The last instar larva of Hellula rogatalis (Hulst) is described and illustrated. Diagnostic characters of the genus are given, and a key included for the North American species. Larvae of this genus are compared with those of Dicymolomia Zeller.

Precipitin test techniques were utilized for the identification of predators on three lepidopteran pests—Anticarsia gemmatalis Hübner, Heliothis zea (Boddie), and Pseudoplusia includens (Walker). The test was sensitive enough to detect these prey in a whole-body extract of one small predator or from a midgut extract of larger predators. Some cross-reactivity among the prey antigens was found which limited somewhat the applicability of the test. However, test results from field-collected predators indicated the precipitin test is a simple and rapid technique which can be used to evaluate the number of encounters between predators and prey in soybean fields.

The threshold temperature of development, life table, and innate capacity for increase of the twospotted spider mite, Tetranychus urticae Koch, were established from life stage development studies at constant temperatures. The threshold for development was determined to be 10.0°C. The durations in degree-days above 10°C from the beginning of the egg stage to adult for females were 141.3, 152.3, and 139.8; for males 134.2, 144.7, and 135.2 at 15°, 18°, and 21°C, respectively. Life tables were constructed and innate capacity for increase was .069, .156, and .372; net reproduction rate 20.8, 38.4, and 58.1; and mean generation time 44.0, 23.4, and 10.9 at 15°, 18°, and 21°C, respectively.

Culex pipiens pipiens and C. salinarius were found equally susceptible in laboratory tests to Bacillus sphaericus strain 1593 with LC50 values for the four instars ranging between 20 and 137 ppb (approximately 820 and 5600 spores/ml). Tests against field collected C. p. pipiens larvae revealed a regularly decreasing susceptibility with increasing larval age, the first instars being between 2 and 5 times more susceptible than fourth instars. In contrast, no significant differences in the susceptibility of second, third, and fourth instars were found in tests of laboratory reared larvae.

Regression models of the form lnY = b0 + b1ln(X−c) + b2X are presented that describe the within-tree distribution of the pupae of Thanasimus dubius (F.), a clerid predator of the southern pine beetle, Dendroctonus frontalis Zimm. More T. dubius pupae/100 cm2 of bark area were found in loblolly pine, Pinus taeda L., than in shortleaf pine, P. echinata Miller, and the number increased with increasing tree diameter class. Peak densities were found at a height of 1–4 m.

Growth, development, and survival were investigated for the larvae of the red turnip beetle, Entomoscelis americana Brown, fed excised cotyledons or first true leaves of four cultivars of Brassica campestris L. (Torch, Echo, Candle, and R500) or three cultivars of B. napus L. (Midas, Target, and Tower) in the laboratory. The red turnip beetle has four larval instars and its growth curve is S-shaped. The seven cultivars of B. campestris and B. napus tested were suitable host plants for the larvae. On all the cultivars, survival was relatively high, the weights and developmental times were similar, and the percentage of malformed adults was low. In B. campestris and B. napus, the cotyledon stage was marginally better than the first true leaf stage as food for the larvae. Survival usually was higher and in one of the three experiments the adults at emergence were heavier on the cotyledons than on the first true leaves. However, the developmental times were similar, except in one of the three experiments where they were longer on the cotyledons, and the incidence of malformed adults was low on both stages of plant growth.

The suitability of nine species of Cruciferae as hosts for the larvae of the red turnip beetle, Entomoscelis americana Brown, was tested in the laboratory using excised cotyledons or true leaves as food and rape (Brassica campestris L.) as the standard. The three types of commercial mustards grown in Canada (yellow-seeded (oriental mustard) and brown-seeded (brown mustard) forms of Brassica juncea (L.) Czern.; and yellow mustard, B. hirta Moench) and three weeds (Capsella bursa-pastoris (L.) Medic, shepherd’s purse; Erucastrum gallicum (Willd.) O.E. Schulz, dog mustard; and Sinapis arvensis L., wild mustard) were suitable food plants. Brassica nigra (L.) Koch (black mustard), Descurainia sophia (L.) Webb (flixweed), and Sisymbrium loeselii L. (tall hedge mustard) were marginally suitable. Thlaspi arvense L. (stinkweed) was a non-host plant. These observations suggest that an important element of the pest management system for the red turnip beetle should be the elimination of volunteer commercial mustards and the cruciferous weeds, except T. arvense, in April and May to prevent population build-up.

Damage to honeysuckle (Lonicera spp.) has been associated with Hyadaphis tataricae (Ajzenberg), an aphid species of European origin previously unknown in North America. A survey indicated that H. tataricae is present throughout much of the Province of Quebec. Marked differences were observed in the degree to which various species and cultivars of honeysuckle were attacked, in both the Montreal Botanical Garden and the van den Hende Garden in Quebec City.

The flight range of Culicoides variipennis was studied in a bluetongue virus enzootic area during the summer of 1977. Field-collected larvae and pupae were reared to the adult stage in a field laboratory. Approximately 82,200 flies were marked with micronized fluorescent dusts and released and 403 were recaptured in CO2-baited baffle traps. The maximum distance traveled was 0.8 km by a male and 4.0 km by a female. One female was recovered on the release night 2.8 km from the release point. The mean distance traveled (MDT) was 0.8 km on the release night, 2.02 km on one night postrelease, and 2.11 km on two nights postrelease. The MDT for all flies recovered up to eight nights postrelease was 1.89 km.

Based on the overall MDT of 1.89 km, the transmission of a disease agent by C. variipennis becomes theoretically possible if the host population density is greater than one per 3.57 km2. The probability of transmission can be significantly reduced if a 3.57 km2 area surrounding a single C. variipennis breeding site is treated with an effective insecticide.

A review of the literature and application of the latest rules show that the justified emendation Paxylommatidae Foerster 1862 is the correct family-group name for Hybrizon Fallén 1813. Because Hybrizon lacks the chief apomorphy of braconids, fused metasomal terga II and III, and also lacks a major apomorphy of ichneumonids, loss of 1r-m and retention of 2r-m in the hindwing, it is placed in a separate family. Some unusual antennal sensilla are illustrated.

A multiple regression analysis was used to establish which weather factors and population parameters were important in determining the emergence pattern of the spring flight of the European corn borer, Ostrinia nubilalis (Hbn.), as measured by light trap catches. Equations which estimated the slope and intercept of a line representing the probit of cumulative percentage emergence vs. degree days had as independent variables the intercept of the previous year’s regression line and the average temperature for the preceding September, December, February, and April. A comparison of methods used to estimate the emergence pattern showed that the average deviation of the average date method was 5.0 days, the average slope and intercept method 2.8 days, and multiple regression method 1.6 days.

The three most important flea beetle pests of western Canadian rape crops appear to be selective in choosing their overwintering sites, as the greatest densities of overwintering adults of Phyllotreta cruciferae (Goeze) and Psylliodes punctulata Melsh. were found in leaf litter and turf beneath hedges and(or) shelterbelts, while that of Phyllotreta striolata (F.) was found in these materials beneath groves of native trees. Most beetles overwintered near the surface in leaf litter and turf rather than in the underlying soil. Within a habitat, sample to sample variation for each species was usually large and the overwintering populations appear to have an aggregated distribution pattern. Winter samples over a 6-year period from all five habitat types combined or from parkland groves reflected the continuously low level of the field population of Psylliodes punctulata, and a marked increase in the field population of P. striolata that occurred in one year. Winter samples taken from hedges and(or) shelterbelts provided little information on population sizes or trends except for indicating the general low level of the Psylliodes punctulata population. Winter mortality was low for all three species. The foregoing information will be useful for developing future sampling plans so that overwintering flea beetle populations can be estimated more reliably.

The oak leaf shredder, Croesia semipurpurana (Kearfott), has been a particularly persistent pest of red oak, Quercus rubra, in southern Ontario for several years. It is capable of completely defoliating mature trees leading either to increased susceptibility to disease or mortality. In 1980 about 800 ha in southern Ontario required spraying with Orthenem insecticide (Howse and McDowall 1980). The development of a sex pheromone lure for the oak leaf shredder would be valuable for survey purposes, post-insecticidal spray analysis of adult survival in treated plots, and for potential direct control by means of the disruption technique. Recently mixtures of (E)-11-tetradecenal (E11-14:AL) and Z11-14:AL in the ratios of 80:20 to 90:lO were found to be attractive to male moths (Weatherston et al. 1978). A local outbreak of oak leaf shredder in Sault Ste. Marie afforded an opportunity to determine the insect's response to modifications of the aldehyde blend in order to improve the efficiency of pheromone trapping of this species.

A study currently under way required non-attractant traps to collect and preserve for taxonomic identification flying insects inhabiting the crown and shrub layers of a slash pine (Pinus elliottii var. elliottii Engelm.) and pondcypress (Taxodium distichum var. nutans (Ait.) Sweet) forest. We concluded that an omnidirectional flight trap was appropriate. After failing to find a satisfactory design in the literature, we developed the trap illustrated in Fig. 1. Our design combines an original upper collecting unit with a modification of the trap described by Hines and Heikkenen (1977).