This paper continues a series revising the South African and Ethiopian species of the bothriothoracine genus Metaphycus Mercet, 1917; the other papers in the series may be found in Annecke & Mynhardt (1971, 1972, 1979), Annecke & Insley (1971) and Annecke & Prinsloo (1977). The species of the group dealt with here all have the maxillary and labial palpi each with two segments, and belong in what Compere & Annecke (1960) called the 'hederaceus-group' of Metaphycus, a group of species named after the old M. hederaceus (Westwood 1837). Graham (1969) showed that this name was untenable, for Westwood's hederaceus belongs not to Metaphycus but to Aphycus Mayr.
The first known southern African Habropogon species, H. capensis, is descriptionbed. The genus Habropogon is primarily Palaearctic in distribution; apart from one other species recorded from southern Saudi Arabia, this is the only Afrotropical representative of the genus. A second species is added to the genus Hermannomyia. H. oldroydi from Lesotho and the Cape Province of South Africa is descriptionbed and compared with the type-species, H. engeli (Hull), which is recorded from Zimbabwe and South Africa.
Two fossilised termite nests from Clanwilliam were shown by radiocarbon dating to have been formed in late Pleistocene times. Clearly discernible in the limestone matrix are traces of structures closely resembling the fragile dark shelving which fills the nest cavities of two extant species of Hodotermitidae in South Africa. It is suggested that the fossilised nests were more likely to have been constructed by an ancestral form of Microhodotermes viator (Latreille) than of Hodotermes mossambicus (Hagen).
Certain understandable morphological changes take place in Trox Fabricius species concomitant with the loss of the hind wings. These changes and their relationship to habitat are discussed, and possible reasons for aptery in Trox are proposed.
This paper concerns the genus Concroce and is the second in a series revising the southern African Crocinae (Neuroptera: Nemopteridae). The first dealt with the genera Laurhervasia Navas and Thysanocroce Withycombe, and provided a general introduction to the series (Mansell 1980).
Data associated with three series of specimens of Ycaploca evansi Nagy from South Africa add to earlier evidence that this species parasitises larvae of Cerambycidae and suggest that many individuals develop on a single host larva.
Six species of Tropiduchidae have been earlier recorded from the Mascarenes, five of them having been assigned to the genus Clardea, the sixth being Conchyoptera unicolor Signoret. Laberia palliata Stal, which was descriptionbed, probably in error, from Mauritius (Stal 1866), and which has sometimes been considered a tropiduchid (Melichar 1923; Fennah 1958), is in fact a nogodinid (Fennah 1978).
C. paralia was found to be a solitary endoparasite. The larva left its host just before completing its development and pupated near the remains of its primary host inside the mummified scale insect. It preferred encyrtids as primary hosts and could develop as a tertiary parasite in larvae of its own species. The developmental threshold was 11,2ï¿½C and the thermal constant was 202,7 day-degrees. Rearing C. paralia in a host only half as big as M. flavus reduced the body size to about half and the female percentage by more than half. Adult life span was little affected by low relative humidity. Females lived longer than males. After a pre-oviposition period of about two days they laid on average 62,6 eggs each, almost all during the first half of their life.
Marietta javensis was found to be a solitary ectoparasite. Eggs were laid on the pupa of the primary host or attached to the inner surface of the integument of the scale insect. The threshold temperature for development was 13,8 ï¿½C and the thermal constant 218,8 day-degrees. The female percentage of hyperparasites emerging from large hosts was more than double that from small ones. The life span of females was not reduced at 0% as compared with 50% RH, but that of males was only one-quarter as long as at 50% RH. Females lived longer than males on honey but not so long as males on water, pollen or without any food.
P. concolor was found to be a solitary ectoparasite. The calculated threshold temperature for development was 9,8 ï¿½C and the thermal constant was 242,6 day-degrees. Only males developed from eggs laid on a small host-species (Metaphycus flavus (Howard)) and were 41% smaller than males that developed from eggs laid on a larger host-species (Microterys flavus). At 28 ï¿½C the life span of females at 0% RH was only one-fourth as long as at 50% RH. The life span of both sexes without any food or with pollen or water was very short (1-3 days) as compared with that with honey (3-30 days).
The object was to find an insecticide to replace BHC for control of L. pardalina. Gamma-BHC and eight other insecticides were applied topically to adults and hoppers. DDVP, cidial, S2957 and naled were more toxic and faster-acting than BHC. The acute toxicities of diazinon and fenitrothion were similar to that of gamma-BHC, but both acted faster than BHC. Carbaryl and mercaptothion were less toxic than BHC but had the same speed of action.