Laboratory investigations were made to determine the persistence of aldicarb and its metabolites in soil (clay loam pH 6.8–7.2) and in water collected from fields. At dose rates of 15 and 20 p.p.m., aldicarb was not detectable in soil after 8 and 12 weeks, respectively. At 50 p.p.m., after 11 weeks chemically detectable amounts of the insecticide were present in the soil.

Soil samples were stored between 23° and 28 °C but temperature at times reached 32 °C.

In field water treated in the laboratory at 100 p.p.m. of aldicarb, the chemical and its metabolites were detectable at 0.4 p.p.m., 11 months later. Water was stored at 16°–20 °C and was exposed for 507.5 hours to sunlight.

Aldicarb was eluted readily with water from soil columns.

When aldicarb was applied as side dressing at the time of planting of sugarbeet roots and potatoes, residues of less than 0.05 p.p.m. were found in soil and potatoes at the time of harvest. One sugarbeet root sample contained 0.2 p.p.m. of the chemical and its metabolites.

Sterility induced by gamma irradiation of the adult male tobacco budworm, Heliothis virescens (F.), was studied in two colonies, one was reared in the laboratory for more than 60 generations (laboratory strain) and the other reared for fewer than 9 generations (wild strain). When irradiated males were crossed with untreated females, the percentage egg hatch for each dose was lower with the laboratory than with the wild strain. When laboratory and wild females were crossed reciprocally with irradiated males, the fertilities were similar to those of the laboratory and wild strains, respectively. When irradiated males were crossed with female progeny from reciprocal crosses, the percentage egg hatch was similar to that of the wild strain.Wild strain females were nearly monogamous for the first several generations, but F0 females mated nearly as frequently as females of the laboratory strain.

The tribe Thoronini Kozlov, 1970 as interpreted here in its broader sense includes also the tribes Pseudanteridini and Tiphodytini as proposed by Kozlov (1970), i.e. the following genera: Thoron Haliday, 1833, Neothoron n. gen., Pseudanteris Fouts, 1927, Thoronella n. gen., Microthoron n. gen., Tanaodytes n. gen., and Tiphodytes Bradley, 1902. The new taxa described are: Neothoron lautus n. gen. and n. sp., Ecuador; Thoronella elegans n. gen. and n. sp., Brazil; Microthoron baeoides n. gen. and n. sp., Malaya; Tanaodytes longipes n. gen. and n. sp., Malaya; Tanaodytes soror n. sp., Ceylon; Tiphodytes godavari n. sp., Nepal; Tiphodytes mymar n. sp., Malaya; Tiphodytes selangor n. sp., Malaya.The genera Thoron, Pseudanteris, and Tiphodytes are recorded for the first time in Canada. The name Calliscelio Ashmead, 1893 is considered a synonym of Calotelea Westwood, 1837 (new synonymy).The species of Thoronini, the biology of which is known, parasitize eggs of water Heteroptera (Gerridae, Nepidae) and it is assumed that most if not all species of this tribe either live in, or are closely associated with, aquatic or semi-aquatic habitats. This is inferred, in the case of species for which definite information is lacking, from the sites in which the adults have been collected, all of which were near water.

The antibiotic effects of foliage extracts of some forest trees on commercial Bacillus thuringiensis (Berliner) var. galleriae were studied with a view to determining whether or not such substances might be inhibitory to development and multiplication of ingested bacteria.

The results indicate that ethyl acetate and petroleum or ethyl ether extracts of the trees tested were particularly inhibitory to the bacteria. Of 24 pure terpenes tested, pinene, pulegone, menthone, 4-terpineol, citral, citronellol, and linalool were highly inhibitory to the production of spores and crystals by the bacteria.

Insects present in western white pine blister rust cankers in northern Idaho were: two weevils, Cylindrocopturus n. sp. and Pissodes sp. near swartzi Hopk.; two bark beetles, Pityophthorus sp. near nitidulus (Mann.), and Procryphalus ? sp.; a drosophilid fly, Paracacoxenus guttatus Hardy and Wheeler; and a phycitid moth, Dioryctria abietivorella (Grote). Mites associated with insect infestation were: Lasioseius ? n. sp., Ameroseius longitrichus Hirschmann, and Histiogaster arborsignis Woodring.

Small numbers (147–388) of Olesicampe benefactor Hinz, a European ichneumonid parasite of the larch sawfly, Pristiphora erichsonii (Htg.), were released in Maine, Nova Scotia, and New Brunswick in 1967. The parasite became established and has survived through two winters at five release points, and three winters on three release sites; on two sites the continued survival of the parasites is unconfirmed because of the collapse of the host population. O. benefactor is known to disperse slowly and even if it is successful in controlling the sawfly in the release areas, control over large areas may require releases at many locations.The subject of the range of host densities at which parasite releases should be made to ensure the greatest parasite production per parasite released, and hence the greatest chance of successful establishment, is discussed.

The annual emergence of 11 chironomid species from more or less shallow ponds in the area of Hazen Camp (81°49′ N., 71°18′ W.) is considered. Features of emergence are very similar in all these arctic species, although different species emerge at slightly different times in the same habitat.In the deeper habitats, emergence from a deep site is slightly later than that from a shallower one in the same pond. There are very marked differences in times of emergence from pond to pond: emergence of 50% of the annual total for a given species may be reached in different ponds up to 3 weeks apart. These differences from habitat to habitat mean that adults are present over the general Hazen area throughout the arctic summer.The time at which emergence begins in a given pond (or given site within a deeper pond) is primarily dictated by the temperature required for pre-emergence development, but also by other features of individual ponds. Pond temperatures near 4° or 5 °C are most important in this respect. The time of first emergence differs between years in the same pond according to year-to-year temperature differences.Emergence of a given species is basically highly synchronized within a pond, but the emergence period may be prolonged by lowered temperatures acting as a threshold for adult emergence at about 7 °C. The emergence pattern is less regular in shallow ponds in which the temperature fluctuates greatly, and it is more regular with lower peaks in deeper ponds.Males of a number of species generally emerge slightly before the females.Emergence of given species within given ponds is synchronized because only larvae which are ready to pupate without further feeding in spring emerge in any year. There must therefore be control of a ’diapause’ type.Aquatic insect species are characterized as ’absolute spring species’ if all potential émergents overwinter as mature larvae (i.e. larvae in which no further growth is necessary before emergence) and also ’diapause’ is present at this stage. To this category all of these high arctic species belong. They are apparently derived from ’absolute spring species’ farther south, the life-cycles of which are pre-adapted to the shortness of the arctic season. Despite the potential for highly synchronized emergence which such species possess, this potential is not fully realized in the arctic because the irregular fluctuations of temperature there operate near values which may directly inhibit development and emergence.

Spruce budworm weights, either of individuals or of population averages, when related to time, provide more precise measures of development than the usually used time from hibernacula to pupation or to eclosion. For determining or predicting the development stage of field populations, average weights are a more precise alternative to time-consuming, instar determinations. Larvae feed only about 10% of the time, in darkness or light, and the pupal dry weight is 20–24% of the dry weight of artificial diet consumed. Growth curves for laboratory individuals and field populations are described.

Sporadic outbreaks of many pine defoliators, including Orgyia hopkinsi Coll., have occurred in many pine plantations in Kenya in the last 20 years. A recent outbreak of O. hopkinsi is reported from young plantations in Turbo. Distribution, hosts, and epidemiology of the insect are discussed. The stages, life history, and habits are described. Eggs are laid on the bark close to pupation sites or on the pupal cases. The larvae feed on the foliage and pupate following the fifth instar. The life cycle lasts 76 to 94 days. Two species of parasites, namely Pimpla mahalensis Grib. and Pimpla sp. (Hymenoptera: Ichneumonidae), have been observed. Other controlling factors are also discussed.

Methyl laurate applied to the surface of house cricket eggs induces a melanization of the extra-embryonic fluid which is due to the oxidation and polymerization of dopamine. Melanization can be delayed or prevented by the addition of 5% vitamin E to the methyl laurate. Methyl laurate appears to activate a phenolase system in the extra-embryonic fluid, and this system or activation of this system is inhibited by vitamin E.

Neosistentes reared from eggs of the final generation of the year only developed under a regime of fluctuating temperature. Progeny of the first generation the following spring developed under both constant and fluctuating temperature. In addition, the latter group displayed developmental variability that might provide a basis from which distinct ecological races could develop. Those individuals that developed rapidly showed little variability in the time required to complete development. On the other hand, those that developed slowly displayed more variability. There was no evidence of two distinct developmental groups among individuals reared under a regime of temperature cycling between 55°F and 75°F as the entire group developed rapidly; this treatment also produced the lowest mortality.

Baeopterogyna nudipes n. gen., n. sp., family Mycetophilidae, tribe Sciophilini, from Yukon Territory and Alaska, is described and illustrated. The male has normal wings; the female has wings greatly reduced in size, a condition not previously known in the family.

The number of predators inhabiting nests of Hyphantria cunea Drury was recorded annually for 13 years in four areas in New Brunswick and two areas on the coast of Nova Scotia. The most common groups were the pentatomids and spiders, which sometimes reproduced within the nests, but the mean number per nest was low in relation to the number of H. cunea larvae in the colonies. The rate of predation on fifth-instar larvae was low. Small or timid predators appeared to prey largely on moribund larvae or small saprophagans during the principal defoliating instars of H. cunea.No relationship could be detected between the number of larvae reaching the fifth instar and the number of predators in the colony; nor could any functional or numerical response of the predators to either the initial number of larvae per colony or the population density of colonies be found. It is concluded that the influence of the nest-inhabiting predators is small and relatively stable, and may be treated as a constant in the development of models to explain the population dynamics of H. cunea.H. cunea is a pest in parts of Europe and Asia, where it has been accidentally introduced from North America. The introduction to other continents of the North American predator, Podisus maculiventiis (Say), is discussed briefly.

Comparatively few laboratory-caged apple maggot flies, Rhagoletis pomonella (Walsh), of either sex arrived at the site of assembly for mating (ceresin wax oviposition domes) and no mating pair or ovipositing females were observed until the flies were 7–8 days old. From then on, the level of all three of these activities progressively increased.With respect to the time of day of activity, in the field, assembly of both sexes of flies on the fruit, mating, and oviposition all occurred predominantly during the afternoon on a day when the sun shone brightly throughout the 15-hr daylight period and the ambient temperature was 16 °C at dawn, 24.8° in mid-afternoon, and 17.5° at dusk. Little or no activities of these sorts occurred before mid-morning and toward dusk. In the laboratory, where light intensity was constant at 1000 lux during the 15-hr photophase, the temporal pattern of these activities was the same as in the field when laboratory temperature was programmed to be the same as in the field for the corresponding hour of daylight. However, when laboratory temperature was programmed to be constant at 24.8°, these activities occurred at a high rate throughout the photophase. None of these activities was observed to have been initiated in darkness. It is concluded that sexually mature apple maggot flies may assemble on the fruit, mate, and oviposit whenever temperature is favorable and light intensity is sufficient to permit adequate vision.

When fatty acid methyl esters or vitamin E are painted on the surface of eggs of the house cricket, Acheta domesticus (L.), second-stage larvae originating from these eggs may show reduction of the tarsi. The effect of the chemicals is on the first-stage larvae which absorb the chemicals through the tarsi during escape from the shell. The reduced tarsi are regenerated at the next moult or next two moults.

The spider fauna of three hayfields and their margins in Nova Scotia was sampled by means of pitfall traps from May to October, 1960. Eleven families were represented and comprised 35 genera and 55 species. Specimens of the genus Pardosa were trapped in greatest numbers.

Fourteen coniferous feeding species of Argyresthia in Canada are dealt with. The following seven species are described as new: canadensis n. sp., Quebec; mariana n. sp., Ontario; columbia n. sp., British Columbia; picea n. sp., Ontario, Quebec, Yukon Territory; abies, n. sp., Ontario; tsuga n. sp., British Columbia; pseudotsuga n. sp., British Columbia. Two species, confused under the name freyella Walsingham, are distinguished. A key is given to the species.

Culiseta minnesotae Barr and Aedes trivittatus (Coquillett) are reported from Manitoba for the first time. A list of mosquitoes previously recorded from Manitoba is given.

The taxonomic concepts of the Ips species of groups IV and X were tested by controlled breeding, bioassay of sex pheromone specificity, and examination of morphological and karyological details. No changes were made in the status of Ips pini, I. bonanseai, and I. avulsus of group IV. I. interstitialis of group X is removed from synonymy with I. calligraphus, and I. ponderosae, also previously considered a synonym of I. calligraphus, is assigned subspecific rank. Assertions of close phylogenetic relationship of the Eurasian I. duplicatus and I. sexdentatus with groups IV and X, respectively, are rejected.I. pini from widely separated localities were interfertile although egg hatchability was subnormal in some crosses involving F1 from matings of beetles from western and eastern North America. I. pini and I. bonanseai readily mated but less than 3% of the eggs hatched and the larvae died. There was no evidence of breeding incompatibility in crosses of I. c. calligraphus from Florida and California or I. c. ponderosae from New Mexico and South Dakota. However, hatchability differed drastically between reciprocal pairings of the I. calligraphus subspecies, possibly as a result of cytoplasmic incompatibility. All eggs produced in pairings of I. interstitialis with either of the I. calligraphus subspecies failed to hatch.First meiotic metaphase of I. pini, I. bonanseai, and both I. calligraphus subspecies invariably showed the formula 15AA + Xyp. This karyotypic formula also applied to I. avulsus except for a few individuals that had 2 small supernumerary chromosomes. The karyotype of I. interstitialis was not determined. Heteromorphic bivalents and univalents were detected in hybrids of the I. calligraphus subspecies.Cross attractiveness to sex pheromones was demonstrated for I. pini from different regions, for I. pini and I. bonanseai, and for the I. calligraphus subspecies. When samples of attractive frass from eastern and western I. pini males were presented simultaneously, eastern females responded equally to both samples but western females favored western frass by a margin of 2 to 1. Similarly, I. c. calligraphus clearly discriminated in favor of consubspecific pheromone while I. c. ponderosae did not.The locality of several of Eichhoff’s holotypes is noted.

Stridulatory structures of the flight wings and elytra, and a dorsal chamber in the thoracic abdominal junction of C. traquebarica Herbst are described. The functions of these structures are considered. A list is provided of 62 species of tiger beetles and 13 species of ground beetles which have stridulatory files on the flight wings.