Pissodes fiskei, a species described by Hopkins from New Hampshire, is shown to occur also in Maine and in all Canadian provinces between New Brunswick and the interior of British Columbia, inclusive, as well as the Yukon. It is readily distinguished from its closest ally, P. lotundatus Lee, both morphologically and cytologically. Maritime P. nigrae Hopk., montane P. alascensis Hopk., and inland P. rotundatus are conspecific.

The cereal leaf beetle, Oulema melanopus (L.), has rapidly increased its numbers and range since it was discovered in Michigan in 1962. We have shown in this report that intraspecific density-dependent mortality is the major constraint on survivorship. We have attempted to quantify survival within a generation from the egg stage to the adult.Larval mortality varies among populations. Density-dependent mortality, caused by intraspecific competition, accounts for most of the variation of within-generation survival of the cereal leaf beetle in wheat and oats. Mortality in the first instar on oats and the fourth instar on wheat and oats is a linear function of the logarithm of total egg density. Establishment of the first instar on oats appears to become more difficult as density increases because leaf surface disturbance and interference with larger larva increases. Competition for food accounts for the increase in mortality of the fourth instar in both wheat and oats as density increases. Egg survival, survival of the first instar on wheat and in the second, third, and pupal stage in both crops are constants with respect to density. These constants can be expected to change with respect to other environmental parameters however, e.g. host variety, planting date, rainfall, etc.

Comparative tests were made in Oregon and Idaho employing sticky traps with three synthetic pheromones of Dendroctonus pseudotsugae Hopkins, frontalin, 3-methyl-2-cyclohexen-1-one, and trans-verbenol, and the host attractants Douglas-fir resin, alpha-pinene, and camphene. The attractiveness of frontalin combined with host volatiles reported earlier from Idaho was confirmed. The combination of trans-verbenol with frontalin plus camphene in Oregon brought the highest response among synthetic treatments, but the addition of trans-verbenol to other treatments with frontalin sometimes decreased beetle response.3-Methyl-2-cyclohexen-1-one almost nullified the attractiveness of all baits tested. The practical use of such a compound to prevent beetle aggregation and protect susceptible Douglas-fir trees as well as to regulate the "spillover" from attractive baits is considered as a possible new method of protection against bark beetles.

Eight new species of Cicadellidae are described, largely from Manitoban material: Macropsis feminis, M. sauront, M. vinea, Gyponana gracilis, Cicadula junea, Laevicephalus bison, Macrosteles (Sagatus) flavalis, and Paraphlepsius varispinus. The male genitalia of Fitchana twiningi (Uhler) is described for the first time. Colour forms of Macropsis nigricans Van D. and Balclutha punctata (Thunb.) are illustrated.

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.

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.

Five species of Noctuidae are known to occur in the Canadian far north: Anarta richardsoni Curt., Lasiestra leucocycla Staud., Sympistis labradoris Staud., Syngrapha parilis Hbn., and an Apamea species that is probably exulis Duponchel. The larvae of these species are described and illustrated. A key to them has been prepared, although they can be distinguished without difficulty except for some specimens of Anarta richardsoni and Lasiestra leucocycla.

The mechanics of coupling in Melanoplus sanguinipes (Fabr.) are described and differences between some species of Acrididae discussed. A high level of coupling activity was revealed with the most active male and female mating 56 and 46 times, respectively. In addition, multiple daily matings, to a maximum of five, were common. The majority of copulations occurred during the morning in both laboratory and field; however, in the latter, unfavourable weather restricted sexual activity. Coupling did not appear to occur at random; significant preferences were shown by certain males for certain females.

Only two species of bird fleas were known from New Mexico: Ceratophyllus celsus celsus Jordan and C. petrochelidoni Wagner, both from the southeastern part of the state. Four new records of the latter species from northcentral New Mexico are added. An unpublished old record and seven new records of C. niger Fox are presented. Records of three rodent fleas, Catallagia decipiens Rothschild, Monopsyllus wagneri (Baker), and M. eumolpi (Rothschild), found in bird nests also are given.

Releases of chemosterilized stable flies, Stomoxys calcitrans (L.), that equalled existing field populations (1:1 ratio) markedly reduced a field population in Florida. The released insects were relatively long lived in the field and did not migrate far from the nearest source of food and oviposition medium.

The effect of temperature on prepupal diapause development in the hymenopteran Megachile rotundata (F.) was investigated by storing prepupae at various temperatures from −20° to 28 °C prior to final incubation at 28 °C. Preincubation temperatures of 5°, 10°, and 15 °C proved equally effective for diapause development and for the synchronization of adult emergence. Lower temperatures resulted in less synchronous emergence and higher mortality. When prepupae were exposed to more moderate temperature regimes prior to storage at lower temperatures, adult emergence became more synchronized and mortality declined. A high percentage of bees emerged after storage at 20 °C but their emergence was poorly synchronized. Over 50% of the prepupae stored at 28 °C developed without prior treatment at lower temperature but emergence was even less synchronized. The results of these experiments show that all prepupae diapause but the rate of diapause development becomes increasingly variable above and below an optimal range of 5° to 15 °C.

Dactynotus nodulus is described and illustrated and its affinities noted.

Measurements of head capsule lengths and widths show that Tipula paludosa Meig. larvae have four instars. The shape and size of the mandibles and labia are good characters for differentiating the instars.

The diel periodicities of emergence of seven species of chironomids from two ponds in the Hazen Camp area (81°49′ N., 71°18′ W.) are considered in relation to physical factors. Emergence of all species is greatest during the middle part of the day: an increase in water temperature induces emergence and a decrease inhibits it, whereas changes in light intensity, ultraviolet radiation, sunshine, and wind appear to have no effect on the diel emergence pattern. In a shallow pond, males emerge slightly earlier in the day than females in some species. In the same pond also, emergence, particularly of females, is sometimes distinctly bimodal. In a deeper tarn where the diel temperature fluctuation is very small there is a single peak, which is less pronounced than in the shallow pond.That temperature controls the periodicity of emergence implies that short-term temperature changes which may inhibit adult activity are of great importance in the high arctic. At these latitudes, changes in light intensity evidently do not reliably indicate to the emerging organisms temperatures which fluctuate near critical thresholds for activity.

In the laboratory, the mean number of eggs laid per female of the dark-sided cutworm, Euxoa messoria (Harris), fed on honey solution was 1303.8; when given water alone 261.3; and 86.4 when held without food or water. Adult food significantly increased the longevity and oviposition period and reduced the pre-oviposition period. There was no significant difference between the weight of male and female pupae. The weight of the female pupae was significantly correlated with: the oviposition period; the number of eggs laid; the longevity, except moths fed on honey solution; but not the pre-oviposition period, regardless of food taken as adults. Females fed on honey solution mated successfully, 30% of them more than once. When given water or nothing the number of mated females was reduced. Dissections showed that adult food accelerated the development of eggs and increased the fecundity potential.

Performance of the pea aphid, Acyrthosiphon pisum (Harris), on a holidic diet containing different metal ions was studied by individually incorporating into the diet a salt of the metal ion to be tested. The performance of the pea aphid was markedly improved when the diet contained iron; the first-generation adults reproduced, and the second-generation nymphs moulted twice or thrice, but did not reach the adult stage. Molybdenum, boron, and copper, at certain concentrations, induced the production of some live nymphs, but manganese, zinc, calcium, and cobalt did not. However, the presence of zinc, cobalt and calcium, at most of the concentrations used, slightly improved growth and reduced mortality. Furthermore, the presence of calcium appeared essential for development to the adult stage. Tolerance to all these metals was fairly high, but sodium molybdate at a concentration of 50.0 mg, and sodium borate at concentrations of 40–100 mg/100 ml of diet, appeared to reach toxic levels.Iron was found to be essential for reproduction and a range of 53–211 μg of elemental iron per 100 ml of diet appeared to be optimum. It is suggested that a synergistic effect between at least some of these metals is required for continuous reproduction of the pea aphid.

Organophosphorus sprays were applied during 1968 and 1969 to an unsprayed but otherwise well cared for apple orchard to destroy the resident phytoseiid predators, Typhlodromus caudiglans Schuster and T. pyri Scheuten. The phytoseiid commonly found in commercial orchards in British Columbia, T. occidentalis Nesbitt, was then released into the orchard.The population density of T. occidentalis increased greatly during 1970 but in the absence of sprays the resident predators reappeared. By the end of the 1971 season, T. caudiglans and T. pyri were once again the main phytoseiid predators and T. occidentalis was relegated to an insignificant role.