Nepytia freemani Munroe reached outbreak proportions in one area in north central Utah in 1965 and subsided in early 1967. The looper has a 1-year life cycle and overwinters in the egg stage. Larvae issue from eggs in mid-May, feed during the summer months, and begin pupation in late July. Adults appear in August and females lay clusters of small oval eggs on both sides of the needle. White fir is the preferred host but Douglas-fir is also fed on. Even though defoliation was extremely heavy, topkill was the only permanent damage. Starved larvae fed on ground vegetation in the understory. Parasitism was heavy but its overall effectiveness in causing the sudden population decline is unknown.

One new genus, Phycoidella, and four new species, Cricotopus macraei, Cricotopus flannagani, Phycoidella dentolatens, and Lenziella cruscula are described in all stages. The genus Lenziella Kieff. is emended. The described species, three Orthocladiinae and one Tanytarsini, have many aberrant, but not necessarily apomorphic features.

Austropsylla brevipecten gen. et sp. nov. is described from a single female specimen collected on a potoroo or rat-kangaroo. The genus is closest, perhaps, to Choristopsylla Jord. & Roths., and brings to nine the number of genera of Pygiopsyllidae to be found in Australia.

This paper discusses the status of three specimens of Aedes simici Baranov that are in the Canadian National Collection. One male labelled by Baranov as "typus" of this species, and one female labelled as a "cotypus", are shown to have no type-status. The remaining male is an authentic syntype and is designated the lectotype of A. simici. This species is left in synonymy with A. pulchritarsis Rondani.

Panonychus ulmi (Koch) and Bryobia rubrioculus (Scheuten) are very serious pests on apple trees in Lebanon. The effectiveness of M2060 (2 fluoroethyl (4-biphenylyl) acetate), Ovamort, Diotol, Genite, and Citronol plus parathion was investigated on the winter eggs of these two mites in the laboratory and in the field. M2060-oil was highly effective and superior to all products at early and late dormant stages of tree growth. The nearer to egg hatch the other products were applied, the more effective they were.

Collections of chironomids have been made in Deep Canyon, a part of the Colorado Desert in Southern California, since 1963. Of the 73 species collected 40 were species new to science. These will be described in later publications. Adults emerged during all months of the year with maximum number of species occurring in June. The fauna is dominated by the Orthocladiinae with 34 species with the Chironominae a close second with 26 species. Of those subfamilies known from North America only the Diamesinae was not represented.

Effects of varying levels (4–132 krad) of gamma radiation on moulting, feeding, co-ordination and locomotion, and wing development in Forficula auricularia L. are described and illustrated. A "radiation profile" shows the increased radiosensitivity of nymphs as compared to adult F. auricularia.

The following new taxa of Quediini (Staphylinidae) are described: Heterothops arizonicus spec. nov. (Arizona), H. aeneiventris spec. nov. (Huachuca Mts. in Arizona), H. marmotae spec. nov. (Ontario), Quedius leechi neomexicanus subsp. nov. (Sacramento Mts. and Sierra Blanca in New Mexico), and Q. leechi chiricahuensis subsp. nov. (Chiricahua Mts. in Arizona).

Though they may hatch on any part of a housefly (Musca domestica L.) pupa, most larvae of Nasonia vitripennis (Walk.) and Muscidifurax raptor G. & S. (Hymenoptera: Pteromalidae) move to the host’s ventral abdominal area, and those of Spalangia cameroni Perk. (Hymenoptera: Pteromalidae) to the dorsal side of the abdomen, before feeding extensively. As many as 25 larvae of N. vitripennis can mature on a medium-sized housefly pupa; if more are present initially, those that hatch last usually die from starvation after the host has been consumed. In contrast, usually only one larva of M. raptor or S. cameroni matures on a host; this is often the larva that hatches first, because it attacks all parasite eggs that it encounters while moving over the fly pupa soon after hatching. Larval crowding in M. raptor or S. cameroni, unlike that in N. vitripennis, does not affect the sex ratio of the survivors.

The variation in several morphological characters of adults and pupal exuviae of Tanytarsus heusdensis Goetgh. sensu auctorum (Tanytarsus usmaënsis Pagast according to Reiss, pers. comm.) in populations from some lakes and from brackish water in Finland was studied in order to check the homogeneity of the material. Significant differences were found in LRI, wing length, AR, and LRIII of males. In pupal exuviae the number of hairs on the anal lobes shows considerable variation in both sexes, and the average length of the spine comb on dorsal tergites III–VI differs in different populations. Nevertheless, from mathematical analysis of the data it is concluded that the differences observed do not indicate the existence of more than one species in the material studied.

A taxonomic treatment of the adults of the 12 known species of Neoleucopis Malloch, a subgenus of Leucopis Meigen, whose larvae prey on Adelgidae, is presented. The genotype, N. pinicola Malloch from North America, and two European species, N. atratula (Ratzeburg) and N. obscure Haliday, are redescribed; a neotype is designated for the former species and a lectotype is selected for the latter one. N. tapiae Blanchard, described from Argentina but known from many parts of the world, and N. manii Tanasijtshuk from India, are also redescribed. Seven new species are described: aciliosa (Japan), ancilla (Oregon), freyi (Switzerland, Finland), militia (Pakistan), nigraluna (India), orbiseta (Finland), and setigera (Chile). The paper includes a key to adults, and 40 figures.

By restricting the swarming behaviour of Chironomus riparius Meigen, in a series of five swarm suppression cages, it was found that reduced swarming resulted in fewer matings and less oviposition. With total suppression of swarming no matings occurred.

When swarming volume was incrementally reduced vertically or horizontally, it was found that the minimum vertical or horizontal dimension for swarming to occur was 2–3 cm. The mating rate was determined by the detection of labelled spermatozoa in autoradiographs. Thus swarming appears to have an epigamic function in C. riparius and is an essential precursor to mating and oviposition.

Several aspects of overwintering were studied in the larvae of selected species of chironomids living in shallow ponds.In two species (Einfeldia synchrona Oliver and Polypedilum simulons (Townes)) from a pond near Ottawa, Ont. (45° N.), development ceased in mid-November and the gut was subsequently evacuated. A species of Chironomus from another pond did not evacuate the gut although feeding ceased. In the laboratory, larval development of Einfeldia collected at any time of year continued except at low temperatures, but pupation occurred only at long day-lengths. Seasonal changes in horizontal distribution were apparently not primarily related to possible winter effects, but to water depth changes. Larvae of E. synchrona penetrated deeper mud layers during winter (as well as in midsummer); those of P. simulans were always confined to superficial mud layers.The later instars, at least in Chironomini, usually predominated during the winter, but season to season variation was marked. In the arctic all instars except the first were present. Closed winter cocoons were found in several temperate and arctic species. Some were made by sealing an existing tube, others by building a more or less transparent tightly applied cocoon. Inside these cocoons, the larvae were tightly folded in different ways more or less characteristic of the species. At Ottawa, cocoons were usually formed well after ice cover, and partly in response to low temperatures. Larvae showed a lower water content in winter than in summer. In the arctic, larvae were also somewhat dehydrated in winter, but there was in addition a different type of dehydration which resulted in shrivelling.There was no significant ability to resist freezing by inoculation with ice. Freezing tolerance was found in some temperate and all arctic larvae and was temperature- and time-dependent. In temperate areas, freezing-tolerant larvae were nevertheless freezing-susceptible in summer.These studies and previous findings are discussed in relation to winter habitat conditions and the remainder of the life-cycle. Generalizations are compromised by complex inter- and intra-species differences and by habitat variations. Freezing tolerance is widely distributed through the genera of most subfamilies except the Tanypodinae, and is probably most general in the Orthocladiinae. Since there are few specializations of larval physiology which explain such tolerance, the Chironomidae can probably be considered as largely pre-adapted to a rigorous winter environment.