In this paper a short revision of the African forms of the genus Aridelus (formerly Helorimorpha) is given and one new species is described. Of the seven African species now known (some of which will almost certainly fall later as synonyms) three, including the new one, are parasites of the important Hemipterous pest of coffee, Antestia lineaticollis, Stål.

The beetles dealt with here were collected while I was acting as entomologist to the Percy Sladen Trust Expedition to Lake Titicaca in 1937. They were all taken on the floor and walls of a room in which Nepal barley was stored. The room—later cleared of grain and used as a dining room—was in the hacienda Camjata, Capachica Peninsula, Lake Titicaca, alt. 3,850 m. The walls were made of adobe (sun-dried brick) and the roof was thatched with Scirpus tatora.

The planting of cocoa in Malaya at the present time must be considered to have reached the experimental stage only, and the data obtained so far are insufficient to warrant a recommendation for its adoption either as a plantation or a small-holder's crop.

1. The behaviour of Anopheles labranchiae atroparvus, Culex pipiens molestus and Aëdes aegypti has been studied before and during oviposition.

2. Anopheles and Culex when ready to lay make repeated descents to the ground and fly about with a skimming-hopping movement, while Aëdes flies about generally, at all heights.

3. On encountering water Anopheles breaks into a hovering flight, laying its eggs during this “oviposition dance” or while settled on the water. Culex stops “dead” on the water and lays its eggs settled there, as does Aëdes but with some fidgeting about. After encountering water mosquitoes may leave it again, but fly about the floor more steadily and persistently than before.

4. Among the factors which stimulate mosquitoes after they have arrived directly over a water surface, contact with the surface is essential for actual oviposition by Culex and Aëdes, and almost so for Anopheles. Good pre-ovipository responses may be induced by water vapour alone and by the reflection from the surface, although how this latter stimulus acts is not clear. A dark appearance, especially if the surroundings are relatively light, facilitates these responses.

5. Direct attraction of the mosquitoes over the short range available in a cage was only induced by a contrastingly dark appearance, but Anopheles and Culex are aided in water finding by diurnal changes, correlated with light and activity changes, in the sense of their geotactic response.

Among the large family of the Eulophidae (Chalcidoidea), the Euplectrini are closely related to the Elachertini and form with them the subfamily Elachertinae. In common with the genus Elachertus, Spin., they have antennae with a 4-jointed funicle, complete parapsidal furrows, often longitudinal furrows on the scutellum and a petiolated abdomen. They are, however, easily distinguished by the large size of the spurs of the hind tibiae, the longest being generally more or less as long as the first two tarsal joints together.

Glossina longipennis is a species of tsetse-fly of which very little is known beyond its general distribution. In Kenya Colony, it inhabits extensive areas of the sparsely populated districts in the north and east. It extends across the coastal hinterland and penetrates into Tanganyika, where it is found in the Pare-Usambara belt (Potts, 1937). The species also occurs in a somewhat isolated belt in the vicinity of the lower Southern Uaso Nyiro in the Masai Reserve and continues into the Sonjo-Natron fly-belt of Tanganyika Territory.

1. A number of generations of Dysdercus howardi, Ballou, bred in the laboratory between 1932 and 1934 are compared with a similar number of generations bred from 1940 to 1941.

2. There is found to be no significant difference in the length of the life-cycle in the two periods.

3. There is a significantly greater number of adult female insects in the earlier generations of D. howardi (eleven generations).

4. In the later generations there is a higher percentage of infertile eggs. The difference between the two groups of insects is highly significant.

5. There is no significant difference in the percentages of nymphs becoming adult in the two periods.

6. The differences in the numbers of adult insects and in the sex ratios obtained in 1932–34 and 1940–41 are found to be non-significant (twelve generations).

The observations here recorded have been made between April and October 1940, at Amani, Tanganyika Territory.

Two distinct varieties of Helopeltis occur on cinchona at Amani, which correspond well with the descriptions of H. bergrothi, Reut. var. rubrinervis, Popp., and H. bergrothi var. disciger, Popp. (Poppius, 1911).

In this paper four new species are described and two already known ones are discussed. The justification for bringing forward new species in a genus whose Old World members are in a state of great disorder lies in the fact that their hosts are known and are Lepidopterous pests of economic importance.

The types are in the British Museum.

The object of this investigation was to discover the extreme length of life of nymphs and adults of Pediculus humanus corporis, de Geer, when starved at different temperatures. It is important to know this for practical reasons. Though it is impossible to complete the experiments as originally designed, it is considered that such information as has been accumulated should be recorded.

Larvae of a flea-beetle, Chaetocnema arida, were found mining in the stems of young barley shoots in June 1939.

Chlorops pumilionis larvae infested barley most heavily in fields where Agriotes larvae were doing most damage. The Chlorops adults showed marked sexual dimorphism in both size and colour. The size range for this species is correlated with a proportionate size range in its parasites Coelinius niger and Stenomalus micans. Perforations 1·3 mm. in diameter in the top of a cage were sufficient for the escape of Stenomalus but not of Chlorops or Coelinius.

Lasiosina cinctipes larvae were commonly synoecious with Chlorops in barley shoots, but in some cases (5–10 per cent.) they were living without Chlorops. In these shoots the nodes were not swollen as in Chlorops infestation. Lasiosina was not attacked by the above parasites of Chlorops.

The larvae of Elachiptera cornuta infested shoots already badly damaged by other species and were accompanied by many Lasiosina larvae. Wet weather in July favours these two species. Their puparia differ in the form of the posterior spiracles. Elachiptera also occurred in maize and wheat.

Meromyza saltatrix var. nigriventris was present in stunted barley shoots in small numbers, producing swelling of the nodes very like that due to Chlorops. The summer pigmentation in both these species in Hampshire differed from that reported by Mesnil in France. Meromyza was also bred from wheat. Meromyza puparia, unlike those of Chlorops, were attached to barley sheathing-leaves by silk.

Oscinella frit larvae, infesting young sweet maize shoots at Gosden, Surrey, were either accompanied or followed by those of Aphanotrigonum trilineatum and Elachiptera. Infesting oat shoots at Long Sutton, Hampshire, Oscinella frit larvae were accompanied by larvae of Lasiosina and Camarota curvinervis. Adults of the latter emerged from stunted barley shoots in September. They showed some resemblance to flea beetles, possibly protective. Oscinella frit was also bred in small numbers from stunted wheat and barley shoots. The Chalcid, Callitula pyrrhogaster, was reared from pupae of this species found in oat shoots.

Larvae of a Muscid, Hylemyia (Phorbia) genitalis, infested a winter wheat crop in large numbers in May 1940. Tropidoscinis albipalpis, Oscinella? gracilior and Agromyza nigripes, were bred in small numbers from potted plants of this crop kept in a cage in the laboratory during the summer. Hylemyia genitalis and Agromyza (Domomyza) ambigua pupated in the soil surrounding the roots of these plants. The adults (together with a Braconxd parasite, Phaenocarpa pullata, Hal.) emerged from the soil in the following spring.

The work which resulted in this paper was carried out in the Department of Entomology of the British Museum (Natural History) at the request of Professor J. W. Munro and on behalf of the Pest Infestation Laboratory of the Department of Scientific and Industrial Research.

As time passes and knowledge accumulates, it becomes more and more difficult and tedious to know whether a certain insect has been recorded from a particular region or country. The present note is an attempt to save other people's time and to set down what is recorded about the geographical distribution of five species of flea, Xenopsylla cheopis, astia and brasiliensis, Nosopsyllus (Ceratophyllus) fasciatus and Pulex irritans.

It has been shown that G. morsitans and G. tachinoides annually shift their breeding-ground in March from the edge of a residual forest island to the centre— a distance of some 40 yards. The move is associated with an increase in mortality amongst the last puparia to be found, death usually having occurred late in pupal life.

The object of the investigation has been to discover what prompts the female to move just before pupal mortality increases.

It has been found that there is little difference in the temperature conditions of the two breeding-grounds, but that the evaporation rate is one-third less in the centre of the forest. However, the abandonment of the forest margin is not explained by attributing to the female the ability to detect differences in the evaporative power of the air, but rather by the negative reaction to light developed by the whole community under conditions of universally high temperature. The period of migration coincides with an abrupt increase in the number of hours when the shade temperature is above 90°F. (32°C), the temperature at which Jack & Williams found that the negative reaction to light begins. During March the diurnal temperature is below this figure only immediately after dawn, when under laboratory conditions parturition rarely occurs. Since the temperature remains above 90°F. until well after activity has ceased at dusk, it is probable that at any rate the non-hungry tsetse spends most of the day and all the night in the centre of the forest. In the evenings field observations suggest that the stimulus of hunger may overcome the negative reaction to light, as then flies will undoubtedly attack in the forest edge, but since pregnant females rarely feed for several days before parturition, this counter-stimulus is unlikely to be operative at the time the female extrudes her larva.

By moving into the centre of the forest the adults will gain a reduction in temperature of only 3 or 4°F., but they will be less susceptible to heat, as the much lower evaporation rate will reduce their water loss.

The climatic conditions in the pupal environment of the forest edge at 1 ½ inches depth were found to favour survival, so it was concluded that the factor which inhibited emergence must have been operative before the puparia were formed. Possibly high surface evaporation and unsaturated soil atmosphere affect the formation of the pupal integument at the time of pupation, rendering subsequent emergence impossible.

The meteorological data collected in this investigation are more detailed and localised than anything yet published by the writer, and should give a better picture of the dry season adult and pupal environments in a locality which is very close to the hot, dry limits of the range of both species.

Puparia are found in large numbers in soils whose mean monthly temperatures range from 69°–82°F. (20·6—27·8°C). Field observations suggest that a constant temperature of 72°F. (22°C.) with a R.H. of 80 per cent., or 77°F. (25°C.) at R.H. 100 per cent., are conditions which should provide very healthy puparia if reproduced in the laboratory (see Appendix).

This short paper summarises and discusses the entomological results obtained from marking experiments done with Glossina morsitans at Kakoma, Tabora, Tanganyika Territory, from July 1938 to May 1940. The first eighteen months' data and results have been given in full elsewhere (Jackson, 1941) and the mathematical treatment explained. The marking experiments occupied three days weekly, and covered an area of 16 square miles of annually fired woodland and seasonal swamp; a similar area was observed in the same way for a year in country protected against fire, and in addition a number of special experiments to check results were carried out. The climate and situation of Kakoma have already been described (Jackson, 1937) for the year 1935; from that year until April 1938, smaller scale routine marking experiments were carried on with few interruptions, so that there is available a fairly complete body of data collected over nearly five and a half years.

Large numbers of the bat, Nycteris hispida, Schreber, have been observed at dusk flying out of the residual forest islands at Gadau. Some have been captured and placed in a large cage containing Glossina morsitans and G. tachinoides. The sleeping bats, hanging head downwards, are perfect complacent hosts; both species of tsetse have been seen to attack and feed on them on many occasions, and to experience no difficulty in becoming fully gorged.

The pineapple plantations of Mauritius have sustained since 1937 severe attacks of mealybugs (Pseudococcus spp.) which threatened to ruin the whole crop in certain localities. These attacks result in a wilting of the plants, which may be due to a toxin secreted by the bugs during their process of feeding.

In the British Museum (Natural History) Ruwenzori Expedition 1934–35 vol. II nos. 3 (1939) and 4 (1940) generic keys to the Muscinae and Coenosiinae and specific keys to Graphomyia, Musca and the Coenosiinae of the Ethiopian region have been published. As there seems no possibility of the Museum issuing any more of these reports in the near future, it has been agreed that suitable extracts from the manuscript of the third part be published in this Journal, so that the keys and some other necessary data shall be available for the use of Entomologists in Africa.

1. Two new methods of trapping Ephestia cautella adults in cacao stores are described.

2. In the first method, devised by Mr. J. K. B. Lee, broom strands are treated with an adhesive and then suspended from twine in the alleyways between the stacked bags. Mr. Lee heated two parts of coagulated até (derived from the latex of a species of Carpodinus) with one part of palm oil and applied the adhesive, while hot, to the strands. The writer carried out a long series of experiments with various adhesives, with the object of perfecting the broom strand method, and finally came to the conclusion that the best adhesives for general use were those made by heating three parts of coagulated até with one part of either shea butter or palm oil. The adhesive should be allowed to cool before applying it to the strands.

3. It was discovered, in the Port Harcourt area, that carbolic soap solution is an excellent medium for use in dish traps. The writer found that carbolic soap solution caught many more moths than the standard medium used in Nigeria. Several other types of soap, both imported and locally made, proved to be nearly as effective as carbolic soap. The best strength for carbolic soap solution was found to be from 1 to 2 oz. soap per gal. water.

4. The infestation of ground-nuts by Ephestia is discussed, and the opinion is expressed that this could be considerably reduced if it were found practicable to reduce the length of the export season from 12 to 7 months.

(1) In seepage-filled borrow-pits in South India it was observed that there was a progressive decline in the density of larvae of Anopheles culicifacies, Giles, as the pits became older. The largest numbers of larvae were tound soon after water entered the newly-dug pits.

(2) There was less ovipositing by culicifacies in older pits than in new ones dug late in the irrigation season. Newer pits seemed definitely more attractive in this species than older ones. These newer pits sheltered more culicifacies larvae late in the season than the older pits.

(3) The decline of culicifacies larva density in a borrow-pit seemed to be due mainly to factors internal to the pits. There was no evidence of the influence of external factors, except from October to January, when perhaps meteorological influences supplemented the internal factors. The attractiveness of new borrow-pits to culicifacies appeared to be due mainly to internal factors.

(4) Certain simple factors studied did not seem to have any significance in relation to culicifacies density in the pits. Rainfall, predators, macroscopic vegetation, pH, CO2, dissolved oxygen, bicarbonate alkalinity, ratio of free to bound and half bound CO2, hardness, chlorine, ammoniacal nitrogen, nitrates, nitrites, sulfates and iron, appeared to have no significance in this regard. Albuminoid nitrogen and oxygen absorbed perhaps had some significance, which was not clear.

(5) Among planktonic organisms, the individual groups of organisms, such as green algae, diatoms, rotifers, and copepods, definitely showed no relation to culicifacies breeding. Protozoa as a group appeared to be negatively associated to a slight degree. Blue-green algae also seemed to have a negative association.

(6) Amorphous organic matter and total plankton, however, showed statistically significant negative association with larval density of culicifacies The decline in culicifacies larvae was clearly associated with increase in total plankton and amorphous matter. The attractiveness of new borrow-pits also seemed to be related to their low total plankton content.

(7) The exact manner in which the total organic matter acted as an inhibitory factor against culicifacies breeding was not determined.