It is often desirable to establish the relationship between the amount of feeding of an insect and the prevailing meteorological conditions. With colonial insects, especially, it is difficult to determine visually whether members of a colony are feeding heavily, moderately, or lightly. If periodic measurements of frass drop are made, more reliable information may be obtained, for such measurements have proved to be reliable indicators of the intensity of feeding (Gornitz (1933); Monro (1935; Morris (1949), and Taranukha (1937)).

Mating frequency and behavior of five color-coded adults of each sex of Trypodendron lineatum (Olivier) were observed for 1 hour periods in petri dish arenas. Mating activity was evaluated by recording each incident in which a male assumed the "precopulatory" position on a female for a minimum of 10 seconds. Newly emerged brood adults mated with very low frequency. The mating activity of revived overwintering beetles increased throughout the winter. In February there was a sudden rise in activity to an intensity approaching that of sexually active "spring" populations of March and April. This pattern, as well as the recovery of locomotion upon warming throughout the winter, provides evidence that overwintering populations undergo only a reproductive diapause, or hibernation. Mating activity of excavating parents fell to one-half that of spring beetles within 2 weeks of host invasion and declined further after 4 weeks. Parents that had recently emerged from brood logs had negligible mating activity. Flight was not an essential prerequisite to mating. There was no prolonged delay between initial contact of the sexes and mounting, and no observable courtship. Behaviorally, the male was the aggressive partner; the female was passive and nonresisting. Multiple matings by both sexes, with the same or different partners, and mounting of mating couples and other males by males were observed. The average duration of mounting was 1.75 minutes and, when copulation occurred, 3.35 minutes; dissections showed that this period was sufficient for insemination. Pronounced reduction of mounting and copulation activity occurred within 30 to 40 minutes of initial contact with the opposite sex. Mating frequency depended primarily on the maturity and vigor of the male, although the maturity of females had a slight effect.

Macrocentrus gifuensis Ashm., a polyembyronic, braconid parasite of the European corn borer, Pyrausta nubilalis Hubn., has been reared in the laboratory at various times over a period of years by the author both for liberation and for experimental purposes. The technique used in rearing this parasite is similar to that used for some other corn borer parasites. No account of this technique has appeared in the literature to date, and it is felt that a description of the method used for rearing M. gifuensis might be useful to others at this time.

Samples of a population of Argia vivida Hagen larvae were taken at about monthly intervals from a series of warm sulphur pools at Banff, Alberta, from June 1973 to December 1974. Changes in head capsule width and wing pad length in field-collected and laboratory-reared specimens show that the life-cycle is univoltine. Only the final (Z) instar can be recognized with certainty, but methods are described whereby the population can be divided into size classes which are thought to correspond well with the last nine larval instars. Periods of rapid growth occur in the autumn and again in the spring. Larvae overwinter in the instars U, V, W, X, and Y and the major shift to the final instar occurs in March and April. Adults emerge from April to August. In the laboratory, growth is temperature dependent until the penultimate (Y) instar and this could be a factor in the field since, although larvae can exist year-round at a constant 26 °C, some larvae live in the cooler areas at the edges of the streams and pools. Entry to the final instar appears to require the long photoperiods that follow the vernal equinox.

Evidence indicates low levels of hybridization in nature between the apple maggot (AM), Rhagoletis pomonella (Walsh), and snowberry maggot (SB), Rhagoletis zephyria Snow, sibling species in the R. pomonella complex. We determined the effects of AM and SB pairings on mating frequencies and production of hybrid offspring in the laboratory. Mating frequency was lowest in SB female × AM male pairings, higher in AM female × SB male and AM female × AM male pairings, and highest in SB female × SB male pairings. A greater percentage of AM female × AM male pairs produced offspring (puparia) than did AM female × SB male and SB female × AM male pairs, and a greater percentage of AM female × SB male pairs produced puparia than did SB female × AM male pairs. Male or female F1 hybrids backcrossed with AM males and with other F1 hybrids were fertile. Results suggest most R. pomonella × R. zephyria hybrids found in nature are the result of R. zephyria males mating with R. pomonella females, with few from reciprocal matings. If true, this asymmetry could lower the incidence of hybridization in nature.

A new species, Onthophagus contrapositus (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini), belonging to the New World O. dicranius species group is described and illustrated. Photographs of cephalic and pronotal configurations of all known females are presented for the first time to ease identification. A replacement name is proposed, Onthophagus kohlmanninew name, for the secondary junior homonym Onthophagus xiphias Solís and Kohlmann, 2003.

Pear psylla, Psylla pyricola Foerster, had three generations in 1968 in Nova Scotia. Laboratory studies indicated that overwintering females require mating in the spring to produce fertile eggs. The adults started activity by the end of March, Psylla eggs and nymphs were preyed on by eight predacious species in the laboratory. These and the larvae of another six predacious species were associated with psylla in the field. A few psylla nymphs were parasitized by Trechnites insidiosus (Crawford). Psylla adults fly or are carried with the prevailing winds and a significant percentage occur above the tops of the trees.

Glypta fumifermae (Vier.) (Ichneumonidae) and Apanteles fumiferanae Vier. (Braconidae) are two of the most common parasites of immature larvae of the spruce budworm, Choristoneura fumiferana (Clem.). Females parasitize the minute host larvae in the fall. Their eggs or larvae lie dormant within the hibernating host larvae, and then resume development in the spring, when the spruce budworm larva breaks hibernation and commences to feed. The budworm host is killed by Apanteles usually when it is in the fifth larval instar or by the Glypta when it is in the sixth instar.

Larvae of the marsh fly, Sepedon tenuicornis Cresson, were used to determine (1) number and approximate volume of snails killed before pupation, (2) time required to make the first kill as a function of distance and snail density, and (3) vulnerability of snails of different sizes to larvae of different sizes.Results1. Mean number of snails killed (by 34 larvae): 8.1 ± 2.5, (S.E.) Volume: 544 ± 256 mm3.2. Regression line relating time required to kill as a function of snail density: T (minutes) = 65.3–111.6 × (snail density).Regression line relating time to kill and snail densities of 0.6 and 1.2 snails/cm as a function of distance from snails: T = 0.79–0.33 × (distance).Data from a snail density of 0.3/cm could not be pooled because of high day-to-day variation in larvae.3. Vulnerability of snails can be expressed for each larva length by the equation: Fraction of snails killed = a + b × (snail size).

Values of a and b are as follows:

The relative toxicities of two formulations (Dipel WP and Foray 48B) of Bacillus thuringiensis Berliner var. kurstaki to the obliquebanded leafroller, Choristoneura rosaceana (Harris), were determined in the laboratory. The effects of application rate (BIU per hectare) and spray volume (litres per hectare) on the efficacy of Dipel WP and Foray 48B against C. rosaceana were determined in raspberry fields. Mortality of C. rosaceana increased with application rate, and decreased with an increase in spray volume. Bacillus thuringiensis exhibited significantly longer residual activity al higher application rates and at lower spray volumes. The half-life (time at which 50% of original activity remains) of B. thuringiensis ranged from 2.45 to 6.68 days, depending upon application rate and spray volume. Laboratory and field studies indicate that Dipel WP and Foray 48B are highly and equally effective in killing larvae of C. rosaceana.

The aphid parasitoid Aphidius rhopalosiphi is the most abundant species of Aphidiinae in cereal fields in northern Europe. Although the larval morphology of other Aphidiinae has been described, the morphology and immature development of A. rhopalosiphi remain unknown. Our goal is to relate growth and larval developmental stages to morphological changes during parasitoid development, using light and scanning electron microscopy. Aphidius rhopalosiphi develops through three larval stages with clear differences in the morphology of the mouthparts, tegument sculpturing, and respiratory features that can be related to the different constraints that the larvae have to face. In the first instar, adaptations to physical combat with competitors take the form of strong mandibles, active caudae, and dorsal spines that allow crawling motion. In the third instar, the larva is adapted to tear tissues with short hooked mandibles and to face aerial respiration. All instars possess sensory structures. The "three instars" hypothesis is supported here by the observation of larvae in exuviation. No differences were found between our observations and descriptions of other Aphidius species, supporting the idea that species of this genus cannot be distinguished by larval morphology but only by morphometric analysis. Some new features of the genus are presented for the first and second instars.

The life cycles and larval feeding habits of Leucopis (Neoleucopis) pinicola Malloch and Chamaemyia polystigma Meigen were studied in northeastern Ohio. The larval stages of L. pinicola are predators of the pine bark aphid, Pineus strobi (Hartig) (Homoptera: Adelgidae). Probably there are only two generations a year, and overwintering occurs as mature larvae or pupae that are in diapause. Larvae of C. polystigma prey on the blue grass mealybug, Heterococcus nudus Green (Homoptera: Pseudococcidae), that infests perennial rye grass, Lolium perenne L. This species has three generations a year and overwinters as diapausing mature larvae and pupae.

The eggs, three larval instars, and puparia of both species are described and illustrated.

Pyrrhalta viburni (Paykull), a native of Eurasia, is reported for the first time as established in North America. In the Ottawa, Ont., area (including Hull, Que.) adults were very abundant and causing considerable damage to cultivated varieties of Viburnum opulus L. and moderate damage to the native V. Rafinesquianum Schultes. Photographs, a comparison with the similar species, P. luteola (Müller), and a brief note on egg laying are given.

The efficacy of diflubenzuron against the codling moth, Laspeyresia pomonella L., was compared with that of azinphos-methyl in two orchards. Two cover sprays were applied to coincide with peak codling moth activity which was monitored daily with pheromone-baited traps. In the Golden Delicious and mixed cultivar orchards, 187 ppm (mg active ingredient/1.) diflubenzuron provided control comparable to that of 187 ppm azinphos-methyl. In the 47 ppm diflubenzuron treatment, more fruit damage occurred particularly in the mixed cultivar orchard. In this orchard, the addition of Tween 20 to the spray mixture reduced fruit damage markedly.

Diflubenzuron appeared non-toxic to the phytoseiid Typhlodromus occidentalis Nesbitt and stigmaeid Zetzellia mali Ewing. In addition, cover sprays did not increase populations of European red mite, Panonychus ulmi (Koch) or rust mites, Aculus spp.

The efficacy of diflubenzuron against the codling moth and its compatability with integrated mite control suggest that the compound is a promising agent for pest management programs in apple orchards.

Laboratory experiments showed that female Lytta nuttalli Say are capable of developing and depositing more than one batch of eggs. The largest number of batches deposited by a female was 5. Batches laid by one female are the same size, and each batch represents one gonadotropic cycle. Most females lay every 4 to 8 days, the most frequent intervals between consecutive ovipositions being 5 and 6 days. The females copulate at least once before the first oviposition and usually again within 24 h after each oviposition. The first copulation stimulates oocyte maturation and probably also deposition of the first batch of eggs. Additional copulations are not needed for the development and deposition of subsequent egg batches, but appear to stimulate egg output. Sufficient spermatozoa are transferred to the female during the one or more copulations preceding the first oviposition to fertilize all the eggs she produces. The largest number of copulations by a male was 9. Males can copulate as frequently as every 24 h, but the most frequent intervals between copulations in virile males are 2 and 3 days. The basic features of the reproductive cycles of male and female L. nuttalli are found in other Meloinae and probably are characteristic of the subfamily. The fairly large quantities of spermatophoral materials from repeated copulations may be important in the nutrition of the female.

During 1977, a detailed study was undertaken to develop efficient sampling procedures for estimating egg and larval populations of the alfalfa blotch leafminer, Agromyza frontella (Rond.), in Vernal alfalfa. Distributions of the stages within and between stems were contagious and stem totals tended to follow negative binomial distributions. Within stems, the density of eggs and larval mines increased exponentially from base to tip. Taking these patterns and the costs of sampling into account, and using the relevant components of variance, four leaves taken systematically from a single stem is proposed as the appropriate sample unit for both eggs and mines. On this basis, 200 stems per field will give adequate precision (less than 10% of the mean with confidence probability 90%) for population estimates. However, the propensity of the leafminer to prefer the middle leaflet to the basal leaflets in the approximate ratio 3:4:3 suggests that sampling costs may be further reduced by restricting counts to the middle leaflet and raising them by a factor of 2.5.

The balsam woolly aphid, Adelges piceae (Ratz.), causes serious damage to balsam fir, Abies balsamea (L.) Mill., in Eastern Canada. It was introduced from Europe before 1900 (Balch, 1952) and has also become established in the northeastern United States. In continental Europe A. piceae is common on Abies alba Mill. but is not so serious a pest as in Canada. It has an extensive complex of insect predators in both Canada (Balch, 1934) and Europe (Delucchi, 1954). Balch (1934, 1952) found those in Canada inadequate as control agents. Some of the predators of Pineus pini Koch and Pineus strobi (Htg.) studied by Wilson (1938) in England, and recommended for introduction to new areas, were imported to Canada and released against A. piceae. Predators were first introdnced from Ensland in 1933 and later from continental Europe beginning in 1951.

Egg masses and eggs of Sialis hasta, S. iola, S. joppa, S. infumata, S. aequalis, S. vagans, S. glabella, S. mohri, S. velata, and S. itasca are described using SEM micrographs. Diagnostic characteristics of chorion surface and micropylar structure and a key for specific determination of eggs of these 10 species are given. Oviposition is confined to leaves and twigs near or overhanging water. Eggs are oriented either vertically or horizontally in the egg mass, and hatch in 5 to 10 days in the laboratory. Hatching larvae are aided by an egg burster which tears the chorion and aids in removing the embryonic envelope.