The following new species of Membracidae from Africa south of the Sahara are descriptionbed and figured: Negus newtoni, Lanceonotus crassicornis, Eumonocentrus sinuatus, Anchonobelus magnificus, Tricoceps laconus, Acanthophyes kenyensis, A. rarus, Distantobelus humilis, Vecranotus ivoriensis, Leprechaunus humilis and L. longicornis.
In 1926 Naudï¿½ published the first comprehensive monograph on the Cicadellidae of South Africa. Apart from transcribing the original descriptionptions of all the species of leafhoppers previously known from this region, he also descriptionbed 71 new species collected by F. W. Pettey in the Western Cape, J. C. Faure in the Orange Free State and E. S. Cogan and C. B. Hardenberg in Natal. Unfortunately Naude did not deposit the types of these species in a museum or similar institution, but kept them in a small private collection where they were not available for study for many years. Only recently, in November 1971, he donated this collection to the National Collection of Insects, Plant Protection Research Institute, Pretoria and the present author is very grateful to the Director of this institute for permission to study the type specimens.
Our collecting experience in South Africa in 1967-1968 has made it evident that the taxon that has been known for many years as Blissus rusticus Stal is actually a complex consisting of a number of distinct although closely related species. Slater (1964) pointed out the heterogeneity of the South African species placed in the genus Blissus, listed a number of species ""groups"" and noted that B. rusticus and B. rostratus were closely related and very distinct from other species placed in Blissus. Ischnodemus darwini Slater, which was descriptionbed in the same paper from a single macropter, belongs to the same complex.
New population studies on T. erytreae in Swaziland are descriptionbed from November 1968 to January 1970 when the study was discontinued. Severe weather extremes in the mid and late summer of the 1968-69 season resulted in extremely low population densities of T. erytreae in which parasite activity was seriously disturbed. Parasites only recovered during the midsummer of the following season. Low population densities of citrus psylla recorded in the 1969-70 season were explained by the unusually low winter nucleus population at the start of the season, the occurrence of lethal weather and irregular flushing rhythm.
In a field trial to evaluate different insecticidal treatments for the control of Aonidiella aurantii (Mask.) on citrus, the effects of the treatments on populations of Panonychus citri (McG.) and its predator Amblyseius addoensis van der Merwe & Ryke were observed for two seasons in 1966-67. Treatments with parathion in March or August and September (but not October) were generally followed by a reduction of A. addoensis and a subsequent rise of P. citri. It is suggested that the rise of P. citri was due to the temporary suppression of the predator mite by parathion. This provides an explanation for the well-attested view that the injudicious use of parathion is responsible for the appearance of P. citri as a pest of citrus in South Africa.
Risbec (1957) descriptionbed Ruandella, a monobasic genus from Africa. This genus, like others descriptionbed by that author, has remained unrecognized. Recently, Subba Rao (March 1971) descriptionbed a new genus, Turnerella, and a month later Annecke (1971) descriptionbed Macchiencyrtus. Annecke based his genus on three species that were reared from known hosts. Turnerella Subba Rao is preoccupied by Turnerella Cockerell (Hymenoptera: Apidae), and my recent studies have shown that both Turnerella Subba Rao and Macchiencyrtus Annecke are junior subjective synonyms of Ruandella Risbec. This new synonymy is shown below.
Two new genera of Acrididae are descriptionbed from South West Africa, viz. Damaracris for the type-species D. rupestris spec. nov. from the Central Namib Desert; and Ovambohippus for the type-species O. anderssoni spec. nov. which is widely distributed over northern S. W. Africa and southern Angola. Brief notes on the habitat preferences as well as geographical distribution are given.
The pathways of the nerves in the eight anterior abdominal segments of Acanthacris, as seen in gross dissection, are descriptionbed and the homologies of muscles in the eighth segment of the female briefly discussed.
Thirty-one species of Mecoptera are listed from southern Africa. Ten new Bittacus species are descriptionbed; viz. B. annae, B. bullatus, B. byersi, B. caprai, B. cottrelli, B. gessi, B. pondoensis, B. smithersi, B. wahlbergi and B. zulu. A key to all southern African species is given.
The response of adult beetles to light, temperature and humidity was investigated. Evidence is presented that the optimum combination of these environmental factors is a moderately high temperature (ï¿½25ï¿½C), moderately high humidity (ï¿½80% R.H.) and darkness. It was found that darkness is the dominating factor, which results in this species being nocturnal, and that a high humidity has a marked influence on its reactions.
On September 18th., 1971 while looking for nests of the Brown sugar ant C. maculatus on the slopes of the Twelve Apostles three fully grown butterfly larvae were found in the first nest encountered. The larvae together with about fifteen ants, large and small workers, were kept in a plaster of paris nest. The larvae pupated at the end of September and were removed from the nest and kept in larger containers. One specimen was kept on moist cotton wool and the other two on moist garden soil.