Radessa n. gen. is described for R. vittilimbalis n. sp., the type-species, from Colombia and R. pardalota n. sp. from Panama. The genus is related to Omiodes Guenée, 1854, but has conspicuous, probably mimetic, orange and black maculation.

Detailed laboratory studies of mated spruce budworm (Choristoneura fumiferana (Clem.)) show that the number of eggs per day, mean cluster size, and mean wet weight of the eggs gradually decrease during the period of oviposition of individual moths. The term mean weight of initial eggs (Ei) is defined and compared with other measurements of mean egg weight based on total egg complement or parts of it. Ei is 6%–12% greater than the mean egg weight based on all eggs laid. In spite of variation in pattern of egg weight distribution among moths, Ei appears to express satisfactorily the differences in mean egg weight among moths and can be used to survey egg weights among populations.

Laboratory rearing studies of individual clusters indicate slightly slower emergence rates (seconds from hibernacula), greater survival, and smaller proportions of male pupae in the third and fourth quartiles of the egg complement; there were no differences in pupal weights related to cluster order. There is no ready explanation for this improved survival of larvae from eggs known to be smaller.

Implications of these results for the population dynamics of the spruce budworm are discussed. The more stressful conditions encountered in the natural environment may counteract the apparently better survival of individuals from the latter part of the egg complement.

This paper presents a sampling plan for estimating numbers of H. postica adults in alfalfa. The plan is based on vacuum samples of foliage and ground litter and uses a half ft2 (465 cm2) as the sample unit. For typical levels of infestation during the oviposition period in early spring, estimates with reasonable precision may be obtained by taking 60 randomly selected units from a field, at a total cost of 6 man-hours. For those in early summer, not more than 20 units are required.

For all population densities, the pattern of counts was well described by the negative binomial distribution. However, at densities below unity, the Poisson function described the data equally well.

The efficiency of Berlese-Tullgren funnels in removing the rusty grain beetle, Cryptolestes ferrugineus (Stephens), from wheat samples was tested by adding adults and larvae to wheat samples. The recovery of adults from 300 g samples was 79% at 12.3% moisture content (m.c.) and 49% at 16% m.c.; from 150 g samples the recovery was 84% at 16% m.c. The number of adults recovered represented at least 98% of those that did not escape from the top of the samples. The number that escaped varied with sample size and moisture content. The recovery of fourth instar larvae was 78% from samples of 300 g at 16% m.c. The percentage of first and second instar larvae recovered was 5.8 when larvae alone were mixed with the wheat sample and left for 65 h, 10.6 when larvae in flour were added to the surface of the wheat sample, and 27.9 when larvae in flour were added to the centre of the wheat sample.

New synonymies and new combinations affecting North American Pityophthorus are proposed as follows: Pityophthorus Eichhoff (= Myeloborus Blackman and Ctenyophthorus Schedl) n. syn.; Araptus obsoletus (Blandford) n. comb.; A. poricollis (Blandford) n. comb.; Gnatholeptus epistomalis (Schedl) n. comb.; G. semiermis (Nunberg) n. comb.; G. shannoni (Blackman) n. comb. (= Pityophthorus gentilis Schedl); G. subscribratus (Schedl) n. comb. (= Pityophthorus zeteki Blackman); Pityophthorus absonus Blackman (= demissus Blackman and inyoensis Bright); P. blandus Blackman (= singularis Bright); P. carinulatus Swaine (= aquilus Blackman, caelator Blackman and opimus Blackman); P. comosus Blackman (=foratus Wood); P. digestus Le Conte (= idoneus Blackman, hopkinsi Blackman and ponderosae Blackman); P. diglyphus Blandford (= leiophyllae Blackman and auctor Blackman); P. guatemalensis Blandford (= quercinus Wood); P. infulatus Blackman (= mollis Blackman and hubbardi Blackman); P. intextus Swaine (= shepardi Blackman, cascoensis Blackman, tonsus Blackman, kenti Blackman, and pilifer Schedl); P. nitidus Swaine (= borealis Swaine, anceps Blackman, alpinensis Hopping and aquilonius Bright); P. nocturnus Schedl (= hidalgoensis Blackman); P. opaculus Le Conte (= abietis Blackman, albertensis Blackman and exiguus Blackman); P. rhois Swaine (= natalis Blackman); P. solus Blackman (= cribratus Blackman); P. toralis Wood (= collinus Bright); P. venustus Blackman (= artifex Blackman); P. virilis Blackman (= fortis Blackman). New species are: P. aciculatus (Guatemala, Mexico), apachae (Arizona), aztecus (Mexico), blackmani (Mexico), chiapensis (Mexico), clivus (Mexico), cortezi (Mexico), culminicolae (Mexico), declivisetosus (Mexico), lecontei (Arizona, New Mexico), lepidus (Mexico), montivagus (Mexico), mormon (Utah), separatus (South Carolina), sulcatus (Arizona), viminalis (Mexico), and woodi (New Mexico).

Male and female adults of Mideopsis (Nudomideopsis) magnacetabula n. sp. are described. This is the first species of this subgenus described from the New World, and knowledge of the new species necessitates modification of the subgeneric concept.

This paper resurrects the genus Tethallotrum Scudder 1962 from synonymy and compares it with Allocentrum Bergroth 1894. A new species Allocentrum impunctatum is described from Madagascar.

Spalangiopelta ciliata n. sp. is described and represents a new record for the subfamily Ceinae (Pteromalidae) in North America.

Mature larvae and puparia of Canace macateei Malloch inhabiting mats of blue-green algae in a Massachusetts intertidal marsh are described and compared with other larvae of the Canaceidae.

Exposure of the prepupal and pupal stages of the bertha arrnyworm to 25°C during development had no obvious effect on pupal or adult survival, but reduced the incidence both of attempted mating and of spermatophore transfer and caused mated females with spermatophores to lay only a small number of eggs, all of which were sterile. Pupae are formed in the soil of rape fields during the latter part of August at depths up to 15 cm, and the frequency of their exposure to 25°C may influence population density the following year. Temperature profiles in the soil of rape fields are unknown, but an analysis of soil temperature records under sod from nine meteorological stations in the rape growing area indicated that they frequently reached 25°C. Thus there is sufficient probability that soil temperatures in rape reach a sterilizing temperature to warrant specific studies on temperature profiles in rape and their correlation with published meteorological data and with the fecundity of natural populations of the insect.

Four species of Exenterus were reared from the European pine sawfly, Neodiprion sertifer (Geoff.), in Ontario. An introduced species, E. abruptorius (Thunb.), last reported in Ontario in 1948, was recovered in very small numbers at one location. The native E. affinis Roh. (= E. walleyi Cush.) parasitized a small proportion of N. sertifer but was the main species attacking feeding larvae. The native E. nigrifrons (formerly called E. canadensis Prov.) and the introduced E. amictorius (Panz.) occurred at all sampled locations. Both species were more numerous in high than in low density populations of N. sertifer, but E. nigrifrons was more destructive, and E. amictorius less destructive, at high than at low density.

About 60% of adults of E. amictorius and 6% of those of E. nigrifrons eclosed in the same summer that attack occurred. Most were unlikely to have reproduced, owing to the scarcity of hosts. In both species females were more frequent in female than in male hosts.

Samples of N. sertifer cocoons in July were superior to larval samples in June and cocoon samples in August and the following May for measuring the rate of parasitism and the relative abundance of Exenterus spp. However, because of mortality of Exenterus before and after sampling, data based on the rearing of cocoons seriously underestimated the impact of the parasites.

Mixed colonies of adults of Lytta nuttalli Say and L. viridana Le Conte, and of L. cyanipennis (Le Conte) and nuttalli, and colonies containing only one of these three species have been seen in various parts of the Canadian prairies, usually in aggregations and most commonly near bodies of water. The flight period of nuttalli extends from early June to early August, of viridana from late May to late June, and of cyanipennis from mid-June to early July. The natural food plants of these three species are a variety of wild legumes, though they prefer certain cultivated legumes when present. Nuttalli and viridana will eat some non-leguminous plants, including species of Iris, Delphinium, and Brassica, and such crops as sugar beets, oats, barley, and wheat. In captivity, males and females of nuttalli and viridana mated more than once and females deposited more than one batch of eggs. Egg batches of nuttalli, viridana, and cyanipennis contained an average of 320, 340, and 390 eggs each, respectively. Cross-mating between nuttalli and viridana and nuttalli–viridana hybrids were observed in the field. Four nuttalli females were seen ovipositing in an area that contained the remains of nesting cells of leafcutter bees (Megachile sp.); these are the first recorded observations of Lytta species ovipositing in the field. The beetles preferred moist, firm soil for oviposition, and the eggs desiccated very quickly when not in contact with moisture. The eggs of these three species developed fairly uniformly at temperatures from 15° to 30 °C, and it appeared to take about 2 to 3 weeks to complete embryological development at temperatures normally encountered during June through August. Relationships among these three species suggested by their behaviour and biology are discussed.

Annual surveys of the adults show that outbreaks of grasshoppers in cultivated crops in Alberta have occurred in 32 of 58 years. Five outbreaks have occurred, lasting from 3 to 14 years, interspersed by periods of low infestation lasting from 3 to 9 years. Some control measures, however, were required every year even during periods of low infestation. The highest recorded adult populations occurred in 1933, 1936, and 1962, and the lowest in 1952 and 1969.

During most periods with low populations, infestation were confined mainly to the area south of the Bow and South Saskatchewan rivers. When high populations occurred, the infested areas increased in size and extended north to the Battle River. The largest infested area covered 48,600 sq. miles and the smallest was 300 sq. miles.

Two species of grasshoppers, Camnula pellucida (Scudder) and Melanoplus sanguinipes (Fabr.), generally predominated in separate regions. Melanoplus bivittatus (Say) predominated only during periods of low grasshopper infestation. Melanoplus packardii Scudder was restricted in its range and became noticeable when the grasshopper outbreaks were declining.

When different size sticky-coated red spheres were positioned within the foliage canopy of sour cherry or apple trees, more Rhagoletis pomonella (Walsh) flies were always captured on 7.5-cm-diam. ones than on 3.4 or 1.5 cm ones. Early in the season, 7.5 cm spheres attracted fewer or about as many R. pomonella as 23 cm spheres, but later on, 7.5 cm spheres always attracted more. R. fausta (Osten Sacken) and R. cingulata (Loew) flies were always more attracted to 7.5 cm spheres than to any other size tested. However, both these species showed a proportionately greater attraction to smaller spheres than did R. pomonella. The phenomena of super-normal stimuli and learning are proposed as possible explanations of certain of these findings.

The maximal emergence of Pissodes notatus (F.) adults takes place during July and August. It results from the different evolution of two populations:

— a first population, whose complete development (from egg to adult) takes 11 or 12 months. This population corresponds to eggs laid after the middle of July (maximum egg laying during September). Most of the larvae having reached the third instar, it shows no more evolution during the winter; the further development takes place during the next spring, and adults emerge from mid-June to mid-July.

— a second population resulting from egg laying, between February and July, of hibernated adults (maximum egg laying during April and May). The whole development being very short (2 to 3 months), the adults, corresponding to these eggs, emerge from the middle of July to the end of August.

The observed differences between durations of the under-bark development (from 2 to 12 months) appear free of diapause and probably result from rates of development changing with temperature and instar.

In our regional field temperature conditions, all the individuals reach finally their under-bark development approximatively at the same time, so that the adult emergence period takes place in July and August.

Bioenergetic studies on populations of the two-striped grasshopper, Melanoplus bivittatus (Say), and the red-legged grasshopper, M. femurrubrum (De Geer), at a natural grassland site in Ottawa in 1971 and 1972 indicated that the former species ingested 0.42% and the latter 0.44% of the green shoot primary production (3057 kcal/m2). An additional 1.22 and 1.30% of this production were cut and dropped by the grasshoppers, so that a total of 1.64 and 1.74% of the green vegetation was removed by M. bivittatus and M. femurrubrum, respectively. These two species assimilated 41 and 35% of the ingested food, the remainder being voided as faeces. Respiration accounted for 62% of the energy assimilated by M. bivittatus and for 63% of that assimilated by M. femurrubrum. Approximately 0.06% of the energy of primary production was converted by each species into body and was available to higher trophic levels. However, 94% of the potential energy of the green vegetation removed by the grasshoppers was returned to the "decomposer compartment" of the ecosystem, with only 6% removed or lost from the system.

The V. arenaria queen was able to heat her nest shortly after it was constructed, and expended up to 550 cal per hour per gram of biomass to accomplish this. In contrast, the V. maculata colony was not heated until it was 11 days old, by which time the brood consisted of about 15–20 large larvae which probably played a major role in the heat production process. When both colonies were about 2 weeks old, energy expenditures of more than 400 cal/h could be maintained for several hours, and the nest temperature could be elevated as much as 4°C above the ambient. During these periods the larvae probably accounted for as much as 66–71% of this energy expenditure. In addition to playing an active role in heating the nest, the larvae apparently provide the queen with a food source while she is producing heat during non-foraging periods.

Characters of male genitalia and sternal coloration are used to supplement the variable characters of head shape and tegminal colour pattern in determining the species of the world Prosapia. Five new species are described: chiapana, hemelytra, ignifera, and isobar from Mexico, and fortior from Panama. One new combination is created: Prosapia miles (Fowler). Four subspecies are considered valid species: ignipectus (Fitch), inferens (Walker), ripalis Fennah (new status), and teapana Fennah (new status). P. simulons (Walker) (1858) is synonymized with fasciaticollis (Stål) (1864), and bicincta (Say) (1830) is synonymized with fraterna (Uhler) (1864). An illustrated key to males of the 14 world species is provided.

In 1975, 19.4% of 6950 marked apple maggot adults, Rhagoletis pomonella, which were released in the center of a 7 × 7 array of unsprayed apple trees were recaptured on Pherocon® AM traps. The distribution of the marked flies was not uniform as most of the flies were recaptured near the release point. The distribution of native flies which migrated into the test area from adjacent infested apple trees was also non-uniform.

Seasonal distributions of adult emergence and larval drop for Anoplonyx luteipes (Cresson), A. canadensis Harrington, and Pristiphora erichsonii (Hartig) are compared. Larval populations of A. luteipes have a significant positive correlation with those of P. erichsonii, while A. canadensis adult populations show a significant negative correlation with P. erichsonii larval populations.