Potato leafhopper, Empoasca fabae (Harris), early-instar nymphs (1–2 instar), late-instar nymphs (3–5 instar), adult males and adult females were caged at various densities on seedling alfalfa cv. Vernal and allowed to feed for 6 days. Feeding by adult females, late-instar nymphs, and adult males retarded plant height, leaf number, and dry weight, about 20 to 50% more than did the early-instar nymphs at most of the leafhopper densities tested, over 6 days. Protein content was affected differently from the other plant parameters; it was reduced most by adult males. This was apparently due to premature death of the plants caused by late-instar nymphs and adult females. The percentage reduction for each of the plant parameters was highly correlated with leafhopper density and was nonlinear, except with the early-instar nymphs. Alfalfa plants exposed to two or four late-instar nymphs or two adult females, significantly increased in height and leaf number during a 7-day recovery period. Plants exposed to four adult females did not recover.

Superparasitism and multiple parasitism of the pea aphid, Acyrthosiphon pisum (Harris), by the solitary hymenopterous parasites Aphidius smithi Sharma & Subba Rao and Praon pequodorum Viereck were studied in the laboratory. In intraspecific competition, an older larva usually eliminated a younger one; exceptions to this rule depended on the relative age difference and developmental stage of the competitors. In interspecific competition, P. pequodorum was intrinsically superior to A. smithi, regardless of the latter's age. The stage of host parasitized and the number of competing larvae had no significant effect on the outcome of the contest. A. smithi females discriminated against aphids previously parasitized by a conspecific female or by P. pequodorum, the degree of oviposition restraint increasing with the time between ovipositions. P. pequodorum females attacked aphids already parasitized by A. smithi, regardless of the age of the Aphidius larva, but avoided oviposition when the aphid contained a Praon larva or embryo. The rate of embryonic development is shown as a major factor in contest-type competition between first-stage larvae.

Distributions of immature stages of the bronze birch borer, Agrilus anxius Gory (Coleoptera: Buprestidae), infesting young European white birch, Betula pendula Roth, were studied on a surface mine reforestation site in Pennsylvania. Eggs of A. anxius were common on boles of trees from mid-June through mid-August, in clusters of up to 14 eggs. Almost 70% of the eggs were in crevices in the dark triangular patch at branch origins. Larvae were present throughout the year. Fourth instars comprised 93.1% of the overwintering population.

Vertical distributions of eggs, larvae, and pupae along the bole were random relative to available surface area. Consequently, each stage was more abundant on the lower half than on the upper half of trees. Eggs and first instars were concentrated on the northeast, or shaded, side of trees. Second and third instars were distributed randomly around the bole. Fourth instars overwintered and pupated primarily on the southwest aspect.

Two new species of Neoathyreus, lyriferus and apiculatus, both from Costa Rica, are described and illustrated. New records for Mexico and Central America are listed for eight other species of Neoathyreus.

Pelosoma pecki is described as new from specimens from the Florida Keys (Upper Matacumba Key) and from Mexico (Oaxaca). The genus Genyon Smetana 1978 (type-species Cercyon navicularis Zimmerman 1869, from eastern North America) is placed in synonymy with Tectosternum Balfour-Browne 1958 (type-species T. exstriatum Balfour-Browne 1958, from equatorial Africa). A lectotype is designated for Pelosoma prosternale Sharp 1882, and Pelosoma praecursor Smetana 1978 is placed in synonymy with P. prosternale Sharp 1882.

Omicrus intermedius Smetana and the genus Cycrillum Knisch, with the species C. strigicolle (Sharp), are recorded for the first time from North America.

Additional data on bionomics, geographical distribution, and synonymy of many species are presented.

Pine oil effectively reduced feeding by the white pine weevil, Pissodes strobi Peck, in a laboratory feeding bioassay utilizing agar discs containing dry, powdered bark of its host Sitka spruce, Picea sitchensis (Bong.) Carr. Possible utilization of pine oil under field conditions is discussed.

Native bee pollinators were collected and observed on cultivated blueberry, raspberry, and cranberry and on natural non-cultivated plants such as blackberry, buttercup, fireweed, thistle, and hairy cat's ear. Higher abundance and diversity of native bees were found on natural vegetation than on berry crops. Native bee populations on berry crops increased from 1981 to 1982, although diversity was similar. Native bees were not abundant enough to ensure adequate pollination of berry crops, and therefore, the use of managed honey bees is advisable. Pesticide impact, competition with managed honey bees, and habitat destruction have probably decreased native bee populations in agricultural areas of the Fraser Valley.

The use of a standard measure of native pollinator abundance, bees observed/min/m2, is recommended for future studies of this kind.

The pheromone specificity of female Choristoneura occcidentalis Freeman and C. retiniana (Walsingham) from several locales, laboratory colonies, and interspecific matings was determined by observing the numbers and wing maculations of males attracted at several sites in southern Oregon. Pheromone specificity of females reared from field-collected brown (typical of C. occidentalis) and green (typical of C. retiniana) larval morphs differed considerably but differed little among sites of origin. Field-collected females attracted more males than conspecific individuals from laboratory colonies. F1 and F2 interspecific hybrids most closely resembled C. occidentalis in the numbers and types of males attracted. As a group, progeny of backcrosses to C. retiniana appeared intermediate between pure lines of the species in their pheromone specificity. Females reared from intermediate-colored field-collected larvae varied considerably in attractiveness. Most attracted groups of males similar to those attracted to female C. retiniana, but others attracted males most similar to those attracted to female progeny of C. retiniana hybrid backcrosses. These findings support the conclusion that hybrid matings occur between these species at a low frequency in nature.

An assemblage of 24 grasshopper species inhabited a mixed grass prairie site near Livermore, Colorado. Ten species were gomphocerines, 9 melanoplines, and 5 locustines; the gomphocerines represented ca. 80% of total density, melanoplines 15%, and locustines 5%. Grass feeders, gomphocerines and most locustines, made up 85% of total density. The dominant species was Ageneotettix deorum which contributed 52% of the grasshopper density in 1981 and 37% in 1982. The grasshopper population was at outbreak density both years, 60/m2 in 1981 and 36/m2 in 1982. The pasture had never been treated with insecticide or herbicide. The Shannon-Wiener index of ca. 2.00 indicated a high grasshopper diversity.

Mutants of Drosophila melanogaster (Meigen) with altered resistance to the insecticide malathion were isolated and tested for their avoidance response to the insecticide. A correlation between sensitivity to the insecticide and increased avoidance was detected. Approximate chromosome map locations were determined for the loci of the mutations.

The smaller European elm bark beetle, Scolytus multistriatus (Marsham), had three distinct periods of adult flight annually in Georgia. Adults of the associated native elm bark beetle, Hylurgopinus rufipes Eichhoff, were trapped on elm logs during only one period in the spring, but some adults were reared from infested bolts in the fall. Seasonal abundance of the S. multistriatus parasite Spathius benefactor Matthews (Braconidae) showed little temporal relationship to its host. However, Entedon leucogramma Ratzeburg (Eulophidae) emergence was highly synchronized with S. multistriatus emergence. Scolytus multistriatus overwintered as fully developed larvae as in other parts of its range.

Four lepidopterous and sawfly species were collected from Lonicera (honeysuckle) in the Ottawa area and reared for hymenopterous parasites. The following new species are described here, with new host records: Triclistus xylostellae n. sp. (Ichneumonidae, Metopiinae) from Plutella xylostella (Linnaeus) (Lepidoptera, Plutellidae), Copidosoma glandiferellae n. sp. (Chalcidoidea, Encyrtidae) from Deltophora glandiferella (Zeller) (Lepidoptera, Gelechiidae). The following are new host records: Mesochorus vittator (Zetterstedt) (Ichneumonidae, Mesochorinae) hyperparasitic in Olesicampe lophyri (Riley) (Ichneumonidae, Campopleginae) from Zaraea americana Cresson (Hymenoptera, Cimbicidae), Oncophanes americanus (Weed) (Braconidae) from D. glandiferella. The following are parasitic species with lepidopterous hosts already recorded: Apophua simplicipes (Cresson) (Ichneumonidae, Banchinae) and Macrocentrus iridescens French (Braconidae), both on Choristoneura rosaceana (Harris) (Lepidoptera, Tortricidae). The cephalic structures of the final-instar larvae of the following species are described: T. xylostellae n. sp., M. vittator, and A. simplicipes.

Three biological control methods were evaluated for the reduction of damage to chrysanthemums by the leafminer Liriomyza trifolii (Burgess). Yellow sticky boards trapped adults and reduced the damage by 50%, Afugan 30 EC effectively controlled the damage to chrysanthemums, and interplanting with field beans as a trap crop showed potential for reducing damage. A specific integrated pest management program can not be recommended as yet; more information is needed.

The two known species in the genus Dodia Dyar are reviewed, and one new species, Dodia kononenkoi, is described from Magadanskaya Oblast, USSR, and Yukon Territory, Canada. The generic name Hyalocoa Hampson is synonymized with Dodia and two new combinations are proposed. Dodia kozhantshikovi (Sheljuzhko) and D. atra (Bang-Haas) are synonymized with D. albertae Dyar. Descriptions and range maps are included, and adults and genitalia of the three species are illustrated.

A small, undisturbed stream in central New Hampshire was treated for 1 min with a 10 ppm suspension of Bacillus thuringiensis var. israelensis (B.t.i.) to determine the effect on an outlet-breeding black fly population and associated nontarget aquatic insects. The black fly larval population was eliminated and susbsequent adult black fly biting activity reduced near the treatment site although weather conditions may also have contributed to an observed decrease in biting activity. Some Chironomidae were killed by B.t.i. but they were not abundant enough to adequately assess impact on their populations. Temporary increases in the drift of two Ephemeroptera and two Trichoptera species were observed following treatment. Increase in rate of drift was inversely related to increase in distance from the treatment point. Slight increases in observed drift of three Plecoptera species could not be attributed directly to the B.t.i. treatment. No direct mortality caused by B.t.i. was observed in any stream insects studied except black fly larvae and some Chironomidae.

The success of introducing natural enemies for biological control was found to be about 75% higher employing new parasite–host (predator–prey) associations than those based on long-evolved associations between parasites and hosts. The lack of evolved interspecific balance in new species associations appears to explain the higher success rate. New exploiter–victim associations expand opportunities for the biological control of both introduced and native pests and should be used as the preferred method in selecting biological control agents.

The order of feeding preference on plant parts of rape (Brassica napus L.) by sixth instar (L6) larvae of bertha armyworm, Mamestra configurata Walker, in laboratory tests was leaves, bracts, immature pods, and mature pods. Field sampling showed that upper, immature pods are attacked with greater frequency than lower, more mature pods. In a greenhouse test, a slightly larger proportion of L6 larvae was recorded on inflorescences of rape plants during darkness than during light; the proportion of larvae found on the inflorescences was about 20%. Larvae pupated more quickly, formed heavier pupae, and gained more dry weight when fed exclusively from mid L4 on leaves than when fed mature or immature pods; mortality for larvae fed mature pods was 30% compared with none for larvae fed leaves or immature pods.The finding that pods are neither as preferred nor as adequate a dietary source as leaves is discussed in relation to the phenology of leaf retention of rape on the economic impact of bertha armyworm infestations.

Aeshna tuberculifera Walker and A. umbrosa Walker were studied in the Shenandoah Mountains, Rockingham County, Virginia for 5 years. Both species had 2-year life cycles. They passed the first winter in an embryonic diapause and the second in a larval diapause. Although A. umbrosa was slightly smaller and developed earlier in the year, growth patterns of the two species were similar. Adults emerged from mid-summer to mid-fall with a slight protandry. Sex ratio at emergence was equal in A. tuberculifera but slightly biased toward males in A. umbrosa. Individuals emerging later in the season tended to be smaller than those emerging earlier, and the decline in size was linear over time. The maturation period lasted 4–6 weeks. Poor recovery of marked teneral and breeding adults indicates either high mortality or high dispersal, but observed movement among ponds by marked breeding adults suggests high dispersal. Breeding males of both species defended entire ponds for short periods. Both males and females were present more frequently in the afternoon than during the morning or at mid-day. Females often oviposited in the late afternoon or early evening when males were usually absent from the ponds. A. tuberculifera used stems of Juncus effusus L. almost exclusively for oviposition, while A. umbrosa used a variety of dead plant or other material and rarely used J. effusus stems.

Bacillus thuringiensis was applied at three dosages (1.0 BIU/tree, 0.1 BIU/tree, and.01 BIU/tree) to balsam fir, Abies balsamea (L.) Mill., and white spruce, Picea glauca (Moench) Voss, with mist blowers. Crystalline proteins were detected on balsam fir foliage for a maximum of 16 days (d) after B. thuringiensis was applied at 1.0 BIU/tree. Higher levels of crystalline proteins were detected on white spruce foliage treated with Thuricide 16B than on that treated with Dipel 4L. On balsam fir, the situation was the opposite. Mist-blower-treated foliage collected for up to 16 d posttreatment caused mortality of spruce budworm, Choristoneura fumiferana (Clemens), larvae. Viable endospores of B. thuringiensis were recovered on white spruce foliage collected 1 year after treatment.

The abdomen of female Pelecinus is uniquely and extremely modified for digging in soil. Segments 2–7 are connected by sternite to sternite articulations allowing vertical movement produced by anteriorly placed muscles acting through long tendons inserting on the adjacent succeeding segment. Segments 3–6 have, in addition to the linkage allowing vertical movement, a detached, posterior section of the sternite that can rotate on a median ventral flexible attachment to the tergal margins. This linkage allows the posterior section of a sternite together with the succeeding segments to rotate through about 135 °relative to its tergite. Tergite 8 bears large spiracles completely covered by sternite 7. The ovipositor lacks the usual 3rd linkage between gonocoxite 9 and gonapophysis 9, allowing the depressor muscle of the gonapophysis to extrude the ovipositor directly backwards.