A study of the anatomy and histology of the alimentary canal of Scolytus multistriatus Marsham suggests that the midgut diverticula are centres for the regeneration of the midgut cells and that the structure of the midgut epithelium and the proventriculus facilitate the rapid uptake of nutrients from food.

A key to the subfamilies of Miridae based on fourth and fifth instar nymphs is provided and the value of some nymphal characters in arriving at relationships between the subfamilies is discussed. It is suggested that the reduction of parempodia to bristles most likely occurred twice in the family rather than that membranous parempodia were twice evolved. The Hyaliodes group is reviewed and the subfamily status accorded it by some authors is confirmed.

Juvenile hormone analogues (JHA) were fed in an artificial diet to laboratory reared Porthelria dispar (L.) larvae. The analogues used were: I: Stauffer R-20458; 1-(4′-ethylphenoxy)-6,7-epoxy-3,7-dimethyl octene. II: Altozar®. III: Hoffmann-La Roche Ro 8-5497; 10,11-epoxy-3,7,11-trimethyl-1-(2-propynyloxy)-2,6-tridecadiene. For JHA I and II mortality occurred primarily during the larval and pupal stages with overall EC50 values from 0.19 to 0.43 p.p.m. in the diet. JHA III was not toxic. The log-probit dose–mortality curves showed low slopes. Morphologic aberrations in treated larvae and pupae were observed.

Esterases present in the hemolymph of last instar Heliothis zea (Boddie) were separated by polyacrylamide gel electrophoresis. Four systems, all polymorphic, were observed. One system, Est-II, appeared especially suited for the study of some of the important population processes of this species; these include host–plant relations, migration, and the effects of environmental pressures such as pesticides on the species.

Est-II was classified as a carboxylesterase, being sensitive only to organophosphate inhibitors. Dichlorvos at 10−5M completely inhibited Est-II activity.

Populations collected from corn from Tifton, Ga., and in two locations in Illinois, at approximately the same time were very similar genetically when compared on the basis of Est-II allele frequencies. A population collected from leguminous hosts in Tifton, Ga., at the same time as the above three populations was different genetically.

Est-IIc, an allele normally rare or absent in the populations studied, was present at a high frequency in one Urbana population collection. Est-IIc may be useful in studying the long-range dispersal of H. zea.

The Nearctic species of the elaterid genus Athous east of the Rocky Mountains are revised. Of the 16 included species, two are described as new (neacanthus known from southern Quebec to northern Georgia and orvus known from Nova Scotia to Michigan to Virginia) and two species are transferred from Denticollis, namely, productus (Randall) and quadrosa Becker (as a new junior synonym of A. appalachius Van Dyke). Other new synonymies are: carolinus Van Dyke as a junior synonym of acanthus (Say), erebus Van Dyke of posticus (Melsheimer), and bipunctatus Provancher of productus (Randall). The European species campyloides is known from North America from near Quebec City and in the Canadian Maritime Provinces. Neotypes are designated for the five species described by Say and Randall and for one described by Melsheimer; lectotypes, when needed, are designated for LeConte’s, Melsheimer’s, and Candèze’s species. A key to the species is presented and the salient features and distribution maps for each species are included. Brief notes are given on three western species of Athous: two common species (rufiventris (Eschscholtz) and nigropilis Motschulsky) that are occasionally found east of the Rockies and orophilus Harold, which is known only by the type from the Bitter Root Mountains. Brief discussions are included of two European species, vittatus (Fabricius) and subfuscus (Müller), which have been intercepted at various eastern ports in Canada and the United States, but which have not become established in North America.

Species of tenebrionid beetles in the genera Coelocnemis and Eleodes share high similarity in dorsal features. Similar species are largely sympatric in occurrence, and the distributions of some species pairs are almost identical. These congruences in appearance and geographic distribution are interpreted as evidence of Müllerian mimicry. All these beetles produce quinonoid secretions, presumably used in defense against vertebrate predators. The widespread occurrence of defensive secretions, and the similarities in dorsal silhouette and cuticular sculpturing, suggest that Müllerian mimicry is of general importance among tenebrionid beetles. The common black coloration of tenebrionids probably has an aposematic function, since black contrasts sharply with most substrates under the crepuscular lighting conditions in which tenebrionid activity typically occurs. The suitability of numerical phenetic methods for the description and analysis of convergence and mimicry phenomena is discussed.

In 1972, an organophosphate resistant strain of the phytoseiid predator Amblyseius fallacis (Garman) from Michigan compared favourably with the endemic Typhlodromus occidentalis Nesbitt, from Summerland, B.C., in laboratory and greenhouse trials against European red mite, Panonychus ulmi (Koch), and was later released into an orchard. By August 1972, A. fallacis had decreased whereas population densities of T. occidentalis increased. Examination of leaves and bark from the trees, and weeds, grass, and litter beneath the trees in 1973 confirmed that A. fallacis failed to survive in the Okanagan environment.

The taxonomic identities of the Lonchaeidae described by Bigot, i.e., Lasiops nitens from Europe and Ophyra andina from Chile, are established from their holotypes in the Hope Department of Zoology collection, University Museum, Oxford, England.