From conversations that the writer has had, it would appear that this thrips (identified by Mr. R. S. Bagnall as Heliothrips indicus, Bagn.) has been known on the Gezira cotton for about three years, and is popularly called “dry asal” in contradistinction to the work of the “asal fly” (Aphis sorghi, Theo.) The natives have been acquainted with this insect for some time. The reason suggested for the enormous damage done by itis that the cotton is too scattered, and it is stated that if cotton were cultivated in larger blocks, the thrips might be viewed with equanimity.

Twenty-four West Indian species of this genus were enumerated in Messrs. Leng and Mutchler’s list of 1914, in addition to which four species from Porto Rico have since been named by Mr. Eugene Smyth (Journ. Dept. Agric. Porto Rico, i, 1917). Two other species have been assigned to the genus Phytalus, which is distinguished from Lachnosterna solely by the claw-tooth making an acute instead of a wide angle with the tip. As H. W. Bates found in his attempt to distribute the Central American species, it is impossible to make this the basis of a natural division, especially as in certain species (as in L. dilemma here described) it is confined to the male.

In June 1918, I arranged to carry out a preliminary investigation of the habits and distribution of the tsetse-flies in the northern portion of the Mossurise district for a maximum period of three months on the understanding that the Mozambique Company would defray the general expenses of the expedition.

This subfamily comprises a large number of genera, which are, as a rule, easily distinguished by the presence or absence of secretionary matter in one form or another. All agree, however, in having the anal ring with a number of hairs and, further, in having the hind margin cleft. The anal ring is covered above by a pair of more or less triangular plates which are usually densely chitinised. The eighteen genera known to be represented in South Africa are tabulated.

A fortunate stay of a few days in July 1919 at Fort Johnston, Lake Nyasa, while waiting instructions, enabled the writer to proceed to the village of Mzeze near the Livingstonia Peninsula, where in 1914–15 some work was carried out on the various insects parasitic on the puparia of this fly.

These notes include observations made on the mosquito fauna of Palestine, for the period July 1919 to August 1920.

The material belonging to this family brought back by the expedition includes representatives of only four species, one of which, however, is apparently new. That three out of the four species obtained should belong to the Aegophagamyia-Bouvierella group is not surprising, in view of the predominance of this group in the Malagasy Subregion.

Most of the following observations were made in the vicinity of Obozerskaya, a small village on the Archangel-Vologda Railway, 474 versts from Vologda or roughly 80 miles due south of Archangel. I arrived at Obozerskaya and reported to the Headquarters of the Vologda Force on 14th June 1919, a few days after disembarking at Archangel.

The effective action of formaldehyde as a fly poison depends on the freedom of the exposed fluid from formic acid, and. to a less extent, from methylamine. That used for fly poisoning should therefore be colourless and free from a fishy odour, and a weak alkali, in slight excess, should be added in dilution to neutralise any acid present and that which will be formed during exposure.

Having received from the Imperial Bureau of Entomology more material of the family LONCHAEIDAE, I am in a position to give the following additional notes to my previous paper* on the Ethiopian species.

Both Culex decens and Culex invidiosus are widely distributed in British West Africa. In the Gold Coast both have been taken in all the three divisions into which the country is divided, namely, the Colony proper, Ashanti and the Northern Territories; the records at Accra showing the following distribution: —

The genus Dociostaurus, Fieb., which is synonymous with Stauronotus, Fisch., includes several species of locusts and grasshoppers injurious to agriculture in South-Eastern Europe, Central and Western Asia and North Africa, the well known Moroccan locust (Dociostaurus maroccanus, Thunb.) being one of the worst pests in Algeria, Tunisia, Asia Minor, the Caucasus and Turkestan. The systematics of the species of this genus are in a very unsatisfactory state, and this, together with the tendency of the species to individual variability, is the cause of many mistakes in their identification on the part of economic entomologists. The object of this paper is, therefore, to establish a more or less natural system of the species enabling everyone to identify them with certainty.

In the introduction to the first part of this paper* it was remarked that very little exact work had been published on the adult European SIMULIDAE. This is equally true of the larvae and pupae ; in fact no one has attempted to describe the early stages of more than two or three of the common species. Moreover, in spite of their great interest, and the ease with which they can be collected and reared, they have apparently been almost entirely ignored by collectors, so that whereas in publishing my previous work I was able to acknowledge valuable assistance from a number of fellow entomologists, the results given in the following pages are, unless otherwise stated, due to my own observations. I wish especially to thank Mr. M. E. Mosely for the early stages of S. subornatum, the last species to come under my notice in the pupal stage. While there are still many important gaps in our knowledge which remain to be filled, it has been thought worth while to state without further delay the results that have been obtained so far.

In the foregoing pages the following tentative views have been put forward in the hope that they may receive either confirmation or criticism from other investigators : (1). The latter part of the dry season is probably, in general, the most favourable portion of the year to the fly. (2). The later the onset of the rains the greater the capacity for increase. (3). Seasons of unusually heavy rainfall are inimical, at least in certain areas. (4).A series of years of lew rainfall is favourable. (5).Regions where the fly commonly attains the greatest concentration of numbers are the regions where it is most liable to be reduced or to die out,namely, parts of the infested areas where first-grade foci predominate. (6).In Southern Khodesia the passage of grass fires has, as a rule, no appreciable effect on the numbers of the fly. (7).Mopani belts are probably of considerable value to the fly in providing limited areas attractive to game in the wet season, where the grass remains short; they possibly also afford a convenient refuge from grass fires in the dry season. (8).The fly does not migrate under the stimulus of hunger or in company with game. (9).The fly as a whole does not follow game about infested areas. (10).The maximum distance at which a hungry fly readily detects its hosts is a short one, possibly less than 100 yards. (11).The maximum following distance of the females remains to be determined ; the writer is not yet convinced that the females seek animals and humanbeings only for the purpose of feeding, though this appears probable.

The following new species of Aphids have been sent from Africa; four are from a collection forwarded by Mr. Claude Fuller of the Department of Agriculture of the Union of South Africa (Macrosiphum cissi, Phorodon violae, Capitophorus chrysanthemi and Forda natalensis); one has been sent by Mr. C. C. Gowdey from the British East African Protectorate which has to be placed in a new genus (Cerciaphis).

The occurrence of mosquitos in crab-holes is tolerably well known both in West Africa and in other countries. It is doubtful, however, whether these sources receive sufficient practical attention, and one hears too often when their presence is demonstrated the opinion expressed that the insects only shelter there and are not likely to use them as breeding-places when so many others are available. One has even found medical officers whose unbelief had to be assailed by demonstration of the larvae and pupae. Others again, though aware of the fact, perhaps think the occurrence of too trifling importance to justify the necessary steps to eradicate them, even when near a dwelling.

With the filling up of Gatun and Mira Flores Lakes, water lettuce (Pistia stratiotes, Linné) and water hyacinth (Eichornia crassipes, Solms.) rapidly increased in numbers until large areas became completely covered by them. Masses of these plants would become detached and float about in these lakes. It was found necessary to destroy these “floating islands,” not because they were serious mosquito habitats, but because they interfered with navigation and the operation of the spillways. The water lettuce is the habitat of the very specialised larvae of Mansonia, of which titillans is the commonest member. Knab (1913) and Busck (comments appended to Mr. Knab' paper) refer to the changes in the mosquito fauna brought about by the rapid increase in Pistia. Both Mansonia titillans. Walker, and Aëdomyia squamipennis (Lynch-Arrib.) Theo., have been collected by me in very large numbers since 1912, and to-day Mansonia is the dominant species caught in the army barracks on the west side of the canal. Knab expressed the opinion that perhaps measures would have to be taken to destroy the Pistia habitats; now that we have found Anopheles larvae in them, this prophesy comes closer home.

Through the kindness of Mons. E. Séguy, of the Muséum d’Histoire Naturelle, Paris, I have recently been enabled to examine a considerable number of mosquitos from Madagascar and the neighbouring French islands, including the types or co-types of all the species described from Madagascar by Ventrillon. As the examination of this material has disclosedthe existence of several species hitherto unrecorded from these islands, aswell as some new synonymy, it has been thought desirable to record the results at once. In the following pages all the species of mosquitos hitherto known from this region are dealt with. The total number is only 28, as compared with about 180 in the African fauna, so that it is highly probable that further collecting would produce many others.