The distribution of animals and plants has important theoretical implications and indeed provided Darwin and Wallace with some of their most valuable evidence for evolution. When species of economic importance are under consideration, questions concerning the spread of organisms raise more practical issues and come within the sphere of interest of the applied biologist. As the problems involved in the distribution of injurious insects have always interested me and have been rarely discussed in the literature, I have chosen this topic as the subject of my address. I propose to discuss these problems along rather broad lines, and to exemplify my theme mainly by insects of economic interest in Southern Africa.
Five species of this very peculiar genus of the Bombyliidae are at present known from Africa south of the Sahara; cirrhata Bezzi from Somaliland, xanthogramma Bezzi from Southern Africa and Southern Rhodesia, nigrifrons Bezzi from Kenya, bella Curran from the Belgian Congo and cercoplecta Hesse from Southern Africa. I can now add two more species, one extending the range of the genus to West Africa (Nigeria), the other apparently a relatively common species at Kawanda, Uganda, which is also a new territorial record for the genus.
In a previous paper I descriptionbed a small collection of nasal mites from South African birds (Fain, 1957c). Through the generosity of Dr. F. Zumpt, of the South African Institute for Medical Research, I received in 1957 and 1958 several new batches of these interesting mites * . This collection includes two specimens (collected from the nasal cavities of a bat) belonging to a new genus and a new species, and 4 new species of Rhinonyssid mites from birds.
The first authentic record of the green peach aphid (Myzus persicae Sulz.) for Rhodesia was made by Hall (1932) from Mazoe; he collected specimens off various Brassicae including rape, cabbage and cauliflower at the end of 1927 and early 1928, and stated ""that probably, as elsewhere, it has a wide range of host plants"". Up to that time M. persicae was not known as a pest in Southern Rhodesia. Ten years later, when Turkish tobacco was first severely attacked by an aphid, Hall identified it as M. persicae.
In the present report, I am descriptionbing some of the new species of crane-flies that were taken at Salisbury, Southern Rhodesia, by Mr. Courtenay N. Smithers, together with one further species from Luabo, Portuguese East Africa, secured by Miss Pamela J. Usher. I am greatly indebted to the collectors for the privilege of retaining the types of the novelties in my extensive collection of World Tipulidae.
Aï¿½des (Mucidus)? mucidus, Karsch, 1887. A male specimen from N'dumu (Tongaland, Natal) collected by Mr. H. E. Paterson, which he has kindly lent to me, has terminalia almost exactly as this species except that the phallosome is not quite so pointed at the apex. It differs from the descriptionption of Edwards (1941, p. 112) in having a median white ring in the middle of the middle tibia and in that the white bands on the second and third hind tarsal segments are rather broader than illustrated (Edwards, lac. cit., p. 111).
The cephalic and thoracic horns of various male lucanid and dynastid beetles have long been considered classical examples of allometric growth, the relation between size of horn and body size being expressed by the exponential equation Y = bXk, where Y horn size, X body size, band k being constants; k is usually referred to as the ""growth coefficient"" of the heterogonic organ. But, as pointed out by Huxley (1931, 1932) there is an important difference between holometabolous insects and other animals exhibiting allometric growth e.g. crabs.
It seems to be necessary to reopen the question of the validity of some of the European species of Chirothrips, in order to settle their status. This problem is believed to be of some practical importance, since aculeatus Bagnall infests grasses and sugar-cane, and manicatus Haliday has been recorded as injurious to grasses and cereals. It is known that the validity of a few species, very closely related to Ch. manicatus, is doubtful, as several authors have emphasized already. But unfortunately these species have been quoted repeatedly in recent catalogues or in keys as valid ones, although they were separated from manicatus in the original descriptionptions on the basis of two or three insignificant characters.
The work descriptionbed in this paper was carried out at Fourah Bay College between December 1957 and March 1958. Attempts had been made to mark and recapture grasshoppers at intervals between October and December 1957, but late rains had made it difficult to catch them in any numbers. The last rain fell in midï¿½ December and towards the end of that month it was possible to begin regular catches. The data accumulated should make possible an estimate of changes in the population. However, this study is not likely to be complete for some time and the present paper therefore deals mainly with evidence of movement of females during maturation of the ovaries.
As a result of work on African species of the sub-family Myzininae as well as the necessary side issues of studying the species of allied genera from other regions, some important synonyms have come to light which appear to have been previously overlooked. It would seem that workers have followed Dalla Torre's Catalogue without checking the relevant references and in consequence some names have been overlooked. This has resulted ill faulty type designation in at least one genus.
With the examination of the types or specimens of the type series of of few more soft scales, the redescriptionption of or comment on the Ethiopian species currently referred to the genus Coccus is nearly complete. Among the species treated in the following pages it is now possible to present a detailed redescriptionption of Coccus hesperidum Linnaeus, 1758. This species, so important for economic entomologists and systematists' alike, was omitted from the previous paper because all specimens then at hand did not entirely agree with the diagnoses of some other modern authors.
Stannardia n. gen. A small insect, body more or less conical, head small, abdominal segment V or VI broader than any other part of the body. Surface of the body only moderately sculptured, abdomen without microtrichia. Head without prominent setae and without prolongation between eyes and bases of antennae, but with a transverse shallow impression across the head behind the eyes; eyes large and bulging, fore ocellus on a hump; mouth-cone short and broadly rounded
This Clypeodytes was taken from a small stream crossing the road from Tunduma, which lies on the border between Tanganyika and Northern Rhodesia, to Fort Hill in Northern Nyasaland. The locality was within the Northern Rhodesian boundary, so to avoid confusion in distributional records, it has not been included in 'The Dytiscidae of Southern Rhodesia and Nyasaland' although it was taken on the same expedition and the locality was only just inside the Northern Rhodesian border.
Apterygothrips carolinae spec. nov. (Figs. 1-5, 8-9) Female (apterous). Length (slightly to fully distended) 0.7-1.3 mm. Colour of head, thorax and abdomen uniformly brown to blackish brown; eyes so deep red as to appear black; antennae: segments i and v-viii rather uniformly dark grey, ii darker, dark brown at base and on both sides, becoming somewhat paler dorsally, with a small circular yellowish grey area around the dark grey areola, iii palest, greyish yellow, rarely pale grey,