Chemical studies utilizing colour tests, gas chromatographic and mass spectrometric analysis have shown that hydrogen cyanide and benzaldehyde are constituents of the defensive secretion of the polydesmoid millipede Apheloria coriacea (Koch).

The effects of various levels of infestation of the corn leaf aphid, Rhopalosiphum maidis (Fitch), on yield of field corn were examined from 1965 to 1970 inclusive when all plants whose yield might have been influenced by factors other than aphid feeding were excluded from the data. A possible relationship between moisture stress in plants and degree of aphid injury was also investigated.

A light infestation (maximum of 400 aphids on the tassel) caused average yield reductions up to 8.3% when plants were under moisture stress, but nil to negligible losses when moisture was adequate. Moderate infestations (many hundreds of aphids on part of the tassel) produced average losses up to 34.8% under drought conditions and up to 11.8% when moisture was abundant. Severe infestations (many hundreds of aphids on most of the tassel) caused average yield reductions ranging from 43.2 to 91.8% when plants were under water stress and up to 58.9% even with abundant moisture. Very severely infested plants (many hundreds on all of the tassel and whorl leaves) were usually barren or had ears with just a few kernels regardless of moisture conditions.

Most injury from aphid feeding appeared to occur before and during pollination. No particular combination of temperature and rainfall favored aphid buildup.

The life history and habits of Zeiraphera improbana (Walker) on tamarack, Larix laricina (Du Roi) K. Koch, are outlined and the immature stages are described. One braconid, one ichneumonid, and three chalcid parasites are listed.

A device designed to measure amount of pesticide solutions consumed by three species of bees (Megachile rotundata (F.), alfalfa leafcutting bee; Nomia melanderi Cockerell, alkali bee; and Apis mellifera L, honey bee) is described in detail. Isolated bees fed freely from capillary tubes filled with known mixtures of pesticides and honey solutions. The change in volume of solution was used in determining the exact amount of pesticide consumed by each individual.

The frequency of insemination of females in laboratory swarms of Chironomus riparius Meigen was investigated using autoradiographic techniques. In swarms in which the sexes were nearly equally represented the majority of females were invariably inseminated. The frequency of inseminations for a given population of males declined with aging. There was variation among individual males in the numbers of females inseminated and the timing of inseminations in a succession of eocrepuscular swarms. Unmated females appeared to be receptive to insemination throughout most of their adult life. Insemination or injection of extracts of males rendered the females unreceptive to subsequent inseminations. Unmated females held in cages for longer than 48 hr were found to resorb the eggs in one of their ovaries.

Induction of supernumerary larval instars in the spruce budworm, Choristoneura fumiferana Clemens, by applying ZR-515, a potent juvenile hormone analogue, is explained in terms of larval differentiation. Application to the early sixth instar where structures are relatively indeterminate results in the formation of a supernumerary larval instar, whereas treatment of the late-larva wherein many structures are committed to differentiate towards the pupa, results in a larval–pupal mosaic.

A study was conducted to determine the effectiveness of a novel insect growth regulator (IGR) with juvenile hormone activity. Tests show the third instar to be the stage most sensitive to the regulator based on reduction of fecundity throughout inhibition of normal adult development. Effective control in most stages was for the first time brought about within the realm of economic feasibility. The IGR could be of value in future control of aphid populations.

Twenty species of ground beetles (Family Carabidae) and one species of carrion beetle (Family Silphidae) were collected in six stations east of a kraft paper mill in Thunder Bay, Ontario, from May to August, 1971. The beetle population decreased markedly towards the mill. There was no apparent statistical difference in size variation of specimens near the mill and those further away.

Populations of Monochamus scutellatus (Say) were found to differ morphologically from populations of M. oregonensis LeConte in color of femora, mouthparts, and antennae; elytral rugosity and shape of scutellum. The genitalia of the two entities differed slightly in the female. Alberta populations of both entities hybridized freely in the laboratory, producing a fertile F1 generation, which was successfully crossed with each parental species. Because of the lack of reproductive isolation between the allopatric entities, M. oregonensis is synonymized under M. scutellatus, but given subspecies status because of the morphological differences. Diagnostic characters of each subspecies are given.

A biological study of Telenomus coelodasidis Ashm. revealed a close temporal synchronization between this egg parasitoid and its primary host, Heterocampa guttivitta (Wlkr.). The wasp reproduced parthenogenetically in the laboratory and completed development in unfertilized host eggs. Wasp activity was greatest at relatively low temperatures, and longevity was significantly greater when individuals were provided with food. The second and third stage larvae and the pupa are described, as well as the sequence of visible changes occurring in parasitized host eggs. The egg stage of H. guttivitia should be sampled about 5–7 days after peak oviposition by the host, and eggs held for 4–6 days to obtain an accurate estimate of apparent mortality.

A new beech-inhabiting aphid, Phyllaphis grandifoliae, is described from Ontario. Its relationships to other species are noted. A key to species of Phyllaphis is given.

Insects cause considerable loss of seed in white spruce, Picea glauca (Moench) Voss, and Engelmann spruce, P. engelmannii Parry, in British Columbia. The most important species are a maggot, Hylemya anthracina (Cz.), and a seed moth, Laspeyresia youngana (Kit.). Other insects are: a seed chalcid, Megastigmus piceae Roh., a cone axis midge, Dasineura rachiphaga Tripp, a gall midge, D. canadensis Felt, a seed midge, Mayetiola carpophaga Tripp, and a scale-feeding midge. These insects also occur in cones of Sitka spruce, P. sitchensis (Bong.) Carr., and black spruce, P. mariana (Mill.) BSP.

The systemic insecticides dimethoate and formothion proved to be effective against these insects when applied as sprays following pollination in mid-June.

The species of the genus Tachinomorphus (Staphylinidae: Tachyporinae) of North and Central America are revised. Five species are recognized as valid. Two species are described as new: arizonensis from the Huachuca and Chiricahua Mountains of Arizona and Durango in Mexico and sharpi from Texas and northern Mexico. Tachinomorphus remotus (Sharp) is placed in synonymy with grossulus (Leconte). Lectotypes are designated for grossulus (Leconte), remotus (Sharp), and major (Sharp). The distribution of each species is mapped and all major diagnostic characters illustrated either with line drawings or scanning electron photomicrographs. The habitat, if known, is discussed for each species. A key is included as an aid to distinguishing the species.

Laboratory assay showed Beauveria bassiana (Bals.) Vuill. to be present in approximately 15% of the combined populations of forest collected living Hylobius pales and Pachylobius picivorus.

Semium villosum n. sp. is described from Mexico. S. hirtum Reuter is known to occur in Canada and Mexico. The 4 known species are keyed and illustrated.

The life history of Epinotia aceriella (Clemens) is discussed and the life stages described. Information is presented on feeding behavior, distribution, hosts, and natural enemies. Control recommendations are made.

Egg masses of the forest tent caterpillar, Malacosoma disstria Hübner, were collected from new and old infestation areas of northern Minnesota before development started in the spring. Mortality of embryos was recorded after laboratory exposure to −10°, −15°, −20°, −25°, and −30° C for 12, 24, and 72 hours at 1, 2, 3, and 4 days before anticipated hatch. Length of treatment and temperatures of −10° and −15°C had minimal effect on survival. Mortality of embryos varied with days before hatch in an erratic cyclic pattern with temperatures and years. Temperature treatments of −20°, −25°, and −30 °C caused about 50%, 66%, and 100% embryo mortality. Mortality in new infestation areas was consistently higher than in older areas for all treatments.

Black-horned tree crickets (Oecanthus nigricornis F. Walker) were reared from rows of eggs laid in the twigs of recently planted peach trees in Essex County, Ontario. Eggs were laid in September and hatched the following June. Egg laying injury was most frequent at the edges of peach blocks. The injuries did not become infection sites for peach canker fungi (Cytospora cincta Sacc. and C. leucostoma Sacc). Twenty-one per cent of the twigs died above the injury and eggs then hatched, but if the injuries healed and the twigs survived, very few eggs hatched.

The dark-sided cutworm, Euxoa messoria (Harris), has a North American distribution and is commonly found in tobacco fields in Ontario. It has one generation a year, and overwinters as an egg in the soil. Hatching takes place in early April and the young larvae feed on the rye rotation crop; later they attack newly transplanted tobacco seedlings. Head width measurements of larvae collected from the field show seven instars, but individual rearing data of E. messoria larvae reveal that small numbers pass through six and an occasional larva passes through eight; however, the eighth instar has the same head width as the seventh. Pupation occurs from late July to mid-August in the soil. The adult emerges from mid-August to October, and oviposition occurs in this same period. Eggs are completely developed before winter. Behaviour and duration of the different stages are described. Natural mortality factors of the species are given.

Six species of small crickets of the subfamily Nemobiinae are found in Canada. These are Allonemobius fasciatus (DeGeer), A. allardi (Alexander & Thomas), A. g. griseus (E. M. Walker), A. maculatus (Blatchley), Neonemobius palustris (Blatchley), and Eunemobius c. carolinus (Scudder). Synonymy is given and all distinctive taxonomic characters such as hind tibiae, concealed male genitalia, female ovipositors, male stridulatory veins, and audiospectrograms of stridulation are described and illustrated. A key to species is given and distribution maps are included.