Our knowledge of the group Aphididæ in California has been limited in the past to certain forms that were of economic importance in their relations to cultivated crops. No systematic list of these interesting insects has heretofore been attempted in this region, and this has not been due to any lack of material, for the varying conditions of climate here seem to be particularly favorable to them.

Mitochondrial cytochrome oxidase I and II genes were sequenced for two invasive alien birch (Betula L. [Betulaceae]) leaf-mining sawflies, Profenusa thomsoni (Konow, 1886) (Hymenoptera: Tenthredinidae) and Scolioneura betuleti (Klug, 1816) (Hymenoptera: Tenthredinidae), accidentally introduced from Europe to North America. Ten North American and two European populations of P. thomsoni were sampled. As no genetic variation was observed for this parthenogenic species in Europe or North America, there is no evidence that this species was introduced more than once into North America. A single Canadian population of putative S. betuleti was genetically characterized and compared with populations of S. betuleti and Scolioneura vicina Konow, 1894 in Europe to resolve the species identity of the introduced Canadian population. Three haplotypes were present in European material but only one haplotype was represented in material collected in Canada. The haplotype in the Canadian population occurred in both S. betuleti and S. vicina in Europe. Thus, this preliminary genetic work cannot provide certain identity of the Canadian species. Moreover, there was no significant genetic difference between putative S. betuleti and S. vicina in Europe, leading us to suggest that S. vicina may not be reproductively isolated from S. betuleti, despite ecological differences.

Incidence of parasitism by Pteromalus venustus Walker in populations of the alfalfa leafcutter bee, Megachile rotundata (F.), in western Canada from 1976 to 1983 was found to average ca. 1%. An average of 17.4 parasite adults emerged from each host cocoon and the ratio of males to females was 1:1. Temperature-dependent development and survival at 8 constant temperatures are described. The range of temperatures for greatest survival of the parasite (30–32 °C) coincided with the recommended incubation temperatures for cocoons of the leafcutter bee. Development data fitted a 4-parameter development model. Linear regression of development rate versus temperature provided estimates of base temperature and development time in degree-days for the egg, larval, pupal, and combined stages.

An experimental component analysis approach is used to define the physiological interactions of carbohydrate nutrition and the manner in which it regulates the crop-emptying rate. The basic components of the crop-emptying rate are frequency of valve opening and the volume of the slug of fluid which passes through the valve. This volume is solely a function of crop volume, but the frequency of opening is a complex function determined by the crop volume, and by gut activity and blood osmotic pressure, both of which are related to nutritional parameters. To guide the formulation of the relationship, a model of the mechanism of valve function is proposed, based in the phenomenon of muscle creep.

The osmotic pressure is estimated by calculating the change in blood trehalose level estimated from observed rates of disappearance of sugar from the crop. Sugar emptying from the crop diffuses from the midgut to the blood, where it is partitioned between trehalose and glycogen according to established biochemical relationships. The model developed fits a wide variety of published data on crop-emptying rates of flies fed different volumes and concentrations of sugar, and may be applied to active, inactive, and flying insects.

Pineus pinifoliae (Fitch) belongs to the Adelginae, a group characterized by unusually complex life-cycles. The typical species have at least five distinct forms, one bi-sexual and the others parthenogenetic. They alternate between two coniferous hosts, one of which is always a species of spruce (Picea). Galls are formed on spruce by a modification of the growth of the new shoot.

The life-history of P. pinifoliae is only partially known. Patch has reported on observations in Maine which showed that the gall-making form flew from “black spruce” to the needles of white pine and that its offspring settled on the new shoots. She also described a morphologically similar winged form which developed on white-pine shoots and which she believed to be the return migrants. Annand made similar observations in Oregon and gave careful descriptions of three forms: the fundatrix, the gallicola migrans, and the exulis.

Eight species of Epidamaeus of arctic western North America and extreme northeast, U.S.S.R. are discussed. Two new species, Epidamaeus hammerae and E. tritylos, are proposed and E. arcticolus, E. kodiakensis, E. mackenziensis, E. bakeri, E. coxalis and E. fortispinosus, previously described by Hammer, are redescribed.

The status of the genus Plega is discussed and a preliminary survey of the North American species is presented. Plega yucatanae, a new species reared from the cells of Megachile exaltata Smith, is described and compared with its near relatives. The immature stages are described and biological information is given.

Mature larch sawfly drop to the ground and spin cocoons in the moss or duff. The ground snrface of tamarack bogs is usually uneven, and the moss is variable in moisture content. During hot dry weather the moss on the tops of hummocks in dry sites becomes dry, while that in the depressions remains moist. During periods of heavy rain, or in wet sites, the depressions may be filled with water, while the hummocks usually remain above the water.

Grylloblatta campodeiformis Walker were collected from a site in the Alberta Rocky Mountains at an altitude of 1300 m. The gut contents in the autumn consist almost entirely of arthropods. Dominant among these was a tipulid fly, equally typical of the cold, montane habitat as Grylloblatta itself. In the laboratory, G. campodeiformis adults eat only live or recently killed animal prey, and neither adults nor larvae grow without animal food. Prey is detected by the antennae and then seized by the mandibles. Five types of sensilla, all of which are probably involved in prey identification, are described from the antennae and palpi.

Three types of traps were tested in 1969 and 1970 for collecting pupae of the eastern hemlock looper, Lambdina fiscellaria fiscellaria (Guen.). Highest numbers of pupae were obtained with burlap traps made from 2-ft-wide bands wrapped around trunks of infested trees. The proportion of the pupae in the burlap traps was estimated. Some of the potential uses for pupae collected by the method are mentioned.

The status of insecticide resistance in field populations of eggplant fruit and shoot borer, Leucinodes orbonalis (Guenée) (Lepidoptera: Crambidae) from the major vegetable growing regions of India was determined during the cropping seasons of 2009–2010 and 2010–2011. Six commonly used insecticides: carbaryl, chlorpyriphos, deltamethrin, endosulfan, fenvalerate, and profenofos were tested against L. orbonalis larvae. The resistance ratios (RR) at the lethal dosage (LD)50 levels were estimated as RR=LD50 field strain/LD50 susceptible strain. The L. orbonalis populations exhibited widespread resistance to tested insecticides. The highest average RR in the two-year study was observed in the assays of populations with deltamethrin (21.50–82.42-fold) followed by assays conducted with endosulfan (24.47–68.26-fold), chlorpyriphos (22.17–63.14-fold), carbaryl (39.18–49.09-fold), and fenvalerate (14.00–44.66-fold); and the lowest average RRs were observed in the assays with profenofos (16.65–39.43-fold). The high levels of LD50 values can be attributed to the long-term indiscriminate use of these insecticides in eggplant (Solanum melongena Linnaeus; Solanaceae) growing regions.

Pine oil (Norpine-65, Northwest Petrochemicals) was assessed as an oviposition deterrent for gravid female onion maggots, Delia antiqua (Meigen), in two types of laboratory experiments. When given a choice for 24 h between a control onion half treated with hexane and an onion half treated with pine oil in hexane, the females oviposited preferentially on or around the control onion half. In a no-choice experiment the females laid over three times as many eggs on or around solvent control onions as on or around onions treated with 1.0% pine oil. The DC50 (deterrent concentration50) was calculated to be 0.09%. The results suggest that pine oil (or its constituents) may have potential as an oviposition deterrent under field conditions.

The spatial and statistical distribution of Zeiraphera canadensis Mut. and Free. (spruce budmoth) within the crown of white spruce (< 4 m high) was investigated in northern New Brunswick. A 15-cm branch segment, measured distally from the scales of the branch’s apical growth and taken from the upper one-third of the crown, is considered an adequate sample unit for density estimates of spruce budmoth eggs and larvae. Sample sizes required to estimate spruce budmoth larval densities with given levels of precision and confidence were determined. A sequential sampling plan to classify spruce budmoth populations as low or high (potentially leading to growth reduction and deformed leaders in white spruce) was also developed.

Whether insects (Insecta) have the subjective experience of pain is difficult to answer. Recent work in humans demonstrated that the experience of pain occurs due to the activation of a “pain network” that integrates nociceptive sensory information, memory, emotion, cognition, and self-awareness. In humans, the processing of nociceptive sensory information alone does not produce the subjective experience of pain. Insect nociception is processed largely in parallel in two higher-order areas in the brain: the mushroom bodies and the central complex. There is little evidence of a coordinated pain network that would integrate these two areas with each other along with other traits thought to be important for a pain experience in humans. However, it is difficult to exclude the possibility that insects could have a modest pain experience using a less integrated neural circuit. This possibility seems unlikely, however, because even a modest experience would require some neuronal investment. It is unclear whether insects would benefit from such an investment. Recent work in artificial intelligence suggests that relatively simple, cost-efficient circuits can produce adaptive behaviours without subjective experience. Given our current understanding of insect behaviour, neurobiology, and evolution, the likelihood that insects experience pain is low.

The lily leaf beetle, Lilioceris lilii Scopoli, was first found in North America near Montreal, Canada, in 1943 (LeSage 1992). It was recovered in Boston, Massachusetts, in 1992 (Livingston 1996), and now occurs throughout all of the New England states and in the Canadian provinces of Quebec, Ontario, Nova Scotia, and Manitoba. It is a serious pest of native and cultivated lilies (Liliaceae) (Livingston 1996). This univoltine insect overwinters as an adult and after initiating feeding in the spring, oviposits in rows on the undersides of lily leaves. Larvae, which carry a fecal shield, pass through four instars before pupating in the soil. In North America, larval feeding often results in complete plant defoliation. Lilioceris lilii apparently originated in Asia (Berti and Rapilly 1976), and now exists throughout Eurasia from Siberia to Morocco and from the United Kingdom to China (Labeyrie 1963; Lu and Casagrande 1998). Based on its Eurasian distribution, L. lilii will likely increase its distribution in North America.

Linaria vulgaris Mill., known commonly as toadflax or butter-and-eggs, is worldwide in its distribution but is a serious weed only in the Canadian provinces of Alberta, Saskatchewan, and Manitoba (Zilke and Coupland, 1954), where it is increasing in importance (Beck, 1954; Carder, 1956; Forbes, 1957). Smith (1956) correlated its relative insignificance as a weed in the other provinces and in the northwestern United States with the occurrence of the curculionid beetle Gylmnaetron antirrhini (Payk.). Investigations on this and other insects that feed on toadflax and an evaluation of their possible use as biological control agents are reported in this paper; also included are some observations on the weedand its natural enemies made since 1950 in all provinces west of Quebec and in the northwestern United States.

Nutritional variability in resources may cause differential mortality between sexes resulting in biased sex ratios. If males and females differ in fitness, then mortality of the more sensitive sex can cause a bias in sex ratios, and can stimulate dispersion of males. We reared three generations of spruce budworm (Choristoneura fumiferana (Clemens); Lepidoptera: Tortricidae) on two artificial diets: a “normal” diet that provided all nutritional requirements for development and a “stress” diet (deficient in sugars and slightly higher in nitrogen), that simulated deterioration of food quality during outbreak conditions and had a detrimental impact on larval survival, development and growth. We tested the effects of continued nutritional stress on the sex ratio of pupae and adults. We found biased sex ratios in favour of males related to diet. Low quality food resulted in fewer females. This distortion was observed from the second generation onward, with a lower percentage of females reaching the pupal and adult stage. These results provide evidence that nutritional variation causes differential mortality between sexes, suggesting that females are more sensitive to nutritional stress. This is the first study that demonstrates sex ratio distortion due to nutritional selection pressure in spruce budworm. Our results indicate the importance of studying sex ratio distortion of spruce budworm in outbreak conditions.

The species known in America as the European spruce sawfly has been shown to be one of two species which have been confused under the name Gilpinia polytoma (Hartig) (1). One is arrhenotokous and is known only from Europe, and the other is thelytokous and occurs in Europe and America. This paper seeks to establish the correct nomenclature and provide adequate descriptions of the two species.

The larva of Chrysopa, in addition to feeding on aphids, takes a sugar meal from floral nectar, honeydew or, in captivity, solutions of sucrose. Sugar sources are located by a questing activity during which it scans the substrate with the antennae and palps. Feeding on honeydew may lead the larva towards aphids, on which it then proceeds to feed, and this is perhaps a normal sequence in nature.

It is pointed out that this duality of the feeding process — sugar meal and protein-rich meal — seems to be unique among endopterygote larvae, although well known in many adult insects. The larval sugar meal of Chrysopa may be a secondary characteristic which originated from the use of honeydew as an indicator when searching for prey.

Population density and parasitism of larch casebearer, Coleophora laricella (Hübner), were monitored for 10 years before parasites introduced for biological control became abundant. Overwintering densities remained fairly stable at about 100 larvae per 100 buds. The factor most closely correlated with population change was something, as yet unknown, other than the native parasites, which tended to be inversely density-dependent. The data will serve as the “before” period in a before and after evaluation of the biological control program.