During July and part of August 1929 an experiment was carried out at Sambala (Western Kondoa), Tanganyika Territory, designed to show that : (i) Hungrier flies marked in Berlinia- Brachystegia woodland left that type for the supposed feeding-grounds (“ female centres ”) earlier than repleter flies ; (ii) conversely, repleter flies remained within the woodland longer than hungrier flies ; (iii) hungrier flies in the supposed feeding-grounds remained in them for the first few days ; and lastly (iv) repleter flies in these situations returned to the Berlinia-Brachystegia woodland to remain there until later.

During the course of certain investigations, the writer had occasion to collect a considerable number of mosquitoes in Nigeria, particularly in the vicinity of Lagos. Several species of Uranotaenia were represented in many of the collections. In view of the difficulties experienced in identifying certain specimens, opportunity was taken during a recent visit to the British Museum (Natural History) to study the African Uranotaenia in the collections there. Subsequent to the publication by Edwards in 1912 of the last generic treatment and key for the separation of the species, several additional species have been added to the list from the Ethiopian region, and more materials have accumulated, thus facilitating further study and permitting a reconsideration of certain specific assignments.

Specimens of the two Coreid bugs described below were submitted by the Entomological Division of this Department to the Imperial Institute of Entomology for determination and were returned shortly afterwards with the intimation that both were new to science.

Among the insects which do serious damage to grasses grown for seed, the larvae of gall midges (Cecidomyidae) are of great importance. Very little is known about their bionomics, except in the case of the Sorghum midge (Contarinia sorghicola), and the Meadow Foxtail midges (Dasyneura alopecuri, Contarinia merceri, and Stenodiplosis geniculati). In view of this and the fact that several grasses are grown for seed with advantage in Great Britain, it has been thought advisable to collect together all the available information.

Through the courtesy of the Imperial Institute of Entomology, I have been able to examine specimens of a remarkable gall midge reared by Mr. E. Hargreaves, in Sierra Leone, from larvae predacious on a species of mealy-bug.

The following notes are the result of investigations carried out at Barberton, in the Eastern Transvaal.

The present paper deals with a further nine species of Diaspinae which are new to science. I desire to express here my sincere thanks to Mr. E. E. Green for his invaluable assistance in working out my material.

In 1927 the writer published a paper entitled “ Notes on the food-plants and habits of some Southern Nigerian Insects,” compiled from observations made between 1922 and 1925 ; the present paper contains additional data obtained since 1925.

In order to investigate the possible means of controlling introduced plant pests, the course that has been considered advisable to follow has been that of a general biological survey of the particular species under its native conditions and, so far as is possible, a comparison between this and a similar survey in the country to which it has become introduced. Such a survey should include the following aspects :—

Germination of seed : Normal percentage germination, germination of fresh and old seed, dormancy, “ hard ” seed, effect of varying external conditions or previous treatment upon germination of hard seed (if present). Seed reserves in soil ; continuous or discontinuous germination.

Establishment of seedlings : Effect of grass, leaf debris, bare soil, etc. ; root development ; causes of mortality.

Flowering : Periods of flowering, number of flowers ; mode of pollination.

Seeds and dispersal : Number of seeds, manner of dispersal, mortality before germination.

Relation to plant communities.

Relation to climate and soil types.

Geographical distribution.

Relation to insects : Insects found on the plant at different seasons ; nature and extent of damage to vegetative parts, flowers and fruits.

Puri has divided the Indian Anopheline larvae into two divisions and four groups according to the character of the pleural hairs. The following is a study of the larvae of some South African Anophelines on the same lines.

I am indebted to the Imperial Institute of Entomology and to Mr. F. Laing, of the British Museum, for submitting to me for classification a small collection of Thysanoptera from the Waite Agricultural Research Institute, Glen Osmond, South Australia. All measurements in this paper are in μ.

The law of population, as finally expounded by Malthus, conceives that increase depends upon the availability of food or upon the ease, difficulty, or ability of procuring it. The consideration of the action of parasites from this point of view, I believe, is of interest and importance, both from the economic and biological standpoints.

Rhembastus pomorum, sp. n. (fig. l).

Oblong-ovate, metallic dark blue ; clypeus, antennae and legs fulvous ; prothorax finely and remotely punctured ; elytra finely punctate-striate, with the interstices glabrous. Length, 4 mm.

Since a fairly extensive collection of the Braconid genus Spathius, largely comprised of bred series of new species, had lately been received for identification by the Imperial Institute of Entomology, and since there were various species in the British Museum awaiting description, it was considered opportune that I should attempt some sort of revision of this comparatively little worked but nevertheless quite interesting group : it is hoped to publish my results shortly. In the meanwhile, however, the following descriptions are presented since most of these names are required at an early date for inclusion in a paper on the biology of these parasites.

The following notes are based almost entirely upon actual rearing records, the hosts in most cases being insects of economic importance. The greatest attention has been paid to parasites of the small moth-borers of sugar-cane (Diatraea spp.). The systematic work has been done entirely at the British Museum and would have been impossible without the facilities in literature and collections there, and the great help of Mr. D. S. Wilkinson and Dr. C. Ferrière, of the Imperial Institute of Entomology. Types of new species are in the British Museum.

Acroclisoides indicus, sp. n. (fig. l).

♂. Head and thorax dark metallic green ; abdomen with bluish reflections ; the short petiole black, the 2nd segment brown or more or less yellow. Antennae brown, scape and pedicel yellow. Mandibles yellowish with dark teeth. Tegulae and legs yellow, only the anterior and posterior coxae (except tip of posterior) green.

In order to follow the changes appertaining to the post-embryonic development of the larva of the Indian lac-insect of the genus Laccifer a knowledge of its external

and internal anatomy was a desideratum. A study of its external and internal anatomy was, therefore, undertaken in order to obtain a knowledge of its organography, and the following account is based on the results of such a study.

When teaching Entomology under University conditions, it is difficult to avoid giving students the impression that the principal, and perhaps the only, function of an entomologist is the examination of insect-corpses in great detail. Some years ago, when appointed lecturer on Entomology at the University of Sydney, I was faced with the problem of how to deal with this difficulty. Eventually I came to the conclusion that the only satisfactory solution of the problem was to obtain photographs of living insects with which to illustrate lectures, for it is almost impossible to arrange for students actually to handle more than a very small number of living insects. As the number of suitable photographs which have been published is small and quite inadequate for lecturing purposes, I found it necessary to take the photographs myself.