Most of the species of plants in the arum family, Araceae, have their flowers arranged on a central spadix which is surrounded by an enveloping spathe. These floral mechanisms have been classified by Müller (1883). The simplest type, represented by the water-arum, Calla palustris, has the spadix fully exposed and the spathe held back from it. Secondly, there is the type in which the spadix is surrounded by the spathe and is only partly visible through the opening of the spathe, as represented by the skunk cabbage, Symplocarpus foetidus. Thirdly, there is the most elaborate arrangement, represented by the cuckoo pint, Arum maculatum. In this type the spathe surrounds the spadix and is constricted a short distance above its base to form a chamber surrounding the flowers which are concentrated at the base of the spadix. Thus there is formed a “pitfall mechanism” or “kettle trap” which entraps insects that have entered the spathe and ensures the pollination of the flowers by the insects (McLean and Ivimey-Cook, 1956; Müller, 1883).

Under certain environmental conditions the resistance of wheats to the wheat stem sawfly, Cephus cinctus Nort., may be reduced or even lost. In addition, these varieties are not suitable for all of the region where the sawfly is a problem. To assist in the improvement of the presently resistant wheats, studies were begun in 1953 to determine the nature of the resistance to the sawfly. The present paper deals with the effects of various spring wheats and of different parts of the stems of these wheats on the hatching of the egg of the sawfly and presents evidence for hypotheses on the cause of these effects. Although several authors have reported on resistance to the sawfly (Ainslie, 1920; Criddle, 1915, 1922; Farstad, 1940; Farstad and Platt, 1946; Kemp, 1934; Platt et al., 1948; Roemhild, 1954; Roberts, 1954), none has dealt with the effects of the host on the egg alone.

The objective of this study is to describe the copulatory and ovipositional behaviour of Hetaerina americana and H. titia, and to depict any differences in such behaviour as may exist between these two species. It is quite important in such studies to understand the mechanisms which assure conspecific mating. Both americana and titia are found breeding together on many of the streams of central Texas. Williamson (1906) pointed out that species in which the abdominal appendages were very similar often had sexually dimorphic and/or specifically distinct wing coloration, while species with clear wings had quite distinct abdominal appendages. These different wing patterns were suggested as functioning in species recognition for conspecific mating. Buchholtz (1951, 1955) experimentally verified that the females of Calopteryx splendens recognize and respond to males of their own species through a set of optical stimuli including the color pattern of the wing. Loibl (1958) and Krieger and Krieger-Lobl (1958) experimentally demonstrated that in Lestes dryas, L. sponsa, Ischnura elegans and I. pumila, all of which have clear, colorless wings, the species recognition factors are the shape of the abdominal appendages and body coloration. Williamson's early inferences appear to have been well documented.

Elsewhere (Scudder, 1957a), I have outlined briefly a revised interpretation of some basal structures in the insect ovipositor. It was shown that in insects other than the Machilidae, the female genitalia has a common plan, this plan differing from that usually taken as the basic type. Whilst Snodgrass (1933) based his interpretations of all the higher orders on the condition in Machilidae, I have shown that a more satisfactory interpretation is obtained if the condition in the tepismidae is taken as the basic tvpe.

In 1958, Pilophorus uhleri (Knight) (Hemiptera: Miridae), Vespula vulgaris (L.) and V. rufa consobrina (Sauss.) (Hymenoptera: Vespidae) were recorded for the first time as being not only active predators of Neodiprion swainei larvae, but also vectors of a virus disease affecting this sawfly (Smirnoff, 1959). The latter vespid was considered to be especially important. In the summer of 1959, in the same area (St. David de Falardeau, Lake St. John region, Que.), more insect species were identified, which preyed on the first- and second- instar larvae of N. swainei. Most active were Lasioglossum (Evylaeus) sp. (Hymenoptera: Halictidae) and Crabro sp. (Hymenoptera: Sphecidae), while three species of Vespula were also observed: V. maculata (L.), V. arenaria (Fab.) and V. norwegica norvegicoides (Slad.) (Figs. 1-4). This completes the list of insects which have been observed to prey on swainei larvae. Data were also obtained on the period of greatest activity of each of these predators.

The Annapolis Valley is about 100 miles long and is one of the largest and most important of the agricultural areas of the province. The general relief is undulating to gently rolling, with general slopes from the North and South Mountains to the Annapolis and Cornwallis Rivers. The soils of the Annapolis Valley and Hants County were described by Harlow and Whiteside (6) and Cann, Hilchey and Smith (1). A wireworm survey was conducted between 1951 and 1958 since it was suspected that economically important species of European wireworms, namely Agriotes sputator (L.), A. obscurus (L.), and A. lineatus (L.), which occur elsewhere in the province, might be invading the area. The results of this survey are reported here.

In the course of our studies of the Trichoptera of the southern Appalachians during the past few years, considerable material of the genus Lepidostoma has been accumulated. In addition to range extensions and previously undescribed females in various groups within the genus, this material has provided four new species in the vernalis group. With the number of species in this group thus doubled, we believe it useful to provide here a revision of the whole vernalis group, with keys to the males and females. Knowledge of the immature stages is not adequate to permit any systematic analysis at this time.

Two aspects of the biological control of R. buoliana are reported in this paper. From 1949 to 1957 rearing techniques were developed for and observations were made of the abundance and biology of parasites received in host material that was collected in Europe (Arthur). From 1955 to 1959 a critical evaluation of the parasites was made, largely based on a study at Elmira, Ontario, of the biology and habits of five representative parasitic species in the field and the laboratory to determine factors that limit their efficiency (Juillet).

In April, 1959, field crickets were collected in Jamaica and brought alive to this laboratory for study. The great majority of these specimens were Gryllus assimilis Fabricius, and it was assumed for some months that all the specimens collected belonged to this species. The senior author, however, noticed certain specimens that appeared to be distinctive; these were segregated and reared separately, crossing experiments were carried out between them and Gryllus assimilis, and the nymphal stages of both forms were compared. These studies revealed thar two distinct species had been collected in Jamaica, and the unknown species was subsequently determined by Professor L. Chopard as Scapsipedus marginatus Afzelius and Brannius.