Pteronidea ribesii, Scop., the common gooseberry sawfly, is widely distributed in Middle and Northern Europe and in North America, and appears to be confined to food-plants of the genus Ribes, particularly R. grossularia and R. rubrum. It has an extensive literature, one of the best and most recent accounts being that of Kemner (1924). In the present account, therefore, only a summary of the author's investigations are given, with emphasis on points of special interest or significance in relation to the present series of studies.

Through the kindness of Prof. Mazza, Buenos Aires, Dr. P. A. Buxton, of the London School of Tropical Medicine, and Prof. Brumpt, Paris, I have had the opportunity of examining a collection of sandflies from South America. It appears that, as in the sandflies of the Old World, the structure of the buccal cavity and spermatheca, and to a smaller degree that of the pharynx, affords an easy mean of distinguishing the five species at my disposal.

The association between insects and virus diseases of plants and the suspicion which at present rests on Jassidae, amongst others, may result in members of this family becoming of increased importance as potential vectors of virus diseases of crop plants. In America leaf-hoppers are already serious pests of cereals and of grape-vines, and in the cotton-growing area of Central and South Africa a Jassid forms one of the most important obstacles to the successful cultivation of this crop, so that in these countries a considerable amount of attention has been demanded by this group of insects. In this country, however, the leaf-hoppers have only been regarded as of minor importance, though in recent years increasing interest has been taken in certain species infesting potatoes and glasshouse crops. It was suggested to the writer that further knowledge of the biology of these insects was desirable, especially in view of the extreme importance of a nearly related species in many of the African cotton-growing areas, and it was accordingly decided to use the common species infesting glass-houses as a type for investigation with cotton as the food-plant.

Illingworth (1926) published his experiences with Sarcophaga fuscicauda, a fly regarded by him as being of medical importance, and he also suggested it was being transported over the Orient by shipping. There can be little doubt concerning the identity of the fly, this being identical with that published under the same name by Senior-White (1924); both authors included Queensland in its distribution.

The so-called short-horned locusts are frequently, for convenience sake, regarded as comprising two classes: the true locusts (Arabic: Girad) and the short-horned grasshoppers (Arabic : Gabura). It is difficult, however, to find definitions of these classes by means of which every species may be correctly assigned to its true place. The swarming habits of the true locust are often cited as connoting this class only, involving, as these habits do, the periodical appearance of excessive numbers of both hoppers and adults. Moreover the true locust is gregarious, in that the hoppers move in bands from one place to another, and the adults fly in vast swarms often over long distances. The fact that the grasshoppers are solitary in habit and manifest mutual independence of action is often taken as their chief distinguishing character. There is no doubt that these features do partly separate these two classes of insects from each other, but there are certain species which appear to occupy a position intermediate between the two. One normally solitary may, in certain circumstances, multiply rapidly and give rise to hoppers, which in certain respects act like those true locusts. Moreover the winged adults may undertake short massed flights resembling the migrations of swarms. On the other hand the fact, now fully established, that most true gregarious locusts have their solitary forms, which never associate, places even them in this respect with the grasshoppers.

The Anglo-Egyptian Sudan has, so far as may be ascertained, always been liable to plagues of the migratory locust, Schistocerca gregaria, Forsk., generally referred to as the desert locust. In the summer of 1930 in addition to this species swarms of another migratory locust, Locusta migratorioides, Rch. & Frm., locally known as the hairy-chested locust, appeared. In most districts natives stated that they had never before seen this second species, but elderly inhabitants of Darfur and northern Kordofan recognised it as having occurred some forty-two years previously for two successive seasons; the first year in large numbers, the second in but small numbers. It was hoped that history would repeat itself and that the hairy-chested locust would be relatively scarce in its second year, but unfortunately this hope has not been realised; L. migratorioides was a more serious plague in 1931 than in the preceding year.

Mosquito larvae and pupae which get their oxygen from aquatic plants have been seldom met with so far; all belong to the genus Taeniorhynchus. Examining Pistia for the latter I found a few times a larva attached to the roots of the plants by means of its modified air-tube. The adults which were bred from these larvae proved to be Ficalbia (Mimomyia) hybrida, Leicester*. The adult has been known for some time, but the larva is new.

In the collections received during recent years by the Geneeskundig Laboratorium in Batavia there were some specimens that seemed to represent new species. Moreover by rearing isolated larvae the hitherto undescribed larval and pupal stages of some species have been studied. In this paper are also included figures of the hypopygia of some species, already described, but not yet figured by other authors.

1. A serious form of coffee flower abortion that occurred in Kenya Colony in 1930 is described.

2. A Capsid, Lygus simonyi, Reut., is shown by experiments to be capable of causing this abortion.

3. It is shown that by feeding on the stamens at an early stage in the bud's development, the bug causes their early blackening and abortion, resulting in the complete failure of the flower.

4. Some notes on the life-history, habits, and natural enemies are included.

5. It is shown that owing to abnormal flowering conditions in 1930 the bug was enabled to do very serious damage.

6. Some other abnormal conditions of the buds, not considered to be caused by the bug are described.

7. A number of control measures that proved unsatisfactory are shortly described.

8. A detailed description is given of the application of a spray prepared by extracting the insecticidal properties of pyrethrum with paraffin. This spray is inexpensive, easy to apply quickly, and seems likely to prove efficacious on a large scale.

9. It is suggested that such sprays may have a considerably wider application.

My acknowledgements are due to the Senior Entomologist, Mr. T. J. Anderson, for kindly reading the manuscript; also to a large number of coffee-planters, in particular to Mr. P. J. Coldham, on whose estate much of the above work was done, and to whose interest and help, particularly with regard to cultural questions, I owe much.

The agricultural importance of the Collembola has in the past usually been regarded with some scepticism by economic entomologists. Recently, however, the activities of certain species, particularly those belonging to the genera Bourletiella and Smynthurus, have resulted in an increasing amount of publicity for this order of primitive insects. The subject of the present investigation is Smynthurus viridis, Linn., which, from its jumping habits and the depredations it causes to lucerne (alfalfa), has come to be known commonly as the “Lucerne Flea,” although the damage it causes to clovers is equally serious.