Egg-pods of the Red Locust (Nomadacris septemfasciata, Serv.) deposited on the 17th January 1933 at Mazabuka, Northern Rhodesia, were kindly sent by air-mail to the Imperial Institute of Entomology by Mr. W. Allan. On their arrival 14 days later, the eggs were found to be perfectly healthy, apart from some having been damaged by pressure. Entire egg-pods, with the surrounding soil, were placed in wet sand in flower-pots and put in a glass cage. The temperature in the cage was kept at 100°F. during the day and 80°F. during the night, but that of the sand was probably somewhat lower. Hoppers began to hatch on the 2nd of March and were kept at the same temperatures, with a humidity as near the saturation point as could be maintained. The first adult appeared on 8th April, and the majority of hoppers became adult by the 18th of April, six and a half weeks after hatching. Owing mainly to cannibalistic habits of the hoppers, only about 40 adults were obtained.

It was obviously impossible to plan any serious experiments with such a small number of locusts available, without risking the loss of the entire stock, and it was decided to use them for a preliminary experimental test of the conditions necessary for the sexual maturation. This particular problem is of great practical importance and no data bearing on it were available.

One of the most important pests of rain-grown cotton in the Sudan is the genus Dysdercus (Pyrrhocoridae) of the Hemiptera Heteroptera. Upon the introduction of cotton into the southern provinces of the Sudan, these insects appeared in great numbers, and in certain districts threatened to render impossible the growing of the crop. In 1926 work was started on the bionomics and control of the cotton-stainers by Cowland & Ruttledge, who were working respectively in the Nuba Mountains and the Fung provinces. Later the crop in the Nuba Mountains proving to be the more important of the two, the study of these insects was confined to that region. Mr. Ruttledge followed Mr. Cowland as entomologist in the Nuba Mountains, and the writer followed Mr. Ruttledge in 1928. The results of the preliminary investigations of Cowland & Ruttledge formed a valuable base from which the writer continued the work.

(1) Asterolecanium coffeae occurs in all the British East African Dependencies and has been the cause of much loss in certain low-lying coffee areas of Kenya. On the crop-bearing parts of the coffee tree (Coffea arabica) it inflicts injuries of an irreparable nature, and a heavy infestation is extremely difficult to eradicate.

(2) A. coffeae is oviparous, and after deposition the eggs pass through a period of incubation within the “ test ” of the mother. The fecundity of the female is low compared with that of the common Lecaniine scales and mealybugs which infest coffee in Kenya. The average number of eggs produced by a single female is about 50. The male is extremely rare and fertilisation of the female must be a very infrequent occurrence.

(3) The duration of development of the female from egg to egg varies between 60 and 70 days. The duration of the first stadium varies from 7 to 12 days, and that of the second stadium from 18 to 25 days. The pre-oviposition period is 28 days.

(4) The various stages of the female scale are described.

(5) Only one primary parasite of A. coffeae was obtained, namely, Metaphycus lounsburyi, How., and it is frequently abundant towards the close of the dry season, but its effectiveness is nearly always considerably reduced, by the high prevalence of a secondary parasite, Perissopterus busckii, How. A Coccinellid, Chilocorus angolensis, Crotch, preys upon the mobile first instar forms.

(6) A. coffeae is not a honeydew secreting Coccid and is entirely ignored by ants.

Prefatory Note.

Having had the privilege of seeing something of Mr. Chorley's very fine work against Glossina palpalis, and having had four of his traps (of the types shown in Pl. xi, figs. 1, 2, 5) in experimental use myself, I would like to state that he has, in my opinion, done particularly excellent service in evolving several good types of trap for this tsetse-fly. They have not been properly tested yet against other species of tsetse. The choice of exactly suitable sites for the traps, as with all tsetse-traps, is a matter of considerable difficulty and demands expert knowledge, but if skilfully sited, the traps catch well. They represent the acme of cheapness. The mere tacking of a skirt on a Conical Hoop Trap (1912), a Hughen's trap (1919) or a Barrel Trap (Burnett 1918) makes a “ Chorley ” Trap for tsetse-fly. A mere sack or trouserleg kept open by a hoop and with a non-return cage on the top suffices ; and the trap collapses, like a lady's dress, into no space at all. It is simply, in some of its forms (as in Pl. xi, figs. 1, 2, 5), a very slight adaptation to tsetse of Richmond's Crinoline Trap for mosquitos, published in 1927 in the Government of India's Health Bulletin, No. 11 ; in its “ ventilator ” forms (e.g., fig. 3), it is an adaptation of the Wahl & du Plessis trap for blow-flies, published in 1923 in the Journal of the Department of Agriculture of South Africa—though even here the form most used has been cylindrical.

The following species of mealybugs have been collected from Coffea arabica in Kenya Colony :—

Pseudococcus lilacinus, Ckll.

Pseudococcus citri, Risso.

Pseudococcus simulator, sp. n.

Pseudococcus virgatus, Ckll.

Pseudococcus perniciosus, Newst. & Willc.

Pseudococcus longispinus, Targ.

It is possible that additional species may be collected, especially from the coffee districts of Western Kenya, which are very distant from Nairobi, but undiscovered species, if they exist, can be little more than entomological rarities.