Pristiphora acidovalva is described as a new sawfly on willow. It has been collected from New Brunswick to British Columbia in Canada. The new species is compared with P. leucostoma (Lindqvist), which it closely resembles.

Tuberculatus cornutus is described from Turkey, its affinities noted, and a combined key to the world species of Tuberculatus Mordwilko and Tuberculoides v. d. Goot is given. Revisionary notes on Tuberculoides are offered and Tuberculoides eggleri (Börner) is transferred to Tuberculatus.

Twelve species of parasitic insects were associated with Eucosma rescissoriana Heinrich in western white pine, Pinus monticola Douglas, cones in northern Idaho from 1963 to 1965. Pimplopterus n. sp. (Hymenoptera: Ichneumonidae), Chelonus petrovae McComb (Hymenoptera: Braconidae), Apanteles starki Mason (Hymenoptera: Braconidae), and Psalidopteryx psilocorsiphaga Brooks (Diptera: Tachinidac), in order of decreasing abundance, accounted for approximately 95% of the total parasitism. One additional species, Bracon rhyacioniae (Muesebeck) (Hymenoptera: Braconidae), was present locally in small numbers. The four major species increased their rates of parasitism from 9.4 to 40.9% in one area during this 3-year study and were shown to be effective natural control agents of E. rescissoriana in seed-production areas.

Nymphs and adults of Podisus maculiventris (Say), reared on four sizes (diet levels) of live larvae of Galleria mellonella (L.), captured prey, consumed food, and grew at rates varying with the size of larvae supplied. For nymphs, a direct linear relationship was obtained between rate of food consumption and daily growth and rate of food consumption and daily development. For adults, male and female, age did not affect food intake significantly, but for females alone, food intake differed significantly at different diet levels. A significant difference was also obtained for both sexes between body weight and diet level. Males and females lived longest on diet 1, apparently because of reduced metabolic activity.The number of eggs laid by each female corresponded to its food consumption for the first 35 days but decreased thereafter with age. The mean dry weights for fertile and infertile eggs at different diet levels did not differ significantly irrespective of the amount of food consumed by egg-laying females.For each nymph in each of instars 2 to 5 and for adults, the consumption quotient, an index of metabolic activity, increased as the rate of food consumption increased. For nymphs, the quotient decreased during ontogeny at each diet level, and for adults, decreased with age at diet levels 2, 3, and 4. The quotient remained constant for adults of both sexes at diet level 1.Results show that nymphs and adults of P. maculiventris can survive and mature satisfactorily for extended periods on small prey but needs larger prey to accelerate development, increase growth, and maintain a high reproductive potential.

Maintenance of predacious arthropods in apple orchards requires both the judicious use of chemical sprays and the presence of adequate food supplies. When the common food source, the European red mite, Panonychus ulmi (Koch), is depleted by either a selective chemical, such as Animert V-101, or by excessive activity of the predators, the apple rust mite, Vasates schlechtendali (Nal.), if present, provides an alternate food. This enables survival of sufficient numbers of predators to prevent resurgence of the red mite within the same season.

Experiments were carried out to determine the effect of age on the functional response of the pentatomid predator Podisus maculiventris (Say), reared in a simple glass jar universe on different prey sizes of Galleria mellonella (L.). Holling’s (1959) ’disc’ equation accurately described the predator’s response at all prey sizes up to 50 days of life. For nymphs, the calculated ’rate of discovery’, a, increased as the predator age increased, but the time of handling prey, b, decreased; for both adult males and females, these calculated values increased gradually up to the 50th day. The relationship between predator age and numbers of prey killed, and predator age and amount of prey body contents consumed (food consumption), was linear at all prey sizes, but mainly negatively so. Prey size was an important component of the predation process for all stages of the predator.It is concluded that ’hunger’ is an important parameter of the attack model since the degree of predator satiation bears directly on b-type activities which in turn affects a-type activities. These findings indicate that under field conditions P. maculiventris will kill more small-sized lepidopterous prey larvae than large-sized ones, and that, because of the greater prey defense of the latter, their survival from predator attacks will increase. These actions may be of considerable importance in the survival of lepidopterous host species.

The following new species and subspecies of Circobotys are described: C. elegans n. sp., Taiwan; C. heterogenalis onumalis n. subsp., Hokkaido; C. heterogenalis pertinctalis n. subsp., Shantung, China; C. obscuralis ahyoui n. subsp., Yuennan, China; C. elongata n. sp., Taiwan; C. cryptica n. sp., Japan and China; C. plebeia n. sp., Tapaishan, S. Shensi, China.

The full-grown larva of Pristiphora acidovalva Wong, a newly recognized sawfly on willow, is described and the occurrence of the species in Ontario is discussed.

The gas chromatograms of some of the volatile chemicals found in the following ants are presented: Pogonomyrmex barbatus (F. Smith), Forelius foetida (Buckley), Conomyrma pyramica (Roger), Iridomyrmex pruinosus analis (E. André), Tapinoma sessile (Say), Trachymyrmex septentrionalis obscura (Wheeler), Pheidole dentata Mayr, Acromyrmex versicolor (Pergunda), and Novomessor cockerelli (E. André). The data and methods are presented to demonstrate their potential value as taxonomic characters in the study of ant systematics.

Untreated male tobacco budworms, Heliothis virescens (F.), fail to transfer sperm in about 15–20% of their matings. Tobacco budworms sterilized by 45 krad significantly fail to transfer sperm in about 50% of their matings. Females that received a spermatophore but had no sperm in their spermathecae produced the same numbers of eggs as virgin females. Females with sperm in their spermathecae laid the same numbers of eggs, whether the sperm came from irradiated or untreated males.Irradiated males did not transfer sperm to the spermathecae of the female because sperm were not incorporated into the spermatophore. The failure to incorporate sperm into the spermatophore occurred because the sperm in the male reproductive system did not move from the duplex to the simplex area where the spermatophore is formed. Males irradiated after mating were able to transfer sperm in a second mating as well as untreated males.

Optimum storage conditions for eggs of Aedes vexans (Meigen) were found to be a temperature of 2 °C and a saturated atmosphere. These conditions are also suitable for storing eggs of Aedes abserratus (Felt and Young) but this species can be stored at lower temperatures. When eggs of both species are stored at 2 °C and placed in a hatching medium at 2 °C, hatching begins in A. abserratus but not in A. vexans. A comparable hatch in the latter occurs at 10°–15 °C. Desiccation and death of A. vexans embryos occur rapidly at a low relative humidity (20%) and a high temperature (21 °C) but slowly at low relative humidity and a low temperature (4 °C). Eggs that lose a substantial amount of water will still hatch and the larvae develop normally, but hatching time is delayed. The hatching time may be twice as long as in eggs kept in a saturated atmosphere at similar temperatures, indicating that embryos must regain some of the lost water before hatching can occur.

Nymphs and adults of Melanoplus sanguinipes (Fabricius) were placed, one stage at a time, into a temperature choice chamber. Their behavior was observed while a temperature gradient was established and then allowed to collapse. The grasshoppers aggregated and remained quiescent at a temperature of about 38 °C. An implication of this preferred temperature regarding behavior in the field is discussed.

A 3-year study in two orange orchards in Egypt showed that when sprays were eliminated, citrus brown mite, Eutetranychus orientalis (Klein), was not a problem. The response of both phytophagous and predaceous mites to cessation of pesticide sprays was determined.

Physical activity in Blaberus giganteus (L.) loosely follows a recurrent temporal pattern corresponding to the light–dark cycle. Differential haemocyte counts were made from serial blood samples taken before and after dark from individual adults in a brief attempt to determine whether the haemocyte population changed regularly also with this cycle. In 4 of the 16 individuals tested there was a substantial increase in the relative number of spherule cells and a somewhat proportional decrease in granular haemocytes after dark. In this species, these two haemocyte categories differ mainly in the size and composition of their cytoplasmic inclusions. The proportional change in their numbers is therefore considered to be the result of chemistry rather than a shift in populations of entirely separate kinds of cells. Retention of the two categories may be useful for indicating physiological changes in the blood. It seems possible that the cyclic change in numbers indicated here for these categories is more usual than shown, but is not revealed by the method employed. It seems sufficiently large however to warrant consideration in the design and interpretation of experiments relating to haemocyte populations.

Survival of Adalia bipunctata (L.) emerging from eggs laid some distance from prey locations, depended on the ability or the larvae to reach a prey location on a host plant. Distances between egg clusters and prey locations, when less than 63 cm in laboratory cages, had little effect on larval survival. Pathways used by a larva to prey was more important than distance. Larvae that had access to prey via pathways, reached prey as distant as 63 cm from eclosion sites.Cannibalistic predation by these larvae on eggs increases their survival chances when prey are scarce.

Populations of the balsam woolly aphid on Fraser fir trees were sampled without replacement. Sampling frequency was based on the embryological period of the aphid at mean monthly temperatures in the field. The sample for each date consisted of 16 pieces of bark, 1/2 in. diameter, from each of 10 trees. Precision of the method was usually within ±10% of the mean. The largest proportion of variance was within trees. Stratification of samples by levels within trees decreased variance estimates.Frequency distributions of counts of most stages of the aphid approximated the negative binomial distribution. Therefore, data were transformed to logarithms in order to approximate the normal distribution.

Four new species of Tarsonemus are described and illustrated: T. ips, T. triarcus, T. subcorticalis, and T. endophloeus. All are subcortical associates of bark beetles in conifers. A key is provided to distinguish these species and other tarsonemids which commonly coexist in habitats provided primarily by ipine bark beetles.

A field investigation was carried out in Chatham, Ont., to evaluate the oviposition preference and survival of Hylemya brassicae (Bouché) on six early cruciferous crops, namely, Brussels sprouts, broccoli, cabbage, cauliflower, Chinese cabbage, and kohlrabi. A significantly greater number of eggs was laid on Chinese cabbage than on any other host. In the first generation, the percentage mortality for each of the life history stages differed significantly on the various crucifers but the total generation mortality did not.