Hibernation is still one of the obscure phenomena in the bionomics of Anopheles, for the nature of hibernation itself, as well as the associative changes of fat deposition and retarded ovarian development, have not as yet been made clear. Despite the extensive investigations on the subject, the factors responsible for hibernation remain unknown.

As a basis for further work on the biology of termites, the need for which is now being generally recognized in view of the importance of this group of insects as pests in all tropical countries, the present list of the termites of Tanganyika Territory has been prepared. It incorporates the results so far obtained from the examination of a collection made by the writer during the past three years in a number of widely separated localities in Tanganyika, with the records given by Sjöstedt (1926). Previous records have been mainly from the Kilimanjaro-Usambara area in the extreme north-east of the Territory.

1. There are four species of Otiorrhynchus which commonly, in both the larval and the adult stage, cause damage to strawberry plants.

2. The morphology of the first larval instar of these species is discussed from the point of view of their determination.

3. It is shown that although the larvae in this stage are superficially very similar, there are considerable differences in the chaetotaxy of the head and also in the form of the labrum and the setae situated upon it.

4. Similarly there are variations in the position and size of the setae on the dorsum of both the thorax and abdomen.

5. A table is drawn up summarising all these characters in each of the four species.

6. A brief description of the present knowledge of the biology of these species is also given. It appears that although all of them are usually parthenogenetic, it is at present uncertain whether they can ever reproduce sexually, since the presence of males has as yet not been recorded.

7. These species usually have only one generation in the year, ovipositing in mid-summer and over-wintering as well developed larvae. In the case of O. sulcatus and O. ovatus, however, adults may emerge late in the summer and, having hibernated as adults, lay eggs in the early spring following.

♀ ♂. Black; head (including palpi), all legs (including the coxae, but excluding the feet which are strongly darkened), tegulae, and certain portions of the basal joint of the scape, pale red testaceous; the lateral membranous portions of the 1st and 2nd tergites, and the basal ventrites, very pale red testaceous; the plate of the 1st tergite only weakly coloured, and of the 2nd not much more strongly so, both probably more rightly describable as pale red testaceous also; 3rd tergite (except laterally and right across apex) also weakly coloured; the flagellum, and certain portions of the scape, brown; wing-veins and stigma brown, and the setae of the wings coloured; apical third of stigma commonly appearing to be to some extent hyaline.

Berlese's fluid has been known to entomologists for many years as a medium for making microscope mounts of small Arthropods; it has not been widely used, for which its unreliable keeping quality is perhaps partly responsible. It was developed by the late Professor A. Berlese, chiefly as a mountant for mites; apparently he did not publish the formula.

1. Methods of controlling ants invading houses are discussed.

2. Various methods have been tried, particularly against Monomorium pharaonis. The more general methods in use such as syrup baiting and the use of various insecticidal powders and sprays show at best a palliative effect and do not exterminate the pest. Destruction of the nest is effective where it can be carried out.

3. The use of a thallium sulphate-syrup as a poison bait devised by Popenoe has been tried with success against M. pharaonis and A. (Donisthorpea) niger. This inexpensive method is likely to prove useful in places where it is not practicable to find and destroy the nest, which invariably involves considerable structural alterations.

(1) A technique was devised for determining quantitatively the “ spontaneous ” locomotor activity of hoppers of Locusta migratoria migratorioides in terms of the distance travelled in half an hour in a special activity cage in which temperature, light intensity and humidity could be accurately controlled and all stimulation avoided.

(2) All the material used was derived from the same stock, and was kept under very constant and accurately known conditions from the time of hatching.

(3) The activity as measured in this way showed extremely great variation, as would be expected from our knowledge of the periodic character of “ spontaneous ” activity in many animals.

(4) Distribution curves were plotted showing the frequency with which various levels of activity were reached, and these curves were used as a basis for comparing the amount of activity shown under different conditions. In all these curves the mode was at the origin; by far the greater portion of the activity was of a very low order, though high activity occurred occasionally. The hoppers showed about 70 per cent, of their activity in the lowest activity group (0–5 cm./min.). The percentage fell very rapidly to the next group (14 per cent.), and then gradually to the 30–35 cm./min. group (0·6 per cent.), beyond which the records did not go.

(5) Hoppers kept throughout development in a very dry atmosphere showed a lower activity than hoppers kept in a very moist atmosphere.

(6) Differences in the relative humidity of the atmosphere in the activity cage had very little effect on activity. The figures obtained suggested, but did not prove, the following:—

(a) First and second instar hoppers were more active in a wet than in a dry atmosphere.

(b) Hoppers of instars 3–5 showed the greater activity in the humidity which represented a change from that at which they had been kept during development: those reared dry showed greater activity in a moist atmosphere: those reared wet in a dry atmosphere.

(7) The figures suggested that males were more active than females.

(8) Broadly speaking, all the various instars travelled the same distance in the same time. A consideration of the facts relating to size in the various instars led to the conclusion that the younger instars must have a higher rate of automatic nervous discharge than the older instars.

(9) Jumps were hardly ever encountered at a light intensity of 3–4 ft.-cands., though quite a number were obtained at about 20 ft.-cands. These jumps were “ spontaneous.”

(10) The underlying causes of activity are discussed. It is concluded that external stimulation was by far the most potent factor in influencing the amount of activity exhibited, and that it was the crucial factor in the production of the gregarious phase, but that

(11) Previous environmental conditions, especially previous conditions of stimulation, modified both spontaneous and reflex activity by influencing the nervous excitability of the insect; and

(12) Certain “ determining ” stimuli in the present environment affected the form, intensity and threshold of reflex, and, to a lesser extent, of spontaneous activity.

The intimate association between a blood meal and ovulation in all female mosquitos, with the exception of a few (de Buck, Roubaud) has been clearly recognised; but the peculiar manner in which the presence of blood in the stomach can influence the formation of eggs is not understood. Two explanations may be suggested: it may either act as a physico-chemical stimulus to the ovarian follicles, or certain constituents in the blood may furnish some nutrient material for the development of the eggs.

The presence of Glossina pallidipes in the great tsetse belts of Central Tanganyika has long been recognised, but owing to its relative scarcity in comparison with G. morsitans and G. swynnertoni it has not merited hitherto the attention and study which has been devoted to these latter species.

In the course of investigations on sawflies of economic importance, Emphytus cinctus, L., and Blennocampa waldheimi, Gimm., have been found causing injury to Rosaceae.

The coffee leaf-miners of the genus Leucoptera, Hübner, are serious pests of coffee wherever it is cultivated and they have often caused great anxiety to planters in many parts of the world. Leucoptera coffeella, Guér., is known from the West Indies, Central and South America, Central Africa, Madagascar, Réunion and Ceylon. Another species, L. daricella, Meyr., seems to be responsible for still more damage in Africa.