Anagyrus beneficians, Compere, obtained in small numbers from shipments of other parasites from Uganda, proved to breed readily in the laboratory.

Numbers were reared, liberated and established on mealybug in coffee districts and native reserves in Kenya.

It is one of several parasites responsible for a marked reduction in the severity of the mealybug.

The genus Schistocerca is one of very great economic importance, since it includes the Desert locust of the Old World, Schistocerca gregaria (Forsk.) and the South American locust, S. paranensis (Burm.). It was therefore considered of value to study the life history of one of the solitary species living in Trinidad, and the present investigations were made during 1942 at the Imperial College of Tropical Agriculture at St. Augustine.

The climate of Trinidad is humid tropical. The annual rainfall over nineteen years at St. Augustine averaged 68·4 inches, but in the north-east of the Island the rainfall is over 100 inches per annum, falling to below 60 inches on the West coast. The rainy season usually begins about June, with a break in August or September, and lasts till the end of the year or the early part of January. November may be taken as one of the wettest months with a rainfall of about 11·5 inches (at St. Augustine), while more than half an inch is not usual for April. The humidity in November averages about 85 per cent. in the morning and 77 per cent. in the afternoon, but it is still high in April, being 75 per cent. and 64 per cent. for morning and afternoon respectively. The night humidities are even higher. The temperature remains practically constant throughout the year, averaging about 84°F. (29°C.) during the day, and 74°F. (23·3°C.) at night. The temperature may reach 95°F. (35°C.) during the day in the dry season, but it seldom falls as low as 65°F. (18·3°C.) at night.

This paper brings together all the species of Microphanurus from the Ethiopian and Indo-Malayan regions that I have written about during the last eight years. I have found that the fauna of neither region could be studied in isolation if a proper understanding of the taxonomic relationships and host-preferences of the genus were aimed at.

The key contains all the species from the regions concerned of which the types or at least authentically named specimens are in the British Museum. Two new African species are described.

For the identification of the Hemipteron, Atelocera stictica, Westwood, and for other information I am much indebted to Mr. W. E. China.

Aëdes (Finlaya) alektorovi, sp. n.

A dark species of medium size ; praescutum with a large quadratic spot covered with golden-yellow scales. Abdominal segments with small white-scaled lateral spots. Hind tarsi with apical and basal bands on joints 1–3.

♂. Head. dark, covered with pale yellowish erect scales ; eye-margins with many long black bristly hairs (ocular chaete). Proboscis black and black-scaled. Palpi a little shorter than proboscis, black, covered with black scales, in apical part a little clubbed ; apical and preapical joint of palpi with some long dark hairs. Antennae dark brown, with paje bands and a tuft of long blackish hairs. Mesonotum black, covered with numerous golden-yellow scales ; lateral area of praescutum with a small spot of blackish-brown scales; lateral area of scutum with a similar spot. Scutum between the dorsocentral bristles covered with blackish-brown scales. Mesonotal bristles golden-yellow. Scutellum covered with pale yellow scales, with three groups golden-yellow bristles. Pleurae brown. Dorsal margin of proepimera covered with yellowish sickle-shaped scales ; caudal margin of proepimera with a small spot of broad silvery-white scales. Dorsal part of sternopleura with a large spot of broad silvery-white scales, in the middle of caudal margin a similar but much smaller spot. Dorsal part of mesepisterna with a distinct spot of broad silvery-white scales. Abdomen black, with dorsum of all segments densely covered with black scales with steel-blue reflexions ; bases of tergites with triangular lateral spots of broad silvery-white scales. Hypopygium : coxite cylindrical, four times as long as broad at base ; basal part of coxite with a small lobe-like prominence, armed with seven long and stout bristles.

One and a half tons of Plate wheat, of water content 12·9 per cent., infested by insects, especially the small form of C. oryzae, Rhizopertha, and Laemophloeus, were placed in an iron bin in May 1941. By the following November the wheat was heating near the surface and was extremely heavily infested in the 25 cm. surface layer. The carbon dioxide concentration beneath this layer exceeded 10 per cent.

During December the hottest depth in the grain was nearer to the surface. The temperature reached 37°C, 27°C. above air temperature. Many weevils came to the surface in early December and walked off the grain. Then in mid December the grain temperature fell rapidly and reached air temperature by the end of the month. A week later many insects were still alive, but by March 1942 very few living insects were found. The carbon dioxide concentration fell rapidly but rose again in March, presumably due to the increased grain water content and the respiration of micro-organisms.

In 1942, conditions became suitable for insect activities in April, and by May an infestation had started, this time predominantly C. granaria. Laemophloeus was also present, having apparently survived the winter in the bin, but neither C. oryzae nor Rhizopertha had survived. Insects were confined to the surface layers by the carbon dioxide present deeper in the bin. Consequently heating did not occur in 1942, and when the grain was moved in October 1942, its temperature was falling after reaching a maximum of 27°C. in August.

The effect of the presence of insects upon grain is discussed. It is shown that the conditions arising in the bin resemble those in general storage, except that the use of an open topped bin with airtight sides and bottom caused a much greater accumulation of carbon dioxide than is usual.

It is suggested that if the grains infested by weevils are buried in the bulk, heating is likely to occur, whilst if the infestation is superficial the grain may not heat. The part played by weevil larvae in the heating of grain is stressed.

It is suggested that regular examination of samples of grain from deep in a bulk should be made for insects and that all bulks should be examined soon after being placed in position. Routine temperature and water content readings should be made at points deep in the grain and about 10–20 cm. below the surface.

The damage done to cacao (Theobroma) in West Africa by certain species of Capsidae has been described by Dudgeon (1910), Cotterell (1926) and Voelcker and West (1940). At the start of a selection programme aimed at developing strains of cacao resistant or tolerant to such damage, it was considered necessary to develop a laboratory technique for testing the palatability of selections. It is noticeable in the field that certain trees appear consistently to escape attack ; this might be due to some form of unattractiveness to the Capsids. One of the most obvious forms of preference which seems to be shown by these bugs is that of Sahlbergella theobroma for seedlings and young trees up to about six years old and that of S. singularis for mature trees. Indeed until very recently there was no field record of S. singularis attacking seedlings in the Gold Coast. Conversely, attacks by S. theobroma on mature trees are confined almost entirely to pods, while the other species causes severe damage to shoots. Dudgeon (loc. cit.) reports old trees “ exhibiting damaged bark and dead branches ” in the presence of S. theobroma, but these may have been feeding on pods.

(1) Previous records of natural enemies of the cacao thrips, Selenothrips rubrocinctus, Giard, are reviewed.

(2) An account is given of the following natural enemies in Trinidad, B.W.I. :—Dasyscapus parvipennis, Franklinothrips tenuicornis, F. vespiformis, Chrysopids, Ninyas torvus, Termatophylidea maculata and Wasmannia auropunctata.

(3) The Eulophid parasite, Dasyscapus parvipennis, was introduced into the West Indies from the Gold Coast in 1935. It is now successfully established in Trinidad, Puerto Rico and Jamaica, but has so far given no indication of economic control of the cacao thrips.

(4) The importance of natural enemies is discussed. Observations are made on the feeding propensities of some of the predators in the laboratory. Chrysopids are regarded as the most important predators and probably exercise some measure of control.

(5) Population counts of the cacao thrips and Chrysopid and Franklinothrips larvae are given.

In 1941 Edwards listed nine species from British Somaliland, comprising one Anopheline and eight Culicines. These were the specimens collected by R. E. Drake-Brockman in 1913 and by T.H. Twigg in 1930, but there appears to have been no datailed mosquito survey of the terrtory.

The present notes are based on a small collection made by the writer in January 1942, as a result of a brief survey in a limited area of the Protectorate, augmented by notes and material, mostly larvae, made by Dr. D. G. MacInnes from March to June 1942. Although only a few places were visited, the survey has added a further thirteen species to the list for the territory. Owing to circumstances, the restricted area investigated was confined to the region along the roads Boramo-Hargeisa to Berbera and Berbera to Burao, the altitude range being from sea-level to 5,000 feet.