Contarinia coffeae sp.n. is described from specimens reared from Coffea arabica in Uganda, and brief notes are given on symptoms, biology, crop loss and distribution. The larvae develop inside young coffee berries. Blister-like external swellings appear on infested berries and they later rot. The pest is known only from arabica coffee in parts of Western Uganda but may be spreading and could appear in other East and Central African countries.

There are in the Sudan three species of migratory locusts : Anacridium moestum melanorhodon, Walk., or the tree locust, Locusta migratoria, L., and Schistocerca gregaria, Forsk., sometimes termed the desert locust. Of these the last-named is the plague locust of the country—the other two species being relatively unimportant—and is the species referred to as the “ locust ” throughout this paper.

From 1899 till 1917 swarms of locusts occurred annually, but then followed a period of ten years during which the Sudan suffered no damage from this pest. In 1927 and again in the succeeding year the locust reappeared as a plague, and there is little doubt but that it is to be expected year by year over an extended period and until the cycle either naturally terminates or is artificially brought to an end. The swarms of fliers appear from May onwards and oviposit in July and August when and where in the arid regions sufficient rain has fallen, the resulting generation of adults emigrating in October. A certain amount of breeding takes place during the winter on the Red Sea littoral, where winter rains occur, but this district is relatively small and easily dealt with ; the main problem is how to prevent breeding during the summer rainy season throughout the vast areas of the central and northern Sudan.

Light-trap catches of Dysdercus bimaculatus Stål and weekly phenological records of its host-plants over a period of three years on Barro Colorado Island, Panama, are discussed in relation to a year-long study of population growth at selected plants. Population build-up of D. bimaculatus occurred on a sequence of seed crops from wild host-plants in the dry season. Each year, the largest number of bugs caught in the light-trap occurred after a drop in vapour pressure deficit marked the end of the dry season. Thus, the population appears ‘poised’ to attack cotton crops maturing in the late wet season. A stepwise linear regression indicated that each year, the variance in size of Pseudobombax septinatum crops (maturing at the end of the dry season) explained the largest proportion of variance in the light-trap capture of D. bimaculatus. However, estimates from the field study indicated that Ceiba pentandra crops were more important than P. septinatum in building up numbers of adult cotton stainers. The discrepancy between the field study and the longterm phonological monitoring survey would be resolved if D. bimaculatus adults experience a dispersal flight at the end of the dry season. This flight would enable the insect to locate better-quality seed crops in drier habitats that mature in the late wet season, such as Sterculia apetala or cotton. Light-trap captures at the end of the dry season in areas such as Barro Colorado Island where Ceiba and Pseudobombax occur, could be an index to the intensity of attack on cotton crops in nearby drier areas.

The new species, described below, have been received from Mr. R. Dupont, Superintendent of Botanic Stations in the Seychelles.

Aspidiotus (Chrysomphalus) ansei, sp. nov. (fig. 1).

Female puparium irregularly circular or broadly ovate ; flattish or moderately convex. Very pale brownish ochreous, semitransparent ; pellicles darker, central. Diameter averaging 1·45 mm.

Male puparium smaller and more distinctly ovate ; pellicle nearer one extremity. Length 1 mm.

Adult female broadly rounded in front, narrowed and bluntly pointed behind. Margins of abdominal segments moderately produced. Pygidium (fig. 1) with six well developed prominent rounded lobes, the median pair indented on each side, the two lateral lobes more conspicuously indented on the outer side. Squames. long and deeply fimbriate : two in each of the median and first lateral spaces, three in the second lateral space, and three beyond the outer lateral lobe, followed immediately by a stout marginal prominence, beyond which the margin is slightly cristate for a short distance. Spines few, small and inconspicuous. Paraphyses, four on each side, elongate, conspicuous. Anal orifice near the extremity. Circumgenital glands in four groups: upper laterals with 3 to 4 pores, lower laterals with 2 to 3. Oval dorsal pores in two series on each side. Numerous long slender ducts communicating with the dorsal and marginal pores. Length, 1 mm.

In practice it is seldom found that any one of the numerous grades of oil prepared from crude petroleum is a satisfactory mosquito larvicide. The final product is almost invariably blended from several constituents. Each of the constituents may confer beneficial properties on the larvicide directly, or it may serve to correct undesirable features possessed by the other ingredients.

Even under world conditions which might be regarded as normal compared with those prevailing to-day, difficulties have confronted those who wished to select or blend a larvicide. There was firstly, in the remoter parts of the world, a lack of any specialised chemical apparatus ; secondly, the lack of a complete minimum performance specification by which to judge laboratory blends ; and thirdly, the difficulty arising from the fact that the specifications supplied for commercial grades of oil do not include data on many properties of the oil which are important to the malariologist but unimportant to the usual consumer.

This paper represents an endeavour to overcome the three difficulties outlined above. It provides a minimum performance specification for a larvicide and describes a series of simple tests which may be applied (a) to a commercially blended larvicide in order to establish whether this meets the requirements of the specification, and (b) to the individual ingredients (e.g., kerosines, Diesel oils or fuel oils) so that, in each case, the one with the most desirable combination of properties may be selected for incorporation in the final blend.

Head black with pale scales; palpi black; proboscis black. Thorax and scutellum purplish brown. Abdomen black, with curved apical bands on the second, third, fourth and fifth segments and with lateral apical spots on the fifth, sixth and seventh segments. Legs black, unbanded.

Females of the white grub beetle, Dasylepida ishigakiensis, release both (R)- and (S)-2-butanol as sex pheromones, but the males are only attracted to (R)-2-butanol. In laboratory-reared females, the proportion of the (R)-isomer decreased significantly as their calling opportunities increased and as they aged. We examined whether such qualitative changes also occur in field populations. We collected virgin females from the field and then trapped and analysed the volatiles emitted during their first and second callings. The ratio of (R)- to (S)-2-butanol (R/S) was 78:22 at the first calling, but shifted to 39:61 at the second calling. While investigating the composition of the female pheromones, the question arose as to whether the male preferences change in response to the shift in female pheromone composition. To answer this question, we observed the behaviour of young and old males in response to various R/S ratios as lures in the laboratory and in the field. In the flight tunnel assay of laboratory-reared individuals, young males touched female models with a 9:1 R/S ratio lure less than those with pure (R)-2-butanol; however, older males touched the two groups with equivalent frequency. In the field trap test, older males were much more attracted to (R)-2-butanol-scented lures. When we tested using lures with the same amount of (R)-2-butanol but added different amounts of the (S)-isomer, we found that increased levels of (S)-2-butanol resulted in lower attractiveness to males. (S)-2-butanol was confirmed to have an inhibitive activity in the attractiveness of (R)-2-butanol.

In the course of a search for parasites of Cercopidae in Central America, made on behalf of the Government of Trinidad in 1916 and 1917, I came across a froghopper of the genus Clastoptera destroying the flowers of cacao in various localities in Panama and just over the border in Costa Rica.

Abgrallaspis pictor is described as new from specimens collected on Cymbidium sp.in a nursery in England. It damages the plants by causing leaf-spotting. The orchid plants were collected in North India in 1968.

A collection of Indian Tachinid flies was received some time ago through the kindness of Dr. A. D. Imms. An examination has shown that most of the specimens are new, and these are described forthwith. In the use of genera a conservative course has been adopted, and the new species have been placed for the time being at least in genera already in use.

The type specimens have been deposited for the present in the National Collection of Insects maintained by the Entomological Branch of the Department of Agriculture at Ottawa.

There has been much confusion in the taxonomy of the species of Dysdercus in the Caribbean area, and this contribution is an attempt to straighten out the nomenclature and synonymy for future workers on these important pests, until such time as a complete revision of the Neotropical Dysdercus can be attempted.

Food-baited dishes were used to monitor the impact of ground-sprayed DDT (4% WP @ approx. 200 g/ha) and deltamethrin (0.05% SC @ 2.6 g/ha) for tsetse fly (Glossina spp.) control, on epigeal ants in mopane woodland in north-western Zimbabwe. Twenty species of ants were recorded at dishes baited with various types of food. Pheidole spp. and Monomorium opacum Forel (Formicidae: Myrmicinae) were predominant, both in the number of baits attended and in the number of workers present at individual baits. Season apparently had a greater effect on the composition and activity of the ground foraging ant assemblage than did either pesticide. There was a decline in the rate at which baits were found and in species richness of the ant assemblage as the dry season progressed and several species also showed changes in their ability to locate baits. There was no major pesticide induced disruption of the species richness or food finding ability of the diurnal ground foraging ant assemblage sampled. However, foraging success by Platythyrea cribrinodis (Gerstaecker) (Formicidae: Ponerinae) was reduced immediately after spraying with deltamethrin. Subtle effects of either insecticide on rarer species cannot be discounted from the results of this study.

The adults of the weevil, Euthyrrhinus meditabundus, Fabr., were frequently taken in the forest country to the south of Darwin, Northern Territory, and on several occasions they were bred from the branches of two species of indigenous trees and from custard apples, Poincianas and two unidentified species of introduced ornamental trees growing in the Darwin Botanic Gardens. As a rule the infestation of these trees was not heavy, although Poincianas occasionally showed considerable injury. Mango trees, which were frequently badly damaged and sometimes destroyed by termites (Mastotermes darwinensis), appeared to be immune from attack by Euthyrrhinus, even when growing in close proximity to infested trees of other kinds.

The family of the Trypetidæ is of great economic importance, for among its numerous genera are to be found many pests of the orchard and farm. The flies of this family are rarely brought to the notice of Europeans in West Africa, for there farming operations are entirely in the hands of the native population and the amount of damage done by these insects is perhaps insufficiently appreciated by Europeans; but from observations made in my own gardens, during a long West African experience, I believe the loss caused by their attacks must be considerable. The flies which are responsible for the damage observed belong to two genera—Ceratitis, MacLeay, and Dacus, Fabricius.

The two weevils associated with the living stems of the banana plant in Uganda are Cosmopolites sordidus (Germ.) and Temnoschoita nigroplagiata (Qued.); the damage caused by the former has been known for many years but the latter, which usually breeds in rotting stems, has only recently been shown to attack living ones. T. nigroplagiata occurs in every banana-growing area in the territory and is particularly abundant in some parts of western Uganda where C. sordidus, which is otherwise widespread, is rare or absent. Other species of Temnoschoita associated with the banana plant that occur in Uganda but that are rare, are T. basipennis Duv., bred from larvae in rotting pseudostems, and T. erudita, Duv., known only from the adult.

The full-grown larva of T. nigroplagiata is described in detail and characters are given for separating the larva and pupa of this species from those of C. sordidus.