The female and male of Asca acornis n. sp. are described and illustrated. This species occurs in arboreal habitats in the southern United States. The absence of the most salient diagnostic character of the genus Asca on adults of this species is discussed.

The mechanics of coupling in Melanoplus sanguinipes (Fabr.) are described and differences between some species of Acrididae discussed. A high level of coupling activity was revealed with the most active male and female mating 56 and 46 times, respectively. In addition, multiple daily matings, to a maximum of five, were common. The majority of copulations occurred during the morning in both laboratory and field; however, in the latter, unfavourable weather restricted sexual activity. Coupling did not appear to occur at random; significant preferences were shown by certain males for certain females.

In Canada and Alaska, the Stratiomyidae are represented by six subfamilies containing 23 genera (less Caloparyphus) and 84 species. This paper treats three of the subfamilies, the Beridinae, Sarginae and Clitellariinae which include 15 genera and 21 species.The vast amount of information that has accumulated over the years since 1927 when Dr. Corran published his synopsis of the family has been assembled and reviewed. This includes recent changes in nomenclature, information on adults and immature stages, notes on biology and distribution records. In addition, keys have been provided for adults and larvae (where possible) at the subfamilial, tribal, generic and specific levels.

Female and larva of the new sawfly Susana fuscala are described and illustrated, based on specimens collected in British Columbia. The new species, feeding on the foliage of Juniperus scopulorum Sargent, is separated from the other six Nearctic species.

The influence of constant temperatures on the non-diapause development of Hyssopus thymus was studied and the results of these studies are presented. A lower threshold for development of less than 12 °C and an upper threshold of about 32 °C were determined. Mean times for and rates of development at different temperatures are presented for all developmental stages. The egg is the stage most sensitive to temperature change. Regression equations describing the relationship between the rate of development and temperature for these stages are given and a thermal constant (K) of about 190 degree-days is calculated for total development. This constant is not applicable to naturally fluctuating temperatures. The results of these studies are discussed in relation to the potential impact of H. thymus on European pine shoot moth dynamics under different climatic conditions. It is concluded that H. thymus should be more effective in warmer seasons and at lower latitudes.

Male Heliothis virescens (F.) were irradiated with 7.5, 15.0, or 22.5 krad of 7-rays and crossed with untreated females. Then fertility of these treated males (PJ and of their descendants was studied for two generations. In addition, the postembryonic survival of the Fx and F2 generations was studied. Fertility (percentage egg hatch) of P1 males was greater than that of Ft males or Fj females. There was more postembryonic survival in the F1 than in the F2 generation. When the Px males received 22.5 krad, few F2 larvae hatched, and none survived. When Pt males received 15.0 krad, the fertility of F1 males and females was less than 5, and 10%, respectively, and less than 20% of the F2 larvae survived; however, sterility factors were nearly eliminated by the third generation. When P1 males received 7.5 or 15.0 krad, the average fertility of F2 males was greater than that of F1 or P1 males but less than that of untreated controls, though fertility of some F2 males was normal. The lower the dose received by P1 males, the greater was the frequency of F2 males with normal fertility.

Fecundity and egg survival had inverse linear relationships with increasing evaporation potentials expressed as vapor pressure deficits. With an increase of vapor pressure deficit from 4 to 24 mm Mg at a favorable temperature of 25.5 °C, mean fecundity could be reduced from 130 to 51 eggs and egg survival from 90% to 20%. Optimal laboratory physical conditions for egg production consisted of a low evaporation rate of less than 9 mm Hg vapor pressure deficit but short of a saturated atmosphere at a room temperature of 25.5 °C. One hour daily exposure of eggs to high temperatures up to 39 °C did not cause a significant increase in egg mortality. In the field there was no difference in fecundity of females between plots in damp western Washington and dry central Oregon (pine region). Egg mortality was always higher at the central Oregon plot, presumably because of higher evaporation rates. Since high vapor pressure deficits are common occurrences during the growing season in most of the pine region, it is possible this factor could limit Rhyacionia buoliana populations in some of these areas.

Tanaoscelio cornopis n. gen. and n. sp. (Scelionidae: Scelioninae) is described from Trinidad, W.I. Specimens were reared from eggs of a grasshopper, Cornops longicorne (Bruner) (Orthoptera: Acrididae), found in leaf petioles of water hyacinth, Eichhornia crassipes (Mart.) Solms. (Monocotyledones: Pontederiaceae). The new genus is compared with the related genus Scelio Latreille.

These preliminary investigations of effects of radiation on black flies were undertaken to develop methods of control based on the "sterile-male" technique. Mature black fly larvae were irradiated at various exposures (from 2 kR to 32 kR) and allowed to complete development in aerated stream water in the laboratory. The larvae were preponderantly Simulium venustum Say, determined by inspection of pupae and adults. It was found that percentage pupation following irradiation remained at a fairly constant level (about 93%), whereas emergence from pupae fell from 54% at 2 kR to 0% at 28 kR. Though variable, the percentage emergence of the controls averaged 47%. Adults inspected for radiation damage appeared unchanged at the lower doses, e.g. 2 kR to 6 kR, compared with controls. At higher doses (e.g. 16 kR) the abdominal cavities usually showed a notable decrease in stored fat bodies. The anterior two-thirds of the abdomens were largely devoid of internal organs, many of which, including the ovaries and testes, were found in a degenerate condition at the posterior tip.

Midila bordonorum n. sp. is described from near Portachuelo Pass, Estado Aragua, Venezuela.

Radiocesium accumulation by Aedes aegypti larvae was greater at 25 °C, than at 20 °C. The activity density (c.p.m./mg dry wt.) of the adults was the same for both sexes, as was the nuclide’s elimination rate. The amount of 137Cs accumulated by the larval instars was inversely proportional to the concentration of potassium in the rearing medium, the suppression of 137Cs uptake being greater at 25 °C than at 20 °C. The possibility that larvae may accumulate 137Cs via the anal papillae and the gut, is briefly discussed.

Adults of Sepedon fuscipennis Loew were sampled periodically throughout the summers of 1969 and 1970 in a backwater habitat. Several overlapping generations of this common marsh fly were present during both summers, and its population density reached a unimodal peak both years. Population estimates based on mean number per sweep agreed well with mark–release–recapture data. These estimates showed a reasonably good fit to the negative binomial distribution and indicated that aggregation of the flies probably is due to some heterogeneity in the environment. Flies lived more than 3 months in laboratory cages, and each female laid an average of 191 eggs.

Estimates were made of larval survival and net production for discrete cohorts followed in the field. The survival and production rates of larvae were greater when small snails were abundant in the habitat and much greater when the larvae were fed once before being released. Survival was not decreased perceptibly by the degree of larval crowding tested (50 larvae compared with 25 in an area of 254.34 cm2).

The rate of ingestion by Podisus maculiventris Say feeding on larvae of Tenebrio molitor L. or Galleria mellonella L. is almost constant with time and from one predator to another. The rate is 1.80 ±.070 mg/hr/individual.No effect of the age or size of the predator nor of the species of prey on the feeding rate could be detected. Different periods of starvation before feeding directly affect the percentage of individuals that feed, but not the actual rate of feeding, until 60 hours of starvation. After 72 hours starvation, there is a drop in the feeding rate which we attribute, tentatively, to a weakening of the feeding mechanism by the starvation.The initial weight of the larva used as prey affects the rate of sucking during the first hour or two of each period of feeding and this relationship is responsible for a slight non-linearity in the individual curves of feeding. This may be an effect of the internal pressure of the body fluids in the prey.The process of ingestion is reviewed and compared with published studies of other species of Hemiptera. It is suggested that after insertion of the stylets of the predator into the body of the prey, the feeding process is affected by the internal pressure of the prey during the early part of a period of feeding but that, thereafter, the sucking action is maintained constant by the action of capillarity and the pharyngeal pump.

Adult sexing characters were found by comparing the arrangements of spines on the elytral declivity. Callows were distinguished by observing the male vas deferens through the semi-transparent pronotum. In pupae, sexing characters were found to be located in the posterior abdominal segment of both sexes.

Codling moth populations on natural apple fruit trees scattered throughout Nova Scotia are compared with those in commercial orchards. In natural fruit, failure of crop, crop size, degree of isolation, amount of crowding by native trees, and natural enemies determine the level of codling moth numbers. Young commercial orchards require artificial control measures within a few years of first bearing fruit to prevent severe crop losses. In older commercial orchards natural controls require an occasional assist by chemical treatment to contain the codling moth below economically tolerable levels. Such treatment is applied to interfere as little as possible with known natural controls.

The effects of seven gamma radiation dosages from 5 to 100 krad on all metamorphic stages of the spider beetle, Gibbium psylloides (Czenpinski), were studied. Five kilorads prevented development of adults from treated eggs and larvae. Some adults emerged from the pupal cocoon at all treatment levels except 50 and 100 krad, but their longevity was greatly reduced. Adults were fairly resistant to sterilizing effects of the radiation. Twenty kilokrads was not completely sterilizing to either males or females, but fecundity was greatly reduced. The longevity of treated adults was significantly reduced, but some survived for 20 weeks after a 20-krad exposure. Adults and pupae of this species were more radiation resistant than were most other stored-product Coleoptera.

Only two species of bird fleas were known from New Mexico: Ceratophyllus celsus celsus Jordan and C. petrochelidoni Wagner, both from the southeastern part of the state. Four new records of the latter species from northcentral New Mexico are added. An unpublished old record and seven new records of C. niger Fox are presented. Records of three rodent fleas, Catallagia decipiens Rothschild, Monopsyllus wagneri (Baker), and M. eumolpi (Rothschild), found in bird nests also are given.

Two types of sensory hairs on the tarsus of the spruce budworm, Choristoneura fumiferana (Clem.), are described using scanning electron microscopical and histological techniques.

Coenopoeus palmeri (LeConte) feeds on the several species of staghorn cacti of the United States. The adults feed externally at night and the larvae mine internally. Adults are active in spring and summer. The larvae feed through the summer and fall and pupate within the larval mine the following spring. The genitalia of both sexes are illustrated and the larva and pupa described.