A full description is given of the life-history of Exenterus abruptorius, Thb., an important parasite of the pine sawfly, Diprion sertifer, Geoff.

The insect is univoltine, like the host. It oviposits on the last stage larva or prepupa and only hatches after the host has spun its cocoon. Only one-quarter of the primary larvae develop immediately, the remainder resting up to two and a-half months during the summer before proceeding with their development. On the completion of feeding the parasite larva spins its cocoon within the host cocoon and enters the prepupal stage, which can be divided into two distinct phases, eonymphal and pronymphal. Hibernation is always in the eonymphal stage. In Sweden 37 per cent. of this species remained in hibernation for two winters, but in Hungary all emerged in the spring following the year of development. Further than this, in Sweden the sexes were in approximately equal proportions; in Hungary females exceeded males by four to one. This may indicate the existence of biological races.

Other Ichneumonidae exhibit the prepupal stage, with eonymphal and pronymphal phases, in their development. The typical facies of this is analogous to that in the prepupal stage in Tenthredinidae, in which, however, ecdysis precedes this stage, which is then a distinct instar. It is suggested that an instar is lost in the development of the Ichneumonidae, though the facies of the prepupal stage is retained.

The Capsid described in the present paper came under observation in Malaya some years ago but was not then specifically determined. Mr. W. E. China, of the British Museum (Natural History), was kind enough recently to examine it, and came to the conclusion that a new genus should be erected to contain it. Specimens were returned to me by Sir Guy Marshall, Director of the Imperial Institute of Entomology, along with some notes made by Mr. China which would be of use in the preparation of the diagnosis of the new genus.

1. Male G. swynnertoni were placed in a cage in the middle of a grass enclosure (to curtail their sight) and their powers of smell tested by recording their reactions when a span of six oxen (with two men) passed to windward outside the enclosure. Reactions were obtained at the ranges of 110 and 180 ft. but failed at 300 ft.

Female G. swynnertoni reacted at 110 ft. but were not tested at greater ranges.

2. Men in groups of two and eight were substituted for the oxen, and human scent was found to be attractive, but in spite of this there was evidence that the oxen and not the men with them were the main attraction in the scent experiments with the oxen.

3. The scents of kamba (onion-scented bark rope), hessian and manure were tested at 110 ft. and were not attractive. There was evidence, however, that the exhaust of a lorry at 300 ft. was attractive.

4. The tsetses did not react to shouting, the trampling of oxen or the noise of a lorry.

5. These results are discussed and the experimental conditions compared with the conditions in the natural environment.

6. Wind of a strength from 1½ to 5½ m.p.h. outside the cage (i.e., from about ¾ to 2½ within it) successfully bore the scent of the oxen at a range of 110 ft. to the tsetses. Lower and higher velocities were not tested.

7. The powers of sight of male G. swynnertoni were tested by passing the span of oxen to leeward of the enclosure, from the circumference of which an arc had been cut. The direction of the wind ensured that the tsetses could receive no scent. A maximum tonal contrast was obtained (to human eyes) by using black oxen against a light background and carrying out the experiments in bright sunshine. Positive results were obtained up to and including a range of 450 ft., but at 600 ft. there was no reaction.

Female G. swynnertoni reacted at 110 ft. but were not tested at greater ranges.

8. There was evidence that as the tonal contrast between the oxen and their background became less (through a weak sun or the background in semi-shadow) so the distance at which the tsetses could see diminished. This was supported by an experiment at 110 ft. in which the effect of a dark-blue background was greatly to reduce the reactions.

9. A small dark screen at 110 ft. gave as good reactions as the span of oxen.

10. The results of the sight experiments are discussed and the experimental conditions compared with those in the natural environment.

The paper deals with Anopheles funestus and its allies as they occur in East Africa. The species dealt with are A. funestus type form, A. rivulorum, A. rivulorum var. garnhamellus and A. leesoni.

1. Differences between adults are so slight that they have until recently all been regarded as A. funestus. They may, however, be separated from one another by the points given in the Key (above). Differences between larvae of the species are much more pronounced.

2. It is also shown that, in this part of Africa at least, A. funestus, though reared from identical larvae and pupae, has four main forms of wing pattern. One of the forms of A. funestus appears to be absent from Uganda, while another form is much more prevalent in coastal regions than inland. A. rivulorum occurs in Uganda, but only two specimens were taken in Tanganyika. A. rivulorum var. garnhamellus is widely distributed throughout E. Africa. A. leesoni was found only in Uganda.

3. A. funestus, A. rivulorum and A. leesoni breed in similar situations, i.e., clear, shaded water with growing vegetation. The larvae are more frequently found among grass than among other types of vegetation. Such breeding-places occur in rivers, streams, pools and swamps. Light readings taken at breeding-places corrobate the many reports that these larvae prefer shaded situations and are absent from exposed waters. Larvae of A. rivulorum var. garnhamellus are found most frequently associated with Pistia stratiotes, though on at least two occasions they were found in water where this plant was absent.

4. All the adults were taken inside buildings and none outside, in spite of continuous searching. Almost all were A. funestus, the remaining few were A. rivulorum and A. rivulorum var. garnhamellus; adults of A. leesoni were not taken at all. At several places, though adults of A. funestus were common in houses, very few or no larvae of this species were found; but larvae of the other forms were present. It is concluded that A. funestus is therefore an habitual house-frequenter and the others are not. Human blood was found in roughly half of the female A. funestus examined (239 out of 456); a very few contained ox blood and the remainder (204) were negative for ox and human blood. They were not tested for other bloods. Of 122 female A. funestus examined for malaria parasites 15 were found infected.

As a result of several years work in the Anglo-Egyptian Sudan (Maxwell-Darling, 1934, 1936, 1936 a), it was concluded that the only outbreak centres of the Desert locust in north-eastern Africa were on the Red Sea coast. It appeared probable, however, that there existed other outbreak centres in Arabia, and unless those could be discovered and controlled, an outbreak originating in Arabia would spread into Africa and the Near East.

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.

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.