The literature dealing with the methods by which the larvae and adults of tachinid parasites escape from sawfly cocoons indicates in certain cases that only circumstantial evidence is available concerning the formation of the exit hole in nature. Among these parasites a large number leave their hosts while the sawflies are in the larval stages. The larvae make their escape as mature maggots through a hole gnawed in the soft host integument. A few species, however, continue to develop within the host after the host cocoon has been formed. Some of these cut through the cocoon as mature larvae and later pupate in a suitable medium, while others form their puparial cases within the host cocoons, the adults later escaping from both the puparial cases and from the sawfly cocoons. The only escape mcchanism possessed by an adult tachinid fly consists ot the alternate expansion and contraction of the ptilinum against the surrounding wall. Since the cocoon is usually quite tough and leathery it is essential that some provision be made in advance to enable the adult to escape. This seemed to occur with adults of Phorocera hamata A. and W. which emerge from their puparia within the host cocoon and then escape from the cocoon proper, leaving a characteristic round cap which appears to have been cut (Fig. 1, C). The method of formation of this cap has been the subject of discussion by several authors.

The following list of specimens is supplementary to two previously published articles (1944, Canad. Ent. 76:163 and 1945, Canad. Ent. 77:214) on Essex County material. Appended to the list are miscellaneous records of 17 species captured in Ontario locations other than Essex County. These have been added to this paper since they are thought to be of noteworthy interest. The species in each part follow as closely as possible C.W. Leng's Catalogue of the Coleoptera of America north of Mexico.

The occurrence of the small moth, Acentropus niveus Olivier, in North America has been recorded by Forbes (1) and Sheppard (2). The former author collected a male specimen at Minetto, N. Y., and the latter captured three specimens at Montreal, Canada.

While collecting butterflies in southern Florida, we were successful in rearing many of the native species. In checking through the literature, no data could be found on the early stages of three of these, although d'Almeida and Costa Lima have published some notes on the metamorphosis of the Brazilian subspecies of Appias drusilla. It was thought, therefore, that it might be helpful to other Lepidopterists if we were to note our observations on the life histories of these butterflies.

In the establishment of insect parasites, the production of large numbers for release in heavily infested areas is often desirable. This was especially true in the case of parasites of the European spruce sawfly, Gilpinia hercyniae Htg. The rapid increase in numbers nad extent of the sawfly infestation in Canada with the resulting losses in timber as reported by Balch (1940) and Baird (1940) created a situation of grave concern, and the need for rapid colonization of insect parasites as part of the general control programme was considered urgent. Of the parasites chosen for introduction, the tachinid Sturmia sp. was considered very promising. Following initial establishment of this species, it was decided that an attempt should be made to propagate it in numbers sufficient for widespread distribution either by improving the methods in use at that time or by devising radically different methods.

Forbes (1938) recorded a single specimen of Acentropus niveus from Oswego, New York, and Sheppard (1945) recorded three specimens taken by him at Montreal, Quebec. These are the only published records from North America of this species, which is well known in Europe.

For some years it has been evident to workers conducting research on grasshopper control methods that those dead grasshoppers which can be found at the scene of application of a control measure do not necessarily represent all the grasshoppers which have succumbed to the treatment. Often, dismembered remains are considerably in evidence and usually only the more resistant parts, such as head capsules, remain to be found. It is reasonable to suppose that many of the dead bodies of grasshoppers may disappear entirely, before sufficient time has elapsed for the final observations on the treatment. It is important, therefore, in relation to the appraisal of the efficiency of control measures in the field, such as baiting, to know to what extent this is true. It is particularly important in the study of baits because, where arsenites are used, at least three days may be required for the poison to take full effect after ingestion and before the appraisal can be made. Meanwhile, a considerable period of time has elapsed during which grasshoppers that died 1 or 2 days after feeding could be removed. Under these circumstances it would obviously be erroneous in appraising the results, to take into consideration only the counts or estimates of numbers of dead on the ground, particularly if compared with the estimated population prior to baiting.

During an examination of the internal anatomy of several specimens of scarabaeid larvae it was found that the gastric caeca varied in number and shape with the species being examined.

Anatomically, gastric caeca are blind pounches varying in number and length and may occur on different parts of the ventriculus. Most commonly they occur at the anterior end surrounding the stomodaeal valve.

An inexpensive, simple, chemical control of wireworms in land to be used for vegetable production has long been sought in the Prairie Provinces. Existing methods of control (3, 4, 5, 6) are not wholly satisfactory for row crops. The cultural measures commonly advocated (6) will reduce wireworm infestations sufficiently that cereal crops can be grown without serious damage, but they are not usually sufficiently effective that potatoes or other row crops can be produced successfully. Crude naphthalene is the most satisfactory of the chemical methods recommended (3, 4, 5) but it is too costly for material, is difficult to handle and apply, and is effective only under certain conditions of soil, moisture and temperature. As a result, commercial potato production on the prairies has been restricted largely to districts and fields where wireworms are virtually absent.

In a previous paper (Simmonds 1946) a curious factor affecting diapause in insects was recorded. In two species of parasitic Hymenoptera the age of the parent female at the time of oviposition has a marked effect on the tendency of the resulting larva to enter a state of diapause when full-grown. The older the female at the time of oviposition the greater is the chance that an egg will produce a larva entering diapause. In a second paper (Simmonds 1948) this maternal influence on the tendencies of her progeny to enter diapause was investigated further. Some general conclusions were drawn as to the nature of diapause, and the experiments were considered in the light of the various theories put forward to explain the phenomenon. In brief it was concluded that the underlying cause of diapause is the occurrence of a physiological disturbance at some stage in the life-history.

The eighth International Congress of Entomology will be held in Stockholm, Sweden, August 9-15, 1948. The fact that all steamship sailings are currently booked to capacity for months in advance makes it seem necessary for those expecting to attend the congress in 1948 to arrange for passage as early as possible. Steamship companies have not issued sailing lists for 1948, but expect to do so in the early fall. A number of lines have listed sailings for the present season, among them, the Cunard, French, Belgian, Swedish, Norwegian, Gdynia (Polish), Holland-American, etc., the first mentioned expecting soon to have two new steamers in service.

Importations into North America of shipments of broom corn (Sorghum vugare var. technicum) have always been a source of anxiety to plant quarantine officials. It is well known that the European corn borer, Pyrausta nubilalis Hbn., was almost certainly introduced onto this continent in this commodity (22), a surmise which receives perennial support from the continued finding of this species in consignments from various parts of Europe. Broom corn is usually imported in bales weighing from 100 to 250 pounds each, (Figures 1 and 2) which contain both the brush and anything up to 12 inches of stalk necessary for the proper binding of the broom. It is interesting to note that in the country of origin, after the broom corn is harvested, it is dried and curcd and is then usually subected to the fumes of burning sulphur overnight in a closed room in order to bring about, through bleaching, a uniform yellowish colour desired in the trade. None of these treatments have any appreciable effect on the populations of living borers found in the stalks. In addition to insect pests which feed in or on broom corn as a normal host, other species may use the borings of the normal pests as sites of hibernation or pupation. Under some conditions, no doubt, stalks may be left lying in the field for some time prior to harvesting, and thus constitute a refuge for many potential pests.

This paper presents descriptions of three new species of Ephemeroptera from Illinois, all belonging to the genus Ephemerella. These are forms segregated from material in the Illinois Natural History Survey collection; the types are deposited in that collection. Two of these species are closely related to the genotype, E. excrucians Walsh, and it was thought for some time that one or the other of them would prove to be that species. Study of the lectotype of excrucians showed, however, that both of these species are recognizably distinct from excrucians.

This list follows closely on the third of three previously published articles in the Canadian Entomologist. Mr. C. A. Frost of Framingham, Massachusetts, has checked and supplied me with identifications of all but two of the specimens. His generous interest in determining some of the beetles for which names have been difficult to obtain made this paper possible.