The apple maggot, Rhagoletis pomonella (Walsh), is an indigenous North American insect whose principal native host is hawthome, Crataegus (Bush 1966). During the past ca. 120 years, this insect has expanded its host range to include fruits of the following introduced plants: apple, Malus sp. (Walsh 1867); domestic plum, Prunus sp. (Herrick 1920); sour cherry, Prunus cerasus L. (Shervis et al. 1970); apricot, Prunus armeniaca L. (Lienk 1970); and pear, Pyrus sp. (Prokopy and Bush 1972). Continuous populations have been established on apple and sour cherry, but apparently only occasional infestations occur on plum, apricot, and pear. Here, we report yet another new host of the apple maggot: the introduced rose hip, Rosa rugosa Thunberg

The effects of parasitism by Hyposoter exiguae (Viereck) on certain developmental parameters of Trichoplusia ni (Hübner) were influenced by host age at parasitism.

Head-capsule growth increments for parasitized Trichoplusia ni became smaller with each successive molt during parasitism so that determination of instar on the basis of head-capsule width became impossible.

Parisitized T. ni showed a proportionately smaller gain in weight from time of stinging until parasitoid emergence the older they were when stung (6 times for 3rd instars; 2 times for 4th instars; and no gain for 5th instars). This retardation was evident 24 h after parasitism. Essentially the same results were obtained for dry weight.

Percentage dry weight of parasitized larvae tended to increase over control values until the 5th stadium when controls abruptly increased. Values for parasitized 5ths remained below the controls. Values found on the last days reflected those of the parasitoid which composed most of the mass inside the host cuticle.

Hemolymph specific gravity in controls and parasitized 3rd instars oscillated with a frequency of one stadium in the 3rd, 4th, and early 5th stadia. Specific gravity of controls then rose to a maximum of 1.0501 in the prespinning phase and dropped by the pharate–pupal phase. Values for parasitized larvae in the 5th stadium rose slightly before leveling off, and parasitized 5th instars rose to a maximum on the next-to-last day. Maximum values attained for hosts parasitized as 3rd and 5th instars never reached that for controls on day 11. This may be related to the complete unacceptability or unsuitability of T. ni larvae for parasitism from day 11 on.

Orgilus obscurator (Nees) (Braconidae) and Temelucha interruptor (Grav.) (Ichneumonidae), parasites of the European pine shoot moth, Rhyacionia buoliana (Schiff.), were imported from Europe and released in Waterloo County Reforestation Area, near Elmira, Ontario, from 1955 to 1959.

O. obscurator is the only braconid of known economic importance as a parasite of the shoot moth in Europe (Thorpe, 1930). Recent importations showed that it is also the most abundant parasite of this host throughout Europe.The species was first imported from England in 1928, but was present in Canada earlier (Watson and Arthur, 1959) which suggests an earlier accidental introduction with the host. A total of 8,878 adults were released in Ontario in 1928 to 1949 (Coppel and Arthur, 1954) and 7,912 in 1955 to 1959.

A field study was performed in southern Alberta, Canada, to assess the native wasp, Trichomalopsis sarcophagae (Gahan), as a potential biocontrol agent for house fly, Musca domestica L., and stable fly, Stomoxys calcitrans (L.). The wasp was readily reared in large numbers, which allowed for the cumulative release of an estimated 4.63 million wasps into three commercial feedlots during the 2-year study. Each of several releases predictably and repeatedly enhanced parasitism of sentinel house fly pupae, whereas parasitism remained low in three paired control feedlots where wasps were not released. Releases every 2nd week had a disproportionately greater effect than releases every 2nd month. In 1998, 1.2 million wasps were released into treatment feedlots resulting in the recovery of 3 952 T. sarcophagae from 31 500 sentinel pupae (0.13 wasps/pupa). In 1999, 3.43 million wasps were released into treatment feedlots, with the recovery of 37 763 wasps from 47 720 sentinel pupae (0.79 wasps/pupa). Hence, a 2.8-fold increase in the number of wasps released in 1999 resulted in a 6.1-fold increase in the recovery of wasps. This result supports industry recommendations of regular, repeated releases of wasps every 2nd or 4th week versus one or infrequent releases throughout the summer. There was no evidence that releases augmented overwintering populations of the wasp in subsequent years. These results provide proof-of-concept for the mass-rearing and release of T. sarcophagae as an inundative biocontrol agent for the control of pest flies in cattle confinements. Further studies will be required to assess the effect of T. sarcophagae releases on natural populations of pest flies.

At least four outbreaks of the larch sawfly, Pristiphora erichsonii (Htg.), have occurred in the Maritime Provinces within the past 70 years. The first (1) occurred from about 1883 to 1885, the second from about 1906 to 1909 (1), and the third from 1919 to 1927. The last outbreak started in 1933 and ended in 1942. Despite extensive sampling by the Forest Insect Survey from 1943 to 1953, only six samples have been taken during this period in the three Maritime Provinces, and each was an isolated colony. Although an ecological study of the insect was not attempted during the latest outbreak, general observations were made by thewriter and other staff members of the Survey. These observations are summarized in the present paper to record the outbreak and some of the factors that contributed to its termination. Another outbreak has persisted in Newfoundland from 1942 and perhaps earlier, but the present discussion is largely confined to events in New Brunswick, Nova Scotia, and Prince Edward Island.

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), is the most serious insect pest of dryland wheat (Triticum aestivum L.; Poaceae) in the southern Canadian Prairies and the northern Great Plains of the United States. We characterized the spatial distribution pattern of C. cinctus eggs and larvae throughout the adult flight period in three dryland winter wheat fields in Montana. Cephus cinctus females laid eggs in wheat stems until a few weeks before wheat maturity, and most wheat stems received only one egg. Wheat stem samples collected along the field edges represented 12%–16% of the samples but 40%–95% of the infested stems. The highest numbers of C. cinctus eggs and larvae found in a single wheat stem were 16 and 4, respectively. On a field scale, both C. cinctus eggs and larvae were significantly aggregated along field edges in most of the sampling events. A comparison of indices of aggregation revealed that C. cinctus larvae were significantly more spatially aggregated than C. cinctus eggs. Based on our spatiotemporal analysis, we speculate that the majority of the eggs are initially laid along field edges, and ovipositing C. cinctus females do not distinguish between previously infested and uninfested wheat stems. Gradually, these eggs hatch and the larvae begin feeding; at the same time, the later emerging C. cinctus females oviposit farther into the wheat fields. One explanation is that ovipositing C. cinctus females avoid stems containing feeding larvae. The analysis of the temporal changes in the spatial distribution patterns of C. cinctus eggs and larvae is discussed in the context of possible integrated pest management strategies.

Studies of insect host-parasitoid relationships are often confounded by the difficulties associated with species delimitation in taxonomically challenging groups. Eurytomidae (Hymenoptera) are common parasitoids associated with galls induced by Cynipidae (Hymenoptera) and are difficult to identify due to their small size, morphological conservatism, and unreliable published host records. This study tests the species limits of eurytomids associated with galls induced by Diplolepis Geoffroy (Hymenoptera: Cynipidae) in Canada using an integrative taxonomy approach including adult morphology, the mitochondrial gene cytochrome c oxidase I, host records, and geographical range. Incongruences between morphological and molecular data were found within the Eurytoma discordans Bugbee complex, as Eurytoma discordans, Eurytoma acuta Bugbee, and Eurytoma calcarea Bugbee were shown to be new synonyms. The results also revealed the presence of cryptic species within Eurytoma spongiosa Bugbee. Furthermore, issues that have impeded ecological and biological studies of eurytomids associated with rose galls such as host specificity and sex association were resolved using DNA barcodes, providing new insights into the evolutionary history of this difficult group.

The western Nearctic genera Neothremma and Farula are assigned to the family Uenoidae, previously comprising only the type genus Uenoa from Asia; a new genus Sericostriata with S. surdickae n. sp. from western North America is also added to the family. Traditionally assigned to the Limnephilidae where they have been always anomalous, Neothremma and Farula are shown to share many synapomorphic larval characters with Uenoa; under close examination, characters of the adults support this relationship. Familial and generic diagnoses are provided, reflecting the revised composition of the Uenoidae. Generic keys to adults, larvae, and pupae are given; species are briefly reviewed and keys given to adults; Uenoa arcuata n. sp. is described from Assam, Uenoa janetscheki Botosaneanu is placed as a junior subjective synonym under U. hiberna Kimmins, and Neothremma laloukesi Schmid as a junior subjective synonym of N. alicia Dodds and Hisaw. Phylogenetic relationships among the genera are considered. This study is an instructive example of the importance of larvae in providing data for the systematics of Trichoptera.

The structure of the parameres (lateral lobes) of aleocharine aedeagi was examined in detail, with special attention to the basal lineages. Paramere structure was compared in the context of a hypothesis of phylogeny of the basal lineages of the Aleocharinae and the Tachyporine Group of subfamilies. The ancestor of all contemporary aleocharines had parameres with the following characteristics: dorsobasal and ventrobasal lobes of more similar size than in extant higher aleocharines; dorsobasal lobe (condylite) continuous with distal lobe (not articulated); a striated velum (velar sac), extended from near the base of the dorsobasal lobe to near the apex of the distal lobe and derived from the dorsal surface of the distal lobe; distal arm entire, without articulations or independently movable parts; and four apical setae on the distal lobe, probably with the most apical and basal ones directed mediad and the two medial ones directed more-or-less laterad. In addition, each paramere was articulated with a separate condyle of the median lobe of the aedeagus near the middle of the condylite of the paramere, and the apices of the dorsobasal lobes of the two parameres articulated with each other substantially distal to the articulation with the median lobe of the aedeagus. The most parsimonious resolution of paramere evolution suggests that aleocharine parameres were derived from structures similar to those found in Trichophyinae, Phloeocharinae, and Olisthaerinae and that they are not de novo structures. Hypotheses about homologous regions between aleocharine parameres and those of these latter three groups are suggested.

Field studies of male sex attraction rhythms in Argyrotaenia velutinana and five other lepidopterous species reveal that the diel periodicity was modified by ambient temperature. The temperature near the mean hour of attraction appeared to be the most important environmental parameter correlated to the shift in rhythmicity.

In laboratory experiments adults and nymphs of the western conifer seed bug, Leptoglossus occidentalis Heidemann, were allowed to feed on mature seeds of Douglas-fir, Pseudotsuga menziesii (Mirbel) Franco. Weight-loss measurements and scanning electron microscopy provided strong supporting evidence for the use of simple radiographic diagnosis as a method of classifying feeding damage to seeds into four categories: light (greater than two thirds of seed contents remaining), moderate (one third to two thirds of seed contents remaining), severe (less than one third of seed contents remaining), and extreme (seed empty). Scanning electron micrographs showed the apparent depletion of lipid and protein storage reserves which was verified by quantitative analyses that showed significant loss of lipid and buffer-insoluble (crystalloid) storage protein from seeds in all damage categories. The amount of buffer-soluble (matrix) protein was reduced in seeds from the severe and extreme damage categories. The increase in buffer-soluble protein observed in lightly damaged seeds was likely due to the solubilization of crystalloid storage protein, as a result of its breakdown into smaller peptides. Our results suggest that through the action of both lipases and proteases, L. occidentalis can have a serious impact on the major storage reserves of conifer seeds. Moreover, our data suggest that L. occidentalis feeds in a different manner than the laceration and flushing method found in other seed-feeding Hemiptera.

Insect infestations in farm-stored grain, country elevators, and grain residues or spillages were detected by probes, traps, and scoops. Of 68 storages examined at 50 Saskatchewan farms in 1970, 25 were infested with the rusty grain beetle, Cryptolestes ferrugineus (Stephens). Of 52 storages examined in Saskatchewan in 1971 none of the permanent buildings was infested, but 27%, 30%, and 45% of temporary cribs, open piles, and grain residues, respectively, were infested with rusty grain beetles, fungus beetles, or both. The fungus beetles found most frequently in the traps were Lathridius minutus L. Cryptophagus varus Woodroffe and Coombs, and Cartodere constricta (Gyllenhal). A survey of different grain storages in Manitoba in 1972 showed that 44%, 45%, and 69% of country elevalors, farm granaries, and open piles of grain, respectively, were infested with fungus beetles. None of the storages contained the rusty grain beetle alone but 5% of farm granaries and 31% of open piles examined were infested with both kinds of insects. The least infestation occurred in country elevators and the highest in open piles. In general, the lowest insect infestations were in grain stored in weather-proof buildings, and the highest in exposed grain. Grain in open piles or temporary cribs suffered considerable spoilage. The traps were useful in determining insect distribution and behavior in stored grain.

St. Helen's Island, the site of Trichoptera studies in 1964 and 1965, is described. The Trichoptera encountered are listed, and taxonomic notes given where appropriate. Catches from a light-trap operated nightly in each year provide information for the different species concerning: relative abundance, frequency and seasonal range of occurrence, pest status, and sex ratio. Of the 99 species recorded, eight were classified as pests (causing a nuisance at light), six having this status in both years; together these eight species made up 87.6% of the seasonal total in 1965. Between late May and late September 1965, when large numbers arrived at light (median nightly catch ca. 3 × 103), a nuisance occurred on about one third of nights. Excluding Psychomyia flavida, of which only females were taken at light, most species showed a slight preponderance of males, but sex ratios varied widely according to species, year and night of capture.

An account is given of host acceptance, the influence of temperature on fecundity and longevity, and searching capacity of Chrysocharis laricinellae (Raczeburg), a parasite of the larch casebearer, Coleophora laricella (Hübner).

Fourth-instar case-bearing larvae were the preferred stages for attack. The size of the parasite progeny varied directly with the size of the host. Fecundity of progeny reared from small hosts was significantly less than that of progeny reared from large hosts. Not all parasite adults could successfully oviposit through the tough skin of the host pupa. C. laricinellae showed poor searching capacity. Superparasitism was common at low host densities of the casebearer and resulted in either one parasite emerging or in total parasite mortality. A sex ratio where females predominated resulted when sufficient numbers of preferred stages of the host were presented to mated C. laricinellae. The temperature threshold for attacking hosts was 55°F, and for development of the parasite 40°F. At 50°F the adults lived 4 months on the average.

Therefore C. laricinellae is able to survive in the field without alternate hosts and at very low host densities. The parasite seems to depend on a continuing supply of suitable instars of host species in sufficient numbers to be effective. If C. laricella is the only available host species in the ecosystem the biological control value of this chalcid must be rated as poor.

Species replacement is most commonly observed among the parasitic Hymenoptera because of their dominance in biological control. Such replacement is necessarily a reproduction phenomenon involving interspecific competition in population-saturated areas. The competitive interactions of parasitic populations are differentiated into two types, “intrinsic” and “extrinsic”, with characteristic conditions and mechanisms.

Intrinsic competition consists of interference between individuals of the interacting populations, being manifested by such factors as cannibalism, mutilation, starvation, suffocation, production of toxic or repellent excretions and secretions, and the differential susceptibility of individual hosts to parasitic attack.

Extrinsic competition concerns the interaction of populations as groups and is manifested largely by host-habitat finding, host-finding, and host acceptance.

Replacement through intrinsic competition takes place regardless of host abundance; replacement by extrinsic competition is an effect of decreased host abundance.

Laboratory studies of seven North American Choristoneura species and two subspecies from widely distributed locations demonstrate the low level of genetic separation among them. No differences were found in numbers (n = 30) or morphology of chromosomes among members of the group or in any of the hybrids examined. High levels of mating success were obtained in all inter se matings as well as in crosses and back-crosses. However, mating success was greater for crosses within host type and within pheromone type than for crosses between types. Viability and fertility were similar in all the hybrids and close to those of the inter se progenies. Mean weights of initial eggs varied by a factor of 2 from the lowest (C. pinus Freeman) to the highest (C. lambertiana ponderosana Obraztsov). Mean weights of initial eggs produced by hybrids were generally close to those of the parental species. However, when one parent was C. fumiferana (Clem.), mean weights of initial eggs were either much larger (male C. fumiferana) or much smaller (female C. fumiferana) than either parental type. These differences could affect survival of some progeny under harsh conditions. This evidence supports other studies in indicating that C. fumiferana is genetically distinct from other species in this group.

Three body dimensions (body length, head width, and abdomen width) were used to determine size differences between laboratory-reared and wild populations of Trichogramma minutum Riley. Six separate groups of T. minutum were measured: three groups were from Sitotroga cerealella (Olivier) eggs, two from spruce budworm Choristoneura fumiferana (Clemens) eggs, and one from wild populations of spruce budworm.

Female T. minutum from spruce budworm (large host) eggs were significantly larger for all body dimensions than T. minutum from S. cerealella (small host) eggs. Male T. minutum from field-collected spruce budworm eggs were significantly larger for all body dimensions than T. minutum reared for more than one generation in S. cerealella eggs.

A significant reduction in female parasitoid size was observed during the initial generations of T. minutum reared in the smaller host (S. cerealella). However, this size reduction was not permanent. Following numerous generations in the S. cerealella host eggs, a significant increase in female parasitoid size was noted within the first generation of T. minutum reared in the spruce budworm host eggs.

This paper is intended as an assessment of the state of knowledge and development of semiochemical methods for control of bark beetles (Coleoptera: Curculionidae) in western North America and as a roadmap for future research and development in this field. It is based on a keynote presentation given at the symposium Managing Bark and Ambrosia Beetles with Semiochemicals, held in 2018 in Vancouver, British Columbia, Canada, at the Joint Meeting of the Entomological Society of America, the Entomological Society of Canada, and the Entomological Society of British Columbia. We describe currently available active ingredients, formulations, and release devices. Furthermore, we describe the most urgently needed new products and techniques, and constraints to their further development. Finally, we speculate about opportunities afforded by new advances in microbial synthesis of semiochemicals, streamlining of regulatory processing, and aerial application using unmanned aerial vehicles.

Pupae and 3rd-instar larvae of Pseudaletia unipuncta (Haw.) survived longer at 0 and −2°C than other immature stages, and insects reared at 15°C were more cold tolerant than those reared at 20°C. Egg survival at 0°C varied greatly among replicates suggesting genetic differences among females. No adults survived 2 weeks at 0°C. Peridroma saucia (Hub.) would not rear satisfactorily at 15°C and, other than eggs, all stages tested were from rearings at 20°C. Eggs from adults at 15°C were more cold tolerant than those from adults at 20°C. There were no differences in survival among any of the larval stages or pupae. Some adults survived 6 weeks at 0°C. No stage of either species survived over 8 weeks at 0°C nor 4 weeks at −2°C indicating that overwintering on the Canadian prairies is unlikely.