The distributions of Scolytus ventralis LeConte attacks, emergence, and parasites were studied by stratified sampling of 20 grand fir. Of the theoretical distributions tested the negative binomial gave the best fit to all three sets of data. Three sample unit sizes were analyzed (1/4, 1/2, and 1 sq. ft) and all gave similar estimates of the mean, although the smallest sample unit influenced the distribution by increasing the frequency of the zero class. Approximate normality was achieved by applying logarithmic transformation to the attack data and the Taylor power transformation to the emergence and parasite data. Analysis of variance showed that the vertical position of the sample in the tree was die most consistent factor influencing the distribution of attacks, emergence, and parasitism, while cardinal aspect had little effect. Considerable variation also occurred among trees within a group. The density of attacks was extremely variable both within and between trees, although it was slightly higher on rough bark. Emergence was generally greater in the basal half of the tree, being reduced in the upper levels by competition with other insects. Emergence increased with attack density up to about 13 attacks per square foot. Thereafter survival was probably limited by intraspecific competition. Parasitism appeared to be reduced near the base of the tree by thick bark and at the top by lack of host larvae.

Sampling designs for the fir engraver will have to consider variations between trees and vertical strata within the tree.

A survey of poultry ectoparasites was carried out on 90 flocks of various types in Nova Scotia and Prince Edward Island. Eighty-one per cent of the flocks were carrying one or more species of ectoparasite. The chicken mite, Dermanyssus gallinae (DeG.), was present on two out of three flocks and was most frequently located in the joints of the roosts. Chicken lice were parasitizing one out of three flocks. The two most frequently found species were the shaft louse, Menopon gallinae (L.), and the chicken body louse, Menacanthus stramineus (Nitz.). One other species of mite and two other species of lice were also found. About 30% of the flocks were infested with the European chicken flea, Ceratophyllus gallinae (Schr.).

Operators were aware of only 42% of all infestations found on their flocks. They were most likely to be aware of the chicken mite and had recognized 54% of these infestations. In most cases operators could not distinguish among the various species of ectoparasites.

Control measures had been carried out on 57% of the flocks surveyed. Nicotine sulphate, the most popular compound, had been used on one-half of the flocks for which control measures were reported. Organic insecticides had been used on one-third of the treated flocks.

Camptomyia pseudotsugae, a new species of midge in Douglas-fir cones from Washington and British Columbia, is described. Notes on its life history and habits in relation to those of its cohabitant Contarinia washingtonensis Johnson are included.

The sex ratio of the polygamous species Ips acuminatus (Gyllenhal) varied in 31 localities of Norway from 1 to 4 females per male in northern and western areas to 20 females and more in some southeastern areas. The number of female galleries per nuptial chamber (usually three to five) varied accordingly and isolated female galleries were also formed. Laboratory breedings showed that the species has two types of females, one which produces only females and one which produces both-sixes usually with a 1:1 sex ratio.

The debris-feeding insects Trogoderma glabrum (Hbst.), Tribolium madens Charp., Cryptolestes ferrugineus (Steph.), and Vitula edmandsae Pack, were controlled by cleaning out die nests of Megachile rotundata L. annually and screening off the debris, and by discarding the cells of M. rotundata after emergence was complete. The chalcidoid parasites Monodontomerus obscurus Westw. and Pteromalus venustus Wlkr. and the depredators Coelioxys spp., were removed by light-trapping them in the incubators in which M. rotundata was being hatched. The removal was made possible because the incubation period of each of the indigenous enemies was considerably shorter than that of their exotic host.

The acid and alkaline phosphatase activity was measured in the developing egg and in the alimentary canal of aging nymphs as well as adult males and females of different ages. Para-nitrophenol was used as colorimetric standard and disodium p-nitrophenyl phosphate as substrate. Activity was measured in terms of micromoles of p-nitrophenol liberated from the substrate as a result of enzyme action.

Acid phosphatase activity was noticed to increase with the embryonic development and was higher than in the case of alkaline phosphatase. The alkaline phosphatase activity was lowest in the freshly laid egg, but increased more sharply than acid phosphatase during embryonic development.

The activity of both the acid and alkaline phosphatases was highest in the first instar and declined gradually to the fifth instar. The activity of acid phosphatase was higher than alkaline phosphatase in all stages except the first instar where it was almost equal. The activity of both the enzymes was higher during the intermoulting period and declined at each moult indicating a hormone–enzyme relationship.

In adults, activity of both the enzymes increased up to the maturation period after which the activity gradually decreased. Acid phosphatase activity was generally higher in males whereas alkaline phosphatase activity was generally higher in females. In almost all cases, the acid phosphatase activity was found to be higher than the alkaline phosphatase.

Lophyroplectus luteator (Thunb.), a European ichneumonid, was liberated in three Neodiprion sertifer-infested plantations in southern Ontario. Following one introduction in 1962, the parasite has survived 4 years and has spread at least 1.4 mites. Six per cent of the hosts collected within the plantation in 1966 produced adult parasites. Another smaller introduction in 1962 was unsuccessful. Following the third introduction, made in 1964, the parasite has survived 2 years and the attack level is now nearly 9 per cent.

The cysts sometimes observed in the intestinal cavity of pupae and in the abdominal cavity of adults of Neodiprion swainei Midd. are not typical tumors. No cell proliferations were observed but rather a precipitation of the cells that accumulated and formed a membrane composed of many layers. The cysts appear to result from encapsulation of incompletely lysed or unlysed cells of the midgut epithelium. They are not necessarily the result of a viral infection.

Larvae of the winter moth, Operophtera brumata (L.), and the Bruce spanworm, O. bruceata (Hulst), differ in the number of instars, in habits, and slightly in morphology. Populations may be distinguished readily by these criteria, but individual larvae sometimes give difficulty. The form of the pupal cremaster is distinctly different.

Uric acid accumulation in the fat body of several species of Tenthredinidae and Diprionidae was determined on a qualitative and quantitative basis. Variations were found in the number of crystal agglomerations per cell and in the nature of the agglomerations between species. Uric acid dosage revealed considerable variations in concentration. Such variations could be useful for taxonomic purposes.

Messa populifoliella (Townsend), long known in the United States but new in Canada, is univoltine and overwinters as a prepupa in the soil beneath the host tree. In New Brunswick the larvae mine the leaves of Populus eugenei Simon-Louis creating blotch mines. The various stages of the sawfly are described and pictured and six parasite species are named.

The length of the spermathecal duct differs in species of Sitophilus. It is suggested that this criterion may be of value as an additional means of separating the two very similar species S. oryzae and S. zea-mais.

The following new pyraustine taxa are described: Thliptoceras formosanum n. sp., Taiwan, China; T. amamialis n. sp., Amami, Japan; T. caradjai n. sp., Kiangsu and Chekiang provinces, China; Toxobotys n. gen., type-sp. Toxobotys praestans n. sp., Hainan I.

Oviposition and hatching of Albia caerulea Marshall, 1927, are reported from laboratory observations of adults collected in Lake Opinicon, Leeds County, Ont., and of eggs deposited by them. A description is presented of newly hatched, unengorged larvae. Figures of the larva and eggs are included. Additional locality records of this species of water mite are reported.

Survival of the balsam woolly aphid on Abies grandis logs was observed to evaluate the danger of spreading the pest while moving logs. Active stages of the aphid survived submergence in sea water for 7 days and periodic sprinkling with sea water for 3 weeks. Dormant stages survived submergence up to 28 days. Active aphids survived on logs in the forest as long as 5 months. Crawlers frequently re-established on logs and completed a second generation there. Dormant neosistentes on autumn-felled trees persisted over winter and resumed development in the spring. Recommendations for moving infested logs through uninfested areas are made.

The initiation of the pupal diapause of the apple maggot, Rhagoletis pomonella (Walsh), was found to be regulated by photoperiod and temperature. The stages of R. pomonella sensitive to these two regulatory factors were demonstrated to be the larva in the case of photoperiod and the larva and pupa in the case of temperature. Measurements with a highly sensitive photocell revealed that enough light passes through the skin and pulp of an apple to permit the response of the larvae to photoperiod to be direct. Diapause initiation was found to be independent of the effect of photoperiod or temperature on the adults and eggs and independent of the amount or type of larval food (apple or artificial).

Where larvae and pupae were reared at 28°C and a photoperiod of 17 or 19 hours of light per 24-hour day, 1% of the pupae completed development in 23 days, 50% in 28 days, 75% in 30 days, and 100% in 64 days. These were the only regimes tested at which there was 100% non-diapause development, a finding which is directly applicable to continuous laboratory rearing of the apple maggot. Irrespective of temperature, diapause was induced in more than 50% of the pupae at a larval photoperiod of 11 hours. Even where larval photoperiod was favorable for 100% non-diapause development (17 or 19 hr), diapause was induced in more than 25% of the pupae if larval and pupal development occurred at 23°C and in a larger percentage if larval and pupal development occurred at 19°C.

These findings are helpful in elucidating those conditions in nature under which a second generation of R. pomonella occurs.

Calaphis manitobensis is described and illustrated. The only known host is swamp or low birch, Betula pumila L.

Five new species of Pison, subgenus Krombeiniellum, are described: stangei from Argentina; duckei, plaumanni, and neotropicum from Brazil; and krombeini from Central America. Pison duckei, plaumanni, and neotropicum are known by females only. A key is provided for the identification of the New World Krombeiniellum; the subgenus is divided into three species groups.

Different stages of the European red mite, Panonychus ulmi (Koch), were immersed in water for periods up to 48 hours. Mortality of eggs was negligible; of active stages it was low but appreciable. Immersion in water inhibited egg hatching, feeding, moulting, and oviposition. It was concluded that if the mite responds similarly under orchard conditions, frequent or prolonged wet periods would delay the buildup of a mite infestation.