Depuis la découverte du pouvoir insecticide du DDT, des recherches intensives ont été faites sur d'autres composés synthétisés à partir de la charpente squelettique du DDT, à savoir le 1,1-diphényléthane:

De ces composés analogues au DDT, certains montrent une valeur insecticide supérieure à celle du DDT; d'autres s'avèrent inférieurs. du moins dans les conditions expérimentales que nous avons choisies. Nous présentons ici les résultats que nous avons obtenus dans nos expériences sur la toxicologie du dérivé cyanuré du DDT. Ce composé a été synthétisé pour la première fois par Perron (4,5) à l'Institut de Chimie de l'Université de Montréal. Nous avons utilisé la méthode mise au point par cet auteur pour préparer les quantités dont nous avions besoin pour notre travail.

Betulaphis viridis is described and illustrated. It is a bright green species that occurs on the upper surfaces of the leaves of Betula pendula Roth and is known only from Ontario.

The effects of temperature on survival during postdiapause development of the pre-imaginal stages of the larch sawfly, Pristiphora erichsonii (Hartig), were investigated in the laboratory using Manitoba material. Pronymph mortality increased progressively between 10° and 30 °C. Developmental arrest occurred in pronymphs exposed to 35 °C for periods up to 10 days prior to their transfer to 15 °C for completion of development. Pupae were more tolerant of high temperatures than were pronymphs.The results are discussed in relation to the possible physiological mechanism involved and the ecological implications for survival in the field.

Plants of the genus Taxus have pharmacologically active materials that elicit hypotensive effects and act on the cardiovascular musculature of dogs (Bourbeau 1954; Duval, unpub. data, 1974). Extracts from Taxus canadensis (Marsh) are more potent than those from T. baccata L. (Vohora 1972). In an investigation of Canadian plants for insecticidal and pharmacological activities, we observed that no insects fed on plants of the genus Taxus. Therefore we tested the toxicity of aqueous extracts of T. canadensis on two species of insects, Macrosiphum euphorbiae (Thomas) (Homoptera: Aphididae) and Tribolium confusum Duval (Coleoptera: Tenebrionidae).

Four species of the Genus Grammotaulius, one of which is now considered a synonym, have been recognized in North America. These have been recorded only from Greenland, Canada, and northwestern United States. In August, 1940, Dr. C. E. Mickel and Mr. H. E. Milliron collected a series including both sexes of a new species in Colorado.

Phyllotreta liebecki Schaeffer, described from Florida, and recorded by the writer (Entom. Amer., VIII, n.s., 1927, p. 27) from Louisiana, Texas, and Plummer's Island, Md., has recently been recognized lrom specimens forwarded for identification by Theo. H. Frison, Illinois State Natural History Survey, from Quincy, Ill., June 11-30. 1883, and Grand Tower, Ill., August 6, 1909.

A new species of Aroga (Lepidoptera: Gelechiidae) is described, and characters separating it from Aroga trialbamaculella (Chambers) and Aroga epigaeella (Chambers) are given.

On December 30th, 1904, I examined for spiders a small cave on the north bank of the Missouri River, three miles below Rochport, Mo. This cave is occupied by a small strea, which enters it by an opening some distance from the river, and leaves it in a narrow gorge cut back in the bluffs.

This report includes descriptions of five apparently new Diptera of the family Dolichopodidae. The Colorado specimens were studied through the cooperation of Doctors M. T. James and R. H. Painter. Doctor James is codescriber of Scellus coloradensis and Rhaphium colutis, which are here described as new.

Female. Length 8 mm.; exserted portion of ovipositor 5 mm. Temples lather flat, strongly sloping inwards, broadest above, narrowing strongly below, especially narrow where occipital carina bends outwards above genae to approach eye, at this point temples distinctly narrower than malar space. Eyes prominently convex; head transverse, width including eyes distinctly greater than height.

Thousands of lepidopterous larvae representing a wide range of species are collected every year in Ontario by the Forest Insect Survey. Many of these require microscopic examination for identification. During a 10-year period I have only found one specimen with an extra pedal appendage.

In June 1963, a larva with an extra anal proleg on the right side was collected by H. G. McPhee near Thessalon, Ont., on the north shore of Lake Huron. The species was Epinotia solandriana Linn., a leaf roller on white birch, Betula papyrifera Marsh. A subsequent large collection from the same area contained only normal specimens.

The green lacewing, Meleoma schwarzi (Banks), is reported from the southern interior of British Columbia. Characters are provided which distinguish this species from other Canadian chrysopids, in particular Chrysopa gravida Banks.

Exentera apriliana, Grote.—Aweme, IV, 30, to V, 21; Beulah. Thirteen specimens. This is a particularly interesting caputre. Grote's descripiton is remarkably brief, and his generic description, occurring on the same page, is misleading on account of an error. He states: “Hind wings 7-veined, 5 wanting.” I know of no Tortricid genus in which 5 is absent; frequently 3 and 4 are coincident or stalked for their entire length, but even this is not the case in any one of these specimens; 3 and 4 are stalked from a quarter to a half.

Molecular analyses of DNA samples necessitate careful attention to experimental protocols to prevent contamination of samples during the specimen collection and DNA extraction, amplification, and visualisation stages. When these studies involve insects that are collected in the field, standard procedures require samples to be individually sorted and stored in single tubes to prevent cross-contamination of DNA between specimens. This additional step can be time consuming and impractical when the survey population is large. The focus of our study was to experimentally determine if this assumed contamination risk is valid and if it varies with storage conditions. To test this, we co-stored a single intact fruit fly (Drosophilia melanogaster) (Diptera: Drosophilidae) known to be infected with the bacterial endosymbiont Wolbachia (Anaplasmataceae) with uninfected flies in tubes for three-hour, 24-hour, and one-week durations. For each treatment time, replicates of five tubes contained one infected fly and either one or five uninfected flies (1:1 and 1:5 ratios). Overall, eight of 30 tubes had contamination regardless of storage duration, and storing samples in crowded (1:5 ratio) conditions significantly increased the risk of Wolbachia DNA transference. Our results suggest that researchers should make efforts to sample and store specimens individually if cross-contamination is a concern in molecular analyses.