Dendrocerus carpenteri (Curtis) was reared in the laboratory on prepupae of Aphidius ervi Haliday (Hymenoptera: Braconidae, Aphidiinae) developing in pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). To test alternative hypotheses about host-marking behaviour and discrimination, we transferred unparasitized and previously parasitized A. ervi prepupae from donor to recipient mummies, which were either "unparasitized" or "parasitized." Females accepted already parasitized hosts within unparasitized mummies, but they rejected unparasitized hosts within previously parasitized mummies. Host discrimination was not influenced by self and conspecific parasitism. Eggs were frequently placed directly on the mummy shell, rather than on the primary parasitoid, or on dummies made from dental wax. Prepupae removed from their mummy shell were not accepted for oviposition. We propose that the "search template" of D. carpenteri is defined, primarily, by the aphid mummy, which is being marked with a contact pheromone after oviposition.

The area of distribution of Thymelicus lineola (Ochs.) now includes much of agricultural Quebec. Several localized, low density populations were observed, especially south of the St. Lawrence River. Heavy infestations were found in the regions of Lac St-Jean, Joliette, and Abitibi–Témiscamingue.

The prevailing method of preparing glycerine mounts of nematodes consists essentially of transferring the specimens from the fixative to 1.5-2.0 per cent glycerine in water and then allowing the water to evaporate very slowly until the nematodes are in pure glycerine. By this method evaporation is completed in not less than four weeks as any attempt to hurry this process will distort the specimens. A desiccator is used to complete the removal of the water from the glycerine.

Mites do not have wings, but in their course of evolution many species have developed an association with insects, using them as a vehicle of distribution. Occasionally they cover the host so completely that the insect cannot fly. The literature is replete with these observations. Except for a single speculation (Fronk 1947), there are no reports as to how many mites Dendroctonus frontalis Zimmerman can support and still fly to its intended destination.

A survey of grasshopper populations in Saskatchewan and Alberta indicated that the fungal disease caused by Entomophaga grylli (Fresenius) pathotype II was present in melanopline grasshoppers in 1985 and 1986. The disease was more prevalent and widespread in 1986, being found at 44% of 128 survey sites in Saskatchewan compared with 11% of 190 sites in 1985. In Alberta a high incidence (≥ three per 100 m2) of infected grasshoppers was found at 6% of 1746 sites in 1986 as compared with less that 1% of 2055 sites in 1985. Levels of infection based on cadaver densities at sites with high incidence of disease in Saskatchewan were similar in both years ranging from 3 to 28% for the total population. Melanoplus bivittatus (Say) was the predominant host species for E. grylli pathotype II; M. sanguinipes (Fabricius) was less affected. Entomophaga grylli pathotype I was isolated from Camnula pellucida (Scudder) hosts from a few sites in both Saskatchewan and Alberta in 1986.

Aerially sprayed fenitrothion (0.21 kg/ha) caused mortalities from 100% among experimentally caged bees in exposed habitats to 47% in cages placed under dense forest canopy. Bumble bees found foraging in sprayed areas during the days immediately following the spray suffered significantly higher subsequent mortality than those in unsprayed areas.

Long-term effects were investigated by comparing late summer Bombus population densities among sites representing various spray histories. For all species combined, abundances in unsprayed areas averaged 3 times higher than in fenitrothion treated areas. Population recovery appeared to be complete within a few years after discontinuation of spraying.

Foraging performance by laboratory reared colonies was significantly higher in sprayed areas with reduced bee populations than in a control area, possibly because of relaxation of competitive stress. The diversity of plant species used for pollen collection was nearly twice as great in the control as compared with sprayed areas, suggesting that the effect of fenitrothion spraying on cross-pollination may be greatest for plants which are subdominant in the hierarchy of bee preference In one such plant, red clover, reduced seed-set was demonstrated.

Nesting materials for use by the alfalfa leafcutter bee (Megachile pacifica Panzer) were compared. When all experimental designs were combined, the leafcutter bees nesting in grooved solid woods, such as pine and fir plywood, and in the polymers, styrofoam and polystyrene, produced a greater percentage of viable cells (i.e., cocoons) than those nesting in drilled boards, soda straws, K3 particle board, aluminum, or corrugated paper. Pine and polystyrene are the only nesting materials now used commercially in Western Canada and chalcidoid parasites occur in low numbers in them because the hives are made precisely. Cells can be mechanically removed from laminated grooved nesting boards so that a loose-cell system of bee management is feasible. Although more expensive initially, these boards are competitive with other nesting materials as they can be reused.

The possible uses of the serological precipitin test for investigating certain entomological problems have been reported previously by West (6). It was suggested that the precipitin test offered a new tool which together with such tools as the electron microscope, paper chromatography and radioisotopes would contribute materially to future advancement in entomology. It is evident to everyone that progress in many branches of entomology is being made currently by the use of new and improved procedures.

The effects of the horticultural oil Purespray Green on oviposition behaviour and egg development in the obliquebanded leafroller, Choristoneura rosaceana (Harris), were investigated through dual-choice and no-choice bioassays and topical applications of oil to developing eggs. A residual 2% (v/v) oil spray on wax-paper and apple-leaf substrates significantly reduced both the number of eggs laid and egg survival in no-choice assays; however, this effect diminished 3 days after treatment. In dual-choice assays, females laid significantly fewer eggs on oil-treated apple leaves than on control leaves, but laid equal numbers of eggs on the oil-treated wax paper and the untreated wax-paper controls. Topical application of oil caused significant dose-dependent mortality of both newly laid eggs and eggs just before hatch, and these two egg stages were equally susceptible to the oil. Topical application of 2% oil caused >99% egg mortality. Our data indicate that gravid female C. rosaceana can assess and reject oil-sprayed surfaces and that the oil can kill eggs through both contact toxicity and suffocation. These characteristics suggest that highly purified horticultural oils like Purespray Green could play a role in an integrated pest management program for this important pest species.

In two recent studies it was reported that feeding on foliage of multiple age classes can improve insect fitness, but it was not determined whether the increase in fitness was due to larvae obtaining a more balanced diet (the balanced-diet hypothesis) or to a difference in the nutritional requirements between young and old larvae (the ontogenetic hypothesis). To test these two hypotheses, we examined the foraging behaviour and performance of young (second or third to fourth instar) and old (third or fourth to fifth instar) larvae of the pale-winged gray moth, Iridopsis ephyraria (Walker) (Lepidoptera: Geometridae), on different-aged foliage of eastern hemlock, Tsuga canadensis (L.) Carrière (Pinaceae), during an outbreak in southwestern Nova Scotia. Defoliation attributed to I. ephyraria was highest on current-year foliage and gradually declined with foliage age. Young larvae were only observed feeding on current-year shoots but old larvae fed on foliage of all ages. When forced to feed on foliage of specific ages in manipulative field studies, survival rates of young and old larvae were highest on current-year and old (≥1 year old) foliage, respectively. However, both young and old larvae had higher survival rates when provided with access to foliage of all age classes than when they were forced to feed on only young or old foliage. Thus, this study supports both the balanced-diet and ontogenetic hypotheses.

The populations of Laspeyresia pomonella (L.) on two cultivars in an insecticide free orchard showed similar trends over a 12-year period. Infestation of fruit was greater on the cultivar with the larger annual crop. Predation of eggs on the cultivar Delicious was greater than on the cultivar McIntosh. Mortality of neonate larvae was greater on McIntosh. Egg-to-egg survival ratios varied from 0.23 to 6.83. The average generation survival of egg to adult for the 12-year period was near 10% which confirms an earlier value established empirically.

A novel “rearing-tube” method was developed and used to investigate the performance of mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), with its three main ophiostomatalean fungal symbionts, Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer, and Wingfield (Ophiostomataceae), Ophiostoma montium (Rumbold) von Arx (Ophiostomataceae), and Leptographium longiclavatum Lee, Kim, and Breuil (Ophiostomataceae). Transparent glass tubes filled with sterile ground jack pine (Pinus banksiana Lambert; Pinaceae) phloem and sapwood (9:1 ratio) were used to rear MPB from egg to adult with each fungus under controlled environmental conditions. Mountain pine beetle mortality was higher and development longer in fungus-free controls compared to fungal treatments. Among fungal treatments, insects developed faster, constructed shorter larval galleries, and had fewer supernumerary instars with L. longiclavatum. Insect survival was not affected by fungal treatments. Hyphal extension through the rearing medium was fastest for L. longiclavatum. Phloem nitrogen was reduced significantly by the presence of L. longiclavatum. Results support the hypothesis that ophiostomatalean symbionts provide benefits to MPB. The rearing-tube method is useful to tease apart confounding interspecific interactions between bark beetles and symbiotic fungus species.

Cleared slide mounts of antennae of 30 species of Ptomaphagus beetles showed two internal sensory vesicles in segments 7, 9, and 10. The vesicles were of similar size in each segment except in segment 7 of cavernicolous species. SEM study showed a narrow circular opening in the distal face of segments 7, 9, and 10 which opens into a widened circular canal inside of and under the segment’s distal surface. Sensory vesicles are pockets in the bottom of this canal. The canal and vesicles are predominantly lined with a unique type of fluted sensilla basiconicum. These sensilla are more elongated and more numerous in cavernicolous species. The origin and evolution of the sensilla and vesicles are discussed.

Second-instar Heliothis zea (more than the 275th generation) larvae from a 16-year-old culture, were fed either green beans or artificial diet until they reached the pupal stage and then were compared to determine their relative fitness to the two diets. They proved at least as well adapted to beans as to artificial diet with regard to most parameters. Final larval weights were equal, as were pupal dry weights. Wet weights were higher in diet-fed than in bean-fed pupae. Dry food consumption was higher in diet-fed larvae than in bean-fed larvae, but the reverse was true of wet food consumption. Total food consumption by larvae was limited by food volume rather than weight or composition. The larval stage was shorter in diet-fed than in bean-fed larvae; and diet-fed larvae had better survival, higher body nitrogen, and body energy content. Oxygen consumption was lower in bean-fed than in diet-fed larvae. Efficiency of food utilization was higher for bean-fed than for diet-fed larvae both in terms of dry matter conversion and energy conversion. Nitrogen utilization efficiencies were the same for both diets.

Opius melleus Gah. and O. lectus Gah. were the only parasites of Rhagoletis pomonella (Walsh) found in southern Ontario during a 4-year survey. The parasites were found only in the Niagara Region on the slope of the Niagara Escarpment and between it and Lake Ontario. The population of parasites was low though they appeared to be well adapted to attack R. pomonella. They were found in, or adjoining, unsprayed sites where there was shrubby growth under the trees infested by R. pomonella.

In 1956, the spruce budworm infestation which had been in progress in the Lower St. Lawrence and Gaspe Peninsula for about eight years, covered the whole territory from the Rimouski River to the eastern tip of the Peninsula (Fig. 1). In many localities throughout the region repeated defoliation had been severe enough to cause some trees to die (3) . Had it not been for the extensive aerial spraying operations practised in this region since 1954, tree mortality would undoubtedly have been even more widespread.

A new species of aquatic firefly, Luciola leiisp. nov., from Hubei Province in mainland China is described from males, females, and larvae. It is the fifth species of aquatic firefly recorded from China, and it differs significantly from Luciola substriata Gorham. Cuticular plates in the female reproductive system (bursa) are described and their possible functions are discussed.

The red turpentine beetle, Dendroctonus valens LeConte, 1860 (Coleoptera: Curculionidae, Scolytinae), is a common bark beetle found throughout much of North America and China. In 2004, we observed that attack densities of the California fivespined ips, Ips paraconfusus Lanier, 1970 (Coleoptera: Curculionidae, Scolytinae), in logging debris were inversely related to D. valens attacks on freshly cut stumps, which led to the demonstration that components of the aggregation pheromone of I. paraconfusus inhibited the response of D. valens to attractant-baited traps. In this study, we test the response of D. valens and Temnochila chlorodia (Mannerheim, 1843) (Coleoptera: Trogositidae), a common bark beetle predator, to racemic ipsenol, racemic ipsdienol, and (−)-cis-verbenol (IPSR) in the presence and absence of two release rates of (−)-verbenone. The addition of a relatively low release rate of (−)-verbenone (4 mg/24 h) to attractant-baited traps did not affect catch and had no significant effect on the response of D. valens to IPSR. IPSR significantly reduced D. valens attraction to baited traps. The addition of high release rates of (−)-verbenone (50 mg/24 h) to IPSR significantly increased inhibition; however, the effect was not significantly different from that observed with (−)-verbenone alone (50 mg/24 h). Temnochila chlorodia was attracted to traps baited with (−)-β-pinene, (+)-3-carene, and (+)-α-pinene. The addition of (−)-verbenone (50 mg/24 h) significantly increased attraction. Traps baited with IPSR caught significantly more T. chlorodia than those baited with (−)-verbenone. Few other beetles were collected. We are hopeful that these results will help facilitate the development of an effective tool for protecting Pinus spp. from D. valens infestations.

Stridulatory structures of the flight wings and elytra, and a dorsal chamber in the thoracic abdominal junction of C. traquebarica Herbst are described. The functions of these structures are considered. A list is provided of 62 species of tiger beetles and 13 species of ground beetles which have stridulatory files on the flight wings.

The parasitic tachinid fly Strongygaster triangulifera (Loew) is widely distributed in North America (Stone et al. 1965). It parasitizes several Coleoptera and sometimes species of other orders such as Lepidoptera, Dermaptera, and Hemiptera (Sabrosky and Braun 1970). Existing records of S. triangulifera found in coccinellid hosts are from eastern North America. One describes low parasitization levels (<1%) in two indigenous species, Coccinella trifasciata perplexa Mulsant and Coleomegilla maculata lengi Timberlake, in Ontario, Canada (Smith 1960). The other existing record describes fluctuating parasitization levels (3.0–31.1% in 1993 and 0–6.5% in 1994) in the exotic species Harmonia axyridis (Pallas) in North Carolina and Virginia (Nalepa et al. 1996).