The occurrence of phases in locusts is now accepted by most entomologists working on locust problems as an established fact. Recent investigations carried out by Faure (1943) and Matthee (1946) showed that Laphygma exempta (Hubn.) and L. exigua (Walk.), both belonging to the family Noctuidae, exhibit phase variation in the larval stage. Breeding experiments were undertaken by the writer. These experiments and other biological observations are discussed in this paper.
Macrophylla Hope (1837) is an endemic South African genus which is little understood although it is of some economic importance. This paper descriptionbes the structure and biology of the Macrophylla found at Humewood, Port Elizabeth.
In 1944 and also 1946 Mr. Bedford of Letaba submitted some Hemiptera for identification which he collected at Letaba in the Northern Transvaal and which were observed by him to be predaceous upon the red scale of citrus. This species belongs to the Hemipterous family Isometopidae, a family of which no representatives have thus far been descriptionbed or recorded from Africa. The species is of some economic importance in that it also plays a small biological role in the natural control of the red scale. The habits and biology of the species is descriptionbed.
In a previous paper (Ullyett, 1945), it was shown that the production of eggs by individual females of Ephestia kï¿½hniella Zell., was markedly influenced by the density of the moth population per unit area. The density of adults per unit area of the oviposition medium therefore constitutes an important factor governing the growth of populations of Ephestia.The experiments were continued and the results obtained are recorded and discussed in this paper.
Exochomus flavipes is an entomophagous coccinellid indigenous to South Africa. It has a fairly wide geographical distribution probably extending throughout Africa. E. flavipes is primarily an insect-feeding ladybird.