The present paper reports the principal results from a survey undertaken with the objects of ascertaining the extent of the natural breeding areas of the red bollworm in South Africa and whether the habitats of the food-plants are well defined ecologically. It has been known for some years that the red bollworm feeds on wild cotton, Gossypium herbaceum, and on Cienfuegosia Hildebrandtii (Parsons), but from increased knowledge of the topography and vegetation of the country there were reasons to suppose that the distribution of these food-plants is quite considerably limited in the present and potential cotton-growing areas, and it was desirable that the situation should be investigated in some detail.

A pronounced variation in the time taken by hopper bands of Nomadacris septemfasciata, Serv., to become adult swarms in different localities in the Nyasaland Protectorate during the four breeding seasons from 1932 to 1936, led to an investigation and comparison of certain climatic factors occurring during the critical months of hopper development at a number of stations where such variation had been particularly noticeable.

It was found that temperature and percentage relative humidity appeared to have considerable influence on the rate of development of the hopper bands, and that the quiescent nature of the bands in certain areas in some years, together with the unexpectedly small adult swarms that matured from these bands, seemed to be correlated with these same factors. It was noticeable that conditions during the first season, when development was generally normal, were somewhat hotter and drier throughout the country than in the later years and that, in most places, a marked increase in humidity usually accompanied by a decline in temperature was recorded each year up to 1936. In certain areas where hopper development occurred each year without much variation in length of time or intensity, such as the lower Shire River Valley, temperatures and humidity were found to have fluctuated only slightly from year to year.

Little is still known about the distribution of mosquitos in Abyssinia. The first record appears to be that of Theobald (1904) who described specimens collected by Balfour along the banks of the Baro and Pibor Rivers, which flow from Western Abyssinia into the Sobat, a tributary of the White Nile. Scott (1927) reported 13 species which he collected from Central Abyssinia, and he refers to two other species previously found by the Mission to Lake Tana (1925).

1. Measurements of the spiracles and the tracheae of 5th instar hoppers and adults of Locusta and adults of Schistocerca have been made (see Tables I, II and IV). These measurements show that particles of dust which had passed a 300 B.S. Sieve (i.e., under 0·053 mm. in diameter) are small enough to enter all the spiracles and that the particles which had passed a 150 B.S. Sieve (i.e., under 0·104 mm. in diameter) could enter spiracles 1 to 4 and 10.

2. It has been proved by the presence of particles of dust in the respective spiracles, that spiracles 1 to 4 are inspiratory in function and spiracles 5 to 9 expiratory under all conditions, while the function of spiracle 10 is expiratory when the locust is flying and inspiratory when it is motionless.

3. The quantity of dust present in the tracheae increases with the length of exposure to the cloud of dust ; the quantity present after 10 seconds exposure is not regarded as sufficient to kill the locust.

4. The action of external poisons is thought to be by direct penetration of the integument or through the nerve endings or both.

5. The results given in this paper suggest that further work on the action of poison dusts should be concentrated on the investigation of direct penetration of the integument and of the nerve action, rather than poisoning through the respiratory system.

In 1935 during entomological investigations related to an outbreak of jungle yellow fever in Restrepo, Colombia, I captured a female Anopheline which shows morphological details justifying its description as belonging to a new species of a new subgenus. I also found specimens of a new species of Goeldia. These two species are described in the following pages.

1. The male of Pseudococcus is co-equal in importance with the female for the propagation of the species. Virgin females of P. citri, Risso (both aerial and root forms), P. maritimus, Ehr., P. gahani, Green, P. longispinus, Targ., and T. peregrinus, Green, are incapable of producing offspring. No form of parthenogenesis occurs in these five species. Only fertilised eggs develop.

2. The relative abundance of the male sex varies greatly from species to species. The specific sex ratio of citri is 101·62± 1·54 ♂♂ per 100 ♀♀, estimated from 11,413 progeny from 47 females; that of maritimus is 59·65± 9·39 ♂♂ per 100 ♀♀, estimated from 4,630 progeny from 42 females; that of gahani is 43·025± 2·28 ♂♂ per 100 ♀♀ estimated from 12,092 progeny from 61 females; that of longispinus (for bisexual families only) is 19·28± 2·27 ♂♂ per 100 ♀♀, estimated from 4,084 progeny from 19 females; and that of peregrinus 37·01± 7·906 ♂♂ per 100 ♀♀, estimated from 3,946 progeny from 24 females.

Clean summer fallow is often recommended for reducing wireworm and white-grub infestations, but our investigations on this subject, conducted during the years 1933–35 at the Ukrainian Rubber Plants Experimental Station (near Kremenchug) showed that in arable fertile “ chernozem ” soil there is no significant decrease in the number of these pests after a clean summer fallow. These divergent results led us to suppose that the reaction of various species of wireworms and white-grubs to soil cultivation and fallow may be different.

Five years ago, when a study was commenced of the Simuliid fauna of Uganda, 24 species were known from the whole of Africa. To-day, Uganda can claim more than that number within its own boundaries. In fact 30 species are known to occur in the country. And yet it is probable that many more species remain to be discovered, particularly as the investigation has not included the Northern Province, which will undoubtedly prove to be one of the richest in Simulium, since within its confines are the River Nile and its many subsidiary tributaries. Quite a number of species found in Uganda occur in other parts of the African continent. Some extend their distribution over to the west and also to the east coast, while other species do not confine their range to the tropics and are found as far afield as the Transvaal and Natal in the Southern Hemisphere. Early observations (1934) indicated a specialised Simuliid fauna on each of the high mountains in Uganda, and while this may still be true in the case of some species, subsequent investigations have shown that several have a wider distribution.

Eriophyes carinatus, Green, is commonly known as “ Purple Mite ” in Ceylon. It was first described by Green under the name of Typhlodromus carinatus, the generic name subsequently becoming Phytoptus, and finally (up to the present time) Eriophyes.

Apanteles myeloenta, sp. n.

♀. Black; the front femora in the apical half or third, the front tibiae and tarsi (save for the black feet), middle femora in about the apical fifth or sixth, middle tibiae (save commonly for some darkening in the apical two-thirds above), middle tarsi (save for the feet and last joint, which are black), and the hind tibiae in about the apical fifth or sixth, red testaceous; tegulae testaceous; palpi pale; tibial spurs white; wings hyaline, the setae apparently coloured; trie costal veins in the basal half more or less colourless, as are all the wing-veins; costal veins apically, and the borders of the stigma, light brown or brown, the metacarp brown or dark brown; stigma otherwise hyaline.

The Seasonal Factor.

1. The period of stress due to extreme climatic conditions is far shorter in the forest than in the meadow-pan.

2. G. tachinoides is primarily dependent upon riverine vegetation or residual forest, and has only a very limited wet season spread. G. submorsitans is primarily an open woodland fly with great powers of dispersal which are annually checked by adverse climate that enforces a temporary dependence upon the riverine forests.

3. G. tachinoides abounds within the stream-bed or residual forest ; G. submorsitans abounds on the forest fringe.

4. The dispersal of both species is closely associated with evaporation and saturation deficiency. A mean monthly evaporation of 20–28 cc. and a saturation deficiency of 5 to 8 millibars results in maximal dispersal ; dispersal yields to concentration as the evaporative power of the air increases above these zones.

5. The extent of the annual dispersal is indirectly governed by the duration of the wet season—the longer the season the more extensive the dispersal.

6. The population of G. submorsitans steadily increases throughout the rains as the evaporation falls, and becomes maximal towards the end when the evaporation is in the optimum zone (20—25 cc.) ; density steadily falls throughout the dry season as evaporation rises, and becomes minimal at the end when evaporation is maximal. G. tachinoides is believed to behave similarly, but the optimum zone of evaporation is probably about 6 to 10 cc.

Blosyrus ipomoeae, sp. n. (Plate XII, fig. 1).

♂. Derm black, with dense brown scaling; prothorax with an indefinite paler patch in a line with interval 3 of the elytra and extending from the base to the middle; elytra with variable black patches on intervals 3 and 5 and the usual ill-defined oblique paler band from the middle of interval 3 to the shoulder.

In connection with his biological researches for the control of the coffee mealy-bugs in Africa, Mr. R. H. Le Pelley recently made a trip to the Far East in order to try to find some Oriental parasites of Pseudococcus lilacinus which could be introduced into Kenya Colony.

1. Details are given of the distribution of the eight species of tsetse occurring in the Tanganyika Territory (G. brevipalpis, G. longipennis, G. fuscipleuris, G. palpalis, G. morsitans, G. swynnertoni, G. pallidipes, and G. austeni).

2. The effect of past climatic changes on the present distribution of some of the species is discussed in a somewhat speculative manner.

3. The detailed information is summarised in a general description and map of the fly-belts of the Territory.

4. The effect of certain broad vegetation types and major topographical features on the distribution of species of tsetse in Tanganyika are discussed.

5. The effect of the major topographical features in limiting the distribution of the fly is always found to reside in some accompanying vegetative or climatic feature.

6. Possible and likely extensions of the fly-belts are briefly indicated ; if these should take place, but little of Tanganyika Territory would remain uninfested by tsetse-fly. The possibility of natural retreat of fly-belts is also discussed.

7. A few details are given of the habits and habitats of some of the lesser known species (G. longipennis, G. fuscipleuris and G. austeni).

During November 1936, a fine powder was noticed dropping from tea cases on the premises of an industrial firm in London. These cases were constructed of three-ply wood which originated probably from Scandinavia ; it had been brought to India and remained there for probably about 18 months. The cargo arrived in this country in March 1936 and had been lying untouched in the warehouse till November. The interior of the cases was lined with tin. When this was removed, large flat cavities containing living larvae were discovered. Samples were sent to the Imperial Institute of Entomology with a request for information if possible as to where infestation of the timber took place.

In the course of entomological investigations of the rubber-producing plants, Scorzonera tau-saghyz, Lipsch. & Bossé, Taraxacum kok-saghyz, Rodin, and Taraxacum megalorhizon, Hand.-Maz., at the Ukrainian Rubber-Plants Experimental Station (near Kremenchug), it was discovered that the destruction of these plants can be caused by root Aphids and the ants associated with them.

It is a remarkable fact that out of the six commonly occurring species of the family Scarabaeidae (chafers, white grubs) in Britain, five are constantly reported as causing damage, either as grubs or as adults, to agricultural and forest crops. Thus, of the six species listed in Table I, only the last named, Anomala aenea, de Geer, which is very abundant locally on sand-dunes, finds agricultural conditions unsuitable to its existence.