Treatment of a pond with a 0.5% sand granule formulation of SIR-8514 yielded a maximum, concentration (4.6 ppb) by 1 day following the application. No residues were detected in the pond sediment and by 28 days posttreatment residues were not found at any depth of the water column. Emergence of pestiferous dipterans was reduced by >99%, and planktonic arthropod populations decreased by >90% following the treatment. Planktonic rotifers and dinoflagellates, and benthic organisms were less severely affected.

Bluegill sunfish (Lepomis macrochirus Rafinesque) and mosquitofish (Gambusia affinis Baird and Girard) accumulated maximum concentrations (ca. 400 ppb) of SIR-8514 by 2 days posttreatment. No residues in fish were detected by 28 days posttreatment, and no fish mortality was observed.

Diets of fresh wheat foliage, rye, or lettuce had to be supplemented with dried wheat leaves, bran, or a dry alfalfa mix to obtain adequate growth and reproduction in the grasshopper Melanoplus sanguinipes (Fabr.). It was concluded that the high water content of fresh plant material makes it necessary for this insect to supplement its diet with dry vegetable material and that this may account for the success of toxic bran baits under field conditions.

Ingested dosages of 10.9 and 16.5 spores of Vairimorpha necatrix (Kramer) 7 and 27 weeks old, respectively, killed 50% of third-instar larvae of the cabbage looper, Trichoplusia ni (Hübner). Time to death of 50% of larvae (LT50) decreased from 14 to 3 days with increases in dosage from 5 × 101 to 5 × 106 spores (2-week-old)/Iarva. The LT50 for 5 × 101 spores/larva increased from 14 to 25 days with storage of spores at 4°C for 2 and 93 weeks, respectively. Spores applied to soil lost little activity during cool weather but spores applied in summer were inactivated within 60 days. Desiccation or exposure to sunlight or artificial light inactivated the spores. Rate of development of disease was increased by feeding host larvae a diet containing increased proportions of casein or sucrose. The optimum temperature for disease development in T. ni was 25°C.

Adults and larvae of Rhinosimus viridiaeneus Randall observed on Vancouver Island, British Columbia, prefer the inner bark of dead branches of red alder (Alnus rubra Bong.) for food. When feeding, the flattened elongated rostrum of the adult is inserted between the papery outer bark and the cambium. The rostrum is also used to prod or flip intruding Rhinosimus away from a feeding site. The larva is described for the first time.

Eggs of the red turnip beetle, Entomoscelis americana Brown, were exposed to temperatures of 0°, −5°, −10°, −15°, and −20°C for 1–8 wk and for 200 days in the laboratory. At −5° and −10°C, there was no death attributable to the cold treatment. At −20°C, the cold treatment caused approximately 15% mortality in the 6- to 8-wk samples and 100% mortality in the 200-day samples. At 0° and −15°C, mortality in the 200-day samples was 39% and 23%, respectively. The data indicate that the embryos of E. americana are able to withstand cold temperatures for long periods and that the optimum temperature range for hibernation (between 0°C and −15°C) is similar to the one this beetle normally experiences in the subnivean air space once the hiemal threshold is established. For Canada, an evaluation of the snow cover and atmospheric air temperature data suggested that egg mortality due to exposure to temperatures of −20°C or lower in the subnivean air space should not occur in the various parts of the red turnip beetle’s range, except possibly the grassland region of the Prairie climatic zone.

A 5-year study of a bivoltine strain of the European corn borer, Ostrinia nubilalis (Hübner), showed that first-generation moths deposited more eggs on early-planted corn, whereas second-generation moths oviposited more frequently on late-planted corn. The second generation was much larger than the first generation and caused the greater reduction in yield, regardless of whether the yields were based on physiological losses or a combination of physiological losses and dropped ears. It was shown that delay of harvest beyond the time that moisture content of the corn was sufficiently low for machine harvesting could result in severe yield losses from broken stalks and dropped ears during autumn storms.

The threshold temperature of development, life table, and innate capacity for increase of the twospotted spider mite, Tetranychus urticae Koch, were established from life stage development studies at constant temperatures. The threshold for development was determined to be 10.0°C. The durations in degree-days above 10°C from the beginning of the egg stage to adult for females were 141.3, 152.3, and 139.8; for males 134.2, 144.7, and 135.2 at 15°, 18°, and 21°C, respectively. Life tables were constructed and innate capacity for increase was .069, .156, and .372; net reproduction rate 20.8, 38.4, and 58.1; and mean generation time 44.0, 23.4, and 10.9 at 15°, 18°, and 21°C, respectively.

Release rates of synthetic attractant of the spruce budworm, Choristoneura fumiferana (Clem.), from a PVC formulation were determined by weight loss. They varied in direct proportion to the initial concentration of the attractant and also with the size of the pellet. Release rates declined by about 50% over the time intervals of 10–40 days and 40–100 days. Initially they were two to three times lower at 10°C than at 21°C, but were far more constant over time at the lower temperature. A pellet weighing 130 mg containing 42 μg of attractant released an estimated .1–1 μg/day, or 4–40 ng/h, which is close to the rate of emission by a calling female (Silk et al. 1980), and field trapping data showed that a lure this size attracted the same number of males as a calling female.

Two formulations of methoxychlor were compared with regard to toxicity and availability to aquatic organisms. A particulate formulation was less toxic than an emulsifiable formulation to chironomid larvae, stonefly nymphs, and fish. Similarly the particulate methoxychlor was less rapidly accumulated from water by those same animals than was the emulsified methoxychlor. With black fly larvae, the only filter-feeding animal used, the two formulations were about equal in toxicity, but the particulate formulation was accumulated more readily than emulsified material. Both formulations induced larvae to detach from substrate but emulsifiable methoxychlor acted more quickly. At the time of detachment, larvae exposed to the particulate formulation contained an average of 68 times more methoxychlor than larvae exposed to the emulsion.

The preoviposition period of R. pomonella (Walsh) varied from 5 to 11 days at constant and 6 to 15 days at variable rearing conditions. Its duration was influenced by the source of the adults, cultivars for oviposition, and rearing conditions: ca. 3 days longer for adults from infested Wealthy apples than for adults from infested Gravensteins, ca. 2 days longer when the apples for oviposition were late season cultivars, and ca. 1 day longer at variable than at constant rearing conditions. Estimates of the preoviposition period of adults in two unsprayed orchards were 14 and 21 days in 1979 and 16 days in both orchards in 1980, and were 7–14 days longer than that for adults at constant rearing conditions.

The oviposition periods of adults were 40–74 days at constant and 25–55 days at variable rearing conditions in 1979, and were influenced by the source of the adults, cultivars for oviposition, and the rearing conditions. Females from infested Gravensteins laid 339.2 and 180.7 eggs/female at constant and variable conditions and those from infested Wealthy 178.4 and 68.8 eggs/female at constant and variable conditions. Females also laid fewer eggs in Red Delicious apples than in Gravenstein, McIntosh, or Cortland apples.

The first spray for control of apple maggot in Nova Scotia can be applied at least 14 days after first emergence or first capture as the preoviposition period in natural (orchard) conditions exceeded the recommended time of 7–10 days.

Ptychopsis phalara new genus, new species of Banchinae from Ecuador is described and figured. Reasons for placement of the genus in the tribe Lissonotini are discussed.

Changes in the numbers of adults of Coccinella californica Mannerheim and C. trifasciata Mulsant in small plots of alfalfa and oats were monitored over the summers of 1974 and 1975 by mark–recapture methods. Aphid population dynamics in the plots were studied concurrently. In the second summer, movements of the beetles were also monitored by means of individual marking and sticky net traps. Approximately 1000 beetles of each species were marked in the first summer; in the second, roughly 5000 and 3000 respectively. The capture–recapture method was tested with a caged population, and was found to be feasible for estimation of the coccinellid numbers. Catch per unit effort, using visual sampling that was not dependent on marking, provided an acceptable index of numbers which could give population estimates when calibrated against mark–recapture estimates.

The number of beetles trapped on the sticky nets was primarily a function of numbers in the plots and temperature, with the two species having different relationships between temperature and flight. But for C. californica, the numbers trapped were also a function of aphid density in the plots; the data suggested that for C. trifasciata the same is probably true, but the range of densities of pea aphids was too narrow to show it. In both seasons, C. trifasciata was predominant in the alfalfa and C. californica in the oats. Plot to plot movements by overwintered beetles reflected the same apparent preference. Changes in the numbers of coccinellids in the experimental plots, and their reproductive success, are discussed in the light of these findings.

Modified versions of the standard Reed-Rich citrus thrips trap were compared for trapping efficiency and labor required. The number of migrant Scirtothrips citri (Moulton) captured per unit trapping area of a PVC-acetate trap was comparable to the number captured per unit area of the Reed-Rich trap, though the PVC-acetate trapping surface was about 35% that of the 929 cm2 standard trap. The reduced counting surface and the use of disposable acetate sheets reduced to one-quarter the time required for field-laboratory handling, preparing, and processing. The PVC-acetate trap is recommended as a new standard trap for monitoring S. citri population levels in California and Arizona citriculture.

In direct contact toxicity tests with four pyrethroid and three standard insecticides, using 24–48 h old crickets, Acheta pennsylvanicus (Burmeister), as test insects, carbofuran was most toxic > cypermethrin > fensulfothion > chlorpyrifos > fenvalerate > fenpropanate > permethrin. In moist (5% water) Plainfield sand, using the same test insect, chlorpyrifos was most toxic > carbofuran > fenpropanate > cypermethrin > permethrin > fenvalerate > fensulfothion, i.e. the pyrethroids, although quite strongly adsorbed by soil, were still moderately active as soil insecticides. All pyrethroids were less toxic in muck soil as compared with Plainfield sand, and in air-dry (0.5% water) as compared with moist (5% water) Plainfield sand, with the effects being less on cypermethrin and fenvalerate and greater on permethrin and fenpropanate. None of the pyrethroids was affected by soil type and moisture to the same extent as was carbofuran. Permethrin, fenvalerate, and cypermethrin showed a negative temperature coefficient of toxicity in moist Plainfield sand, being from 1.4 to 1.9× more toxic at 15° than at 32°C. Fenpropanate, like carbofuran, was slightly more toxic at 32° than at 15°C. Generally, soil type, moisture, and temperature had minimal effects on the toxicity of the four pyrethroid insecticides. In persistence studies over 48 weeks, using Plainfield sand, the pyrethroids were more persistent than chlorpyrifos, but less persistent than dieldrin. Under these laboratory conditions, permethrin and fenvalerate were slightly more persistent, while fenpropanate and cypermethrin were as persistent as carbofuran. Trans-isomers of permethrin and cypermethrin declined more quickly in the sand than did the cis-isomers and of the trans-isomers the 1S,trans declined much faster than the 1R,trans while little difference was observed for the corresponding 1S- and 1R,cis-isomers.

The longevity and age specific fecundity, as well as the sex ratio of the progeny, were obtained for Aphidius nigripes Ashmead females given access to the five developmental stages of the potato aphid, Macrosiphum euphorbiae (Thomas). Neither female longevity nor fecundity, as measured by the total number of aphids parasitized, were significantly different for the various host stages. The percentage of females in the progeny decreased as the female parasite aged, and the overall sex ratio of progeny was significantly affected by the host stage attacked although no direct relationship with host size was evident. However in a separate experiment where parasitism was controlled (females not permitted to attack more than 10 hosts per day), the host stage (size) significantly affected the sex ratio of progeny, with more females emerging from larger than smaller hosts.

These data indicate that all developmental stages of M. euphorbiae, when presented separately, are suitable to A. nigripes.

Venom of the hyperparasitoid Asaphes lucens (Provancher) immediately paralyzed and stopped development of the larva of the aphid parasitoid Aphidius smithi Sharma and Subba Rao, which did not void a meconium and deteriorated into a soft, blackened mass. On the other hand, venom of a second hyperparasitoid, Dendrocerus carpenteri (Curtis), did not immediately paralyze the larva of A. smithi, which developed up to the prepupal stage, voided a meconium, and remained bright yellow for up to 4–6 weeks before decaying.

The genus Hebrolethaeus Scudder is not monobasic, but contains five distinct species. H. aurantiacus (Distant) from New Caledonia is redescribed. The four other species described as new are H. albus from the New Hebrides, H. concisus from New Caledonia, H. nigrus from the Loyalty Islands, and H. pullus from New Caledonia. H. concisus is also recorded from Norfolk Island, and a key to species is presented.

Culex pipiens pipiens and C. salinarius were found equally susceptible in laboratory tests to Bacillus sphaericus strain 1593 with LC50 values for the four instars ranging between 20 and 137 ppb (approximately 820 and 5600 spores/ml). Tests against field collected C. p. pipiens larvae revealed a regularly decreasing susceptibility with increasing larval age, the first instars being between 2 and 5 times more susceptible than fourth instars. In contrast, no significant differences in the susceptibility of second, third, and fourth instars were found in tests of laboratory reared larvae.

The relationship between feeding rate and egg production of Coccinella trifasciata Mulsant and C. californica Mannerheim feeding on pea aphids, was investigated in the laboratory at 15.0°, 18.5°, 21.5°, and 25.5°C. Both species increase their feeding rate with increasing temperature above 13.6°C, with C. californica, the larger species, increasing its food consumption faster. C. californica also has the higher maintenance requirement but when food consumption is expressed relative to the beetles’ body weight, there is no difference between the species in either attribute. Coccinella californica converts excess food to eggs more efficiently than C. trifasciata.

No significant influence of temperature on either the conversion rate or the maintenance requirement could be detected. The adverse effects of a very low feeding rate, whether due to restricted food supply or low temperature, influenced the beetles’ response to subsequent treatments.

The alfalfa blotch leafminer, Agromyza frontella (Rondani), typically develops through three complete generations a year. It overwinters as a partially developed pupa that completes its development in mid-May. Three distinct adult flight periods occur: mid-May to mid-June, late June to late July, and early to late August. Eggs are deposited singly in alfalfa leaflets beneath the lower epidermis and on hatching, the larvae move toward the upper leaflet surface where they feed on the mesophyll and develop through three instars to form blotch mines, each representing about 27% of the leaflet area. The mature larvae emerge from the mines and drop to the soil to form light brown puparia, mainly in the top 2.5 cm of soil.

Duration of each stage decreased with rise in temperature up to 25° but none of the stages survived 30°C. Developmental rates plotted against temperature gave highly correlated linear relationships for all stages. The theoretical threshold for the egg, larva, and pupa was 7°, 3°, and 4°C, respectively; thermal requirements for these stages were 55, 123, and 333°D, respectively.

Survival of the larvae was higher in leaflets with solitary mines than in those with multiple mines; only 25% of the leaflets with two mines gave rise to two mature larvae. Three larvae seldom survived in a single leaflet.