In view of the fact that many blood-sucking Diptera are carriers of pathogenic micro-organisms of animals and human beings, the study of the structure of their mouth-parts has attracted the attention not only of zoologists but of medical men as well.

The present paper deals with a small collection of Tachinidae received from Mr. H. Hargreaves from Uganda, together with other material of the various species forwarded by the Imperial Bureau of Entomology. The types of the new species, unless otherwise stated, will be deposited in the British Museum of Natural History.

The following article includes the results of observations on the number and species of mosquitos breeding in two tree-holes during a period of more than ten months.

The khapra beetle, Trogoderma granarium, Everts 1898, has been referred to in recent years as Trogoderma khapra, Arrow, and Attagenus undulatus, Mot. Investigations on the pest have been carried out by Barnes & Grove (1) in India, and by Dendy & Elkington (2), Mason (3), Parker & Long (4), and Morison (5) in England.

Blosyrus aequalis, Har. 1879.

This species, originally described from Angola, has recently been bred from larvae found in tubers of sweet potatoes at Haut-Lepori, Belgian Congo, by Lieut. J. Ghesquière.

The variation of A. mauritianus was discussed long ago by Alcock (Jl. Lond. Sch. Trop. Med., i, pp. 89–93, 1912), who concluded that the differences observed were due to mere individual variation. In my key to African Anopheles (Bull. Ent. Res., iii, p. 250, 1912) I suggested that an East and a West African form might be distinguished by the amount of white on the hind tibia and first tarsal segment. Careful study of more extensive material has shown that this generalisation cannot be maintained, but that there are four varieties of the species which can be rather easily distinguished, and fortunately the published names can be applied to them. Diagnoses of these varieties have been given by Miss A. M. Evans in her recently published guide to the African Anophelines (Memoir No. 3, New Series, Liverpool Sch. Trop. Med., Oct. 1927), but the definitions are somewhat expanded in the notes below, and a further account of the distribution is given. The variations are certainly of more than individual significance, because they show a distinct tendency to localisation, and bred series from one place do not exhibit much variation. On the other hand, I do not consider that there is more than one species, because no differences are apparent in the male hypopygium; I have mounted specimens of each of the four varieties and find them all to agree rather closely with Christophers' description and figure. In one point, however, Christophers' account seems to be at fault: the mesosome has always two or three pairs of distinct leaflets, the longest of which are nearly one-third as long as the tube.

It is highly regrettable that in the past whenever Cecidomyid or midge larvae have been found in ears of wheat the presumption has been that the species concerned was the wheat midge, and it was therefore recorded as Contarinia tritici (Kirby).

The Mediterranean fruit-fly (Ceratitis capitata, Wied.) first reached Bermuda about 1865, and since that time has been a pest of the first importance on all kinds of thin-skinned fruits. Peaches, which formerly grew in great abundance in the island, were rendered unproductive, and loquats, sapodillas, Surinam cherries, peppers, and to a lesser extent citrus, papaws, sugar-apples and guavas, were severely infested.

The inclusion of species of the order Collembola among the list of injurious insects has, from time to time, given rise to considerable scepticism among those concerned with economic entomology. It is, therefore, thought desirable to place on record controlled experiments which leave no doubt as to the depredations of one species, Sminthurus viridis, Lubb., of this primitive group of insects. Further, our knowledge of the bionomics of Collembola is so scanty that data obtained with reference to the life-history and habits of this particular species may be of interest.

The black currant gall-Mite, Eriophyes ribis (Westw.) Nal., may reasonably be described as being one of the most important amongst the numerous pests that infest soft fruits in this country.

The small and obscure leafhoppers of the subfamily Typhlocybinae are assuming increasing economic importance, firstly by direct damage to the plants on which they live, and secondly as carriers of “ virus ” diseases.

Various species of Curculionidae are injurious to orchards in Ukraine, but Sciaphobus squalidus, Gyll. (fig. 1) is considered by fruit-growers to be the most harmful, as it attacks the buds of all fruit trees. Mr. Znamenskii was the first to make an adequate study of the life-history of this insect. The following notes give an account of my own observations and deal principally with methods of control.

(1) There are two forms of D. superstitiosus, F., in Nigeria, which are designated banded and spotted forms in the present paper. The banded form appears on cotton earlier in the season than the spotted, and it remains on the crop longer. Migration to cotton is gradual in the case of the banded form, while a sudden influx of migrants of the spotted form commences in October. Many spotted adults migrate to Bombax and Sterculia between January and March, whereas the banded form remains on the cotton until it is uprooted at the end of March. The spotted form is far more numerous than the banded on maize and guinea corn.

(2) There is considerable variation in the colouration of adults of the spotted form; at Ibadan about 99 per cent. of the migrants to cotton are yellow or orange in colour, while the adults of the filial generations produced on cotton are almost always red in colour (a few individuals are deep orange-red). These colour variations are thought to be of seasonal origin.

(3) D. superstitiosus is the most prevalent species on cotton at Ibadan, Ilorin, Oyo, Zaria and Kano; melanoderes is of equal or greater importance in the forest zone at Ilugun and occasionally is numerous at Ibadan; fasciatus is of importance in savannah country at Oyo; haemorrhoidalis is rare on cotton. No evidence has been obtained that any one of these species is a varietal form of another species. Both forms of superstitiosus are widely distributed in Nigeria.

(4) Migration to cotton is induced by the flowering of that crop. The maximum weekly migration has occurred between the weeks ending 15th October and 7th November in five localities in the last three years; viz., at the time of, or soon after, the maximum flowering of the cotton crop. There are indications that there is a tendency for stainers to migrate in a southerly direction, probably as a result of the desiccating harmattan wind from the Sahara.

(5) The principal alternative food-plants of stainers in the Ibadan district are: Bombax sp., Sterculia sp., Hibiscus esculentus, H. sabdariffa, Urena lobata, and Abutilon zanzibaricum. At Ilorin, silk-cotton trees (Bombax), H. esculentus, H. lunariifolius and U. lobata are the most important alternative food-plants.

(6) A rhythm exists in the weekly proportions of the sexes during the cotton season; males predominate among the early migrants to cotton and among the first individuals to mature of each generation. This rhythm appears to be the result of shorter period of post-embryonic development in the case of males than in that of females derived from the same batch of ova.