In Neodiprion sertifer (Geoff.), mortality is greater in males than in females in the egg stage and probably also among early larvae, but in the late larval period females are more susceptible. The evidence consists of the difference in mortality between all-male and mixed (male + female) colonies, as well as the relationship of secondary sex ratio to preceding mortality and the number of survivors per colony. The effect of differential mortality on estimation of the primary sex ratio is discussed.

Overwintering adults of the social wasp Polistes fuscatus (Fabricius) were collected in the early spring and placed in nest boxes under controlled conditions. Colonies were initiated, and one-, two-, and three-foundress associations were formed. Successful single-foundress colonies were similar to successful multiple-foundress colonies in developmental time for immatures, nest size, and total production of offspring. Multiple-foundress colonies were more likely to produce offspring than were single-foundress colonies. Half of the foundress wasps failed to reproduce, either because the colony failed or because they were non-reproductive subordinates. Apparently, wasps that were likely to fail at reproduction tended to join colonies rather than to initiate colonies. The relevance of this data to hypotheses on the selective advantage of foundress associations is discussed.

The course of the host–parasite relationship between Pollenia rudis (Fabr.) and Eisenia rosea (Sav.) is determined largely by the behaviour of the earthworm host, which in turn depends on soil conditions. Encystment of the host, which occurs mainly at low levels of soil moisture and bulk density, increases the success rate of the infection. Autotomy of infected segments by the host occurs in a higher percentage of active than encysted worms.

The following new pyralid taxa are described: Nehydriris excellens n. gen. and sp. (Pyraustinae), Brazil; Udea tenoalis n. sp. (Pyraustinae), Chile; Synclitodes decoripennis n. gen. and sp. (Nymphulinae), Bolivia and Brazil; Proschoenobius forsteri n. gen. and sp. (Schoenobiinae), Bolivia.

Two new species of aphids are described, Pleotrichophorus villosae new species from Chrysopsis villosa (Pursh) Nutt. in Manitoba, and Chaitophorus longiunguis new species from Salix sp. in Utah.

The following new Pyraustinae are described: Goliathodes n. gen., type-species G. shafferi n. sp., New Guinea and Waigeu; Spoladea mimetica n. sp., New Guinea; Meekiaria n. gen., type-species M. lignea n. sp., New Guinea; Aiyura n. gen., type-species A. linoptera n. sp., New Guinea.

Six brands of commercial dichlorvos-vaporizing solids were tested individually in a 28.3 m3 test chamber simulating home conditions to evaluate their effective life. The dichlorvos vapor concentrations developed and maintained by the vaporizers in the chamber, varied from ca. 0.5 μg to 0.005 μg/liter during approximately a 2-month test period depending on the brand and ventilation of the test chamber. Any increase in ventilation correspondingly decreased the level of dichlorvos vapor concentration and vice versa. The vaporizing samples became depleted rapidly at higher than at lower rate of air exchange. At either rate of ventilation (1/3 or 1 air change/h) some of the samples, depending on their potentiality, were completely depleted whereas others produced very low concentrations during the 2-month exposure.

A 70–90 min exposure to a dichlorvos vapor concentration of ca. 0.1 μg/liter gave almost 100% mortality of susceptible and 85% of DDT-resistant caged female house fly, Musca domestica L. However, a similar exposure killed only 16% of the field-collected female house flies. When exposed, as free flying, to a similar concentration it took only 45 and 85 min to cause 95% kill of the susceptible and 85% kill of DDT-resistant house flies respectively. However, a 61/2 h exposure of field house flies to a similar concentration killed only 35.5% of them.

A dichlorvos concentration of ca. 0.1 μg/liter gave 100% kill of Tineola bisselliella (Hummel) larvae and Blattella germanica L. male adults in 6 and 3 days respectively, and of Aedes attopalpus Coquillett adults in a 30-min exposure. However, only 19% kill of Attagenus megatoma (F.) larvae occurred in 7 days with a similar concentration.

Trypsin has been partially purified from the midguts of Glossina morsitans. It is inactivated by tosyl-l-lysine chloromethyl ketone, phenylmethane sulfonylfluoride, and 2-mercaptoethanol. Mammalian sera inhibit G. morsitans trypsin in vitro. Sheep serum contains at least two inhibitors of G. morsitans trypsin and a high molecular weight material which protects against serum inhibition. Very low levels of trypsin inhibitor are found in G. morsitans primary excreta and in the salivary glands, Malpighian tubules, and anterior midguts of unfed flies. High concentrations of trypsin inhibitor are found in the anterior (non-digestive) section of the midgut for at least 48 h after flies fed on goats.

Four species of Lizerius Blanchard, L. cermelii, L. intermedius, L. costai and L. brasiliensis, from South America and four species of Paoliella Theobald, P. reticulosiphon and P. melanocallis from South America, and P. pteleopsidis and P. longirostris from Africa, are described as new. Redescriptions of L. tuberculatus (Blanchard) and P. kenyensis (Eastop) are also given, with keys for the species of Lizerius and Paoliella. Neolizerius is made a synonym of Lizerius. A new subgenus Paralizerius is established. Adhesive vesicles are reported for the two South American Paoliella species. The phylogenetic relationships of the Lizerini are discussed. It is concluded that this tribe branched off from Mindarus–Neophyllaphis-like aphids and that the Schoutedeniini evolved from ancestors that were related to the Lizerini.

Twice as many larvae of the dark-sided cutworm, Euxoa messoria Harr., were found in rye fall-seeded tobacco field plots than in winter-fallowed tobacco field plots. There were corresponding differences in numbers of injured tobacco plants. Cutworm aggregations were more prominent in the winter rye than in the winter fallowed area of the tobacco field with low populations of dark-sided cutworms.

Larvae of the variegated cutworm, Peridroma saucia Hbn., appeared 2 to 4 weeks later than dark-sided cutworm larvae and winter cultural methods had little effect on their numbers.

Eggs, larvae, and pupae of Culex tarsalis Coquillett were treated with ecdysones, juvenile hormone analogs, and 6-oxooctanoic acid. Effects of these agents on mortality, induction of supernumerary stages, and adult emergence were determined. Topical treatment of eggs with CRD9499 (a juvenile hormone analog), β-ecdysone, and 22-isoecdysone caused a reduction in adult emergence. Treatment of fourth-instar larvae with these chemicals not only induced mortality but also caused the formation of supernumerary intermediate stages. Larvae of C. tarsalis were very susceptible to CRD9499, but pupae were resistant. The ecdysones caused some mortality but only at very high doses and would thus be of little use as larvicides. 6-Oxooctanoic acid caused high rates of mortality at 0.001 M concentrations.

When trichloronat or fensulfothion was applied to the soil surface, the toxicity of both compounds to first stage root maggot larvae increased during the first few days, then decreased at a constant and relatively rapid rate. When trichloronat was mixed with the top 1 in. of soil, its toxicity or that of its metabolites increased for about 3 months, then gradually decreased. When it was applied in a band below the surface, its persistence increased with the depth of application. When fensulfothion was applied in the same manner, its toxicity was not greatly influenced by the method of application; this decreased during the first 4 or 5 days, rose to a peak in 15 to 30 days, then gradually decreased. Fensulfothion was highly systemic in rutabagas. Its toxicants were most bioactive 60 to 80 days after application and decreased gradually thereafter. Trichloronat toxicants were slowly absorbed by the roots but toxic residues did not degrade in storage.

When Hypera postica (Gyll.) was held at 11 constant temperatures, the hatching rate for eggs increased with rise in temperature from 8° to 20 °C and remained maximal to 32 °C. None hatched at 6 °C. Larvae survived at 10° to 35 °C with high mortality only at these limits. Pupae survived at all temperatures above 10 °C but at 35 °C half of the adults were deformed. Duration of all stages decreased with rise in temperature up to 32 °C. Developmental rates plotted against temperature did not deviate significantly from fitted curves of the form 1/y = K/(1 + ea−bx).

The optimum temperature, based on maximal rates of development and survival, for eggs and young larvae was near 32 °C and for older larvae and pupae, 30 °C. Accumulated degree-days above a base of 10 °C during development of H. postica at two Ontario locations did not differ significantly from thermal requirements calculated.