Aspects of the biology of Cystiphora sonchi (Bremi) (Diptera: Cecidomyiidae) were investigated and releases were made on perennial sow-thistle (Sonchus arvensis L.) (Compositae) in six provinces of Canada. Fecundity, determined by dissection of newly emerged females, averaged 86.2 eggs. Cystiphora sonchi became established in Alberta, Saskatchewan, Manitoba, and Nova Scotia, and produced three generations at Vegreville, Alberta. In fall, mature larvae enter the soil, and most can pupate in temperatures of 4 °C. The gall fly thrives in shady and sunny locations. Cattle caused considerable fly mortality by feeding on galled leaves of perennial sow-thistle. Extremely dry or moist soils reduced the number of adults that emerged from pupation and extremely moist soils increased the lengths of the pupation periods. Flooding caused greater mortality of pupae than of larvae but 2% of the larvae survived flooding up to 8 weeks.

Second- and 3rd-instar nymphs of Melanoplus sanguinipes (Fab.) were more susceptible to Nosema cuneatum Henry infection than were 5th-instar nymphs. Lethal times were significantly lower for 2nd- and 3rd-instar nymphs inoculated with 1.0 × 106 and 104N. cuneatum spores/individual than for similarly treated 5th-instar nymphs and a much higher percentage of the latter were uninfected at the end of the experimental period (40–60 days post-inoculation). Fifth-instar nymphs inoculated with 1.0 × 106 spores/individual showed reduced adult longevity. The number of eggs laid per female was not significantly different for inoculated or untreated 5th-instar nymphs. However, the dry weights of eggs laid by inoculated grasshoppers were significantly lower and fewer eggs hatched than for those laid by untreated grasshoppers. Twenty to 30% of the progeny from inoculated 5th-instar nymphs had detectable levels of N. cuneatum sporoblasts and spores.

Litoleptis alaskensis, a new genus and species from Alaska, and Bolbomyia melanderi, a new species from the Appalachians, are described. Cekendia wuorentausi is redescribed, and the genus synonymyzed with Bolbomyia. Further records of the Nearctic species of Bolbomyia are given. A generic group composed of Hilarimorpha, Litoleptis, Bolbomyia, Archicera and Austroleptis is proposed.

Field tests were continued during 1970, 1971, and 1972 in southwestern Ontario to evaluate experimental and registered insecticides for control of Euxoa messoria (Harris) larvae on tobacco. Insecticides were applied before planting as broadcast applications to the rye cover crop or to the soil.

Of 10 chemicals tested, chlorpyrifos, leptophos, and N-2596 (S-(p-chlorophenyl O-ethyl ethyl-phosphonodithioate) gave the most consistent control, and Biothion® (O,O′-thiodi-p-phenylene O,O,O′,O′-tetramethyl phosphorothioate) and methoxychlor gave variable control. Fensulfothion was slightly phytotoxic, and trichlorfon and Mobam® (benzo [b] thien-4-yl methylcarbamate) were ineffective in the present study. Supracide® (O,O-dimethyl phosphorodithioate S-ester with 4-(mercaptomethyl)-2-methoxy-Δ2-1,3,4-thiodiazolin-5-one) and Orthene® (O,S-dimethyl N-acetyl phosphoramidothioate) showed promise for control of E. messoria larvae.

Levels of reducing sugars and total alkaloids in the cured leaves were unaffected by treatment, indicating that these insecticides had no effect on tobacco quality.

Endecascelio stipitipennis n. gen. and n. sp. is described from Central Africa (former Belgian Congo). The extent and interrelationships of the tribe Embidobiini are discussed. A diagnosis of the tribe and a key to genera of the world is given.The genus Embidobia Ashmead is for the first time reported from the Oligocene of Baltic amber.

Distinguished from allied species by the relatively narrow head and smaller eyes; width of head acrloss eyes about equal to basal width of pronotum; length of second antennal segment much greater than width of head.

Studies were conducted to document the oviposition biology of female white pine weevil, Pissodes strobi Peck. Data were recorded on female fecundity and daily feeding and oviposition activities. In addition, we compared fecundity of 1- and 2-year-old females. Female white pine weevils laid a mean ± SE total number of 132.3 ± 7.5 eggs (range 40–344 eggs) during an average oviposition period of 5.8 ± 0.4 weeks. It is during the first 5 weeks that white pine weevils lay the most eggs, with an egg-laying peak in the second week of the oviposition period. For a few females, egg production did not cease until the 22nd week. There was no difference between the number of eggs laid in the photophase and in the scotophase, but higher numbers of feeding punctures were observed during the night than during the day. The oviposition and feeding results for 2-year-old female white pine weevils were similar to those for 1-year-old females. This information contributes to the management of white pine weevils by providing a better understanding of some of the mechanisms of its population dynamics.

The surviving material of C. F. Baker's collection of aphid parasites comprises a total of 107 specimens of which 27 are syntypes representing 9 species described by Baker. Lectotypes are designated for Ephedrus californicus, E. nevadensis, Praon nanus, P. occidentale, Aphidius delicatus, A. coloratus, A. ferruginosus, A. pulcher, and Diaeretiella (= Diaeretus sensu auctt.) californica. The synonymy of all taxa is discussed, and redescriptions of most of the species are given. The remaining 80 specimens of the collection represent 7 genera and 14 species.

Pharate adult (adult within the pupal cuticle) diapause was discovered in Barbara colfaxiana (Kft.) and is reported. This phenomenon is uncommon in insect development. It was also shown that both the termination of diapause and the subsequent advancement of pharate adult development can occur at 0 °C.

Sex attractant traps for males of the clover cutworm, Scotogramma trifolii (Rottenberg), on farms in southern Alberta caught more moths within crops or on fallow than those near or within the farmyards except for traps immediately on the south side of the yard For males of the army cutworm, Euxoa auxiliaris (Grote), two trap placements in open areas were more effective than locations within the farmyard, again with the exception of the traps on the south side of the yards. Traps 2 m high caught significantly fewer moths than those at 1 m or ground level and the crop in which the trap was placed had no significant influence on catch of either cutworm.

The pear rust mite, Epitrimerus pyri (Nal.), overwinters in a semi-active state in old leaf scar crevices and under bud chips of the leaf clusters. It becomes active within the bud in mid-April, as soon as the weather warms, and passes through three generations in the growing season as indicated by distinct peak egg populations observed in May, June, and July. The first generation eggs are laid within the swelling bud. The mites feed on the ventral surface of the leaves causing bronzing and on the calyx end of the fruit resulting in russeting of the epidermal tissue. Deutogynes of the third generation begin to enter hibernation by mid-August. Occasionally population levels reach economic injury level resulting in the downgrading of fruit.

Neoleucopis pinicola Mall. is a common predator on the pine bark aphid, Pineus strobi (Htg.) in New Brunswick. The host adelgid occurs throughout most of the United States and southern Canada on white pine, Pinus strobus, L., Scots pine, Pinus sylvestris L., and Austrian pine, Pinus nigra Arnold (Craighead, 1950). It is also an occasional predator on the balsam woolly aphid, Adelges piceae (Ratz.) (Brown and Clark, 1956b). No reference to N. pinicola was found in the literature other than Malloch's (1921) description.

The distribution, ecology, and host-plants of the European skipper, Thymelicus lineola (Ochs.), are described, and notes given on its biology and abundance in continental Europe. Agricultural practices are responsible for its virtual absence from hay-fields; however, even in undisturbed wild host-plant communities, it is never abundant, and has never required control measures as in Canada. Parasites of T. lineola are listed, with notes on their life-histories, distribution, host spectra, relative abundance, annual fluctuations, and interpopulation variations. Parasites reared were Phryxe vulgaris Fall., Thecocarcelia incedens Rond, (both attacking larvae, but sometimes emerging after host pupation), Rogas tristis Wesm. (larval parasite), Labrorychus delarvatus Grav. (larval–pupal parasite), Stenichneumon scutellator Grav. and Brachymeria intermedia Nees (pupal parasites); an undetermined mermithid was reared from larvae and also once from an adult S. scutellator. Rogas tristis was attacked by the hyperparasite Mesochorus macrurus Thoms., and S. scutellator by Gelis cursitans F. Potentialities of the more important species for biological control of T. lineola in Canada are discussed. S. scutellator, which is well synchronized with the host, regularly parasitizes 30–50% of pupae and is the most promising natural enemy for introduction, although in Canada it will compete with the native Itoplectis conquisitor (Say). R. tristis (3–57% parasitism) and P. vulgaris (8–44%), with high constancy in Europe, might be considered for introduction to Canada because of the absence there of effective native larval parasites. T. incedens, although probably a specific hesperiid parasite, is uncommon (usually 1–5% parasitism) and has low constancy in central Europe. All other species encountered are rare on T. lineola. Comparison of parasite complexes in Europe and Canada, where the host has acquired 22 natural enemies, shows that four genera are represented in both areas; of three holarctic species two have been found associated with T. lineola only in Canada, and one only in Europe.

In most entomological textbooks and other general summaries the pupae of the order Trichoptera are characterized as having strong mandibles which are used to make a hole through the pupal enclosure, thereby permitting the escape of the pharate adult. For the vast majority of caddisfly genera for which pupae are known this description is probably accurate enough, but it is somewhat less than accurate to describe the pupae of all caddisflies in this way.

Seasonal activity of carrot weevil, Listronotus oregonensis (LeConte), adults, eggs, larvae, and root feeding was studied in plots of parsley, Petroselinum crispum (Mill.) Nyman ex A.W. Hill, by sampling weekly from mid-May to the first week of September in 1998 and 1999. The initial population of overwintering adults, one complete generation, and at least a partial second generation were observed. The majority of eggs were deposited in June and most of the larvae were counted in July; the greatest damage was noticed from July onward. In both 1998 and 1999, the overall seasonal means of adults, eggs, larvae, and root feeding were significantly different among plots that were planted on different dates. Root feeding and all carrot weevil life stages sampled steadily decreased from the earliest to the latest planting. Most of the damage occurred in parsley plantings sown from late February until the third week of April. The number of eggs removed from parsley plants during the first cutting was significantly different among planting dates, but the impact of this removal may not be significant in infestation reduction. Results of this study will help parsley growers to target when control measures for carrot weevil will be most effective and which plantings are most likely to be damaged.

It is proposed to consider the taxon Leptochironomus Pagast as a genus which includes: L. tener (Kieffer), L. aegyptius (Kieffer), L. stilifer (Freeman), and L. deribae (Freeman). L. paraderibae La ville and Tourenq is regarded as a synonym of L. deribae.The juvenile stages of L. stilifer are described. The opinion is expressed that the juvenile stages described as Chironominae genuinae No. 4 (Lipina 1927), Microchironomus conjugens Kieffer (Lenz 1926), and Microchironomus No. 1 (Zavrel 1931) belong to Leptochironomus.

Larvae of the winter moth, Operophtera brumata (L.), and the Bruce spanworm, O. bruceata (Hulst), differ in the number of instars, in habits, and slightly in morphology. Populations may be distinguished readily by these criteria, but individual larvae sometimes give difficulty. The form of the pupal cremaster is distinctly different.

Mosquito eggs were hatched by artificially flooding dry pond beds and estimates of population size were made through larval development for one population of Aedes spencerii, two of A. cataphylla, and three of A. vexans. Overall daily mortality rates were between 8 and 21% and survival to the pupal stage was generally less than 20%, even though water levels were maintained. Mortality appeared to be higher in early larval stages than in later larval stages. Predation was unimportant and survival rate may have depended on food supply or temperature or an interaction between the two. In normal ponds populations often suffer heavy mortality when ponds dry up before development is complete. A. cataphylla, a spring species, developed faster than A. vexans, a summer species, at low temperatures but more slowly at high temperatures.

The Holarctic genus Symphoromyia, the biting snipe flies, is discussed and a taxonomic history of the group is reviewed. Five subgenera including Symphoromyia s. str., Paraphoromyia Becker, and three new subgenera, Axinicera, Pogonaria and Ochleromyia, are established and a key for their separation and recognition of included species-groups is presented. Each subgenus and its associated species-groups are discussed and compared with respect to distribution, morphology, and evolutionary trends. Known aspects of biology for the genus are presented to include: (1) a generalized life cycle; (2) immatures; (3) natural enemies; (4) female biting activity; (5) male swarm behavior.

The reproduction of Forficula senegalensis Serv. was studied in fields of bulrush millet (Pennisetum typhoides Burm.), 40 km south of Maradi, Niger. Flight activity, as determined by light trapping, follows a seasonal cycle in two phases: first the arrival of adults of the previous year in the fields at the onset of tillering; and second, the dispersal of adults of the new generation at the time of blooming and maturation of the plant, and their departure at harvest time. Females lay their eggs at the collar of the plants during tillering; hatching and nymphal dispersal occur soon afterward. From the second instar on, nymphs migrate to the intermediate and upper levels of the plant. The reproductive cycle of F. senegalensis thus appears closely synchronized with the development of bulrush millet.