The New World species of the staphylinid subfamily Micropeplinae are revised. Three genera are recognized: Kalissus Leconte with 1 species, Micropeplus Latreille with 11 species, and Peplomicrus Bernhauer with 3 species. Of the three previously recognized subgenera of Micropeplus, Arrhenopeplus Koch is placed in synonymy with Micropeplus, and Peplomicrus is elevated to generic status. New species are: M. durangoensis from Mexico, M. neotomae from California and Oregon, M. browni from eastern Canada and the United States, M. robustus from California and Oregon, M. lecontei from southern California, and P. dybasi from Costa Rica and Panama. Micropeplus obliquus Leconte is placed in synonymy with M. sculptus Leconte, and M. oregonensis Hatch is placed in synonymy with M. punctatus Leconte. The genus Micropeplus is divided into six species groups based on an examination of both Old and New World species. A checklist of the species of Micropeplinae places all the described species in the proposed classification. Two African species, M. africanus Cameron and M. carayoni Jarrige, and one Central American species, M. acumen Sharp, are transferred to the genus Peplomicrus.

Three new species of the westermanni group of the genus Euxoa are described: Euxoa cryptica occurs in the southern Sierra Nevada and White Mountains of California, Euxoa juliae occurs in the central Sierra Nevada, and Euxoa austrina is evidently confined to the San Gabriel Mountains of southern California.

Two new species of aphids are described: apterous and alate viviparous females and oviparae of Macrosiphum hamiltoni new species, on Humulus lupulus L. in Manitoba; and apterous viviparous females and oviparae of Kakimia canadensis new species on Lonicera involucrata (Richards.) Banks in British Columbia and Idaho.

Certain mayflies and stoneflies were present in a forest stream in New Brunswick after frequent yearly sprayings with DDT. Tests showed that a stonefly, Nemoura sp., apparently the most likely insect to have developed DDT tolerance, had not done so. Presence of mayflies and stoneflies in the stream was probably because they survived spraying while in the egg stage, or recovered quickly after spraying, or both.

The location of types of Bruchus limbatus Horn, B. pruininus Horn, B. sordidus Horn, B. pauperculus LeConte, and B. distinguendus Horn is discussed, and lectotypes designated where needed. The confusion in American literature involving the names Bruchus obtectus Say, B. obsoletus Say, and B. distinguendus Horn is reviewed. Bruchus erythrocerus, inadvertently validated by Riley (1871), is synonymized with Meibomeus musculus (Say).

The following oils were evaluated for control of the pear psylla, Psylla pyricola Foerster, phytotoxicity, and persistence on Bartlett pear trees; Orchex 696, Orchex 796 with 0.46% emulsifier, Orchex 796 with 1% emulsifier, PGSO-1, PGSO-2, and Volck Supreme. The oils were applied at the rate of 5 gal per acre in a three-spray program, one at the delayed dormant period and two during the summer.

Orchex 796 (1% emulsifier) and Volck Superme oil gave the best control of pear psylla, PGSO-1 and PGSO-2 were intermediate, and Orchex 696 and Orchex 796 (0.46% emulsifier) were the least effective. Each of the oils gave excellent control of the European red mite, Panonychus ulmi (Koch).

The oils caused enlargement and corkiness of the bark lenticels on 1-, 2-, and 3-year old wood. The pear fruits showed darker green lenticels than unsprayed fruit, but this green spotting did not persist when the pears were ripened.

Analysis showed each oil to be persistent upon pear foliage. There was little loss after 8 days and an average of 28% loss after 25 days.

It is necessary to demonstrate the host specificity of an exotic phytophagous insect before introducing it for the biological control of a weed. The widely-used "starvation test" made on economic plants is considered inadequate for this purpose and we propose that studies should be broadened to include the following: (1) study of the insect’s biology, including host–plant records, with particular attention to adaptations likely to restrict the host range, (2) review of the plants attacked by related insects, (3) determination of the laboratory host range of the insect, (4) investigation of the chemical or physical basis of host–plant recognition, (5) starvation tests on economic plants to confirm the limits of the previously established host range, (6) establishment of the insects’ potential effectiveness for weed control. A limited amount of feeding on economic plants in the laboratory is not reason for rejection, if other criteria show the insect has a high degree of specificity.

Several statements and conclusions in the recent paper on diapause in the cabbage maggot by McLeod and Driscoll (1967) are quite misleading and require clarification. In my paper (1965), I was not in a position to critically appraise the results of earlier workers and I therefore simply presented my data as factual information. In their paper, McLeod and Driscoll present data to support the findings of earlier researchers in England, France, and Russia and they concluded that these records did not agree with the results of studies at Charlottetown. The disagreements were obvious but McLeod and Driscoll give no valid explanation as to why the results were different.

The proportion of fruiting to non-fruiting clusters on apple trees influences the distribution of predators within and between trees. The mirids Atractotomus mali (Meyer), Campylomma verbasci (Meyer), Hyaliodes harti Knight, Diaphnocoris pellucida (Uhler), Pilophorus perplexus Douglas and Scott, and the anthocorid Anthocoris musculus (Say) all showed greater preference for limbs (or trees) bearing a high proportion (or percentage) of fruiting clusters. The predacious mite Anystis agilis Banks exhibited no preference.

The cysts sometimes observed in the intestinal cavity of pupae and in the abdominal cavity of adults of Neodiprion swainei Midd. are not typical tumors. No cell proliferations were observed but rather a precipitation of the cells that accumulated and formed a membrane composed of many layers. The cysts appear to result from encapsulation of incompletely lysed or unlysed cells of the midgut epithelium. They are not necessarily the result of a viral infection.

The initiation of the pupal diapause of the apple maggot, Rhagoletis pomonella (Walsh), was found to be regulated by photoperiod and temperature. The stages of R. pomonella sensitive to these two regulatory factors were demonstrated to be the larva in the case of photoperiod and the larva and pupa in the case of temperature. Measurements with a highly sensitive photocell revealed that enough light passes through the skin and pulp of an apple to permit the response of the larvae to photoperiod to be direct. Diapause initiation was found to be independent of the effect of photoperiod or temperature on the adults and eggs and independent of the amount or type of larval food (apple or artificial).

Where larvae and pupae were reared at 28°C and a photoperiod of 17 or 19 hours of light per 24-hour day, 1% of the pupae completed development in 23 days, 50% in 28 days, 75% in 30 days, and 100% in 64 days. These were the only regimes tested at which there was 100% non-diapause development, a finding which is directly applicable to continuous laboratory rearing of the apple maggot. Irrespective of temperature, diapause was induced in more than 50% of the pupae at a larval photoperiod of 11 hours. Even where larval photoperiod was favorable for 100% non-diapause development (17 or 19 hr), diapause was induced in more than 25% of the pupae if larval and pupal development occurred at 23°C and in a larger percentage if larval and pupal development occurred at 19°C.

These findings are helpful in elucidating those conditions in nature under which a second generation of R. pomonella occurs.

Glyphina longiseta, a new alder-infesting aphid, is described from Nova Scotia and its affinities noted.