Prosimulium albertense new species is described from southern Alberta, Canada, and is differentiated from the closely related species P. clavatum Peterson.

Mature larvae and puparia of Compsobata univitta (Walker) found beneath a pile of decaying vegetation by a stream near Austin, Man., are described and compared with immatures of other Micropezidae.

The peak of phototactic response of Trialeurodes (Asterochitori) vaporariorum (Westw.) to equal numbers of quanta of monochromatic light in the range 475–625 mμ occurred at 540–550 mμ. and a hump of "red" sensitivity occurred near 600 mμ. This coincided with the transmission spectrum of host leaves. The response to light intensity was hyperbolic but it was linear within the variance in the range used for the action spectrum. Corrections were made for decreasing sensitivity during experiments. The absorption spectrum of a pigmented eye-preparation included a shoulder at the wavelength that caused maximal phototaxy. Work on greenhouse light traps is recommended. Preliminary colorimetric data did not support a capacity for colour vision.

Haemocytes are described and illustrated for 16 species of cockroaches, and data are given on haemocyte size and numbers. Each family in the suborder Blattaria is represented. In all of the species, the haemocyte complex comprises plasmatocytes and granular haemocytes in addition to mainly germinal elements, the prohaemocytes. Spherule cells, a distinctive form of granular haemocyte, occur in most "modern" species (superfamily Blaberoidea), but are absent from most species in the more primitive group (superfamily Blattoidea). Taxonomic relationships at other levels are reflected particularly in morphological features of granular haemocytes. Although the haemocyte complex alone offers insufficient evidence for systematic arrangement, it provides additional characters for classifying species.

Both males and females of Rhagoletis pomonella (Walsh) showed three distinct modes of aggressive behavior: (1) a wing-waving display, (2) charging headlong into another fly, and (3) "pawing" with the prothoracic legs. The flies were aggressive toward their own and the opposite sex. The aggressive patterns were similar to those of R. suavis (Loew) and R. completa Cresson.

Sporadic outbreaks of many pine defoliators, including Orgyia hopkinsi Coll., have occurred in many pine plantations in Kenya in the last 20 years. A recent outbreak of O. hopkinsi is reported from young plantations in Turbo. Distribution, hosts, and epidemiology of the insect are discussed. The stages, life history, and habits are described. Eggs are laid on the bark close to pupation sites or on the pupal cases. The larvae feed on the foliage and pupate following the fifth instar. The life cycle lasts 76 to 94 days. Two species of parasites, namely Pimpla mahalensis Grib. and Pimpla sp. (Hymenoptera: Ichneumonidae), have been observed. Other controlling factors are also discussed.

The taxonomic concepts of the Ips species of groups IV and X were tested by controlled breeding, bioassay of sex pheromone specificity, and examination of morphological and karyological details. No changes were made in the status of Ips pini, I. bonanseai, and I. avulsus of group IV. I. interstitialis of group X is removed from synonymy with I. calligraphus, and I. ponderosae, also previously considered a synonym of I. calligraphus, is assigned subspecific rank. Assertions of close phylogenetic relationship of the Eurasian I. duplicatus and I. sexdentatus with groups IV and X, respectively, are rejected.I. pini from widely separated localities were interfertile although egg hatchability was subnormal in some crosses involving F1 from matings of beetles from western and eastern North America. I. pini and I. bonanseai readily mated but less than 3% of the eggs hatched and the larvae died. There was no evidence of breeding incompatibility in crosses of I. c. calligraphus from Florida and California or I. c. ponderosae from New Mexico and South Dakota. However, hatchability differed drastically between reciprocal pairings of the I. calligraphus subspecies, possibly as a result of cytoplasmic incompatibility. All eggs produced in pairings of I. interstitialis with either of the I. calligraphus subspecies failed to hatch.First meiotic metaphase of I. pini, I. bonanseai, and both I. calligraphus subspecies invariably showed the formula 15AA + Xyp. This karyotypic formula also applied to I. avulsus except for a few individuals that had 2 small supernumerary chromosomes. The karyotype of I. interstitialis was not determined. Heteromorphic bivalents and univalents were detected in hybrids of the I. calligraphus subspecies.Cross attractiveness to sex pheromones was demonstrated for I. pini from different regions, for I. pini and I. bonanseai, and for the I. calligraphus subspecies. When samples of attractive frass from eastern and western I. pini males were presented simultaneously, eastern females responded equally to both samples but western females favored western frass by a margin of 2 to 1. Similarly, I. c. calligraphus clearly discriminated in favor of consubspecific pheromone while I. c. ponderosae did not.The locality of several of Eichhoff’s holotypes is noted.

The relative importance of position and color in nest-entrance recognition was tested in two bumble bee species, Bombus griseocollis (Degeer) and B. occidentalis Greene, using two identical sheds, each bearing a horizontal row of four nest-entrances marked with colored discs to which workers returned after foraging in the field. The bees were trained successively to either a yellow or a green disc on each of the four positions (alternating between the sheds), the other three positions being marked with black discs during each training period. The positions to which bees returned after moving the colored disc to each of the other three positions following each training period were recorded.The results indicate: (1) that the importance of position relative to color was greater at the end positions than in the inner positions; (2) that whereas B. griseocollis relied more on color relative to position than did B. occidentalis when the bees had been trained to the outer positions, the converse held true for inner positions; (3) that position was more important relative to color when the bees were homing than when they were choosing a position at which to alight or enter. Ecological and behavioral implications of the results are discussed.

Fecundity and colony size of Hyphantria cunea Drury were measured in six census areas for 13 years, and wing length was measured in one area. Colony size in the fifth instar was closely correlated with fecundity, and the percentage mortality from the egg stage to the fifth instar was an inverse function of fecundity. Wing length was not a sensitive index of fecundity where there was insufficient competition for food to cause severe reduction in moth size.Seasonal differences in fecundity and colony size within years, as well as differences between areas and between years, followed patterns expected from laboratory studies. Decreases during each season, proximately attributable to the age of foliage available to the larvae and ultimately attributable to genetic differences in the heat requirements for diapause termination, made it difficult to estimate mean fecundity for any area or year. Fecundity seemed slightly higher in coastal than in inland areas. Both population quality and weather appeared to influence annual differences, but because of the complex interaction between them and the high variability in fecundity and colony size, the relationships could not be modeled effectively with the available data.Differences in fecundity and colony size associated with both time and place were negligible in comparison to the changes in the population density of colonies, as measured in the same areas over the same period of years. It is concluded that priority should be given to survival rather than fecundity in the development of population models for H. cunea, at least in areas where competition for food is not severe.

Radiocesium accumulation by Aedes aegypti larvae was greater at 25 °C, than at 20 °C. The activity density (c.p.m./mg dry wt.) of the adults was the same for both sexes, as was the nuclide’s elimination rate. The amount of 137Cs accumulated by the larval instars was inversely proportional to the concentration of potassium in the rearing medium, the suppression of 137Cs uptake being greater at 25 °C than at 20 °C. The possibility that larvae may accumulate 137Cs via the anal papillae and the gut, is briefly discussed.

The western spruce budworm, Choiistoneura occidentalis Freeman, which normally passes through an obligate diapause in nature, was reared in the laboratory without diapause. The critical factor for preventing diapause appeared to be the physical environment presented to the first stage larvae. The response of C. occidentalis was flexible. The 2nd stage larvae could be made to diapause or forego diapause, depending on their rearing experience in the first stage. By eliminating diapause it was possible to rear about 7½ generations per year as against about 2¼ under normal diapause conditions. The diapause of the jack-pine budworm, C. pinus pinus Freeman, and C. lambertiana californica Powell, could be prevented by the same technique. The diapause of the spruce budworm, C. fumiferana (Clemens), could not be eliminated except after several generations of selection.

The lipids of loblolly pine phloem, particularly the neutral lipids, were fractionated and bioassayed for feeding stimulant activity with the pales weevil, Hylobius pales (Herbst). Activity was evidently reduced by the fractionation procedures. Significant feeding occurred in response to the fraction whose principal constituent was β-sitosterol. Also, evidence indicated that substances occurring with the sterols may play a part in inducing feeding.

The chorionic structure of the main body and the specialized opercular region in the egg of Zelus exsanguis (Stål) is described. The chorionic architecture of this species is typical of the ova in the Harpactorinae.

This deals with the distributions of Papilio machaon L., Oeneis chryxus strigulosa McD., and Boloria napaea Hoff., as correlated with the basic geological formations to which they are evidently restricted.

Three species of two genera in the family Ceratopogonidae, namely Culicoides obsoletus Meigen, Culicoides yukonensis Hoffman, and Dasyhelea sp. near tristyla Wirth were collected from the area near Fort McMurray, Alta. (lat. 56°44′ N., long. 111°23′ W.). The order of abundance of the three species was C. obsoletus, C. yukonensis, and Dasyhelea sp. C. obsoletus and C. yukonensis were most active during the evening hours and Dasyhelea sp. was most active during daytime hours. Both species of Culicoides were serious pests of humans and animals in the community.