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.

Intra- and inter-plant spatial patterns were determined for adults and nymphs of Orius insidiosus (Say) and O. tristicolor (White) on greenhouse sweet pepper for three greenhouses using four sampling methods. The population density of the Orius was monitored biweekly for 4 months from May to August using plant tappings, blossoms, plant leaves, and whole plants. The intra-plant spatial patterns of adult and nymphal populations of Orius were aggregated with the majority of the Orius collected from the top one-third of the plant. The inter-plant spatial pattern for the nymphs also was aggregated. However, the adults exhibited a random inter-plant spatial pattern. The accuracy of plant tapping, blossom, and leaf samples was determined for monitoring the adult and nymphal population densities of Orius throughout the growing season. The blossom sampling method for adult Orius was the best sampling method for monitoring the population density of Orius on greenhouse sweet pepper throughout the growing season.

Any evidence which would help us to forecast grasshopper outbreaks, or to anticipate and check them before they become acute, is worth considering and on this account the recently annunciated “phase” theory, and the still later “reservation” theory, should secure the careful consideration of American entomologists.

Eggs of the ichneumonid endoparasite Pimpla turionellae (L.) were observed by Bronskill to develop and hatch in physiological saline solution. This raised the question whether the larvae could be reared on unnatural food. Early attempts (Simmonds, 1944) to rear ichneumonid ectoparasites on nutritive gelatin slopes and raw beef were unsuccessful. Heuristic attempts at Belleville have succeeded in raising a small number on such a food.

Linolenic acid, added to a defatted diet in which wheast and alfalfa meal were the only protein sources, optimally reduced wing syndrome (defined as crumpled wings) in Mamestra brassica Walker at 1.1 mg/g (w/w dry wt.) of diet, increased survival to pupa at 2.2 mg/g, and reduced pupal syndrome (defined as improper formation of the 4th abdominal sternite) and increased survival to adult at 5.8 mg/g. Pupal weight increased and incidence of diapause decreased as dietary linolenic acid increased. Linoleic acid substituted for linolenic acid only in survival to the pupal stage. Pupae from larvae fed artificial diets had more fat (20.6–25.5% dry wt.) than pupae from larvae fed rape leaves (16.5%). Absolute levels of linolenic acid increased in pupae in proportion to dietary levels including pupae from larvae reared on rape leaves but the relative amount of linolenic acid sequestered in pupae from leaf-fed larvae was greater.

Pupal syndrome is a sensitive indicator of dietary adequacy and its occurrence is affected by dietary linolenic acid and possibly other fat soluble components.

Adult Cryptolestes ferrugineus (Stephens) were reared at 30 °C or acclimated to 15, 25, or 35 °C for different periods (2 days or 1, 2, or 5 weeks). Populations 1 day old, 1, 5, 10, or 20 weeks old, or of mixed age were held in 10 cm × 10 cm × 100 cm wheat columns (14.5% ± 0.2% moisture content) with a temperature gradient (10 °C/m, 25–35 °C) or a constant temperature (25 or 30 °C) for 1, 6, or 12 days; movement and distribution were then determined. Acclimation to 25 °C for a short time (less than 2 days) did not influence adults' response to temperature in the wheat column. Adults acclimated to 15 and 35 °C responded differently to temperature in the wheat column, preferring temperatures above 30 and 35 °C, respectively. Increasing the duration of the acclimation to 15 or 35 °C resulted in higher aggregation. Acclimation temperature might be more important than exposure time for influencing insect behaviour. During their movement in the wheat columns, adults were also acclimated to the tested temperatures, and they did not always stay in a warmer area if the "cold" area was warmer than 25 °C. Adults that were 1 day old had a lower response (i.e., less movement) to temperature gradients than the older insects. Among the older insects, the response to temperature gradients did not decrease with increasing age, even at 20 weeks.

The mean freezing point of adults of T. pyri was about −20° F., of T. finlandicus −22° F., and of T. rhenanus −24.5° F. The responses of T. fallacis and P. macropilis to low temperatures were about the same as T. pyri. The effect of the duration of exposure on the last three species was to increase the mortality about 12 to 15 per cent for each doubling of the duration of exposure from 0.5 to eight hours at −10° F. or lower.

The phytophagous brown mite, B. arborea, had a mean freezing point of −26° F. and the effect of duration of exposure was to increase the mortality eight to ten per cent each time the period of exposure was doubled from 0.25 to 16 hours at −24° F. or lower.

Performance of the pea aphid, Acyrthosiphon pisum (Harris), on a holidic diet containing different metal ions was studied by individually incorporating into the diet a salt of the metal ion to be tested. The performance of the pea aphid was markedly improved when the diet contained iron; the first-generation adults reproduced, and the second-generation nymphs moulted twice or thrice, but did not reach the adult stage. Molybdenum, boron, and copper, at certain concentrations, induced the production of some live nymphs, but manganese, zinc, calcium, and cobalt did not. However, the presence of zinc, cobalt and calcium, at most of the concentrations used, slightly improved growth and reduced mortality. Furthermore, the presence of calcium appeared essential for development to the adult stage. Tolerance to all these metals was fairly high, but sodium molybdate at a concentration of 50.0 mg, and sodium borate at concentrations of 40–100 mg/100 ml of diet, appeared to reach toxic levels.Iron was found to be essential for reproduction and a range of 53–211 μg of elemental iron per 100 ml of diet appeared to be optimum. It is suggested that a synergistic effect between at least some of these metals is required for continuous reproduction of the pea aphid.

Coccinellids are a conspicuous group of aphidophagous predators in maize, Zea mays L., in the Northern Great Plains of the United States. Numerous studies have been conducted on the ecology of coccinellids in maize in North America (Ewert and Chiang 1966a, 1966b; Smith 1971; Foott 1973; Wright and Laing 1980; Corderre and Tourneur 1986; Corderre et al. 1987). However, there have been few long-term surveys of coccinellids in maize. Foott (1973) reported on the abundance of coccinellid species inhabiting maize in eastern Canada over a 4-year period; no surveys of this type have been reported for the Northern Great Plains. We sampled coccinellids in maize fields at three sites in eastern South Dakota for 13 consecutive years to determine the species inhabiting the crop and levels of variation in their abundances among sites and years.

Specifications and construction of an automatically recording insect flight mill are described. Revolutions of individual flight mills are recorded, by means of photocells, on electric counters.

A statistical analysis of U.S.DA. studies of insect attractants provides the first direct evidence for the reality of "primary" odors (heretofore inferred indirectly from abstract principles). Molecules of a single substance may carry more than one primary osmic character and the presence of one does not preclude another, but some primaries may overlap others. Thus the molecular qualities responsible for osmic properties appear to be distributed along a continuum. Molecular vibrational frequencies are so distributed, and the far infrared absorption spectra of some attractant and non-attractant substances show correlations of the sort predicted by the theory.

Six of the nine most common indigenous species of noctuid moths caught in a light trap at Glenlea, Man., over an 11-year period were univoltine and three were typically bivoltine but sometimes trivoltine. For the univoltine species, the day of peak catch and the day of 50% catch differed only by 3 days or less during 11 years. The timing of flight periods of Feltia jaculifera (Gn.), F. herilis (Grt.), Agrotis venerabilis Wlk., and Nephelodes minians Gn. were not influenced by the degree-days above 10 °C and the standard deviation of the date of 50% catch for these species was within 5–6 days. The date of 50% catch was more variable for Crymodes devastator (Brace) and Euxoa ochrogaster (Gn.), and the variation for the latter was partly explained by a relationship between flight dates and accumulated degree-days above 10 °C. For the multivoltine species, Pseudaletia unipuncta (Haw.), Discestra trifolii (Hufn.), and Xestia adela Franc., the day of peak catch for two generations also varied little from the day of 50% catch for each generation, but the day on which peaks occurred varied from year to year. Only for the first generation of D. trifolii was the day of 50% catch correlated with accumulated degree-days over 10 °C. Moth numbers for each species were not necessarily high when there were reports of crop damage by their respective larvae. There was no correlation between catches of moths in the first and second generation of multivoltine species, and there were no patterns of population trends among any of the economically important species. The life history, feeding habits, and economic importance of each species are discussed.

The alfalfa weevil, Hypera postica (Gyllenhal), first found in Michigan in 1966, caused considerable damage to alfalfa throughout the state by 1971. In contrast to more southern regions, the alfalfa weevil lays very few eggs in the fall in Michigan. As a result, most eggs and larvae are present when the fields are ready for cutting in the spring.

Different cutting dates were evaluated to determine the effects of cutting on populations of the alfalfa weevil, its primary parasite in Michigan, Bathyplectes curculionis (Thomson), and damage to the crop. Cutting at 507 degree-days (base 48°F (8.9 °C)) caused a 79% reduction in the number of alfalfa weevils produced and a 57% reduction of B. curculionis, while almost eliminating crop damage. Cutting at earlier and later times caused different reductions in populations of both insects and different crop damage.

Some 35 species (mostly Neotropical, 22 new) of acalypterate flies representing 17 genera (3 new) in six families, as follows, are treated: Family Cypselosomatidae. One species from Nepal, Cypselosoma gephyrae Hendel (?), is discussed.Family Pseudopomyzidae. The classification of the family is reviewed, and a key to the world genera is provided. The genus Latheticomyia Wheeler is placed here for the first time, and two new species, L. longiterebra (Peru) and L. rotundicornis (Mexico), are described. Two new genera, Pseudopomyzella and Rhinopomyzella, are erected for three new species, P. flava (Peru), R. albimana (Brazil), and R. nigrimana (Brazil).Family Periscelidae. The genus Periscelis Loew is recorded from Mexico and Peru. Neoscutops peruvianus and Scutops striatus, both from Peru, are described as new.Family Aulacigastridae. The classification of the family is reviewed and a key to the world genera is provided. Schizochroa plesiomorphica (Peru), S. minuta (Ecuador), S. ecuadoriensis (Ecuador), Cyamops neotropicus (Peru), C. australicus (Queensland), and Planinasus venezuelensis (Venezuela) are described as new.Family Odiniidae. The classification of the family is reviewed and a key to the subfamilies and the world genera is provided. Two new species of Schildomyia Malloch, S. peruviana (Peru) and S. trinidadensis, are described. A new genus, Shewellia, is erected for the species S. agromyzina (Peru).Family Heleomyzidae. One new species of Cephodapedon Malloch, C. nigriventer (Chile), is described. The genera Mayomyia Malloch and Cinderella Steyskal are reviewed and placed in this family for the first time. Four species of Cinderella, C. macalpinei (Ecuador), C. pollinosa (Chile), C. hirsuta (Chile), and C. steyskali are described as new.The paper is accompanied by 72 illustrations.

The eggs of several species of cutworms of the subgenera Chorizagrotis, Crassivesica, Longivesica, Orosagrotis, and Pleonectopoda in the genus Euxoa Hübner are described. Within the genus eggs are of two main types, those with smooth chorions and those with ridged chorions, but all have the same basic chorionic design. Variations in the degree of ridging and in the detail of the design make the egg useful for species determination, and a key to some species is provided. However, the egg is of little value in distinguishing the subgenera as they are currently constituted.

South American Trichogrammatidae are poorly known. In this paper we describe a new species of Trichogramma and two new species of Uscana from Chile. The Trichogramma species belongs to the perkinsi group and parasitizes the eggs of Rhyacionia buoliana (Lepidoptera: Tortricidae). One Uscana species belongs to the senex group (new name proposed for the B group) and parasitizes eggs of Pseudopachymerina spinipes (Coleoptera: Bruchidae), and the other Uscana species belongs to the fumipennis group (new name proposed for the C group) and parasitizes eggs of Bruchus pisorum (Coleoptera: Bruchidae). These new species might be useful in biological control, especially against R. buoliana and B. pisorum, important pests of pines and peas, respectively, in Chile.

Within white spruce stands near Fairbanks, Alaska, and on the Kenai Peninsula, Alaska, Dendroctonus rufipennis, Ips spp., and Trypodendron lineatum disperse in late May and early June; other scolytids fly during June and July. Flight in interior Alaska precedes by about 2 weeks that on the Kenai Peninsula. Mean daily temperatures during spring and early summer are generally warmer in the interior than in coastal areas. There was a large increase in the total number of beetles in a thinned area, mostly of Dryocoetes affaber.

The premating period in the parasitoid Priopoda nigricollis (Thos.) is about 2 days, and females are receptive for up to 4 days, after which time the oviducts contain mature eggs. Copulation behaviour in specially built chambers, and oviposition pattern are described. The structure of the ovaries is illustrated. Host feeding by adult P. nigricollis was observed, but it is not a prerequisite for initial egg maturation. Hosts are located by random stabbing with the ovipositor into the mines of Fenusa pusilla (Lep.). Data on the age-specific fecundity of this parasite in laboratory experiments are given. The importance of liberating mated parasite populations is emphasized for successful biological control.

In laboratory experiments at Belleville and Guelph, Ont., four species of coccinellids, Cycloneda munda (Say), Adalia bipunctata (L.), Coccinella transversoguttata richardsoni Brown, and Coleomegilla maculata lengi Timberlake, revealed strong attractances to Juniperus virginiana L. (juniper) for oviposition. This attractancy was due to the specific odour of Juniperus wood. Egg laying rates were not affected by distances up to 70 cm in laboratory cages in a greenhouse where temperatures ranged from 24.0° to 29.5 °C. This phenomenon may be used to aggregate ovipositing coccinellid females in places where aphids are expected to occur in damaging numbers.

Daily periods of activity of eight colonies of the eastern tent caterpillar, Malacosoma americanum (F.), were monitored photoelectronically under a simulated springtime photoperiod in the laboratory. Colonies averaged 3.7 ± 0.1 (S.E.) activity periods per day (N = 103 colony-days), separated by an average interval of 6.6 ± 0.1 h (N = 389). Foraging trips lasted an average 2.8 ± 0.1 h (N = 397). A plot of 336 activity period midpoints (seven colonies) showed all colony activity peaks to occur between 0600 and 0800 h, 1100 and 1600 h, 1900 and 2100 h, and 0100 and 0400 h. The first three peaks correspond well to previously reported field observations but the early morning foraging trip, which occurred in darkness, was previously unreported by field investigators. The temporal placement of activity peaks shifted from day to day within colonies but the occurrence of evening foraging trips was the most consistent. Dark onset appeared to trigger foraging in resting colonies. Recruitment of hungry caterpillars to food finds appears to be a common component of the foraging strategy of this species.