Defoliation by the birch casebearer, Coleophora fuscedinella Zeller, the most important pest of white birch, Betula papyrifera Marsh., in Newfoundland, is correlated with leaf size but the differences in defoliation associated with leaf size are too small to be of practical importance. Thus, a sample of at least eight leaves from either the top crown quarter or from mid crown will give consistent estimates of tree defoliation, and 14 trees should be sampled to classify a stand for appraisal surveys or for evaluation of damage to scenic areas. Evaluation of stand defoliation in three broad classes is recommended: up to 30% defoliation appears as light browning not noticed by the general public, 30% to 90% results in distinct browning, and over 90% defoliation denotes intensive browning and bud and branch mortality.

Concentrations of the insecticide fenitrothion in water varied greatly among streams, depending upon spray history and weather. Sprays at 3 oz/ac (210 g/ha) resulted in measurable concentrations in streams as far as 2.5 mi (4 km) from the sprayed area. Concentrations (usually < 15 ppb) diminished quickly in fast flowing streams, and still faster when a spate followed spray application.

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.

The larva, adult female, and adult male of Chrysomelobia labidomerae n. sp. are described. The adult female is compared with that of the only other described species in the genus, C. mahunkai from Europe. Chrysomelobia labidomerae is a parasite of adult milkweed leaf beetles, Labidomera clivicollis (Coleoptera: Chrysomelidae), in North America. Morphological similarities of all stages of Chrysomelobia with those of the generalized podapolipid Dorsipes support the retention of Chrysomelobia in the Podapolipidae as a most primitive genus in that family and the only one with 4 pairs of legs in the adult female.

Ooencyrtus ennomophagus n. sp., an egg parasite of the elm spanworm, Ennomos subsignarius (Hübner), from Connecticut, U.S.A., is described and illustrated.

Kills of arthropods in three streams containing fenitrothion up to 6.38 ppb were measured using drift nets. Stoneflies and some species of mayflies were most affected. The drift responses of various taxa to the insecticide and to stream discharge are documented. The benthos was not seriously depleted.

The cherry scallop shell moth, Hydria prunivorata (Ferguson), is a colonial feeder on black cherry, Prunus serotina Ehrh. Pupae overwinter in the litter and adult emergence occurs from May through September. Eggs are laid on the foliage in pyramidal-shaped masses 23–26 days after adult emergence. Eggs begin to hatch 4 days following oviposition and each of the four larval stages lasts 4–6 days. There is one generation per year in New York. The egg parasite Telenomus sp. is the principal mortality factor occurring in populations that have remained at outbreak levels for 2 or more years. The life stages of H. prunivorata are described and control recommendations discussed. The peach bark beetle, Phloeotribus liminaris (Harris), may kill black cherry trees that are stressed by heavy defoliation.

Adult females of Chrysomelobia labidomerae Eickwort lay eggs on the upper surfaces of the hind wings of Labidomera clivicollis (Kirby). The eggs hatch in approximately 7 days and male and female larvae feed at the base of the wings and in the meso–metathoracic crevice and swell to about twice their original length. For about the second half of the approximately 7-day larval stadium, the larvae are inactive (pharate adults) and are usually cemented to the undersurfaces of the elytra. Inactive female larvae are accompanied by adult males that apparently copulate with the newly emerged adult females. The pharate adult is enclosed in a cuticular sac that may represent a calyptostatic nymphal instar. Adult females feed on the beetle’s abdominal terga and sometimes also occur on its venter where they do not feed. Females disperse from host to host when the beetles copulate. The species is arrhenotokous. Mites overwinter on the diapausing adult beetles and do not infest the immature stages of their host. Even at high population levels, the mites do not noticeably affect the longevity or fecundity of their hosts.

Two-sample and four-sample methods of assessing insecticidal control efficacy are explored. Respective indices of survival and mortality including methods of constructing confidence intervals and minimizing bias are discussed. Procedures for determining the number of samples required for specified statistical limits are presented

Five new species of western Rhyacophila, leechi, siskiyou, lurella, arcella, and tehama, are described; siskiyou is remarkably different from other described species. The vedra complex, comprising five species, is discussed with descriptions of two new species.

Two Old World limnephilid genera are recorded from North America for the first time: Chilostigma with C. itascae n. sp; and Ecclisocosmoecus to which is transferred the former Ecclisomyia scylla Milne. Three new species are also described in other genera: Dicosmoecus schmidi n. sp., Cryptochia denningi n. sp., and Neothremma andersoni n. sp. The taxonomic status of the genus Psychoronia is reviewed.

The immature stages of Euxoa basalis (Grote) are described and illustrated. Both the egg and pupa are similar to those of other Euxoa species and are virtually indistinguishable from some of them. The larva although morphologically quite similar to other Euxoa larvae is distinctive in coloration, particularly in the penultimate and ultimate stadia. Each of the larval instars is described; the ultimate instar in detail, the others briefly. A redescription of the adult is also given.

Well-fed, mated female spruce budworm (Choristoneura fumiferana (Clem.)) show little activity during the first 24 h after emergence. During the second 24 h they lay between 33 and 50% of their egg complement. During the third 24 h most flight activity occurs. Smaller, artificially starved females are much more active, especially during the second 24-h period, when many fly before ovipositing. Timing of oviposition and flight is under photoperiodic control: female flight occurs just before dark after peak oviposition while male activity starts before dark, but peaks after dark, with a morning peak of variable intensity.

Until mid- or late July, most larvae of the wheat stem sawfly generally move into the upper internodes of the host stems. Then, as the stems mature, the larvae migrate down to the basal internodes and cut the stems at about ground level.

The migration is initiated in response to the visible and infrared light transmitted through the ripening stems. The direction of the migration, toward the basal internodes, results from the orientation of the larvae to the vertical axis of the stems reinforced by a positive larval response to gravity.

The larvae cut the stems at ground level because they are shielded there by the soil from visible and infrared radiation. The location of cutting is also influenced by the preference of the larvae for drier sites in which to cut.

The date of cutting is directly related to the loss of moisture from the stems, but not to a precise level of stem moisture. The larvae may form their cocoons in response to desiccation.

Four insecticides, carbofuran, chlorpyrifos, methidathion, and dimethoate, were tested against grasshoppers in laboratory and field experiments. Carbofuran was the most effective compound in all tests but it was concluded that, over-all, it would be difficult to predict field performance on the basis of laboratory data alone.

Adult emergence of Simulium verecundum was reduced 75 to 100% by 0 001 to 0.1 ppm Altosid SR–10 at 25 ± 3 °C and 10 °C. No reduction in adult emergence was observed with 0.0001 ppm Altosid SR–10. 0.1 ppm of the granular R–20458 4–G reduced adult emergence 56 to 98% whereas 0.02 ppm was not effective. Exposure of black fly larvae to 0.1 ppm R–20458 4–G for 24 h gave a maximum of 50% reduction in adult emergence of those flies which had not pupated during the 24-h period.

An outbreak of the forest tent caterpillar began in northern Minnesota in 1964 and ended abruptly in 1972. During 1968–71 when egg densities ranged from 1 to 9 million per acre, caterpillars caused virtually complete tree defoliation in all study plots. As a result, tree stem densities and basal areas were reduced per plot by 41 and 27%, respectively. Tree mortality was more severe on plots having higher water tables. Graphical and components of variance analyses both showed that: (1) variations in annual egg densities were due mostly to variations in survival during the egg to 30-day larval stage (SI) and secondly to variations in survival during the 30-day larval to adult stage (S2), (2) S2 tended to change in the opposite direction from S1, (3) the net result was a tendency to produce a constant amount of eggs per unit area. Variations in S1 were due primarily to pharate larval mortality and mortality of larvae 2–3 weeks after hatch while variations in S2 were due mainly to unmeasured mortality factors such as starvation, disease, dispersal, etc. Survival during the egg stage (SE) and fecundity (F) varied significantly by years, but not by plots and both were apparently related to weather conditions. Plots of two simultaneous equations were presented to demonstrate the nature of population change in relation to the densities of eggs and 30-day larvae per acre.

The shape of one single category of hemocytes served as a critically distinguishing character between larvae of two closely related species of Euxoa (Lepidoptera: Noctuidae) that were otherwise practically identical in external features. The ratio of length/width of fusiform plasmatocytes in heat-fixed blood films was significantly smaller in larvae of E. campestris (Grote) than in E. declarata (Walker).

Soluble extract of Macrosiphum euphorbiae (Thomas) was separated electrophoretically into fast moving and slow moving protein bands These bands were fractionated and studied for their amino acid content. Glycine was the most prominent amino acid in both bands. Aspartic acid, serine, glutamic acid, alanine, and leucine were present in high concentrations in the fast moving protein band. Lysine, alanine, valine, tyrosine, and phenylalanine were present in traces in the slow moving protein band.

By beating foliage with a stick, insects inhabiting the foliage can be dislodged onto a sheet held beneath it. In an attempt to develop this as a quantitative method for sampling lepidopterous defoliators feeding on exotic conifers in New Zealand, the size of the sheet and method of beating were standardized. Analysis of samples made over a period of 2 years revealed that differences between individual collectors were minimal, and that although very similar proportions of larvae were captured on the three areas of sheet used, the middle size gave the optimum balance between precision and cost of sampling. It also showed that as the number of larvae captured increased, the number of samples could be decreased in a semi-sequential manner.