A collection of 70 Medicago introductions were field tested for resistance against potato leafhopper, Empoasca fabae (Harris), damage. All M. sativa L. ssp. sativa and most ssp. mixtures were susceptible. All ssp. falcata (L.) Arcangeli, one ssp. mixture sativa and caerulea (Lessing ex Ledebour) Schmalhausen, ssp. × varia (Martyn) Arcangeli and M. pironae Vis were resistant receiving one-half or less damage than the standard cultivars during four seasons of testing. Resistant introductions were slower in regrowth, attained less height, had smaller leaflets, thinner, tougher stems, and more prostrate growth than standard cultivars. Results suggest most observed resistance is due to avoidance of tough stems for oviposition.

Adults and larvae of Rhinosimus viridiaeneus Randall observed on Vancouver Island, British Columbia, prefer the inner bark of dead branches of red alder (Alnus rubra Bong.) for food. When feeding, the flattened elongated rostrum of the adult is inserted between the papery outer bark and the cambium. The rostrum is also used to prod or flip intruding Rhinosimus away from a feeding site. The larva is described for the first time.

The preoviposition period of R. pomonella (Walsh) varied from 5 to 11 days at constant and 6 to 15 days at variable rearing conditions. Its duration was influenced by the source of the adults, cultivars for oviposition, and rearing conditions: ca. 3 days longer for adults from infested Wealthy apples than for adults from infested Gravensteins, ca. 2 days longer when the apples for oviposition were late season cultivars, and ca. 1 day longer at variable than at constant rearing conditions. Estimates of the preoviposition period of adults in two unsprayed orchards were 14 and 21 days in 1979 and 16 days in both orchards in 1980, and were 7–14 days longer than that for adults at constant rearing conditions.

The oviposition periods of adults were 40–74 days at constant and 25–55 days at variable rearing conditions in 1979, and were influenced by the source of the adults, cultivars for oviposition, and the rearing conditions. Females from infested Gravensteins laid 339.2 and 180.7 eggs/female at constant and variable conditions and those from infested Wealthy 178.4 and 68.8 eggs/female at constant and variable conditions. Females also laid fewer eggs in Red Delicious apples than in Gravenstein, McIntosh, or Cortland apples.

The first spray for control of apple maggot in Nova Scotia can be applied at least 14 days after first emergence or first capture as the preoviposition period in natural (orchard) conditions exceeded the recommended time of 7–10 days.

The Nearctic species of the genus Metaclisis are revised. Of 18 species recognized, 16 of them new to science as follows: M. acericola (Quebec, Ontario), M. acerina (Quebec, Ontario, Illinois), M. aceris (Quebec, Ontario), M. acuta (Arizona), M. alticola (New Mexico), M. annae (Texas), M. attenuata (California), M. borealis (Labrador), M. ensifer (California), M. filicornis (Ontario), M. longula (Illinois, Maryland, Ontario), M. masoni (Manitoba), M. pumilio (Ontario, Quebec, Illinois, Maryland, N. and S. Carolina), M. sulcata (Eastern Canada and U.S.A., Tennessee), M. verna (Ontario), and M. vernalis (Quebec, Ontario, Maryland). M. carinata (Ashmead) ♀ and M. floridana (Ashmead) ♂ are redescribed and the male of M. floridana is newly described. A generic diagnosis of Metaclisis and keys to females and males of Nearctic species are given. The higher classification, bionomics, world distribution, and character states of Metaclisis species are discussed.

In greenhouse tests conducted in moist acid mineral soils, propoxur was highly toxic and fast acting as an adulticide against flies of the cabbage maggot, Hylemya brassicae (Bouché), and many other types of adult insects. Some flies in contact with the surface of treated soil were killed in 30 sec or less. When banded at depths of 1, 3.5, and 7 cm, propoxur moved upward and reached peak toxicity to flies standing on the surface in ca. 5, 20, and 35 days, respectively. Deeper placement of the insecticide resulted in lower levels of peak toxicity. Toxicant from 5 to 10 cm depth treatments was still detectable 6 months after soil treatment. Adulticide tests demonstrated that propoxur could be leached downward by addition of excess water to the soil surface. Under the conditions of tests where flies in cages landed at random on treated soils in miniplots, no toxicity was detected when the surface of the treated soil became air dry.

A single preplanting subsurface application of propoxur banded below the soil surface in field experiments provided all season protection against cabbage maggot infestations during normal to relatively dry growing seasons but was ineffective during abnormally wet seasons.

Percentage parasitism by seven insect parasites of the western spruce budworm, Choristoneura occidentalis Freeman, was not significantly different among crown aspects. Parasitism by two hymenopterous parasites was significantly different among crown levels in either one or both hosts. Other parasites were either insufficiently abundant to provide an adequate test, or percentage parasitism differed insignificantly among crown levels or host types. Because percentage parasitism was not generally different among crown levels, any level could have been sampled.

Adoption of the term “tonofibrillary platelets” for the small, sclerotized areas of muscle attachment on the cuticle of Lepidoptera larvae is advocated and a simplified system of abbreviations for the names proposed by Mutuura (1980) for these areas is suggested.

The number of large embryos in adult Macrosiphum euphorbiae (Thomas) was investigated in 1974–77 as a means of forecasting population trends on field tomatoes. In an incubator the embryo count (e) of apterae and alatae was related to the daily birthrate (N) by the equation N = 0.45 e + 0.33, except in the first 4 days of adult life of the apterae. On field plots of tomatoes, e was only satisfactory for forecasting population trends in 1 of 4 years of observations. This probably occurred because the adults were mainly apterae. The relationship between flights of alatae and populations on tomatoes appeared to differ from year to year. In 1974 the number of alatae in large populations in tomato plots was more closely related to the number of alatae trapped in flight with a suction trap in the week after than in the week before the tomatoes were sampled, suggesting many alatae were leaving the tomatoes. In 1975–77, populations on tomatoes were low and the number of alatae on the plots was more closely related to suction trap catches in the week before than in the week after the counts on tomatoes, suggesting many of the alatae on the plots had recently arrived there. The percentage of alatae among adults on field tomatoes declined with days from planting each year. Red forms always constituted ≥ 50% of populations on tomatoes and in flights, the rest being green.

The spread of Thymelicus lineola (Ochsenheimer) in North America has been extensively documented (Rawson 1931; Clench 1956; Pengelly 1961; Arthur 1966; Burns 1966; McNeil et al. 1975; McNeil and Duchesne 1977). In Canada, T. lineola has been recorded from British Columbia, Ontario, Quebec, New Brunswick, Nova Scotia, Newfoundland, and now Manitoba (Gregory 1975; Jackson 1978). In the north central United States T. lineola has been recorded from St. Louis Co. and International Falls, Minnesota (Brewer 1977; Lundeen 1980). Pengelly (pers. comm.) observed T. lineola at Dryden, Ontario in 1972. McCabe and Post (1977) did not include this species in their list for North Dakota. The purpose of the present note is to report on the presence and collections of T. lineola in Manitoba and in northwestern Ontario.

In the course of my search for Miridae in Newfoundland in 1980, I collected a series of six bugs which proved to be the males of Myrmedobia exilis (Fallén), family Microphysidae. The specimens were collected by sweeping the ground cover on the east side of Gibbet Hill just west of the Information Centre (Signal Hill National Historic Park), St. John's, Newfoundland, 20 July 1980. The vegetation on the hill site consisted mainly of a dense, but short mat of heather (Calluna vulgaris (L.) Hull) intermixed with moss, clumps of grasses, and a few herbaceous plants. Thus sweeping was right along the ground. Collecting at the Signal Hill site, and generally across Newfoundland was limited by wet weather and although I spent three nights at St. John's only minimal collecting was possible.

Chrysocharis laricinellae (Ratz) is a European parasite of the larch casebearer, Coleophora laricella (Hbn.), and was one of several species introduced into eastern North America in the 1930's for biological control. Following their release, C. laricinellae and the braconid Agathis pumila (Ratz.) became established and reduced casebearer poulations drastically (Graham 1949). Both parasites are now being used for biological control of the casebearer in western North America. A. pumila was first released in northern Idaho in 1960 (Denton 1979). C. laricinellae was not intentionally released until 1972 (Ryan and Denton 1973), although it probably became established in certain areas earlier (Ryan et al. 1974). The purpose of this paper is an historical documentation of the early distribution and relative abundance of C. laricinellae, made possible largely because of an extensive, one-time survey in 1977 by entomologists of the USDA Forest Service, Northern Region (Flavell 1979).