All species of the subgenus Microsaurus Steph. of the genus Quedius Steph. (Staphylinidae), known to occur at present in Mexico, are treated. A key is given. Three species are described as new.

A new genus and species of Phoridae, Zyziphora hirtifrons, is described from Colorado.

The habits, biology, and distribution of Mimopria species are discussed and new data presented; M. campbellorum n. sp. from Brazil (Para) is described and compared with M. ecitophila Holmgren. A key to distinguish the two species is given.

Philodromus Walckenaer 1826 and its seven component species groups in the Americas are defined and diagnosed. The 12 species of the aureolus group are keyed, diagnosed, and mapped. P. obscurus Blackwail, 1871 is placed in synonymy under P. cespitum (Walckenaer, 1802). P. lutulentus Gertsch, 1934 is raised to species status from synonymy under P. laticeps Keyserling, 1880, and P. eremus Buckle, 1973 is placed in synonymy under P. lutulentus. P. agreutes Schick, 1965 is placed in synonymy under P. californicus Keyserling, 1884, and P. decolor O. Pickard-Cambridge, 1899 under P. satullus Keyserling, 1880. The South American species P. fuliginosus Nicolet in Gay, 1849, P. junior Nicolet in Gay, 1849, and P. meridionalis Keyserling, 1891 are removed to the genus Petrichus, and P. setosus Petrunkevitch, 1929 is removed to the genus Thanatus, where it becomes a junior synonym of T. vulgaris Simon, 1870.

A key is given to the species of Aphis L. on Ribes spp. in North America, including, A. bulleri new species and A. manitobensis new species. A. ribigillettei Knowlton and Allen and A. sanborni Patch are declared to be synonyms of A. neomexicana Cockerell, and A. tonahasa Hottes is considered to be a nomen dubium.

A strain of the alfalfa leafcutter bee, Megachile pacifica Panzer, that has produced less than 1% second-generation adults for 3 consecutive years was produced by selection against bivoltinism. The selection process also resulted in the production of bees that reproduced at a much higher rate than the unselected parent stock.

A new species of the genus Quedius Steph., Q. infernus spec, nov., is described from Oregon and Washington.

Additional data on taxonomy, bionomics, and geographical distribution of many species are presented.

A brief infestation of near outbreak proportions by larvae of Hylemya extremitata Malloch occurred on bromegrass, Bromus inermis Leyss and B. pumpellianus Scribn., at Beaverlodge, Alta., in 1971–72. Larvae feeding primarily on meristematic tissue caused injury to as many as 20% of the grass tillers examined. Mature larvae overwintered within the tillers. Adults emerged in mid-June. Descriptions are given of the three larval stages of this species and of mature larvae of the first two of the following four species of Chloropidae, which were also found living within the bromegrass: Olcella provocans (Becker), Oscinella coxendix (Fitch), Oscinella incerta Becker, and Conioscinella melancholica Becker.

Three new species of the genus Xylocoris Dufour are described: hirtus from Saskatchewan, Ontario, Quebec, and New York, pilipes from New York, and punctatus from Utah. A lectotype for Xylocoris discalis (Van Duzee) is designated. Scoloposcelis mississippensis Drake & Harris and S. occidentalis Drake & Harris are synonymized with S. flavicornis Reuter. Adults of new species are illustrated and electron microscope photographs of their osteolar canals, and that of flavicornis are included.

The previously undescribed adult male and female of Analetris eximia Edmunds are treated. Additional features of nymphs are illustrated. In the Saskatchewan River system the species is found in areas unaffected by reservoirs; nymphs develop in May?, June, and July; adults emerge in late July. Nymphs are carnivorous (chironomids were the main food item in field collected specimens), live in backwaters adjacent to the main river current, and are morphologically adapted to life on an unstable silty substrate. Invasion of the Saskatchewan system was apparently via Missouri tributaries from the Colorado system. It occurred in recent times in the latter but apparently not the former. Because of habitat destruction, the species is considered endangered.

Larvae of the mountain pine beetle, Dendroctonus ponderosae Hopk., were reared to adults in naturally infested bolts of lodgepole pine, Pinus conforta Dougl. var. latifolia Engelm., at 21 ± 3 °C. The mean pronotal width of the emerging beetles of both sexes decreased, and the male:female ratio increased, during the emergence period. On the average, larger individuals of both sexes survived longer when adult beetles were stored at 1 ± 2 °C. Also, the male:female ratio of the surviving beetles decreased with increased storage duration. These and related results in the literature suggest that in natural populations of the mountain pine beetle average adult size increases, and the male:female ratio decreases, following stress-induced mortality in the larval and(or) adult stages.

Dispersal from earwig nests includes an inter-brood dispersal by female parents and two nymphal dispersals. One nymphal dispersal occurred in nature, but was not evident in the laboratory. The two other types were associated with heightened activity and a rejection of the nest in the laboratory. This locomotory behavior, which is probably adapted for dispersal, is termed “dispersive behaviour.”

Overwintering eggs of the European red mite, Panonychus ulmi (Koch), were killed on McIntosh and Red Delicious apples by 4½-h fumigation treatments with ethylene dibromide. Constant concentrations of 8 mg EDB/1. at 14 °C achieved 100% mortality, and absorption of the fumigant by the apples, the bins, and the chamber was determined so that the amount of fumigant for various size commercial loads could be calculated. Treatments increased scald on McIntosh but reduced it on Red Delicious. Taste and other qualities of the fruit were not affected.