Individuals of Umbonia crassicornis Amyot and Serville (Homoptera: Membracidae) form aggregations both as nymphs and adults. Each adult female deposits one set of eggs and remains with them. Prior to egg hatching the female moves off the egg mass and makes a series of spiral bark slits with the ovipositor. First instar nymphs aggregate along these slits with the female positioned below the cluster. Adult females use the front tarsi to stroke the backs of moving nymphs to return them to the aggregation.

Adult females remain with the nymphs until they become adults. Aggregations of adults fragment when sexually mature; mating takes place before and during dispersal. Mating behavior consists of four components, the precopulatory position being prolonged.

Various models of a device for detecting insects in stored grain were effective for trapping adults of the rusty grain beetle, Cryptolestes ferrugineux (Stephens), in laboratory experiments in which the insect population was known. At 30 ± 1 °C and 65 ± 5% relative humidity the number of beetles trapped increased with the time the traps were immersed in the grain. The number of beetles caught was affected by population density, duration of trapping period, position and contour of the trapping surface, location of the trap, size and shape of the container, and chemotactic stimuli. The distribution of beetles in wheat-filled containers was influenced by the shape and size of the container, duration of the sampling period, and geotactic factors. More beetles were recovered from wheat nearest the floor of filled containers of 3.8-1. capacity than from higher levels. In similar containers held in darkness, as many beetles were found near the surface as near the floor up to 14 days, but at 21 days nearly 41% were found near the floor. Drums of 105-1. capacity kept in darkness contained approximately equal numbers of beetles in the top and bottom one-third portions of wheat. More beetles were found in traps baited with rotting grain than in unbaited traps. Males and females were found in equal numbers in baited traps, or near the floor of wheat-filled containers.

The composition of the tachinid genus Allophorocera, including species formerly placed in Erycilla and Pilatea, is discussed and a key to the Palaearctic species is provided. Allophorocera lapponica n. sp. from Kilpisjärvi, Finland, is described and figured.

A population index for the estimation of the neosistens stage of pine leaf chermid on white pine is described. This is based on the observation that increasing numbers of the chermid produce increased stunting of length of pine needles. A regression relating chermid population density to needle length produced a correlation coefficient of −0.88, suggesting that measurements of needle length alone adequately estimate chermid populations under most conditions. The numbers and distribution of needles that must be measured to estimate length with reasonable precision are calculated. The total sampling plan for the four cyclic generations of the chermid is reviewed.

Four species of Lizerius Blanchard, L. cermelii, L. intermedius, L. costai and L. brasiliensis, from South America and four species of Paoliella Theobald, P. reticulosiphon and P. melanocallis from South America, and P. pteleopsidis and P. longirostris from Africa, are described as new. Redescriptions of L. tuberculatus (Blanchard) and P. kenyensis (Eastop) are also given, with keys for the species of Lizerius and Paoliella. Neolizerius is made a synonym of Lizerius. A new subgenus Paralizerius is established. Adhesive vesicles are reported for the two South American Paoliella species. The phylogenetic relationships of the Lizerini are discussed. It is concluded that this tribe branched off from Mindarus–Neophyllaphis-like aphids and that the Schoutedeniini evolved from ancestors that were related to the Lizerini.

Nine species of hymenopterous parasitoids were trapped on sticky traps as they were attracted to red cedar logs infested with the eastern jumper bark beetle, Phloeosinus dentatus (Say). All were successfully reared from infested logs. The parasitoids Cheiropachus arizoninsis (Ashmead), Eurytoma aequabilis Bugbee, Heydenia unica Cook & Davis, and Spathius impus Matthews were reared directly from P. dentatus larvae.

Five species of parasitoids reared from P. dentatus larvae or from infested logs commonly attack the southern pine beetle and Ips spp. beetles, indicating that P. dentatus may be an important alternate host when the other host populations are low.

Macrosiphum euphorbiae (Thomas) was fed on artificial diets containing coumarin, phloridzin, kinetin, kinetin riboside, royal jelly, ALAR-85, and chlorogenic acid. Incorporation of chlorogenic acid in the artificial diet improved the growth of the potato aphid which was studied up to 17 generations. Coumarin and kinetin riboside at higher concentrations inhibited growth whereas phloridzin prolonged the developmental period of aphids in the second and third generations. The inhibitory effect of ALAR-85 and kinetin became apparent in the third and second generation nymphs, respectively, which did not reach the adult stage. Addition of royal jelly neither enhanced growth nor fecundity of M. euphorbiae.

The impact of natural enemies on Trichoplusia ni (Hübner) is reviewed. Disappearance of eggs and small larvae (presumably due to predation) is consistently the major intrageneration mortality. Parasitoids and a nuclear polyhedrosis virus effect mortality of larvae surviving early-instar predation. From the analysis, it is argued that natural enemies capable of effective colonization of the habitat and rapid exploitation of the prey population (i.e., r-strategists) are suitable agents for biological control of pests of annual or short-cycle crops. Polyembryony, polyphagy, and polyhedrosis represent attributes which enable the particular natural enemy to implement the rapid-host-exploitation strategy. This interpretation gives added theoretical support for importation of exotic natural enemies of pests of non-perennial crop plants.

With the current advances in insect population modelling, the need for more accurate simulation of temperature-dependent growth rates has become vital. The day-degree concept, with its linear temperature–rate relationship, has not been adequate for simulation of field populations under highly variable temperature conditions. Similarly, several of the non-linear relationships proposed in the past (Janisch’s catenary, parabola) have also been inadequate. All of these relationships produce large errors at temperature extremes.

This paper presents a comparison of various functions which have been used for developmental time estimation and an algorithm for a sigmoid function which can be used in simulations having either a calendar or a physiological time base. Validation of the algorithm is presented for three insect species.

Twice as many larvae of the dark-sided cutworm, Euxoa messoria Harr., were found in rye fall-seeded tobacco field plots than in winter-fallowed tobacco field plots. There were corresponding differences in numbers of injured tobacco plants. Cutworm aggregations were more prominent in the winter rye than in the winter fallowed area of the tobacco field with low populations of dark-sided cutworms.

Larvae of the variegated cutworm, Peridroma saucia Hbn., appeared 2 to 4 weeks later than dark-sided cutworm larvae and winter cultural methods had little effect on their numbers.

The mountain pine beetle, Dendroctonus ponderosae, and 68 associated insect species were reared from infested sugar pine, Pinus lambertiana. Portions of three infested trees were sectioned by height and the insects emerging from each were identified and recorded. In one tree the number of woodpecker strikes also was noted. The tops of two of the three trees were infested by another bark beetle, Pityophthorus confertus, and from these same two trees the most common parasite obtained was Macromesus americanus.

Balsam woolly aphid nymphs, Adelges piceae (Ratz.), settle primarily in the apical 3-year growth of a branch. This portion of a branch is a natural population unit that can be designated a sample universe for detailed studies of aphid survival and mortality.

The toxicity of residues of three carbamate and nine organophosphorus insecticides in rutabaga, measured by bioassay with larvae of Hylemya brassicae (Bouché), for periods from 60 days after drilling (when roots were 5 to 6 cm diam.) until 150 days after harvest (roots in storage at 4 °C) are presented graphically. The insecticides were applied 3 to 4 cm below the soil surface in a 10 cm band at several rates ranging from 2.8 to 33.6 kg a.i./ha. Maximum toxicity for carbofuran and fensulfothion residues occurred within 75 days of drilling followed by a steady decline. Conversely, the toxicity of residues of trichloronat and chlorpyrifos increased steadily over the growing period with little or no decline during storage. The remaining insecticides exhibited toxicity patterns between these extremes. At high rates, phytotoxicity was recorded for all compounds except trichloronat and fonofos. Phytotoxicity was so severe with AC64475 ((2-diethoxyphosphinylimino)-1,3-dithietane) that all plants were destroyed with rates in excess of 11.2 kg a.i./acre. AC64475 was the most toxic insecticide to H. brassicae larvae. The nine organophosphorus insecticides included in these tests were mostly concentrated in the peel of rutabaga, whereas the carbamates were mostly concentrated in the pulp.

Thermoregulation in nests of two colonies of Vespula arenaria and two colonies of V. maculata was studied in relationship to seasonal changes in colony biomass. The colonies achieved maximum ability to resist ambient temperatures of 5 °C and maintained high nest temperatures on or within a week of achieving maximum biomass. During this period the colonies were capable of producing about.20 to.35 cal per gram of biomass per minute. The caloric production per gram required to maintain the normal nest temperatures of 30 °C and 32 °C in an ambient temperature of 25 °C was much less, but was greater for the V. maculata colonies than for the V. arenaria colonies. The greater efficiency in thermoregulation by V. arenaria is largely due to the fact that nests of this species have a greater biomass of wasps than approximately equal sized nests of V. maculata.

Diurnal activity of Aedes and Culex spp. was observed near Banff, Alta., and Hope, B.C., when naturally polarized light was present, reduced, or absent in relatively open habitats. Resting mosquitoes attacked as soon as they were approached closely, whether or not polarized light was present. In contrast, mosquitoes made long, roving flights only when there was polarized light overhead. Roving flight stopped whenever zenith polarization was disrupted by passing clouds or by the unpolarized glare surrounding the sun. As overhead polarization is most intense near sunrise and sunset, it could be employed then by mosquitoes travelling to and from feeding or oviposition sites.

The sex-pheromone-producing gland of the eastern spruce budworm, in addition to producing the sex attractant (E)-11-tetradecenal, has been shown by gas chromatographic and mass spectral data to contain (E)-11-tetradecen-1-ol, a known inhibitor to the sex attractant.

An examination of the female genitalia of forms belonging to the redimicula complex of the genus Euxoa disclosed that the group consists of four species, redimicula (Morrison), servita (Smith), auripennis new species, and arizonensis new species. Diagnostic characters of the species in the group are discussed. A discriminant analysis was successfully used on characters of the male genitalia to segregate the males. A key to females and males of the species and subspecies of the redimicula group is included.

The genus Masistylum is redescribed. It is recorded for the first time in North America. M. stenommatum n. sp., from the Rocky Mountains of northern British Columbia, is described and figured.

A procedure is described for evaluating commercial residual pesticides commonly used for cockroach control. Tempered masonite panels, five per product and standard (3% chlordane), were treated uniformly on their smooth side and aged up to 5 weeks. During aging, these panels were tested at 1, 3, and 5 weeks after treatment for efficacy based on mortality of male cockroaches exposed to them for 48 h. A product is satisfactory if the average percentage kill obtained is equal to, greater than, or within 5 percentage points less than that of the standard tested in conjunction with it. A product meeting the first and third week mortality limits is also considered acceptable.