Larvae of Neodiprion swainei Midd. were reared to the adult stage under controlled conditions of temperature and photoperiod. The effects of temperature are particularly evident during the larval stage, cocoon spinning, and adult emergence and are also observed through variation in cocoon weight and fecundity. Feeding, fecundity, and diapause are directly related to photoperiod. Larvae eat more when the photophase is long, an effect that is detrimental to the organism because there is a parallel loss of energy expressed in the number of day-degrees required to complete development.

Inferences regarding the value of Nasonia vitripennis in the natural control of Musca domestica based on laboratory research should consider the general absence of this parasite on that host in nature. Predominant natural parasites of M. domestica are listed.

The oribatid mite genus Megeremaeus is redefined, with the addition of information on leg chaetotaxy and immature instars. Three new species are described, Megeremaeus hylaius from northeastern North America, and M. keewatin and M. kootenai from northwestern North America. Descriptions of the former two species are based on adults and immatures, the latter species on adults only. Nymphs of M. montanus Higgins and Woolley are described. A key is given for the six known species in the genus.

E-Myrcenol reduced catches of the pine engraver, Ips pini (Say), to ipsdienol-baited, multiple-funnel traps in a dose-dependent fashion. The sex ratio was unaffected by E-myrcenol treatments. Lures containing E-myrcenol in ethanol solution failed to protect freshly cut logs of lodgepole pine from attack by I. pini. Rather, I. pini preferentially attacked logs treated with devices releasing E-myrcenol and ethanol, over nontreated, control logs. Our results demonstrate that E-myrcenol is a new pheromone for I. pini, and emphasize the importance of understanding basic pheromone biology before utilisation of a semiochemical in forest pest management.

Rose gall wasps, Diplolepis Geoffroy (Hymenoptera: Cynipidae), induce structurally distinct galls on wild roses (Rosa Linnaeus; Rosaceae), which provide gallers with food and shelter. These galls are attacked by a wide variety of micro-hymenopterans, including Periclistus Förster (Hymenoptera: Cynipidae), which act as inquilines. Both Diplolepis and Periclistus are difficult to distinguish based on adult morphology, instead the structural appearance of galls is often used to distinguish species. Using the mitochondrial gene cytochrome c oxidase subunit I, we tested the species boundaries and built phylogenies of both Diplolepis and Periclistus. The molecular results have largely supported the validity of species described in the literature, with notable exceptions in four species groups. Periclistus exhibits a divide between the Palaearctic and Nearctic clades, and ranges from specialists to generalists in terms of host specificity. While it is premature to enact any taxonomic changes without additional molecular markers, this incongruence between morphological and molecular data indicates these groups need taxonomic revision and gall morphology alone may be inadequate to delimit species.

Electrophoretic characterizations of sibling species in the Simulium venustum–verecundum complexes are presented based on nine enzymatic loci. Simulium verecundum s.l. is easily separable from S. venustum s.l. by unique complements of electromorphs for lactate dehydrogenase. Quantitative and minor qualitative differences also exist between most pairs of sibling species within S. venustum and S. verecundum. Not all pairs are separable using the nine enzymatic loci scored in this study. This close genetic affinity of species pairs that are not separable by electrophoretic methods parallels their chromosomal and ecological affinity.

The effect of temperature on prepupal diapause development in the hymenopteran Megachile rotundata (F.) was investigated by storing prepupae at various temperatures from −20° to 28 °C prior to final incubation at 28 °C. Preincubation temperatures of 5°, 10°, and 15 °C proved equally effective for diapause development and for the synchronization of adult emergence. Lower temperatures resulted in less synchronous emergence and higher mortality. When prepupae were exposed to more moderate temperature regimes prior to storage at lower temperatures, adult emergence became more synchronized and mortality declined. A high percentage of bees emerged after storage at 20 °C but their emergence was poorly synchronized. Over 50% of the prepupae stored at 28 °C developed without prior treatment at lower temperature but emergence was even less synchronized. The results of these experiments show that all prepupae diapause but the rate of diapause development becomes increasingly variable above and below an optimal range of 5° to 15 °C.

In this second paper on the North American Proctotrupidœ, I have taken up the sub-family Platygasterinœ, comprising, for the most part, small black species, all parasitic in larvæxs belonging to the Dipterous families Cecidomyiidœ and Tipulidœ.

It will be seen that I have recognized in our fauna species in all of the described genera but Iphetrachelus Haliday, and one new genus parasitic on Cecidomyious hickory galls.

A new species, Contarinia brassicola Sinclair (Diptera: Cecidomyiidae), which induces flower galls on canola (Brassica napus Linnaeus and Brassica rapa Linnaeus (Brassicaceae)), is described from Saskatchewan and Alberta, Canada. Larvae develop in the flowers of canola, which causes swelling and prevents opening, pod formation, and seed set. Mature larvae exit the galls, fall to the soil, and form cocoons. Depending on conditions, larvae will either pupate and eclose in the same calendar year or enter facultative diapause and emerge the following year. At least two generations of C. brassicola occur each year. Adults emerge from overwintering cocoons in the spring and lay eggs on developing canola flower buds. The galls produced by C. brassicola were previously attributed to the swede midge, Contarinia nasturtii (Kieffer) in Saskatchewan; here, we compare and list several characters to differentiate the two species.

The disruption of insect mating with sex pheromones by the air permeation technique is a complex problem influenced by a number of variables. Not least among these is the actual atmospheric concentration of pheromone during the course of the experiment. While closely related to the measured release rate from a formulation, the atmospheric concentration should be regarded separately since a number of other factors may intervene, e.g., chemical instability, foliage adsorption, and the differential effects of formulation weathering in the laboratory and the field.

The present study was conducted in conjunction with small scale field trials involving an aerially applied hollow fiber formulation of the sex pheromone of the spruce budworm, Choristoneura fumiferanu (Clem.), I1 -tetradecenal (97:3::E:Z). (Hereafter referred to as pheromone.)

The balsam-fir seed chalcid, Megastigmus specularis Walley, destroys a high percentage of seeds of balsam fir, Abies balsamea (L.) Mill. The insect was first recorded in Canada in 1928 from New Brunswick and in 1932 was described by Walley (1932). It has been taken in the United States as far west as Minnesota (Peck, 1951). In 1953 the insect was reared from seeds of balsam fir taken at the Forest Nursery Station, Indian Head, Saskatchewan. Further investigations in 1954 showed the insect to be abundant at Indian Head, and also in natural stands of balsam fir in Riding Mountain National Park, Manitoba.

Four of ten common varieties of cabbage tested at Ottawa from 1960 to 1963 were slightly or moderately resistant to Hylemya brassicae. Red Acre was the most resistant and Viking Golden Acre the most susceptible of the ten. Red Acre and Danish Ballhead were damaged less than Viking Golden Acre and harbored fewer maggots. Market Topper and Jersey Wakefield were also damaged less than Viking Golden Acre but harbored as many maggots. Resistance in Red Acre and Danish Ballhead was evidently due chiefly to low-attractiveness, and in Jersey Wakefield and Market Topper to tolerance. Differences in plant height and width, either between or within varieties, had little effect on the numbers of eggs laid on the plants. Of the Hylemya specimens identified, 99% of the eggs, 89% of the larvae, and 83% of the pupae were of H. brassicae and the remainder were of the H. liturata-platura complex.

The effects of root damage by larval cabbage maggots, Delia radicum (L.), on yield of canola, Brassica campestris L., were examined in laboratory experiments. Inoculations of eggs or first-instar larvae resulted in significant root damage. Damage that exceeded 50% of taproot surface area resulted in fewer racemes, fewer productive seed pods on axillary racemes, lower total biomass, and reduced yield of seed. Despite the latter effect, damage that restricts the number of flowering racemes and induces abortion of seed on axillary racemes may increase the efficiency of yield in canola, which flowers indeterminately over a short growing season.

Coleophora deauratella Lienig and Zeller is reported for the first time in North America. This casebearer species was introduced accidentally from Europe almost 30 years ago but remained unrecognized. It currently is known from eastern Canada and northeastern United States. Larvae feed on seeds of red clover, Trifolium pratense L. Diagnostic characters of the larval case and the adult, as well as features separating C. deauratella from two similar casebearer species, are presented.

The relative importance as pollinators of alfalfa of each of the 14 species of Megachile that occur in southern Alberta has been assessed on the basis of Alberta distribution, frequency and abundance in mixed prairie, nesting habits, pollen preferences, and flight period; two ground-nesting species of the subgenus Xanthosarus Rob., Megachile perihirta Ckll. and M. dentitarsus Slad., were judged the principal pollinators (Hobbs and Lilly, 1954).

The accuracy of visual observations in estimating numbers of tuber flea beetles, Epitrix tuberis Gentner, on young potatoes was determined. Potential sources of observational error examined were as follows: (a) observer competence and experience; (b) time spent observing each plant; (c) time of day; (d) plant height; and (e) weather. Observational accuracy versus tuber flea beetle density on plants followed a linear relationship for both experienced and inexperienced observers. Marked differences between experienced and inexperienced observers generally were reduced after 2 h of sampling experience, but some observers were consistently less accurate at sighting beetles than others. When observing small plants, 5-s observations generally were more accurate at sighting beetles per second of observation than 2-, 8-, or 10-s observations. Under uniform weather conditions, accuracy was the same in the morning as in the afternoon. Observer accuracy was significantly reduced under the combined influences of observer fatigue and wind. The relationship of 5-s-per-plant sampling accuracy to plants between 14 and 56 cm in height was linear; however, a quadratic relationship is suspected for plants over the full range of plant heights (i.e. >1 cm). From these data, total tuber flea beetles per plant estimated by 5-s visual observations per plant would be: TFB = TFB0/EhE0n where TFB0 is the total number of flea beetles observed, n is the total number of plants sampled, Eh is a sampling accuracy constant for the mean plant height sampled, and E0 is the observer accuracy constant calculated as a proportion of the most proficient observer(s).

The weight and size of coccinellid adults varied with species, sex, and feeding. Intraspecies variation in weight was generally similar in the eight species studied. Females were more variable than males in body size. Females of some species were heavier and larger than males, and species can be classified on a basis of difference in the weight and size of the sexes.

An increase in the food supply after a period of food scarcity affected the sex ratio, as the minimum food requirement of females was greater than males. Females increased in weight more rapidly than males after feeding. The availability of food in the field affected the weight and size of some species. Adult water content was influenced by feeding but not by sex or the quantity of food given to the larva.

Males were more abundant in species with small sexual differences in weight and size. The degree of difference in weight and size between males and females may be used as a criterion to select species that are best adapted to survive when food is scarce.

Morphological and histological details of the sex pheromone glands of male Vitula edmandsae (Packard) are reported. Several hypotheses concerning the functions of these glands are discussed.