The calling behavior of females of three interfertile sibling species of Euxoa was studied in the laboratory at 20°, 15°, 10°, and 5 °C. At 20 °C the calling posture of E. campestris and E. rockburnei differs from that of E. declarata. However, with decreasing temperatures the calling posture of both campestris and rockburnei becomes indistinguishable from that of declarata. The pattern and duration of calling bouts was similar in all three species and at all four temperatures. Calling occurred progressively earlier in scotophase as temperature decreased but temporal separation between the calling periods of the three species is maintained at all temperatures above the threshold for mating activity. This confirms that temporal separation of mating persists over the range of temperature normally encountered in nature and strengthens the evidence that species-specific rhythms of mating activity are largely responsible for maintaining reproductive isolation between sympatric populations of these species.

Live cultures believed to be aphids of Aphis fabae Scopoli from New Brunswick, Manitoba, and British Columbia were compared by several methods. Cultures from British Columbia lived on faba bean, Vicia faba L., but not on garden nasturtium Tropaeolum majus L. Cultures from Manitoba lived on nasturtium but not on faba bean. Some of the aphids from New Brunswick lived on nasturtium only, and some on faba bean only. The aphids which live on faba bean are believed to be Aphis fabae, and those which will not live on faba bean are considered to be a distinct species.

An aphid, Aphis barberae new species, is described from garden nasturtium, Tropaeolum majus L. and burdock, Arctium minus (Hill) Bernh. It differs from A. fabae Scopoli mainly in that it can not be cultured on faba bean, Vicia faba L.

A crown-boring noctuid, Amphipoea interoceanica (Smith), has suddenly become a serious pest of commercial strawberries in Manitoba. Eggs are laid in August on dead strawberry leaves and hatch in early May. Young larvae feed in the leaf stalks; older larvae bore in the crowns and kill the plants. There are six instars, pupation occurs in late July and adults emerge in August. The plants are first attacked in the second year of growth and by the fifth year the entire crop may be lost.

One-day-old P1 males of the almond moth, Ephestia cautella (Walker), were irradiated with 5, 10, 15, or 2 krad of gamma radiation and paired with untreated virgin females. Progeny were collected through three generations, and lines were established in theF1and F2 with all possible degrees of inbreeding and outbreeding. Radiation effects were assayed by determining mating success, sterility of pairs, average number of progeny/fertile pair, and sex ratio for pairs with males (U♂ × F1♀ U♂ × F2 ♀), females, or both sexes (F1♂ × F1♀, F2 ♂ × F2 ♀) from each dose. Results showed the greater the initial dose, the greater the reduction in the number of progeny and the greater the male to female ratio. Radiation effects on both F1 males and F1 females were greater than effects on the P1 males, though effects on F1 males were greater than effects on F1 females. Except for extinct lines, partial recovery occurred in the F2 generation though recovery was much greater in F2 females than in F2 males. In each generation males were more affected than females from the same breeding line when they were outcrossed with untreated moths. The greater the degree of inbreeding in irradiated lines, the greater the effect on both males and females. Although a high degree of population reduction occurred only in the F1 generation at a dose of 15 and 20 krad, population models showed inbreeding at the lower doses caused sufficient depression to greatly reduce abundance of a natural population for several generations after a single inundative release of substerilized males.

The pattern of blood feeding in males of Stomoxys calcitrans L. is different from that of females. Female flies ingest more blood than males. Females fed only blood or blood and sugar-water ad libitum showed a periodic pattern of blood ingestion. The amount of blood ingested at the time of first feeding is partly dependent upon the age of the flies; in addition flies fed only blood ingest more than flies whose blood diet is supplemented with sugar-water. During the period prior to blood feeding the weight loss per day increased as the fly aged. On the other hand if the flies were fed with sugar-water from the time of emergence they gained considerable weight. The rate of weight loss after one blood meal was of the same pattern in flies fed 24 or 48 h after emergence. The pattern of weight loss was also similar in flies fed sugar-water ad libitum and blood 24 h after emergence.

A number of ketocatechols have been isolated and identified from acid hydrolysates of larval and pupal exuviae of the spruce budworm, Choristoneura fumiferana. The most abundant of these, 2-hydroxy-3′,4′-dihydroxyacetophenone, represented 5.8% of the dry weight of pupal exuviae, 4.6% of larval head capsules, and 0.3% of the remaining larval exuvium. This compound is thought to be the primary breakdown product arising from crosslinks between cuticular proteins and the aliphatic sidechain of a phenolic tanning compound. The yields therefore reflect the extent of β-sclerotization, one of two mechanisms proposed for the hardening of insect cuticle. Budworm is similar to other species with respect to the types of hydrolysis products recovered although three previously undescribed compounds were detected.

A chemical mixture highly attractive to males of western pine shoot borer, Eucosma sonomana Kearfott, were dispensed from manually applied polyvinyl chloride releasers on 15 ha of ponderosa pine plantations during spring 1978 near Bly, Oregon. Mating disruption treatments, replicated 4 times, were 3.5 g/ha from 100 releasers/ha spaced at 10 m, and 14 g/ha from 400 releasers/ha spaced at 5 m. Both were equally effective; the number of damaged terminal shoots was reduced 83.0% with the low dosage and 84.2% with the high dosage.

Hollow fibers containing a mixture of synthetic sex attractants of western pine shoot borer, Eucosma sonomana Kearfott, were applied by an airplane to 19 ha of ponderosa pine plantations in southern Oregon. Nominal dosage was 15 g active ingredient per hectare. A behavioral evaluation of treatment effects, based on moth responses to pheromone-baited traps, showed nearly 100% disruption of female to male sex pheromone communication. Tree damage in treated areas was reduced by an average of 67% for terminal shoots and by 79% for terminal and lateral shoots combined.

Two synthetic pheromones, frontalin and seudenol, were tested on living host (Picea) trees and on non-host (Abies) trees to determine their relative attractiveness to the spruce beetle (Dendroctonus rufipennis) and a clerid predator (Thanasimus undatulus). On host trees, frontalin attracted significantly more spruce beetles and induced significantly more attacks on the trees than did seudenol. On non-host trees, more beetles and a higher male ratio were attracted to seudenol than to frontalin. Frontalin has a positive effect on the behavior of female spruce-beetle attack, whereas seudenol has not. The resulting natural secondary attraction of attacking female beetles creates strong aggregation of both sexes of spruce beetles on host trees (Picea) baited with frontalin, but not on host trees baited with seudenol or on non-host trees (Abies). The clerid predator (T. undatulus) was attracted to frontalin in significatnly larger numbers than to seudenol.

A series of sod-lined pools were constructed and used to monitor repeated applications of diflubenzuron as Dimilin WP-25 and mefhoprene as Altosid SR-10. Diflubenzuron and methoprene "disappeared" rapidly from the pool water as determined by bioassays using Aedes aegypti (L.) (Culicidae) larvae and by gas-liquid chromatography (GLC). Chemical assays for a diflubenzuron derivative were positive for several days; bioassay indicated the presence of diflubenzuron (or at least growth regulator activity) at levels toxic to mosquito larvae for up to 16 days. In contrast methoprene "fell" below GLC detection within 2 days although biological activity persisted for approximately a week after treatment. Neither parent compound should cause a long-term persistence hazard when used for mosquito control in Canadian prairie waters.

Effects of three temperatures and three prey types on the developmental time (egg to adult) of Thanasimus dubius (F.) from two different geographic areas were investigated in the laboratory. The developmental time decreased with increasing temperature. Larval T. dubius exhibited longer developmental times with small prey larvae as compared with larger prey. However, the prepupal and pupal period was shorter for T. dubius fed small prey. Prey type did not affect the overall developmental time. Significant difference in developmental time was observed between the two groups. Elytral lengths of adult T. dubius were indicative of rearing temperatures and prey type consumed by the immature predator.

Landing rates as monitored by landing traps indicate that the mountain pine beetle, Dendroctonus ponderosae Hopkins, is not attracted to lodgepole pine, Pinus contorta Dougl., prior to the first gallery start. Bark terpene odors and DBH were not correlated with beetle landing rates, with the exception of beta-phellandrene which accounted for a statistically significant 18% of the variation in landing rates. Beetles were unable to distinguish between hosts, dead hosts and nonhosts during landing. The elderberry pith bioassay indicated the presence of a gallery initiation stimulant in the bark.

At least two species of parasitic larval mites of the erythraeid genus Leptus were found on male spruce bud worm, Choristoneura fumiferana (Clem.), moths attracted to pheromone-baited traps. Mites were found on 28.5% of 2298 male moths captured during three trapping days in July 1977. Numbers of mite-infested moths were positively correlated with catch density. Percentage mite infestation increased with time. Red larval mites were also collected from both male and female free-flying budworm moths. Attachment sites include: wing veins, cervix, compound eye, femur, and abdomen. As many as four mites were collected from one female moth.

Pine oil, derived from pulp mill by-products, and oleic acid significantly delayed and reduced the attack by ambrosia beetles Trypodendron lineatum (Oliv.) and Gnathotrichus spp. on Douglas-fir logs. Pine oil also appeared to interfere with the attack by bark beetles. The possibility of combining the use of repellents with a pheromone-based diversion scheme is suggested as an effective protection strategy.

The critical photoperiod for fourth instar diapause of the western treehole mosquito, Aedes sierrensis, varies among geographic populations. When reared together in the field at different latitudes, larvae from northern (ca. 45°N), central (ca. 39°N), and southern (ca. 33°N) populations all develop more rapidly through the early instars at more southerly latitudes. The order of pupation dates among the populations, however, depends on their critical photoperiods, and can be predicted from laboratory data on photoperiodism.

Receptive fields of the infrared receptors located in sensory pits adjacent to the mesocoxal cavities of Melanophila acuminata were measured using a goniometric apparatus and plotted on a Mollweide homolographic projection. The receptive fields extend mainly in a lateral and ventral direction. The total receptive area in units of solid angle is 5.80 steradians but the simultaneous field of perception of infrared radiation of all the sensilla in a pit is only 0.42 steradian. Based on these findings and on other evidence we believe that the infrared-sensitive sensilla function during flight and are used by these beetles for detecting point sources of heat, such as forest fires, from long distances.

The wharf borer, Nacerdes melanura (L.) (Fig. I), is widely distributed throughout the world. It has been recorded in England, New Zealand, Denmark, Germany. Siberia, Japan, and the Bahama Islands (Balch 1937). Walker (1936) reported N. melanura from Syria, Shanghai, Korea, Japan, South Africa, Brazil, Argentina, Costa Rica, and the United States. In the United States, it has been found in most coastal states, and also in Michigan, Indiana, Missouri, Kansas, and New Mexico. In Canada, it is known to occur in Newfoundland, Nova Scotia, New Brunswick, Quebec, Ontario, Manitoba, and British Columbia. The life history of the wharf borer in Canada has been outlined in detail by Balch (1937) and Spencer (1957).

The common June beetle, Phyllophaga anxia (LeConte), is an indigenous pest of agricultural crops in North America (Hammond 1948; Ritcher 1949). A bionomic study and survey for natural enemies of P. anxia was conducted in southern Quebec from 1975 to 1977. Pasture soils were searched for immature stages of P. anxia, and any natural enemies found in situ were collected. A prepupa and pupae of Pelecinus polyturator (Drury) were found in the pasture on several occasions. Previously, P. polyturator had been reported as a parasite of grubs of Phyllophaga spp. (Davis 1919; Petch and Hammond 1925, 1926; Brues 1928; Hammond 1944), and its distribution ranges from Canada to Argentina (Masner 1979).

Tussock moths of the family Lymantriidae are an important group of forest defoliators that characteristically have periodic outbreaks. The sex pheromone of the female Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), has been identified as (Z)-6-heneicosen-11-one (Smith et al. 1975) and shown to be sexually stimulating to males of seven tussock moth species in two genera, Orgyia and Dasychira (Daterman et al. 1976; Grant 1977). Laboratory tests demonstrated that this compound could disrupt mating of both the whitemarked tussock moth,O. leucostigma (J.E. Smith), and rusty tussock moth, O. antiqua (L.), when the adults were maintained in an atmosphere containing the chemical (Grant and Frech 1976). Subsequently field tests in small plots treated with the same material released into the atmosphere at a rate equivalent to 20-50 mg/ha/day demonstrated that pheromone communication of whitemarked tussock moths and a conifer-feeding tussock moth, Dasychira plagiata (Walker), could be disrupted in their natural habitat (Grant 1978). Similar disruption was obtained with field populations of the Douglas-fir tussock moth (Sower and Daterman 1977). The present report describes the disruptive effects of (Z)-6-heneicosen-11-one in the field on the pheromone communication of another species, the rusty tussock moth.