The original larval description of Epinotia criddleana Kearfott (MacKay 1959) was based on misidentified material, and a description and illustration of the true larva of this species is presented here. The eastern Pseudexentera sp. and the western Pseudexentera oregonana Wlshm., both feeding on trembling aspen, are now considered to be one species, P. oregonana Wlshm. The identity of P. oregonana has been confirmed by comparison of adults with the Walsingham type in the British Museum (Natural History).

The trefoil sawfly, Atomacera debilis Say, is reported for the first time from Canada. The larvae are redescribed to illustrate their unusual morphological characters. The known distribution in North America and biological information on the species are presented.

The eastern subterranean termite has been present in Ontario for over 25 years. Economic damage caused by the pest was first reported in 1944 and has increased considerably in the last decade, particularly in the Toronto region. Termites have also been found in four other localities in the Province.

A detailed description of the larva of Agrilus liragus Barter and Brown, and the distinctive characters of Agrilus anxius Gory are given with a short discussion on the taxonomic value of some morphological characters.

Dermestid larvae, Trogoderma versicolor (Creutzer), and adult American cockroaches, Periplaneta americana (Linné), were affected by ruby laser pulses of two intensities, 0.06 ± 0.04 per 10−7 second duration and 0.57 ± 0.06 joules per 0.2 milliseconds. Laser impact areas were 1.5 mm. in diameter. The first intensity, directed at cephalic regions of dermestid larvae, caused mortality in 3–48 hours. The same intensity directed at larval mid-abdominal areas caused visible outer integument and body-hair scorching, cessation of feeding, growth rate, and movement, and loss of negative phototactic responses. Directed at posterior abdominal regions of larvae, it caused damage to the epidermal layer noticeable in four succeeding moults. It caused temporary (10-15 min.) immobility and loss of negative phototaxis when directed at pro-thoracic regions of cockroach adults. P. americana adults were more severely affected by the second laser treatment, exhibiting immobility, loss of negative phototaxis, and cessation of eating. Total mortality in the five treated specimens occurred in 8-14 days as compared with 45-68 days in controls.

Parasitism of pupae of G. mellonella (L.) by P. turionellae (L.) was found to prevent adult emergence. The effect was manifest within 24 hours of parasitization. Experiments are described which indicated that the source of the factor preventing eclosion of the imago is the developing parasite egg.

A new Nearctic species of Euderus Haliday is described and illustrated. Description is based on eight specimens reared from poplar twigs containing galls formed by Saperda moesta Leconte (Coleoptera) at Gore Bay, Ontario, seven specimens collected at Indian Head, Saskatchewan, and three specimens reared from poplar trunks at Kerrick, Minnesota.

In the laboratory 90.7% of both sexes of moths of the pale western cutworm, Agrotis orthogonia Morrison, emerged from pupae between noon and midnight; almost half emerged between 2 and 4 p.m. Mating, evidenced by spermatophores in the bursa copulatrix, occurred almost always at night, within 3 days of emergence, and at temperatures between 5 and 35 °C. Most females mated only once. Multiple matings, with a maximum of 3 times, occurred in less than 20% of females. Males mated with a maximum of three females. Eggs developed during the pupal stage and were ready for fertilization when the moths emerged. Oviposition began on the first or second day after mating, peaked soon after, and continued until just prior to death of females. Maximum oviposition by one female was 564 eggs, with means from 90 to 342. Oviposition occurred at all temperatures from 5 to 35 °C. with an optimum between 10 and 25 °C. More eggs were laid in the dark or in subdued light than in continuous bright light. Females when unfed could oviposit but when fed water or sugar solutions they laid more eggs. Longevity varied directly with feeding and inversely with temperature. Mean longevity of moths fed honey solution in the laboratory was 12 days for both sexes. A diurnal rhythm of oviposition occurred with distinct peaks; 80% or more of the eggs were laid between noon and early evening. Rhythm of oviposition was apparently initiated by light and could be reversed by reciprocal light regimens but was maintained in continuous dark or light. The maximum distance flown on a flight mill was 14.7 miles for males and 3.5 miles for females. Speed varied from less than 1 to almost 3 m.p.h.

Larvae and adults of Haplothrips faurei (Hal.) that prey on the tetranychid mites Panonychus ulmi (Koch) or Bryobia arborea Morgan and Anderson attacked mainly the eggs. When no eggs were present, they attacked the motile stages of the mites but their growth and oviposition were slowed. Adult thrips that fed on winter eggs of the tetranychids lived only a short time, unless they also had access to peach leaves. The mite Aculus cornutus (Banks) and fresh pollen of Chenopodium album L. were eaten by H. faurei; pollen was less satisfactory than tetranychid eggs for growth and oviposition. Adults lived for long periods on leaf juices alone.

One larva ate an average of 143 summer eggs of P. ulmi during its developmental period of 8 to 10 days at 24 °C. An adult ate an average of 44 eggs per day at 24 °C. when fed ad libitum.

Females did not fly when fully fed and ovipositing, but they did so during the preoviposition period and after a short period of starvation.

Most individuals of all stages of H. faurei were on the twigs, in crevices find other places of concealment on peach trees, bur a greater proportion of individuals were on the leaves of apple and plum. This difference in distribution was attributed to differential effects on behaviour by the glabrous foliage of peach and the pubescent foliage of apple and plum. The presence of H. faurei on twigs complicated population sampling in peach orchards.

The egg was the stage most sensitive to low humidity, but there was no evidence that humidity limited the population in orchards.

H. faurei was usually scarce in spring. Later, its numbers usually increased with those of the mites and it may have retarded growth of the mite populations, but its most obvious effect was the destruction of winter eggs in the fall.

Synergus pacificus McCracken and Egbert (Hymenoptera: Cynipidae) is an inquiline of oak gall cynipids in the Pacific Coast area from southern British Columbia to central California. Approximately 1,000 specimens were examined during the course of this study. Descriptions of the egg and larval stages are given, and information on life history and ecology is presented.

A species of Cupressobium Börner is described. The aphid was collected from Cryptomeria japonica, the Japanese Cedar, on the Island of Maui, Hawaii. This species differs from the others in the genus in that the terminal process of antennal segment VI is much longer than the diameter of the main rhinarium of this segment while the length of rostral segments IV + V exceeds that of antennal VI.

Sisyphus submonticolus n. sp. is described from Durango, Mexico, and compared to the only other New World species, S. mexicanus Harold.

Hippelates pusio Loew. pupae in Puerto Rico were parasitized internally by Ooencyrtus submetallicus Howard, egg parasite of the southern green stink bug, Nezara viridula var. smaragdula Fab. Another case of divergent host preference is noted for Eupteromalus hemipterus (Walker), and the importance of soil-breeding Diptera in the propagation of beneficial organisms is demonstrated.

A technique for rearing Neodiprion sertifer (Geoff.) in individual isolation from egg to adult is described. Larvae so reared under optimal conditions experience mortality only slightly greater than that sustained by larvae growing in the normal feeding aggregations. The comparative capacity of the isolated larvae to withstand even slight departures from optimal conditions of food, temperature and humidity is low. These observations together with data on the responses of isolated and normal larvae to physical factors are discussed in their ecological context.

The seasonal development of N. swainei was recorded in northwestern Quebec for six consecutive years from 1956 to 1961. Larvae normally spun cocoons during September when temperatures were usually below the optimum for survival. An earlier and more favourable spinning period depended principally upon an early adult emergence which, in turn, was governed by prevailing temperatures, the degree of shading of the humus, the presence of encapsulated tachinid parasites, the prior period spent in prolonged diapause, and the geographic origin of the specimens. It was concluded that early emergence of adults followed by rapid development of the immature stages for successive years are prerequisites for epidemics of N. swainei in northwestern Quebec, and are unlikely in very dense jackpine stands.

Trachyphloeus Germar, 1817, is judged to be introduced in North America; the two species described from the United States are considered European imports. Consequently, the names T. davisi Blatchley, 1916, and T. bifoveolatus (Beck), 1817, are considered synonymous, as are the names T. asperatus Boheman, 1843, Chaetechus setiger Horn, 1876, and T. olivieri Bedel, 1883. Chaetechus Horn, 1876, is synonymized with Trachyphloeus. T. aristatus (Gyllenhal), not previously reported from North America, is recorded from Carleton Place, Ontario.

The ridingsiana group of the genus Euxoa is defined, and the eight constituent species are distinguished by means of a key. Euxoa macrodentata, most closely related to Euxoa cooki McD., is described as new. Euxoa exculta (Sm.) and its nominal subspecies criddlei Sm. are synonymized with Euxoa perpolita (Morr.), and Euxoa perolivalis manitobana McD. is raised to specific rank.

An insect emergence trap for quantitative studies in shallow ponds is described and figured. Details of its operation are given.