mechanism. The modified mesocoxal articulation of females is hypothesized to function in rotating the middle legs cephalad to protect the head and antennae during landing. It is questioned whether female eupelmines can fly, and the adaptive significance of enhancement of jumping at the expense of flight in females, and of sexual dimorphism in the subfamily, is discussed.

Parasitism by Aphidius smithi reduced the fecundity and population growth of pea aphid, Acyrthosiphon pisum. Aphids that were parasitized during the first or second instar period died as fourth instars without producing offspring. Parasitized third or fourth instars usually reached maturity and produced a variable number of progeny. Parasitized adult aphids stopped producing nymphs approximately 7 to 8 days following attack by A. smithi. Equations are given for the relationship between the mean total fecundity, the intrinsic rate of increase, and the doubling time of apterous and alate viviparous pea aphid and the aphid age at the beginning of parasitism.

The scale insect Toumeyella numismaticum Pettit and McDaniel occurred in small areas of heavy infestation in jack pine, Pinus banksiana Lamb., stands of southeastern Manitoba, where it was present in the same areas every year. The large populations of Formica obscuripes Forel present in the scale-infested areas lessened the effectiveness of the main predator of the scale, the coccinellid Hyperaspis congressis Watson, through interference with the Hyperaspis adults.

Deposits of the nuclear-polyhedrosis virus of Trichoplusia ni (Hübner) and of the granulosis virus of Pieris rapae (Linnaeus) were largely inactivated within 10 days after sprays were applied to field plots. Deposits on plants retained in a growth room or in a greenhouse were inactivated but more slowly than those exposed to direct sunlight. Deposits on plants kept in the dark lost little activity indicating that exposure to light was responsible for inactivation.

Activity of deposits of the viruses was extended substantially by addition of protectant materials to the sprays. The addition of charcoal mixed with skim milk powder, egg albumen, or brewer’s yeast resulted in a 3-fold increase in the period over which an LD50 of virus was maintained on the plants.

In 1958, intensive studies on the population dynamics of the diamondback moth, Plutella maculipennis (Curt.), on cabbage were initiated in long-term study plots at Merivale, Ontario. The object was to construct ecological life tables (Morris and Miller, 1954) for successive generations of the insect, and, ultimately, to develop a mathematical model describing survival of field populations. This paper reports on the variation between samples of immature stages of the moth, and between some of the mortality factors affecting its abundance, and on the use of these data in designing a sampling plan with acceptable limits of precision.

Bees are important within terrestrial ecosystems, providing pollination, which facilitates plant reproduction. Agricultural regions are large landscapes containing varying proportions of cropland, natural, and semi-natural habitats. Most bees are not restricted to any of these and move freely throughout, exploiting food and nesting resources in favourable locations. Many factors affect bee diversity, and knowledge of these is crucial for promoting healthy bee communities. The main objectives of this study were to compare diversity and guild structure of bee communities across a range of land disturbance levels within the Annapolis Valley, Nova Scotia, Canada, in habitats ranging from managed apple orchards to old fields. The two habitat extremes differed significantly; intensely managed orchards had significantly lower species richness (∼50%) than observed/estimated in old fields, but orchards with intermediate levels of adjacent natural/semi-natural habitat showed affinities to either extreme depending on the metrics used for estimating species richness. Species assemblages in orchards had lower proportions of several guilds, particularly cavity-nesters, bumble bees, and cleptoparasites, than other habitats. These guilds accounted for over 30% of bees collected in old fields but only 3–10% in orchards, increasing with habitat complexity. The use of guilds for assessing the health of bee communities is discussed.