To attempt even a brief historical sketch of the development of all branches of Entomology in South Africa would be beyond my capacity, since my studies have for many years been restricted to only one order of insects, and have been mainly of a taxonomic nature. I may therefore be excused if the floodlight is perhaps focussed too much on this branch of Entomology, leaving the other branches in the dark.
At the request of the committee of the Society I contribute these sketchy notes on the pioneering period of economic entomology in South Africa, to supplement the instructive survey of the development of systematic entomology given in Dr. Janse's presidential address at our last meeting. The information I record is not presumed to have any practical value but the members of the Society, particularly those occupying government positions, may find in it enough recreational merit to justify its publication.
In this paper a new species of Pseudopedinaspis Brauns and an interesting new genus of the Idopompilini are descriptionbed. Apterism in the Pompilidae is of rare occurrence and is confined to a few genera, and is of particular interest on account of the marked alteration in the proportions of the thoracic segments which is correlated with this condition. There is an absolute. and not merely relative, elongation of the pronotum, and usually also of the epinotum, giving these insects such an unfamiliar appearance that their true affinities may easily be overlooked.
Hercothrips helini sp. nov. (Fig., 1a). Female (macropterous).-Length about 1.1 mm. (fully distended, about 1.3 mm.). Colour dark brown, darkest in abdomen and along sides of head and thorax, the head with extreme front and an adjoining area along eyes in front of posterior ocelli, yellow; femora about concolorous with body, yellow at base and at apex, the fore pair paler and more extensively yellow; fore tibiae largely yellow, with a brown area beyond basal fourth which extends forward along inner surface to near tip, the middle and hind tibiae darker, yellow at extreme base and in about apical third, the intermediate portion concolorous with femora;
This is the first of a series of articles I hope to publish, with coloured plates, based on close observation of the larvae in the different instars. The species will be dealt with irrespective of their systematic position, as material becomes available. The paintings were done by the author from life, and the pictures of the adults are scale impressions with the bodies painted in.
Leptoneura dingana clara subsp. nov. (Figure 1, a, male holotype, b, female allotype). Holotype: male, Wolkberg, Pietersburg district, Transvaal (5,000 feet), 12 November, 1939 (D. A. Swanepoel), in the T.M. Collection. Allotype: female, same locality and date, in the T.M. Collection. Paratypes: 5 male male, 2 female female, same locality and date, of which two males are in the T.M. Collection and the remaining specimens in Mr. Swanepoel's collection.
Ctenophthalmus calceatus septentrionalis subsp. nov. male (Fig. 1) Clasper as in cabirus J. & R. with the apical processes divided by a deep sinus and Pi with three bristles but less rounded apically and dorsally than in cabirus and ansorgei R. and unlike calceatus (Waterst.) it is not rounded ventrally.
Professor J. C. Faure, professor of Entomology at the University of Pretoria, has very kindly submitted to me for identification a number of specimens of a species belonging to the genus Triphleps Fieb. which, according to Mr. E. C. G. Bedford a research student, is predaceous on the South African citrus thrips (Scirtothrips aurantii Faure) in the Transvaal.
On a number of occasions it was observed by the authors that nymphs of the Brown Locust, Locustana pardalina (Walk.), moved their hind legs very rapidly and in such a manner that the hoppers appeared to be stridulating. The hopper rapidly moves the hind femora upwards and downwards in a vertical plane, the femora articulating on their basal joints. The angle between the femur and tibia apparently remains constant. Both legs are in action simultaneously. The movements are very rapid, and the speed is estimated at about five times per half second.