The chorionic architecture including the general and fine structure of the various shell layers and specialized areas in the newly-laid egg of Amathes c-nigrum (L.) is described. The chorion is, primarily, two-layered. The lamellate outer layer, comprising the main bulk of the shell, appears to be very porous over the ventral surface of the egg but much more solid over the lateral and upper surfaces. Here it is traversed by aeropylar canals which convey air to the inner layer. The trabecular inner layer completely surrounds the yolk except in the micropylar area. The micropyles protrude from the inner side of the chorion to form entomicropylar tubes which project towards the yolk. Each is enclosed by thickened vitelline membrane.

A method which uses the number of large embryos per adult to predict increases or decreases of green peach aphids, Myzus persicae (Sulzer), on potatoes over 3–4 or 7–8 days is presented. The population change between two successive counts 1 and 2, expressed as an increase factor (count 2 divided by count 1), is related to the average number of embryos per adult, at the time of count 1, by a linear regression (significant, P < 0.001). If there are more than about three embryos per adult, the population increases. Parasitism by Aphidius nigripes Ashm. reduces the number of embryos per adult in the field. In the laboratory, with no parasitism, the number of embryos per adult declines with age and is directly related to the daily birth rate which also declines with age.

The control of larvae of the cabbage looper, Trichoplusia ni, and the imported cabbageworm, Pieris rapae, by viruses, bacteria, and chemical insecticides was compared. In small field plots five applications of the nuclear-polyhedrosis virus of T. ni (1.8 × 1011 polyhedra/acre) and the granulosis virus of P. rapae (4 ×1011 granules/acre) controlled the respective host larvae as well as five applications of the chemical insecticide methomyl (0.5 to 1 lb/acre). Dipel HD-1 (0.25 lb/acre) and Thuricide HPC (60 fl. oz/acre), formulations of Bacillus thuringiensis, were as effective against T. ni larvae as methomyl but not as effective as Fundal (0.5 lb/acre) or Dipel at a higher rate (0.5 lb/acre). The control obtained by combinations of viruses with endosulfan or methomyl suggested an effective method of reducing use of chemical insecticides. Control of T. ni and P. rapae in plots up to 3 acres in area in growers’ fields demonstrated the effectiveness of the viruses when used as commercial insecticides.

Scarabatermes amazonensis n. g., n. sp., is described from Leticia, Colombia. The species occurs in the nests of Neocapritermes braziliensis (Snyder).

A key is given to the three genera of the Phloeocharinae. Full generic descriptions with comparative and distributional notes are given for Rimulincola Sanderson, Vicelva paradoxica new genus, new species, Ecbletus Sharp, and Olisthaerus Dejean.

Embryonic development in the mosquito Aedes (O.) sticticus (Meigen) was studied on moist surfaces at five constant temperatures between 5° and 34 °C. Time for complete embryogenesis was 608, 272, 192, 152, and 120 h at 10°, 15°, 20°, 25°, and 30 °C, respectively. Upper and lower temperature thresholds were 33 °C and from 6° to 8 °C, respectively. Embryonic development proceeded normally when eggs were submerged in water at 25° and 30 °C, and no difference in developmental rate was observed between eggs on moist filter paper and those submerged in water.

Bryophaenocladius brincki (Freem.) comb, nov., B. productus (Freem.) comb, nov., B. laticaudus spec, nov., and B. digitatus spec. nov. are described or redescribed.

The new genus Tokunagaia is given for Adactylocladius Sæther 1969 pro parte, nec Sæther 1968. A new name, Orthocladius (s. str.) curtiseta, is given for O. brevisela Sæth. nec Kieff. Some new synonyms and records are given.

Economic injury levels of the alfalfa weevil on alfalfa were investigated in New York State. The dry weight food consumption for the larval stage of the alfalfa weevil averaged 7.34 mg/larva. For every gram (dry weight) of alfalfa consumed, 1.59 g (live weight) in insect tissue was produced. In the laboratory, it was found that insect food consumption could account for only about 50% of the total weight loss in alfalfa plants after 10 days of larval feeding. Therefore, alfalfa weevil damage to alfalfa was more than the larval food consumption, and this was believed to be due to the loss of the plant’s photosynthetic potential. In the field on first growth alfalfa, the economic injury level was calculated to be 56 larvae/stem. First growth alfalfa was less severely injured by alfalfa weevil larvae than our second growth alfalfa infested with equal populations of alfalfa weevils. It was shown that first growth alfalfa was able to compensate for 87% of the insect feeding while second growth alfalfa could compensate for only 50%. Since the alfalfa plant’s capacity to compensate for alfalfa weevil feeding can vary due to environmental conditions and plant characteristics, economic injury levels must be adjustable. To provide more reliability to economic injury levels, we propose that in alfalfa the following seven measurements be made: (1) alfalfa weevil larval density; (2 and 3) parasites and predators of the weevil; (4) rainfall and moisture level; (5) plant nutrients; (6) alfalfa variety; and (7) stage and previous management of alfalfa stand.

Euxoa oberfoelli, closely related to Euxoa obeliscoides Guenée, is described from the Great Plains of western North America.

The reproductive behaviour of Chrysopa oculata Say females shows a high degree of dependence on diet. Females remain unmated when maintained on a regimen of sugar and water, whereas they mate and produce fertile eggs when given pea aphids prior to pairing. In contrast, the males do not require a diet other than sugar and water in order to produce fertile matings. Pea aphids constitute suitable prey for continuous rearing.

Descriptions and figures are presented for Leptohyphes dicinctus, L. melanobranchus, L. brunneus, L. consortis, L. ferruginus, L. hispidus, L. lestes, L. lumas, L. pilosus, L. spiculatus, Tricorythodes notalus, and T. ulmeri from Mexico and Central America.

The foraging and tending behavior of the ant Dolichoderus taschenbergi (Mayr) was studied for 5 years in southwestern Pennsylvania. The ant used well-defined foraging trails and avidly collected honeydew from tuliptree scales, pine aphids, and less abundant sources. The ants increased the survival rate of tuliptree scales from 8.2 to 46.8%, probably by interfering with the activities of parasites and predators.

Cretonomyia pristina new genus and new species, a fossil fly in amber from Cedar Lake, Manitoba, is described and assigned to the Ironomyiidae. This fossil establishes that the family, heretofore known from a single Australian species, Ironomyia nigromaculata White, existed during Mesozoic times in North America. Comparison of the extinct species with the living species shows that the family appeared little different 73 million years ago than it does today. In points of difference, the fossil species usually shows the more primitive conditions. It is postulated that the family arose in North America in late Jurassic – early Cretaceous times, dispersed to South America late in the Cretaceous Period and thence to Australia via Antarctica while the latter three were contiguous — 43 million years ago.

Insects cause considerable loss of seed in white spruce, Picea glauca (Moench) Voss, and Engelmann spruce, P. engelmannii Parry, in British Columbia. The most important species are a maggot, Hylemya anthracina (Cz.), and a seed moth, Laspeyresia youngana (Kit.). Other insects are: a seed chalcid, Megastigmus piceae Roh., a cone axis midge, Dasineura rachiphaga Tripp, a gall midge, D. canadensis Felt, a seed midge, Mayetiola carpophaga Tripp, and a scale-feeding midge. These insects also occur in cones of Sitka spruce, P. sitchensis (Bong.) Carr., and black spruce, P. mariana (Mill.) BSP.

The systemic insecticides dimethoate and formothion proved to be effective against these insects when applied as sprays following pollination in mid-June.

Laboratory assay showed Beauveria bassiana (Bals.) Vuill. to be present in approximately 15% of the combined populations of forest collected living Hylobius pales and Pachylobius picivorus.

Profenusa lucifex (Ross), a blotch-mining sawfly on oak, Quercus L., is occasionally abundant in Ontario. The adults occur on host trees in June. The larvae, which are described and illustrated, mine the leaves from about mid-June to late July with a small partial second generation in the fall. The insect overwinters in the soil. Three species of chalcid parasites are known to attack eggs and larvae.

It was found that five different starches incorporated into artificial diet in place of sucrose made the diets significantly less nutritious for spruce budworm larvae (Choristoneura fumiferana (Clem.)).

The applicability of this to the natural situation — budworm larvae feeding on growing foliage — is unknown.

The fat soluble components of raw wheat germ were extracted with diethyl ether, and the extracts assayed for aggregant or arrestant activity with adults of the confused flour beetle, Tribolium confusum. Some extracts elicited a strong response, others had little effect, and still others were repellent. The concentration of peroxide in the ether was shown to be inversely correlated with the aggregating response evoked by the extract. In the preparation of extracts of biological material, therefore, solvents other than ether should be used unless the peroxide component is completely eliminated immediately before use.

A list of carabid beetles of the Magdalen Islands, Quebec is given, which includes 107 species.

Alternating temperatures resulted in higher intrinsic rates of increase (rm) than constant temperatures within the range of temperature favourable for growth and reproduction of the pea aphid. This difference was due to slightly faster development and earlier attainment of maximum fecundity at alternating temperatures.

Preliminary mathematical models relating rm to constant and alternating temperatures are derived. These are:

for constant temperatures and

for alternating temperatures of 5°, 10°, and 15° amplitudes respectively. Average deviation between empirical and computed values is 2%. The efficacy of these models is restricted to temperatures favourable for development and reproduction of the pea aphid.