Eight species of the genus Piagetiella are discussed and illustrated. There are two new synonymies: P. africana (Bedford) (= Tetrophthalmus australis Bedford) and P. titan (Piaget) (= Tetrophthalmus subtitan Bedford). A key is given to the species.

The morphology and histology of the internal reproductive system of the male spruce budworm moth, Choristoneura fumiferana (Clemens), is described and discussed.

The following new Chrysauginae are described: Mimetauge n. gen., type-species M. napeogenalis n. sp., a mimetic species from Peru; Zaboba unicoloralis n. sp., California; Caphys arizonensis n. sp., Arizona. Acallis mitchelli Dyar is transferred to Zaboba.

Some individual processes, e.g., moulting, in the development of Panonychus ulmi (Koch) can proceed at temperatures as low as 7.2 °C but not at 6.3 °C. the threshold for complete postovarial development lies between 9.2° and 11.7 °C. The threshold for deposition of viable eggs is between 10.7° and 11.7 °C, though some females eclosing at 7.2 °C lay inviable eggs at 9.8 °C. Experimental values obtained in the determination of threshold temperatures can be expressed as two temperatures: the permissive, the lowest experimental temperature allowing a particular process to proceed; and the inhibitive, the highest experimental temperature (below the permissive) preventing completion of the process. The actual threshold lies between these temperatures.

The genus Cuerna Melichar as represented in Canada is reviewed. Cuerna costalis (Fabr.) is recorded for the first time. Seven new species of Cuerna are described from the Prairie Provinces and British Columbia: cuesta, fenestella, inflata, nielsoni, pseudoalba, reducta, and xyla. The identities of C. striata (Walker), C. lugens (Walker), and C. septentrionalis (Walker) are determined. All the species are described and illustrated, and a key is provided to the species-groups and species from Canada.

The seven nominal species of Lonchaeidae described by Kertész, namely, Lamprolonchaea metatarsata (Kertész), Lonchaea megacera Kertész, Silba albisquama (Kertész), Silba biroi (Kertész), Silba pollinosa (Kertész), Silba excisa (Kertész), and Lonchaea cyaneonitens Kertész are redescribed and figured. Lectotypes are designated for metatarsata, albisquama, pollinosa, and excisa; biroi is sunk as a synonym of albisquama. Figures of the male genitalia of Lonchaea dasyscutella McAlpine, related to Lonchaea megacera, and of Silba imitata McAlpine and Silba emulata McAlpine, two species that are closely related to Silba albisquama, are provided.

Methods of sampling to measure factors affecting fluctuations of a population of the Oriental fruit moth, Grapholitha molesta (Busck), on the Niagara Peninsula of Ontario were investigated from 1963 to 1967 in peach orchards in which no insecticides were used during the study. In most years females tended to be distributed evenly throughout the orchard and even at low fruit moth densities the trees were relatively evenly infested. Several sampling methods gave estimates of the numbers of larvae overwintering in the orchard only within wide limits but indicated that the numbers were probably small in all years. Eggs could be sampled but it was not practicable at the low densities of the moth in this study. No satisfactory method of sampling summer cocoons or adults was found. Destructive sampling of the larvae, in which they were removed from the trees and reared to maturity on green apples, gave the most precise estimates of numbers in each generation. The method also gave a measure of mortality, parasitism, and times and duration of each generation.

An infestation of Neodiprion virginianus complex and its abrupt termination in a stand of jack pine, Pinus banksiana Lamb., in northeastern New Brunswick is described. The life history, habits, and parasites of the sawfly are reported.

After diapause was initiated in reproductively active adults, short-day (LD 12:12) maintained diapause and prevented oviposition for 66 ± 22 days. Subsequently all females remaining in the conditions that produced diapause (LD 12:12), began to lose the red-brown diapause coloration and began to oviposit. When animals were transferred to long-day at various intervals during diapause, oviposition resumed within similar time periods, thereby indicating that the intensity of diapause did not differ at the times tested.We suggest that in nature the short days of early autumn induce diapause, that the short days of late autumn maintain this diapause, that subsequently diapause ends under short-day conditions and that factors other than photoperiod, such as temperature accumulations, play a primary role in timing the initiation of reproduction in late spring.

Dendroctonus rhizophagus sp. n. collected from small pine trees in Mexico is described. Notes on seasonal development and habits are given.

Biological data are given for Coeloides pissodis (Ashmead), Dendrosoter sulcatus Muesebeck, Heterospilus sp., Spathius pallidus Ashmead, Eurytoma conica Provancher, Cecidostiba polygraphi Ashmead, Heydenia unica Cook and Davis, Roptrocerus xylophagorum (Ratzeburg), Rhopalicus pulchripennis (Crawford), Rhopalicus tutela (Walker), and Tomicobia tibialis Ashmead. Only Coeloides pissodis was always closely associated with its host. The other larval parasites were often found disassociated from any host, suggesting an ability to seek out hosts in Ips galleries and the potential to attack more than one host. Observations indicated that pupal parasitism may be significant. Comment on the potential of some parasites as control agents is included.

A new host record for the sawfly Monostegia abdominalis (F.) was obtained in Quebec. The host plant, terrestrial loosestrife (Lysimachia terrestris (L.) BSP), was abundant on a lake shore due to regular flooding, enabling the sawfly to reach a high population level. Two generations occurred each year. The immature stages and aspects of their behaviour, and female oviposition behaviour, are described.

Iziphya grandipes is described and illustrated. It is a Carex-infesting species that is known only from Ontario.

A lectotype for Hylurgus sericeus Mannerheim is designated. It is located in the Museum of Comparative Zoology, Harvard University, Cambridge, Mass. Pseudohylesinus pini Wood is placed in synonymy.

The piercing mouthparts of three species of mosquitoes were examined with a stereoscan scanning electron microscope. The structures observed are discussed in relation to existing morphological studies. Two pairs of peg-like organs were seen at the tip of the labrum and sensory-like structures measuring approximately 1.2 μ were shown at the tip of the hypopharynx of all species. Differences were observed in the numbers of maxillary teeth of different species. The stylets of Wyeomyia smithii appear functional despite the belief that this species does not take a blood meal.