An investigation of the parasites of the pest species of grasshoppers in Canada is now being carried out as a co-operative project between the Field Crop Investigations Unit of the Division of Entomology and the Parasite Laboratory of the Dominion Department of Agriculture.

Studies on the damage and losses of wheat crop caused by the migratory grasshopper, Melanoplus sanguinipes (Fabr.), were carried out under field conditions during 1972 and 1973. A significant inverse relationship was evident between grasshopper density and grain yield. Loss in yield may occur due to grasshopper infestation in different ways: (1) early hatching of grasshoppers may completely destroy newly-germinated seedlings; (2) a gradual defoliation of the crop throughout the growing season reduces yield and grade of the seed due to reduction of plants’ photosynthetic efficiency; (3) headclipping occurs towards the end of the season when leaves have been completely destroyed. The role of weather factors in shaping the impact of grasshoppers on the crop is discussed.

The following observations and reflections on the primititive composition of the clypeus and labium of insects were made during the course of a study of the head capsule and its appendages, together with their musculature, of Grylloblatta and other orthopteroid forms.

During 1958 a general infestation of Pineus coloradensis (Gillette) was observed on red or Norway pine, Pinus resinosa Ait. This insect is widely distributed throughout western United States where it attacks a number of pines. The Annand collection has a slide with specimens of P. coloradensis (Gillette) taken from red pine on the Universitv of California campus dated February 10, 1925. However, there are few reports of any Pineus species attacking red pine in its natural range from the region of the Great Lakes to the Atlantic coast. Shenefelt and Benjamin (1955) have reported the white pine bark aphid or a closely related form on red pines in Wisconsin. Bean and Godwin (1955) also mentioned the presence of an unidentified species of Pineus on red pine.

Thirty-four species of insects associated with Scolytus multistriatus (Marsham) were reared or collected from several species of elm collected throughout California. Few of these species occurred in large numbers and many of their ecological roles in this subcortical habitat are unknown. Predators were uncommon; only 6 species of parasitic Hymenoptera were reared, 3 of which were not previously known from California. One, Dendrosoter protuberans (Nees), had previously been released for biological control of S. multistriatus only as far west as Colorado. The most abundant insect associate reared from northern California, Cheiropachus quadrum (F.), exhibited a maximum percentage parasitism of 2%. Seven species of mites, including 2 new species, were also collected in association with S. multistriatus.

The aphid Acyrthosiphon svalbardicum Heikinheimo, which is endemic to Svalbard and feeds exclusively on eightpetal mountain-avens, Dryas octopetala L. (Rosaceae), has developed a series of adaptive traits to cope with the harsh conditions of the High Arctic. Prior to this study, only a single specimen of the winged morph of A. svalbardicum had been found, suggesting extremely low dispersal potential. In 2006 we collected many winged females in several places at Kongsfjorden, Spitsbergen. Although winged individuals were generally found in high-density populations, no significant relationship existed between aphid abundance and wing development. We discuss whether this sudden increase in winged-morph production by A. svalbardicum is related to a warmer than usual summer in Svalbard.

The only confirmed host plant of Tingis ampliata H.-S. (Tingidae: Heteroptera) is Canada thistle (Cirsium arvense (L.) Scop.). For this and other reasons, T. ampliata appeared to be a promising biocontrol agent for use in Canada. However, in the laboratory, T. ampliata developed fertile eggs while feeding on the two economic plants globe artichoke (Cynara scolymus L.) and safflower (Carthamus tinctorius L.), and nymphs developed to adults on globe artichoke. Therefore, T. ampliata should not be released in Canada.

Effects of three temperatures and three prey types on the developmental time (egg to adult) of Thanasimus dubius (F.) from two different geographic areas were investigated in the laboratory. The developmental time decreased with increasing temperature. Larval T. dubius exhibited longer developmental times with small prey larvae as compared with larger prey. However, the prepupal and pupal period was shorter for T. dubius fed small prey. Prey type did not affect the overall developmental time. Significant difference in developmental time was observed between the two groups. Elytral lengths of adult T. dubius were indicative of rearing temperatures and prey type consumed by the immature predator.

A comprehensive study of insects affecting the low-bush blueberry in New Rrunswick was begun in 1946 largely because of the destructive outbreak of Actebia fennica (Tausch.) in 1944 and 1945. The work was carried on in Charlotte County, where most of the commercial blueberry areas of the Province are located. This paper deals only with the lepidopterous larvae, among which are found the most important pests, such as climbing cutworms, loopers, and leaf tiers.

The life histories and habits of four curculionids, Hylobius congener, Pissodes affinis, P. approximatus, and Magdalis perforatus, are outlined; and their role in relation to red pine plantations and a serious red pine mortality problem in the Algoma district of Ontario is discussed. A key to the adults is provided and control measures are recommended.

The order of feeding preference on plant parts of rape (Brassica napus L.) by sixth instar (L6) larvae of bertha armyworm, Mamestra configurata Walker, in laboratory tests was leaves, bracts, immature pods, and mature pods. Field sampling showed that upper, immature pods are attacked with greater frequency than lower, more mature pods. In a greenhouse test, a slightly larger proportion of L6 larvae was recorded on inflorescences of rape plants during darkness than during light; the proportion of larvae found on the inflorescences was about 20%. Larvae pupated more quickly, formed heavier pupae, and gained more dry weight when fed exclusively from mid L4 on leaves than when fed mature or immature pods; mortality for larvae fed mature pods was 30% compared with none for larvae fed leaves or immature pods.The finding that pods are neither as preferred nor as adequate a dietary source as leaves is discussed in relation to the phenology of leaf retention of rape on the economic impact of bertha armyworm infestations.

Pityophthorus orarius Bright is a small beetle which mines and kills shoots of Douglas-fir. The adult tunnels into the shoot in early summer and lays its eggs. Tunnelling of the larvae causes twig mortality indicated by characteristic "flagging".

The proportion of fruiting to non-fruiting clusters on apple trees influences the distribution of predators within and between trees. The mirids Atractotomus mali (Meyer), Campylomma verbasci (Meyer), Hyaliodes harti Knight, Diaphnocoris pellucida (Uhler), Pilophorus perplexus Douglas and Scott, and the anthocorid Anthocoris musculus (Say) all showed greater preference for limbs (or trees) bearing a high proportion (or percentage) of fruiting clusters. The predacious mite Anystis agilis Banks exhibited no preference.

In studying populations of wood-boring beetles in dead trees or logs, it is usually the larval form with which the worker must deal. The various species have different habits and although they may be present in very large numbers, some may do no direct damage to the wood. For any estimate of the existing damage-potential, larval identification is therefore an obvious prerequisite. During recent studies of wood-boring beetles in fire-killed pine in northern Ontario, the larva of Acmaeops proteus was by far the most common encountered, but its identity remained uncertain until a programme of rearing larvae from known adults was carried out. The apparent absence of a published larval description of this, one of the most common cerambycids in our eastern coniferous forests, has prompted the preparation of this brief description.

Twelve species are recognized in the abietina group of Pristiphora. A key to species and illustrations of the lancets and penis valves are presented. Only P. erichsonii (Hartig) is holarctic in distribution. P. gerula (Konow) is re-established as a species since it is not a variety of P. saxesenii (Hartig). A new species P. thalenhorsti is described. The name P. takagii is proposed for laricivorus Takagi nee Brischke.

Laboratory tests, at constant temperatures, were conducted to evaluate quantitatively the influence of temperature on development of the Oriental fruit moth, Grapholitha molesta (Busck). The results showed that at the highest temperature (30°C) some larvae had four instars and some had five, indicating a mixed population. Fifth instar larvae developed only at the highest temperature (30°C) where larval development was also most rapid. It can, therefore, be assumed that the Oriental fruit moth has four distinct larval instars when reared in the laboratory at 15°–24 °C.

The balsam woolly aphid, Adelges piceae, has a complex distribution in the crown of trees; The sample universe and sample units are defined, and methods of detecting, monitoring, and measuring population levels at stated levels of confidence, accuracy, and assurance are described. Suggestions are given for sampling aphids on the stems of trees.

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is considered oligophagous on Brassicaceae. We determined the preferences and performance of P. xylostella on canola, Brassica napus L., and flixweed, Descurainia sophia (L.) Webb ex Prantl (Brassicaceae), spider-plant, Cleome hassleriana Chod. (Capparaceae), and garden nasturtium, Tropaeolum majus L. (Tropaeolaceae). Females deposited most eggs on B. napus; T. majus was least preferred. The rate of survival from neonate to pupa was highest on B. napus followed by C. hassleriana, T. majus, and D. sophia. The rate of development of female larvae on Brassicaceae was similar to that on non-Brassicaceae; pupal development was slowest on non-hosts. Female pupae were heaviest on B. napus and lightest on D. sophia. Adult females were heaviest when reared on B. napus and lightest on T. majus and D. sophia. Females reared on D. sophia had the smallest forewings; forewing areas for females on other plants were similar. Females reared on B. napus and C. hassleriana lived longer without food than those reared on D. sophia or T. majus. Males reared on T. majus lived for the shortest time without food. This specialist herbivore can exploit a range of food plants, including suboptimal Brassicaceae and species from other families. This trait appears to facilitate survival and reproduction of P. xylostella when preferred food plants are limiting or absent.

Canada is host to a number of native and introduced forest insects that negatively affect the goods and services provided by forests. Some insects affect forests on a fairly predictable, ongoing basis, while others have impacts that are intermittent, difficult to predict, and sometimes catastrophic. Economic analysis has provided important insights that have informed our understanding of the impact of forest pests and pest management. At the same time, interactions between forests, forest insects, forest management, and economic welfare are complex, and credible assessments may be time consuming and may not always provide results with the certainty sought by policy-makers. This paper reviews the contribution of economics to forest pest management in Canada and suggests future directions for this important field of research.

The parasitic mite Varroa destructor (Mesostigmata: Varroidae) is the main culprit of honey bee (Hymenoptera: Apidae) colony mortality in Ontario, Canada. Most beekeepers use synthetic acaricides to control V. destructor infestations in their colonies, but the use of these products increases the risk of V. destructor developing resistance to the active ingredients, which is a growing concern. This study sought to determine the efficacy of three synthetic acaricides approved for use in Canada for control of V. destructor infestations, amitraz (Apivar™), tau-fluvalinate (Apistan®), and flumethrin (Bayvarol®), using the Pettis test. The mite mortality rate in populations of V. destructor differed for the acaricides tested. Amitraz caused a significantly higher mite mortality rate (92%) than flumethrin (78%) and tau-fluvalinate (72%) did. Amitraz was classified as “mostly effective” (90–97%), whereas flumethrin and tau-fluvalinate were classified as “minimally effective” (< 80%) for V. destructor control in the mite populations studied. Variation in mite mortality due to acaricide exposure was observed between apiaries and regions. The results highlight the importance of periodically assessing the varroacidal activity of acaricides to inform decisions to control the parasite when implementing integrated pest management strategies.