No abstract

Laboratory tests showed that a Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), strain collected from potatoes on a farm near Sherbrooke, Quebec, and known in 1979 to be resistant to most recommended organochlorine, organophosphorus, and carbamate insecticides, also had developed 23- to 38-fold levels of resistance to the pyrethroid insecticides permethrin, fenvalerate, and cypermethrin by 1982. Piperonyl butoxide (PB) had only a minor effect on fenvalerate and deltamethrin toxicity to insecticide-susceptible CPB and on deltamethrin toxicity to pyrethroid-resistant CPB. However, PB effectively synergized fenvalerate in pyrethroid-resistant CPB, e.g. a 1:8 fenvalerate:PB mixture was 12-fold more toxic than fenvalerate alone.

The effectiveness of 16 experimental compounds as soil insecticides was assessed under laboratory conditions. Chlorpyrifos, carbofuran, and dieldrin were included as standard insecticides. Spectrum of activity as contact insecticides was determined using 24–48 h nymphs of the field cricket, Acheta pennsylvanicus (Burmeister), 24–48 h onion maggot adults, Hylemya antiqua (Meigen), third stage darksided cutworms, Euxoa messoria (Harris), northern corn rootworm adults, Diabrotica longicornis (Say), and honeybees, Apis mellifera L. First stage crickets were used to assess the biological activity of experimental compounds relative to soil type, moisture, and temperature and also their volatility in moist sand and persistence of biological activity over a 48 week period. All of the insecticides showed broad spectrum contact activity. Twelve showed fair to very good potential in soil. Four insecticides, Shell WL 24794 (O,O-dimethyl-S-1-[3-(5-methyl-1,2,4-oxadiazolyl)] ethyl phosphorodithioate), Shell WL 25735 (O-[2-chloro-1-(2,5-dichlorophenyl) vinyl] O-methyl methylphosphonothioate), Shell WL 26738 (O-[1-(2,4-dichlorophenyl) vinyl] O-methyl ethylphosphonothioate), and chlorpyrifos-methyl showed good potential. Two others, Counter® (S-[(tert-butylthio) methyl] O,O-diethyl phosphorodithioate) and Shell WL 24073 (O-[2-chloro-1-(2,5-dichlorophenyl) vinyl] O-methyl ethylphosphonothioate) were considered to have very good potential as soil insecticides.

The Canadian Entomologist 126: 1363 -1368 (1994) Four species of Tychius have been introduced into North America from Europe: Tychius picirostris (Fabricius) (host plants: Trifolium spp.), widespread in North America; T. cuprifer (Panzer) (host plants: Trifolium spp., Teline monspessulana L.), known only from Maryland, USA; T. meliloti Stephens, new North American record (host plants: Melilotus spp.), known from scattered localities in Saskatchewan, Manitoba, Ontario, and Quebec, Canada; and T. stephensi Schoenherr (host plants: Trifolium spp.), widespread in North America. Keys to separate the species are presented. Anderson, R.S., et A.T. Howden. 1994. D6couverte de Tychius meliloti Stephens au Canada et courte r6vision des espkces du genre Tychius Germar introduite en AmCrique du Nord (Coleoptera: Curculionidae). The Canadian Entomologist 126: 1363 -1368. RCsumC Quatre espbces de Tychius ont Ct C importkes d'Europe en AmCrique du Nord: Tychius picirostris (Fabricius) (plantes h6tes: Trifolium spp.), rCpandu en AmCrique du Nord; T. cuprifer (Panzer) (plantes h6tes: Trifolium spp., Teline monspessulana L.), rencontrC seulement au Maryland, E.-U.; T. meliloti Stephens, une espbce mentionnCe pour la premibre fois en ArnCrique du Nord (plantes h6tes: Melilotus spp.) et rencontrCe en des points dispersCs de la Saskatchewan, du Manitoba, de I'Ontario et du QuCbec, Canada; et T. stephensi Schoenherr (plantes h6tes: Trifolium spp.), rCpandu en AmCrique du Nord. Des clCs permettront de distinguer les diverses espbces. [Traduit par la RCdaction]

Can. Ent. 114: 447-454 (1982)

THE compression of fluorine into nickel and steel cylinders at 100 pounds per square inch has been accomplished by the liquefaction-pressure distillation method.To prevent icing conditions during the liquefaction, the hydrogen fluoride content of the electrolytic fluorine was reduced below 0.5 volume per cent. This was accomplished by a combination of refrigeration at -70°C. and absorption at 100c C. with sodium fluoride. The efficiency of removal of hydrogen fluoride from fluorine by both methods was studied.Extensive investigation of the IN ORDER to provide facilities for transporting fluorine, it was necessary to develop methods for purifying the gas as produced electrolytically, techniques for compressing it, and tests for selecting cylinders that could be approved by the Interstate Commerce Commission for shipment via common carrier.

Can. Ent. 110: I 275-283 (1978) Collections of Amitus (Hymenoptera: Proctotrupoidea, Platygastridae) from the Western Hemisphere are referred to the following species: from Canada and the United States, A . aleurodinis Haldeman, A. granulosus n. sp., and A . gibbosus n. sp.; from Mexico and South America, A . spiniferus (Brethes), A. pigeanus n. sp., A. hesperidum Silvestri, and A. fiscipennis n. sp.A lateral plate-like process on the male fourth antennal segment is regarded as a phenocline, characteristic of species or species groups.

The European skipper, Thymelicus lineola (Ochs.), first reported in Quebec by Arthur (1966), has spread throughout much of the province (McNeil et al. 1975). Control methods considered at the experimental level include: early harvesting to reduce potential oviposition sites (Arthur 1966;Arthur and Smith 1972); silica sprays combined with feeding and(or) oviposition deterrents (Arthur and Smith 1972); and Bacillus thuringiensis Berliner (Arthur and Angus 1965;Arthur 1968). Doyle and Richard (1971) suggested carbaryl would be effective and, as the skipper has been at epidemic levels in the Lac St-Jean region for several years, some producers treated with carbaryl (85W), 3/4 Ib/ac, in 1974 and 1975. As no insecticide screening tests had been made, this study was undertaken as the first step in the development of a realistic chemical control program. Methods and MaterialsInsects used were field collected as T. lineola is difficult to culture. Collections were made from two separate locations in order to obtain both third and fifth stage larvae for testing. Third stage larvae were collected at St-FClicien, approximately 170 miles NW. of Quebec City, while fifth stage larvae were obtained at St-Ftlix de Valois, approximately 50 miles N. of Montrtal. All larvae were held at 23k 1°C, 6 0 t 5 % R.H., and 16L:8D photoperiod in plastic containers with a fresh supply of timothy grass, for 24-48 h prior to treatment.Details of the bioassay technique have been described elsewhere (Harris and Mazurek 1961). The direct contact toxicity of 11 insecticides (95-99% purity) was assessed using a Potter spray tower. Chemical designations of insecticides without accepted common names are: Niagara 33297: 3-phenoxy (+) cis-trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate); Stauffer N2596: S-(p-chlorophenyl) 0-ethyl ethylphosphonodithioate. Carbaryl was considered the standard for purposes of comparison. The solvent for all insecticides was 19: 1 acetone : olive oil mixture. For each insecticide a control (solvent only) and concentrations of 0.001, 0.01, 0.1, and 1 .O% were tested with the exception of Nia 33297 where 1.0% was not used. Two replicates, each containing 10 fifth stage larvae, were treated at each concentration. After treatment the insects were placed in waxed-paper cups (10 larvaelcup) with ample timothy grass and held at 27+ 1°C, 65 +5% R.H., and a 24L:OD photoperiod. Mortality counts were made 24 h after treatment. No control mortality occurred.The five insecticides most effective against fifth stage larvae were then utilized to test for differences in larval susceptibility. Two replicates (10 larvaelreplicate) of third and fifth stage larvae were used with each insecticide. The insecticide concentration utilized varied with each compound, being the dose calculated to cause 0-10% mortality of fifth stage larvae (based on the results obtained in the first part of the experiment). Control groups were treated with solvent only. Posttreatment conditions were as above.Correction for natural mortality (never > 5%...