Five new species of Megapenthes are described: apacheorum from Arizona and New Mexico; texanus from Texas, New Mexico, and Arizona; fuscus from Arizona; antennatus from Arizona and Durango (Mexico); and elongatus from Arizona and New Mexico. Four species are redescribed: longicornis Schaeffer, variolatus Van Dyke, megalops Van Dyke, and obtusus Van Dyke. The male genitalia of these species are illustrated, and a key to the 29 nearctic species is included. The position of aterrimus Motschulsky is discussed, Dolopiosomus Motschulsky is considered as a nomen oblitum under Megapenthes, and caprella californicus Brown is synonymized under caprella LeConte.

A method is described for observing, photographing, and video-taping the mouthparts of Rhodnius prolixus Stal., a blood-feeding insect, as it feeds on an artificial diet. This method was combined with another for recording the electrical resistance between the haemolymph of a feeding insect and its diet. By using a split-screen television technique simultaneous recordings were made of the changes in electrical resistance and feeding events such as mouthpart movements, salivation, and ingestion. Slow speed and stop-frame playback allowed accurate analysis and correlation of rapid events. The techniques described could be applied to many other types of investigation.

The following new taxa are described: Aurorobotys n. gen., type-species Ebulea aurorina Butler, Japan; A. crassispinalis n. sp., Chekiang Province, China; Tenerobotys n. gen., type-species Hapalia teneralis Caradja; T. t. tsinlingalis n. subsp., Shensi Province, China; T. subfumalis subfumalis n. sp. and subsp., Taiwan; T. s. continentalis n. subsp., Hunan Province, China; Carminibotys n. gen., type-species Pyrausta carminalis Caradja; C. c. iwawakisana n. subsp., Honshu, Japan.

Dissection of 400 diapausing eonymphs of Neodiprion lecontei (Fitch) yielded 149 live planidia larvae of Perilampus hyalinus Say. Of these 87% were embedded in the brain and in the ganglia of the ventral cord, and the remainder in various other internal organs, including the malpighian tubes and silk glands. Numerous encapsulated planidia were found in the haemocoel. To avoid encapsulation in this host, planidia of P. hyalinus must enter an internal organ. Resumption of development of N. lecontei stimulates the emergence of surviving planidia, which commence feeding as ectoparasites. During the second instar, feeding is suspended while the parasite larvae search the body of the host for competitors and destroy them.

Some of the eonymphs examined contained larvae of the tachinid Spathimeigenia sp. in addition to planidia. None of these planidia survived, nor did they become hyperparasitic.

Both sexes of a new species of Psococerastis, a new species of Trichadenotecnum, a new species of Stenopsocus, and single sexes of a second new Trichadenotecnum, a new species of Pseudocaecilius, a new species of Ectopsocus, a new species of Dasypsocus, and two new species of Caecilius are described from material collected in Nepal. Augmented descriptions of Psococerastis nirvanus (Banks) and of P. taprobanes var. bengalensis (Kolbe) are given, and a description of the female of Scytopsocopsis hirtipenna Lee and Thornton. A total of 14 species were identified.

The number of valid forms of Acanthopsylla Jordan and Rothschild in Australia now stands at 12 including, as new species, dunneti and incerta, and as new subspecies, rothschildi multidentata, scintilla rectangulata, and scintilla tasmanica. Descriptions are provided for these and notes and illustrations on some of the others. A. rothschildi victoriana is reduced to synonymy with A. r. rothschildi.

Eighteen new host records were established among 12 species of parasites and 4 species of Ips beetles. Large numbers of Ips spp. and their associates were secured by mass rearing in specially constructed rearing drums. Confirmation of parasitism was accomplished by individual rearing of parasites in gelatin capsules from Ips larvae and pupae taken from logs. Some parasites were typically associated with a particular tree host, but it was not determined if it was due to tree host, Ips host, or the physiographic province. Parasitism was highest in the upper bole, especially in loblolly pine, but no correlation with bark thickness was established. The density of Ips attack and the time during which Ips infestations were maintained at one location also did not appear to affect the rate of parasitism. Parasitism was highest in the overwintering broods of Ips.

Two general models are presented to describe the relations between the average number of insects bisected by sampling unit boundaries, the per cent edge-effect bias of mean-brood-density estimates, the shape and size of the average individual, and the shape and size of the sampling unit. The two general models, when expanded specifically for sampling late-stage mountain pine beetle broods, gave excellent fit to experimental data. The expanded equations are approximations since individual insects were considered as being rectangular in shape and the angles of the long axes of their orientation relative to the sampling unit boundary were considered to have a uniform frequency distribution. Edge-effect bias was a function of the size and shape of the organism and those of the sampling unit. Edge-effect bias resulting from faulty sampling-unit-area delineation is also considered, and suggestions are made for its reduction in sample surveys of sub-cortical insects.

Sexupara production in the pear root aphid, Eriosoma pyricola Baker & Davidson, was closely associated with the cessation of shoot growth of its host in the field in irrigated and non-irrigated plots in two successive, but phenologically different years. Neither the environment nor the host plant were unfavorable at the time the sexuparae were formed, indicating that the aphid uses the host plant as a source of seasonal information.

The nature of synchronization between active development of univoltine insects and trees is discussed. It is concluded that the initiation of dormancy in trees and diapause in insects is not likely to be synchronized by a common set of environmental factors. Either regulation of insect diapause by host trees is more common than is currently recognized, or environmental and age differences in tree growth have favored selection for obligate diapause.

The flour mill insect, Cyrptolestes turcicus (Grouvelle), was reared on seven diets at 28 ± 1 °C and at relative humidities of 90% and 60% as follows: flour from a mill previously infested with C. turcicus, commercial flour sterilized with propylene oxide, unenriched commercial flour, and four laboratory-prepared diets each containing a different concentration of fungi isolated from the previously-infested flour.

At 90% relative humidity, larvae developed fastest on the infested flour and on the prepared flour–fungi diets, and slowest in sterilized flour. Fungal concentration and rate of larval development were inversely correlated. The highest survival of larvae occurred on the flour–fungi diets and the highest mortality on the flour from the infested mill. There was no clear relationship between rate of pupal development and concentration of fungus. Of the prepared diets, that with the largest concentration of fungus promoted the fastest rate of pupal development. Survival of pupae was about 20% higher on the flour–fungi diets than on the sterilized flour. At 60% relative humidity about 50% of larvae and pupae survived and completed development on the flour–fungi diet containing 1% by weight of fungi, and on the flour from the infested mill but none survived on any of the other diets. Sixty per cent of larvae and 83% of pupae survived and developed on the flour from the infested mill. None of the larvae survived on any of the other diets.

Platygymnopa new genus, type species P. helicis new species, is described from the northern United States and southern Canada, with type locality McHenry Co., North Dakota. In Montana, P. helicis was reared from larvae feeding within dead snails (Physidae, Aplexa hypnorum (L.)).

A new species of Forcipomyia from Singapore is described in all stages. Although the female adult could be placed in Lepidohelea Kieffer (1917) by the possession of scales in addition to bristles and hairs, the male genitalia are distinctive. A new subgenus, Schizoforcipomyia, is erected to accommodate this species whose larva has a bilobed anal pseudopod and whose male genitalia are intermediate between Forcipomyia s. str. and Proforcipomyia.

The rye jointworm, Harmolita secale (Fitch), caused economic damage to fall rye in Alberta in 1968, 1969, and 1970, a first such record for Canada. Infested stems reached an average of 21 galls. Individuals in the laboratory required added moisture for pupation and to facilitate emergence of adults, which occurred during the first week of June in 1970. In 1970, the reproductive potential of about 70 was more than counterbalanced by the failure of almost 90% of the galls to produce adults.

Winter survival of the rye jointworm depends upon the intensity and duration of subzero temperatures, depth of snow cover, and the height at which the larvae hibernate in the stem.