Observations on the feeding and mating behaviour of Rhamphomyia spp. in the high arctic are reported. In R. nigrita Zetterstedt the males catch their prey especially in the male swarms of mosquitoes, etc., and carry it to their specific swarming (mating) site, a station controlled by a typical visual marker. In the swarm the male responds to insects hovering above, by rising to within a few inches and then holding a steady distance for some moments. The upper insect, if a male, moves away; if a female, pairing soon takes place, the prey is transferred, and the female feeds on it during mating. Apparently the female obtains insect food in no other way. The prey is rather small, and insufficient for the completion of one ovarian cycle; and the swarming flight, with mating and prey transfer, occurs repeatedly.In R. ursinella Melander hunting and mating are accomplished on the ground. The prey is very small and mating is frequent. The species is virtually non-flying, and the specialized form of the male eye, on which mating in flight depends, is considerably reduced. Similar adaptations occur in other arctic Diptera. R. nigrita, in contrast, maintains fully the normal dependence on sustained flight.The general structure of mating behaviour in the specialized Empidinae (Rhamphomyia, Empis, Hilara) is discussed. As in many Empididae, and other Diptera, mating takes place at an assembly station controlled by a visually recognized swarm marker, and the response to the female is mediated by the large ommatidia of the upper part of the male eye. The "holding flight" however signifies an interposed courtship, or display of prey by the male to the female. In most species only the male captures prey (perhaps without feeding on it himself); the female does not hunt and obtains insect food only by transfer at mating. Courtship with transfer becomes a firmly established behavioural element, and persists even in species which use objects of no value as food (ritualization of prey).The original significance of the prey, on which its role as sign stimulus in mating is based, is its significance as food required by the female for ovarian maturation. When the prey is small in relation to the requirements of the female, the mating process, including the courtship and prey transfer, is repeated (ritualized) so as to provide the female with sufficient food. It is suggested that this ritualization would develop easily once insect prey had become established as the sign stimulus for mating; and could lead on to the sex differences in habits of hunting and feeding.

An olfactometer is described for determining the responses of individual pedestrian beetles to attractants. The main features are a covered runway, a general air flow containing a well-defined narrow odor stream, and an on–off control of odor flow.

In 1966–67, the following fungi were isolated on Adelges piceae (Ratz.), a serious pest on fir trees in the Gaspé Peninsula: Fusarium larvarum, Cephalosporium coccorum, Entomophthora sp., Aspergillus fumigatus, Aspergillus nigra, Penicillium thomii, Penicillium sp., Cladosporium sp., Isaria farinosa, and Beauveria sp. F. larvarum showed more evidence of pathogenicity for Adelges, while C. coccorum was considered a facultative pathogen. There were not enough cases of infection by Isaria, Beauveria, and Entomophthora to determine their activity. Remaining species were saprophytic. Pathogenicity tests were conducted in the field with F. larvarum and C. coccorum. The fungi were introduced in the population by spraying or dusting, or by mites. However, a variety of external factors made it impossible to determine accurately the degree of virulence of these fungi for Adelges.

High fecundity from Chrysopa carnea was obtained from an inexpensive diet containing a commercially available product of dried, inactive Saccharomyces fragilis yeast and whey proteins. The effective diet consists of this product mixed with sucrose and water. S. fragilis autolysed 17 hours was more effective in diets than when autolysed for 36 hours or unautolysed, and was as effective as autolysed brewers’ yeast, S. cerevisiae.

The generic concept of Heterotarsonemus Smiley is reviewed and redefined. The type-species, H. lindquisti Smiley, is redescribed and illustrated along with a new species, H. bicornis; the only described European species, H. coleopterorum Schaarschmidt new combination, is compared with the above two nearctic species. The known species of this genus are associates of bark beetles in conifers.

Haemocytes of the Pacific beetle cockroach, Diploptera punctata (Esch.), are described and figured as they appear in vivo and in stained blood films. Although the haemocyte complex in this species is comprised of the same main categories as found commonly in other cockroaches, it is somewhat unusual due to morphological specialization among one category, the granular haemocytes. Most of the cells in this category are similar to those in other species, but some contain distinctive vesicles of mainly proteinaceous material, some are ovoid and contain spherule-size granules, and some are large, fusiform cells that are actively amoeboid in vivo. The other main categories, prohaemocytes, plasmatocytes, and spherule cells are fairly typical.

Methods were developed to standardize sampling of the Douglas-fir tussock moth. Population density was estimated in terms of the number of eggs or larvae per 1,000 sq. in. of branch area of Abies concolor (Gord. and Glend.) Lindl. The density of eggs and larvae varied significantly in different parts of the tree crown. In an outbreak, egg masses were concentrated on inside branches near the bottom of the crown, but in light populations they were most common on outside branches in the top of the crown. Larvae were found over the entire tree, but they were especially concentrated on foliage in the top. Mean density of larvae in the middle crown was representative of the whole tree. Egg density is estimated from whole branches sampled representatively from three crown levels; however, density of larvae is estimated accurately from 17-in. twig samples taken from just the middle crown. Because eggs are clumped in masses and larvae are dispersed over the foliage, larval density can be estimated with much less sampling than can egg density for the same precision.

The cephalic structures of the final instar larva of 278 species of 140 genera of Braconidae were examined. On the basis of these and biological data, modifications are proposed in the classification of the higher categories. Zele (Helconinae) and Eubadizon (Blacinae) are placed in the Macrocentrinae (endoparasites of larval Lepidoptera) and Meteoridea is moved from the Helconinae and ranked as an independent subfamily. The Blacinae is completely dismembered: Aliolus, Triaspis, Urosigalphus, Blacus, and Calyptus form a tribe of the Helconinae (endoparasites of larval Coleoptera); Microtypus, Orgilus, and Stantonia form a tribe of the Agathidinae (endoparasites of larval Lepidoptera); and Pygostolus, Centistes, and Syrrhizus a subfamily near Euphorinae with Cosmophorus (endoparasites of adult Coleoptera). Present genera of Microgasterinae are separated into two tribes with the addition of the Cardiochilini as a third tribe. The Dacnusinae is reduced to a tribe of the Alysiinae. The Rogadinae is reduced to one tribe, Rogadini, containing only Rogas and allied genera (endoparasites of larval Lepidoptera). Rhyssalus is transferred to the Hecabolini, and Exothecini, Pambolini, Hormiini, and ectoparasitic Rogadini to the Braconinae (ectoparasites of larval Coleoptera, Lepidoptera, etc.). The problematic genus Gnaptodon is also placed in the Braconinae.

The possible origin and site of introduction of Berytinus minor (H.-S.) (Hemiptera: Berytidae) into North America are discussed and new North American records given. B. minor exists in both a long winged (macropterous) and short winged (brachypterous) form. Differences in morphology of the pronota and wings of both forms are given and compared with a description of the differences found in the literature. Inapplicability of the terms macropterous and brachypterous as applied to B. minor is discussed. Notes on biology and ecology at Ithaca, N.Y., are given. The species appears to overwinter as an adult and to disperse in April to its food plant, white clover, Trifolium repens. Mating and oviposition begin in late April and May with the adults of the season maturing in late July or August.

Females of Nasonia vitripennis (Walk.) (Hymenoptera: Pteromalidae) discriminate between unparasitized housefly pupae (Musca domestica L.) and those parasitized by either Muscidifurax raptor G. & S. or Spalangia cameroni Perk. (Hymenoptera: Pteromalidae) and lay fewer eggs on parasitized hosts. Oviposirion restraint is more pronounced towards hosts attacked by M. raptor than towards those attacked by S. cameroni, but less than that exhibited towards pupae previously parasitized by N. vitripennis. Damage to the fly pupae, from piercing by the female’s ovipositor and probably also from a "venom" injected by the female, is responsible for inter- as well as ultra-specific discrimination and restraint.

The "secondary" attraction occurring after log attack by the female ambrosia beetle, Trypodendron lineatum (Oliv.), and the reduction in attractiveness after males arrive on the log are not dependent directly on mating. The reduction seems to be associated with the males’ presence, which suggests that they produce a masking substance.

A review of the literature published during the past 80 years concerning caste differentiation and caste ratios in the social Hymenoptera reveals considerable evidence that caste is determined trophogenically in the embryo (alimentary castration) rather than in the larval instars and that the caste ratios of the embryonic populations in well-established colonies are soon modified by worker action, i.e. selective cannibalization of queen-biased eggs and young larvae, in order to establish the caste ratios of the adult population that are essential to the economy of the colony.

A new genus and new species, Peckelachertus diprioni, is described and illustrated. Material was reared from eggs of the nursery pine sawfly, Diprion frutetorum (Fabricius) in Quebec, Canada.