Nine new species of Slaterocoris Wagner are described from North America: pilosus from British Columbia; alpinus from Colorado; apache from Arizona, Colorado, and Utah; flavipes, solidaginis, and sparsus from California; argenteus, grandis, and simplex from Durango, Mexico. The other species in the genus are: ambrosiae (Kngt.), atratus (Uhl.), atritibialis (Kngt.), breviatus (Kngt.), croceipes (Uhl.), hirtus (Kngt.), longipennis Kngt., mohri (Kngt.), pallidicornis (Kngt.), pallipes (Kngt.). robustus (Uhl.), rubrofemoratus Kngt., sheridani Kngt., stygicus (Say), and utahensis Kngt. Strongylocoris uniformis Van D. is placed in synonymy with Stiphrosoma robusta Uhl. Strongylocoris albibasis Knight does not belong to Slaterocoris and will be dealt with in a subsequent paper. All species are keyed and the male genitalia illustrated.

Methods are presented for sampling and constructing life tables for Scolytus ventralis LeConte with the objective of comparing the histories of populations inhabiting individual trees. A bark area of 72 sq. in. was an effective sample unit. Within-tree variation was minimized by taking two sample units from two vertical strata at each sampling date. Trees were serially sampled several times during development of the insect.

Population tables were constructed for each sampling date and life tables were developed from the complete series of population tables. The precision of the life table estimates varied between 10% and 40% of the mean and generally decreased as population density diminished during development. A sampling design is presented for increasing the precision of life tables, and methods are given for determining the number of trees required for estimating the mean density when studying populations occupying large areas.

Ebo dondalei and Xysticus posti, two new species of crab spiders from North Dakota, are described.

A window flight trap was altered by replacing a collecting fluid trough with a horizontal cylinder, covered at both ends with clear plastic or screen. Insects falling into the cylinder move toward the light at the ends and are readily-collected. Sample data illustrate the usefulness of the traps for collecting scolytid beetles.

Within an egg gallery of the mountain pine beetle (Dendroctonus ponderosae Hopk.) only one male is found with one female even though the virgin female or its frass may have been equally attractive to more than one male. To ascertain how the number of males joining a female is determined, a series of 10 lodgepole pine rearing slabs and 10 observational plates (Reid 1962) were infested with virgin mountain pine beetle females. The females were allowed 1 day to become established prior to the experiments. On the second day one virgin male was placed in each gallery. The next day a second was placed near the entrance to the gallery and its behavior was noted, as well as that of the first male.

Swarming of 16 species (three genera) of Lonchaeidae is reported for the first time, and is related to the occurrence, nature, and evolutionary significance of insect swarming in general. The theory that aerial swarming is basic to the two-winged condition in Diptera is proposed. Evidence is presented to show that various swarming habits and associated morphological adaptations are primitive features of not only the Lonchaeidae, but of all Diptera. Four new species of Lonchaea from Ontario are described.

The adult Arthropoda occurring in, on, or emerging from 2,660 sporophores of the bracket fungus Polyporus betulinus (Bull.) Fr., growing on dead birch, are listed. Collections were made in New Brunswick, Quebec, Ontario, and Manitoba. Two hundred and fifty-seven species of Arthropoda, mainly insects and mites, were recorded; over 49,000 specimens were examined. Old, twice-wintered sporophores produce more species and more individuals. In general, the fungus is rich in species but rarely produces sizable populations of any one species.

Neuquenaphis papillata is described from material collected on Nothofagus obliqua Blume in Chile. Its affinities with other known South American Nothofagus-infesting aphids are noted and a key to the known species of Neuquenaphis is given. In addition to papillata, species included in the review are: Neuquenaphis edwardsi (Laing), N. michelbacheri Essig, Spicaphis chilensis (Essig), and Spicaphis michelbacheri Essig.

Iziphya brevipes is described as new from Ontario and Quebec and illustrations and descriptions of the other known Nearctic species are offered. This includes the following species: albipes Richards, americana (Baker), flabella (Sanborn), nigriceps Richards, umbella Richards, punctatella Richards, spenceri Richards, and vittata Richards. A key to the Nearctic species is also included.

The length of the spermathecal duct differs in species of Sitophilus. It is suggested that this criterion may be of value as an additional means of separating the two very similar species S. oryzae and S. zea-mais.

Calaphis manitobensis is described and illustrated. The only known host is swamp or low birch, Betula pumila L.