Seed produced by Fraser fir, Abies fraseri (Pursh) Poir., infested by the balsam woolly aphid, Adelges piceae (Ratzeburg), was compared with that originating from uninfested trees during a cyclic year of heavy seedfall (1969) in western North Carolina. Cones were significantly shorter and seed uniformly lighter and smaller from trees infested by the aphid. X-ray examination indicated the number of full seed from uninfested trees averaged nearly 70% and 42% higher than in comparable seed samples from infested trees. Germination tests indicated viability of seed from infested trees exceeded 32% and that from uninfested trees exceeded 75%. An important factor affecting survival of seed from the two sources appeared to be the relative susceptibility of seed to attack by Megastigmus specularis Walley. Almost 28% more seed were destroyed by these seed chalcids for aphid-infested trees than for uninfested trees.

The light brown apple moth, Epiphyas postvittana Walker, is a highly polyphagous native pest of Australia that has recently caused widespread damage to pome, citrus, and vine crops in Victoria and Tasmania. Populations of the pest were followed in a young pesticide-free orchard for two seasons and showed a survival trend of less than 1% of the total eggs laid in each season. An evaluation of its natural enemies by numerical, serological, and forced feeding techniques showed that spiders, particularly the theridiid Achaearanea veruculata (Urquhart), were valuable predators and that they were supported by chrysopids and mirids for short periods of time. Egg, larval, and pupal parasites also contributed to mortality. Brief biological notes on some of the predators are given.

Females of Nasonia vitripennis (Walk.) lay a smaller percentage of fertilized (i.e. female) eggs on house fly, Musca domestica L., pupae previously parasitized by their own species, by Muscidifurax zaraptor K. & L., or by Spalangia cameroni Perk. (Hymenoptera: Pteromalidae) than on unparasitized hosts. They respond to changes in the fly pupae associated with death, and in the case of house flies attacked by N. vitripennis, to "venoms" injected at that time or to changes unrelated to death. By not fertilizing eggs that they lay on attacked hosts, the females also conserve sperm, for immature N. vitripennis on previously-attacked fly pupae are usually killed by parasite larvae already present.

During courtship in Lytta nuttalli Say the male assumes the active role. Mounted above the female, he repeats a cycle of three stereotyped, stimulatory activities: antennal manipulation, abdominal vibration, and attempted genital insertion. The male uses both his antennae together to stroke alternately the tips of the female’s antennae, which he holds upright with his fore legs. With rapid lateral vibrations of his abdomen, he brushes the ends of the female’s elytra and her eighth tergum with the long bristles on his eighth sternum. He also repeatedly probes the end of the female’s abdomen with his aedeagus, attempting to establish genital contact. Abdominal vibration is performed alternately with genital insertion attempts; antennation usually is carried out at the same time as the other activities. Courtship lasts for a few minutes to 1 hour or more. Copulation is initiated by successful genital insertion and is executed with the male and female aligned end-to-end. Its average duration is 8 to 10 hours. Abdominal vibration seems to be unique to Lytta, whereas the dorsal orientation during courtship and the genital activity are similar to those observed in many other Meloinae. Though antennal manipulation is common in Meloinae, the method employed by L. nuttalli is different from that in other meloines. Anatomical modifications related to courtship are discussed.

Larvae and eonymphs of the diprionid sawflies Neodiprion lecontei (Fitch), Neodiprion swainei Midd., and Diprion hercyniae (Htg.) were dissected and stained to demonstrate the nervous system and endocrine organs. Morphologically and anatomically the endocrine organs in both larvae and eonymphs of all three species are very similar. The cephalic structures comprise lateral and medial neurosecretory cells in the brain which discharge their secretions through a single pair of nerves (NCC) to the corpora cardiaca. The NCC divide before they enter the corpora cardiaca sending a branch to the corresponding corpus allatum. No other nervous connections with these organs are apparent.

Paired neurohaemal organs occur in each thoracic segment, forming distinct dilations on slender nerves arising from the ventral cord connectives. They receive secretions from groups of lateral neurosecretory cells in the thoracic ganglia.

Each abdominal ganglion has three neurohaemal organs associated with it, a single small spherical structure antero-medially, and paired lateral organs of a diffuse structure, overlying the base of each segmental nerve. They are less conspicuous than the thoracic organs and have different staining properties.

The question of whether the evolutionary origin of the parasitic bumble bees (Psithyrus Lep.) was monophyletic or polyphyletic has not been convincingly resolved by conventional systematics. In this study numerical taxonomic (NT) analysis was applied to data on wing venation from a set of 13 species of Psithyrus and 60 species of non-parasitic bumble bees (Bombus Latr.), representing 16 of the subgeneric divisions recognized by Richards. The resultant cluster analysis gave an almost perfect grouping of the constituent Bombus species into their ’correct’ subgenera. This was taken as evidence that the NT procedure had yielded discriminant criteria of evolutionary significance. Since the same criteria also produced a single grouping of the Psithyrus species, the results support a monophyletic origin for Psithyrus.

The morphological differences in the larva and the adult of Tetropium parvulum Casey and T. cinnamopterum Kirby are reported. Diagnostic characters are the urogomphi of the larva. The shape of the eye, scutellum, and genitalic structures and the number of punctures on the pronotum distinguish the adult. The genitalia are also compared with a third species, T. velutinum. Larvae of T. cinnamopterum have been recorded from a number of conifers, while T. parvulum larvae have only been recorded from spruce.

A lectotype is designated for T. cinnamopterum. Examination of type specimens confirmed that T. alaskanum Fall is a synonym of T. parvulum and that T. schwarzianum Casey and T. parallelum are close to T. cinnamopterum. A key is given to distinguish T. parvulum from T. cinnamopterum.

The wood borer Tetropium parvulum Casey is an economically important borer of white and engelmann spruce logs in Alberta. It has a 1-year life cycle. The adults emerge in early summer, the larvae mature by September, overwinter in L-shaped galleries, and pupate in the spring. The L-shaped galleries penetrate the wood to an average of 25–35 mm. Four natural mortality factors were: a suspect disease, the parasite Rhimphoctona alaskensis (Ashmead), excess heat, and woodpeckers. Of these, the suspect disease was the most evident, killing 57% of the mature larvae in one sample.

Insect developmental inhibitors applied to colonies of the green peach aphid, Myzus persicae (Sulzer), on peach trees in early May reduced the production of winged migrants as much as 75% and delayed migration for as long as 15 days. However, these compounds affected mainly the alatoid nymphs and not the reproductive adults; therefore, apterous aphids would be available as prey to the natural enemies that are present on peach trees in the spring. A reduction in the number of aphid migrants and a delay in their migration from peach trees would result in a subsequent reduction in the number of aphids produced on diseased secondary hosts and a delay in the migration of these aphids to host crops. In most cases, this would result in an increase in yield and an economic gain to the growers.

A previously undescribed entomopoxvirus was isolated from larvae of Choristoneura conflictana Wlk. Samples of larvae taken from several points in Ontario indicated that the virus was widespread in the Province.

The morphology of the virus is described. The inclusion bodies are larger than those of another entomopoxvirus originally isolated from Choristoneura biennis Free. and propogated in Choristoneura fumiferana (Clem.). The virions are of the same order of size for both viruses. Microspindles are associated with these viruses and some of the spindles are occluded along with the virions within the oval inclusion bodies. The C. conflictana entomopoxvirus is also infectious to C. fumiferana.

Conflicting taxonomic decisions by classical systematists in the genus Iphiseius are examined against a numerical model. The relative weights given to characters are estimated by the amount each character must be changed to minimally permit each classical taxonomic decision. In the genus Iphiseius the taxonomic disagreements are due to heavy weighting of different small sets of characters based on groupings of historically prior clustering cycles.

A physiologically active fraction inducing oviposition in Itoplectis conquisitor (Say), and isolated from the hemolymph of some insects, was studied in detail using hemolymph from Galleria mellonella (L.) and Celerio euphorbiae (L.). The active fraction consisted of hexoses and some 19 common amino acids. The hexose component may act as a synergist in inducing oviposition while not all amino acids were necessary to induce oviposition. I. conquisitor laid eggs in the hemolymph of species of Lepidoptera, Hymenoptera, Coleoptera, and Trichoptera, but did not oviposit in the hemolymph of species belonging to Hemiptera, Orthoptera, Neuroptera, Plecoptera, and Crustacea.

Populations of Monochamus scutellatus (Say) were found to differ morphologically from populations of M. oregonensis LeConte in color of femora, mouthparts, and antennae; elytral rugosity and shape of scutellum. The genitalia of the two entities differed slightly in the female. Alberta populations of both entities hybridized freely in the laboratory, producing a fertile F1 generation, which was successfully crossed with each parental species. Because of the lack of reproductive isolation between the allopatric entities, M. oregonensis is synonymized under M. scutellatus, but given subspecies status because of the morphological differences. Diagnostic characters of each subspecies are given.

Adults of Tenebrio molitor L. can copulate on the second day after eclosion, but the majority of them do not do so until after the third day. Almost all adults copulated at least once within the first 4 to 5 days. Young females initiated copulation at a slightly earlier age than young males. Crowding enhances mating success in young adults, for which there appears to be a critical minimum adult density. The initiation of copulation was not inhibited at very high densities; this suggests that there is not a critical maximum adult density for mating success.

Two new species of aphids are described from Manitoba, Acyrthosiphon assiniboinensis new species from Potentilla fruticosa L., and Masonaphis pinawae new species from Ledum groenlandicum Oeder.