A key is given for seven species of Aphis L. that occur on Cornus species in North America: caliginosa Hottes and Frison, corniella (Hille Ris Lambers), cornifoliae Fitch, helianthi Monell, maculatae Oestlund, neogillettei Palmer, and a new species that is described, nigratibialis Robinson. Host transfer attempts with helianthi and corniella are discussed.

Five species of Limnoporus Stål (L. canaliculatus [Say], L. dissortis [Drake and Harris], L. nearcticus [Kelton], L. notabilis [Drake and Hottes], and L. rufoscutellatus [Latreille]) were each sampled at 20 electrophoretic loci. Twofold differences among species in mean heterozygosity appear to be unrelated to presence of wing dimorphism. Low heterozygosity in some populations within species may reflect geographic isolation. There were substantial differences in allele frequency among, but not within, species. Limnoporus rufoscutellatus from western Europe and L. nearcticus from Alaska were the most similar pair of species, with a Nei’s standard genetic identity that is generally found only between populations of the same species. Limnoporus canaliculatus was the most divergent species, and the relationship among L. dissortis, L. notabilis, and the L. rufoscutellatus – L. nearcticus pair is resolved as a trichotomy.

Two distinct experiments were carried out to assess the trans-generational and within-generational effects of the parasiticides ivermectin and moxidectin to dung beetles (Coleoptera: Scarabaeidae). In the first experiment, the fertility of Euoniticellus intermedius (Reiche) (Scarabaeinae) was assessed for individuals developing in dung containing 10 µg ivermectin/kg fresh dung, a residue concentration previously shown to be sublethal to larval development. Our results showed that the fertility of adults exposed to these residues as larvae was unaffected. In the second experiment, the fertility of Agrilinus constans (Duftschmid) (Aphodiinae) was determined after females were allowed to feed for three weeks on dung containing different concentrations of moxidectin residues (five concentrations ranging from 0.32–32.00 mg/kg dry dung). The fertility of females was not affected, regardless of the concentration to which they were exposed, even when they were exposed to high moxidectin residues that killed all the offspring. The combined findings of these two experiments emphasise that sublethal effects should be included in models that assess the nontarget effects of faecal residues to insects breeding in dung of livestock treated with veterinary medicinal products.

The family Nudomideopsidae fam.nov. is proposed on the basis of an analysis of morphological characters of larvae and adults of species of Nudomideopsis and related genera, and consideration of the zoogeography of the group. The systematics and distribution of North American species are reviewed, and adults of Nudomideopsis (Allomideopsis) wichitaensis subgen.nov., sp.nov. are described.

The structure, distribution, and type of sensory hairs on the palptarsus of female Varroa jacobsoni Oudemans were examined by scanning electron and phase contrast microscopy. The two large, peg-like setae with apical pores are chemoreceptor sensilla chaetica. The seven slender, round tipped setae, stained with crystal violet at the hair cuticle, are considered to be the chemoreceptor sensilla trichodea. A number of long hairs that did not stain with crystal violet are trichoid tactile setae. The possible functions of these sensilla were discussed.

Laboratory bioassays and field tests demonstrated that the (+) enantiomer of endo-brevicomin is an antiaggregation pheromone for the western balsam bark beetle, Dryocoetes confusus Swaine. (+)-endo-Brevicomin significantly reduced the response of beetles of both sexes to the aggregation pheromone exo-brevicomin in laboratory bioassays and in field experiments using multiple-funnel traps. It also prevented attack on subalpine fir, Abies lasiocarpa (Hook) Nutt., trees baited with exo-brevicomin. The (−) enantiomer of endo-brevicomin was inactive. These results suggest that (+) or (±)-endo-brevicomin has potential for protecting selected trees from attack, or suppressing western balsam bark beetle activity in high hazard or infested stands.

Early in July, 1953, a yellowish mite was observed feeding on active forms of the European red mite, Metatetranychus ulmi (Koch), in an orchard at Rougement, Qué., where a minimum of pesticides (insecticides and acaricides) detrimental to the natural fauna had been used for two years. The mite increased considerably in numbers during 1954 and 1955, contributing noticeably to the control of the European red mite.

A leaf miner on ironwood, Chrysopeleia ostryaella Chambers, is recorded for the first time from Canada. Information on distribution, life history, habits, morphology of immature stages, and parasites is given.

The symbiosis between bark beetles and microorganisms, mostly fungi, has been investigated and reviewed by Graham (1967) and Whitney (1982). Bark beetles and their habitat fungi have been studied separately but a suitable method for studying them in combined culture is lacking. To study bark beetles in the laboratory, a method for axenic rearing was developed by Bedard (1966), then improved by Whitney and Spanier (1982). Beetle development was retarded or nil without the addition of Brewer's yeast to the diet (H.S. Whitney, Pacific Forest Research Station (PFRC), Victoria, BC, pers. comm.). The inclusion of yeast in the diet precludes studies of symbiosis, such as the role of fungi in beetle nutrition. I describe a method for rearing bark beetles with or without a fungal complement to investigate this symbiosis

Using a series of photographs, the mechanism of host location and oviposition by Rhyssa lineolata (Kirby) are described.

The two-spotted spider mite, Tetranychus urticae Koch, showed a pronounced two-peak diel periodicity of susceptibility to dicofol, in a natural regimen of light: dark. The first occurred between 0200 and 0500 hours and the second between 1300 and 1800 hours. Mortality dropped sharply after sunrise (0441 hours) and again an hour before sunset (2002 hours). Lowest mortality occurred near midday. Egg-laying was inversely related to mortality over the 24-hour period.

In the apple orchards of Nova Scotia DDT, azinphos-methyl or lead arsenate control the winter moth, Operophtera brumata (L.). DDT, even at a low dosage, is detrimental to predators but not to the phytophagous mites Bryobia arborea M. & A. and Panonychus ulmi (Koch); azinphos-methyl is toxic to B. arborea but not to P. ulmi; lead arsenate is of low toxicity to both the phytophagous mites and predators but effective in control of the winter moth when applied against the maturing larvae.

The relationship between temperature and ovarian development rates, as well as the cumulative probability of a female becoming gravid, were determined for the house fly, Musca domestica (L.), based on previously published information. These relationships were combined to form a model that simulates oviposition of house fly populations using average daily temperatures, eggs per cycle, and daily survival as input. Simulation results were compared with observed oviposition in three caged populations of house flies exposed to field temperatures. A high correlation occurred between simulated and observed eggs laid (r = 0.88), as well as between simulated and observed lxmx (r = 0.91). The model overestimated the onset of oviposition for one population, but closely simulated the timing of oviposition for the other two. The model also tended to overestimate the reproductive contribution of flies during the second and subsequent ovarian cycles.

Radioactive phosphorus was used as a tracer in assessing the number of red-legged grasshoppers (Melanoplus femurrubrum (De Geer)) eaten by the European praying mantis (Mantis religiosa L.) under seminatural conditions. The predator showed a functional response to changing prey densities with a continuously decreasing increase in the number of prey removed from the population.

Laboratory olfactometer experiments made at constant ambient temperature (29°C) demonstrated that the protection afforded mammalian hosts by 2-ethyl hexanediol-1,3 (’6–12’) against Aedes aegypti L. was greater at high (82%) than at low (35%) ambient relative humidity. The physical and physiological implications are discussed.

A new genus, Melastola, with type-species Gymnonychus resinicolor Marlatt, and two new species, Pristola clarki and Melastola ferruginosa, are described. Keys to the genera and known species of the tribe Pristolini are presented. New distribution records for Pristola macnabi Ross are reported in North America.

Parasitism in natural populations of Hyphantria cunea Drury was measured in New Brunswick and Nova Scotia, 1957–1973. Thirteen parasite species were recovered during this period but only a few caused an appreciable degree of mortality. The per cent mortality showed an immediate rather than a delayed response to host density, the relationship being direct up to a density of about 10 host colonies per mile, then inverse. Possible reasons for this sort of relationship are discussed.

The information to be obtained from thorough life-history studies is an extremely useful tool, perhaps especially so when ecology is being emphasized, as it is to-day, by the life-table and other mathematical approaches to the study of population processes. This information is desired by workers in many fields of entomology – by the biological and chemical control experts, the biomathematicians, the theorists and even the taxonomists. However, much of the knowledge that these workers require, for instance the fine distinctions of behaviour and environment, has been overlooked in most life-history studies, and I strongly suspect that one of the weaknesses of studies of this nature has been the failure to analyse the mode of living of an insect (or, in the case of Lepidoptera, of the immature forms) in relation to the anatomy on one hand and environmental circumstances on the other. To look for these relationships, I believe that one requires (a) the ability and perseverance to perceive detail as minute as that required for a taxonomic study, and (b) a considerable knowledge of the taxonomic detail that is to be obtained from basic morphological studies. Therefore, in this paper, attention is drawn to pertinent structural characters of lepidopterous larvae and their probable connection with the behaviour and microhabitats of the larvae, in the hope that some guidance may be offered to future students of life-histories, at least in Lepidoptera.

In 1955 and 1956, while sampling corn stalks for larvae of the European corn borer in experimental plots at St. Jean, the author noted 23 adults of Coleomegilla maculata lengi Timb. and two adults of Coccinella novemnotata Hbst. that were parasitized and attached to the upper surfaces of corn leaves. Each beetle was astride a freshly formed cocoon and was held by a network of silk; many were alive when found. The parasite cocoons and the hosts were placed in closed petri dishesfor observation. The parasites that emerged were identified by Dr. W. R. M. Mason, Entomology Division, Ottawa,as Perilitus coccinellae (Schrank) (= Dinocampus terminatus (Nees).