The antifeeding compound AC 24055 (4′-(3,3-dimethyl-1-triazeno) acetanilide) was added to the diet of Drosophila melanogaster at several concentrations. Larval mortality and the duration of larval development increased significantly with increasing concentration from 125 to 625 parts per million (p.p.m.), and these effects were the same in males and females. Within this range of concentrations the weight of recently emerged adults declined with increasing concentration, the loss being greater for females than males. Egg production declined with increased concentration from 200 to 1000 p.p.m., particularly during the second week of egg production. Egg hatchability was not affected at 200 p.p.m., but from 400 to 1000 p.p.m. it declined rapidly from the second to the sixth day; with continued exposure, fertility was partly restored. The life span of adults decreased as the concentration increased from 500 to 1500 p.p.m. Concretions were observed in the Malpighian tubules of females reared in food containing 400 p.p.m. or more of the compound, but not in males.

Application of a juvenile hormone analogue (ZR-777), prepared from an emulsifiable concentrate, to adults or to host foliage retarded the developmental and growth rates of the progeny. Possible means of transmission of the effect to the progeny are discussed.

Four insect developmental inhibitors were tested against different stages of the apple maggot, Rhagoletis pomonella (Walsh). ZR515 was the most effective compound, completely inhibiting adult development from larvae and pupae treated at concentrations of 10 μg. Larvae were more susceptible than pupae. Sensitivity declined as pupae aged. Dissection of puparia showed a pupal/adult intermediate, usually with some adult characters developed in the thoracic region. ZR512 inhibited adult movement from larvae or pupae exposed to concentrations of 1.0 mg whereas R20458 gave inhibition of adult development at 10 mg concentrations. RO 20-3600 inhibited adult development from larvae exposed to concentrations of 10 mg. ZR515 and ZR512 applied to fruit had little effect on larval development but numbers of adults emerging from pupae from treated fruit were reduced. Adults from all tests produced viable eggs in the following generation.

Sampling techniques for all life stages of the apple maggot, Rhagoletis pomonella (Walsh), were developed and their precision and accuracy evaluated. Reliable estimates were obtained for the egg and larval stages (standard error < 10%), but at the low population levels often encountered in the pupal and adult stages it was necessary to accept a lower level of precision (S.E. ≏ 25%). Eggs and larvae were uniformly distributed within trees. Variation between tree quadrants, and sections at different radii from the trunk, showed that stratification within trees was necessary for reliable estimation of the later stages. Predators acting in a heterogeneous environment under the trees were considered to be the major contributors to this variation. The most consistent source of variation was that between trees.

The apple rust mite, Aculus schlechtendali (Nal.), is active on the apple leaves from late May until early August and passes through three generations as indicated by the peak numbers of eggs. This species overwinters as deutogynes under bud scales and crevices in the bark. During the latter part of May the deutogynes lay eggs that develop into first generation primaries, followed by a second generation the latter part of June. Eggs laid by the second generation primaries produce the overwintering deutogynes. Injury to the leaves, mainly bronzing to the ventral surfaces, becomes noticeable early in July. The numbers of A. schlechtendali varied between cultivars within orchards. The differences were not consistent between orchards.

The factors responsible for heavy mortality of Culex tarsalis populations in saran plastic screen cages were investigated. Two compounds, Dow Corning® Antifoam A and Aldo® MLD (glyceryl monolaurate, Glyco Chemicals Ltd.), used as foam preventatives in screen processing, were tested with C. tarsalis. One of the compounds, Aldo® MLD, was shown to be toxic to mosquitoes. Toxic principles were removed easily from saran screening by washing with detergent and water.

Hexacola sp. near websteri (Crawford), an imported larval–pupal parasite of Hippelates eye gnats, was reared in the laboratory on this host and its immature stages were diagrammed. The duration of each stage at 26 °C was as follows: egg, 2 days; first instar larva, 2 days; second instar larva, 3 days; third instar larva, 4 days; and pupa, 6–7 days. The morphological characters are compared with those of related species and the feeding activity of the larva is described.

Ten new species of Trichobius are described from the Neotropical Region: T. intermedius (Dominican Republic, Haiti, Bahama Islands, Cuba, Jamaica, Puerto Rico, Virgin Islands, Lesser Antilles, Mexico, Guatemala, Honduras, and El Salvador); T. neotropicus (Dominican Republic); T. cognatus (Dominica and Cuba); T. wenzeli (Cuba); T. dusbabeki (Cuba); T. cernyi (Cuba); T. frequens (Cuba, Dominican Republic, and Jamaica); T. macroti (Cuba and Bahama Islands); T. robynae (Puerto Rico); and T. dominicanus (Dominican Republic).

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.

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.

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.

Six species of Apanteles (Hymenoptera: Braconidae) that attack microlepidopterous larvae in growing tips of spruce and fir are described, figured, and keyed. They are: A. fumiferanae Vier., A. petrovae Walley, A. absonus Mues., A. renaulti n. sp., A. milleri n. sp., and A. morisi n. sp.

Hydraulic, fan-spray nozzles (Teejet 650067) at 50.8 cm (20 in.) spacing, 55.9 cm (22 in.) above the target surface, and operating at 2.8 kg/cm2 (40 p.s.i.) produced very uneven coverage when applying aqueous sprays containing uranine. Deposits immediately below the nozzles were 2 to 3 times more than those between nozzles.

Deposits on grasshoppers (Melanoplus sanguinipes F.) were directly proportional to their plan area. Since this area increases as the square of the linear dimensions and weight increases as the cube, second instar grasshoppers collected twice as much spray/unit weight as fourth instar nymphs and 3 times as much as adult females. These differences were reflected in the mortality caused by insecticide sprays. A spray applying dimethoate at 140 g/ha (2 oz/ac) in 39.3 l./ha (3.5 Imp. g.p.a.) killed 90% of second instar nymphs but only 14% of adult males.

The Nantucket pine tip moth, Rhyacionia frustrana (Comstock), and the pitch pine tip moth, R. rigidana (Fernald), often occur together in young stands of southern pines, but the former is more common.

A review of studies of mayfly fecundity (number of eggs produced per life span) indicates that some of the larger mayflies, e.g. Palingenia and Hexagenia, have total potential fecundity values that are higher than found in most other insect groups. For 12 mayfly species of a brown-water stream in Alberta, Canada, fecundity of the subimagoes was generally predictable from the size of the female regardless of the particular species. An exception was Leptophlebia cupida, which, for a given length, had a much higher fecundity than any of the other species and a much larger increase in fecundity per unit increase in body length. L. cupida averaged 362 eggs/mm body length, while the other species had an average egg production of between 100 and 200 eggs/mm body length. The small species, although having a relatively low total fecundity, produced more eggs per unit volume of abdominal space than did the larger species. By combining quantitative emergence data and fecundity data, we calculated that the entire mayfly fauna produced about 300,000 eggs/m2 per year and that it takes an average of 934 eggs to produce one subimago of the next generation.