Four species are recognized in the genus Holcopsis Enderlein: bifenestrata (Osten Sacken 1886), fenestrata Enderlein 1923, bequaerti (Philip 1943) and pilifera (Philip 1943). All specimens for which the locality is known are from the State of Durango, Mexico. The genus is characterized and its possible relationship with Bolbodimyia Bigot is indicated. Collection data for all known specimens are given. The species are characterized by the use of a descriptive key. The wing, third antennal segment, and second palpal segment of the female of each species is illustrated.

The new species Actornithophilus canuti is described and illustrated from specimens found within the quills of primary flight feathers of a knot, Calidris canutus (Linnaeus).

Morestan applied at the white bud, calyx, or white bud plus calyx stage on Bartlett pears gave good control of the pear rust mite, Epitrimerus pyri (Nal.), and prevented fruit russet caused by rust mite feeding. A June spray of Morestan or ethion also controlled the mite but did not prevent fruit russet. During the white bud and calyx stage, the rust mite is found at the base of leaves and flowers but moves to the fruit shortly after the calyx stage. By early June, it can cause considerable fruit russet, especially on the calyx end of the pears.

The larvae of Culicoides denningi F. & P. may be unique among Ceratopogonidae in that they appear to be restricted to rivers. In the South Saskatchewan River the larvae overwinter in the sand across the entire river bed. Several weeks after the ice breaks up in the spring the larvae swim to shore to pupate. Man and livestock near the river are sometimes severely attacked.

Drepanaphis pallida is described from specimens collected on Acer saccharum Marsh. in Ontario. In structure and colour it is very similar to Drepanaphis granovskyi Smith and Knowlton, from which it can be distinguished by the relative sizes of the dorsal abdominal tubercles and the length of the cornicle.

Five insecticides (Baygon, diazinon, Dursban, Furadan, and menazon), previously shown to have some effect on control of the balsam woolly aphid, Adelges piceae (Ratz.), on branches of Abies balsamea (L.) Mill., have been tested more intensively. Individual trees were sprayed from the ground with 1.0, 0.5, or 0.25 litre of solution containing 5% active ingredient (an approximate per acre dosage rate of 12 to 25 lb). Dursban, Baygon, and diazinon caused 85, 75, and 72% mortality respectively. Furadan and menazon were less effective, causing 56 and 34% mortality.

Four new species of aphids are described: alate and apterous viviparous females of Masonaphis patriciae new species from Tsuga heterophylla (Raf.) Sarg. in British Columbia; apterous viviparous females of Masonaphis menziesiae new species from Menziesia ferruginea Smith in Alberta; apterous viviparous females, oviparae, and males of Aphis rubiradicis new species from Rubus chamaemorus L. in Saskatchewan; and apterous viviparous females of Aulacorthum capilanoensis new species from Rubus spectabilis Pursh in British Columbia.

A new species of Eremocharis (Orthoptera: Pamphagidae) is described, E. zaheri, from Paktia Province, Paywar, Afghanistan.

Drawing retrospectively and collectively on results of a single individual and his associates covering some 22 years of field and laboratory studies, the authors present three documented case histories of technically complete biological control. They use these examples to illustrate the potential for greater use of this method of pest control, and they discuss the theory of biological control as related to whether or not introductions of a complex of enemy species will inherently lead to competitive interference and a lesser degree of control than if only the "best" species were introduced. They conclude that the three case histories are a refutation of this thesis, as are certain theoretical considerations, and the net results from all biological control programs on a worldwide basis.The authors also point to weaknesses in the use of currently available methods for quantitatively rating or appraising the control and regulating power of density-dependent factors that act with a lag (entomophagous parasites and predators), and emphasize chat regression and modelling methods should be used in conjunction with "check-methods" or other experimental means.

A technique is described whereby an average of 99% (96–100%) of known numbers of eggs of Ctenicera destructor (Brown) were removed from units of soil 1/2 pint in volume. Average time to process each unit was 11/2 man-hours.

The summer forms of two aphids, Rhopalosiphum padi (L.) and R. fitchii (Sand.) are similar morphologically, but R. padi has a chromosome count of 2n = 8, and R. fitchii of 2n = 10. Observations were made on these species on wheat, oats, and barley in the field and laboratory, using chromosome counts to verify species identity. Although they inhabit overlapping niches on the same host plants, there are small differences in behavior. Both species were found on barley in the field, although R. padi is much more abundant than R. fitchii. Both species were successfully reared on Poa pratensis L. and P. trivialis L. in a growth room. R. padi could be reared on shepherd’s-purse, Capsella bursa-pastoris (L.) Medic, but not R. fitchii.

The description of a new species of Phytodietus, subgenus Neuchorus, is presented. A closely related species is transferred to Neuchorus, also, and a key is provided to separate the two.