Larvae of potato tuber moth were exposed to infection by granulosis virus material on potato tubers and tobacco plants. Significant mortalities were generally recorded at the different dosage rates in larvae of all instars on potatoes. Injury to tobacco leaves however, remained at an economically unacceptable level even after virus infection. An electron micrograph of the pathogen confirms its identity as a granulosis virus, similar to a virus which controls tuber moth on a field scale in Australia.
In a sample of 29 males and 102 females of Ixodes pilosus Koch, removed from Bush Buck and Duiker, 51,7% of males were attached to the host. The remainder were in association with females; 24, I % in copula and 24, I % attached to females. Of the females, 90,2% were unpaired, 6,9% in copula, while I % were parasitized by a single male and 2% were parasitized by 3 males. A large spermatophore sac protruded from the genital aperture in 5,9% of females, while in a number of others spermatophores were in various stages of deflation.
Collections of adult and nymphal Odonata were taken from semi-arid aeolian sand regions of Wankie National Park in which the only aquatic environments range from ephemeral rainpools to larger seasonal lakes. Both imaginal and nymphal collections include large numbers of a few species. Hemianax ephippiger (Burm.), Pantala flavescens (Fabr.) and Palpopleura sp. comprise 90% of identifiable nymphs. Lestes pallidus Rambur f. ochraceous Selys., Ceriagrion suave Ris., Hemianax ephippiger (Burm.), Brachythemis leucosticta (Burm.) and Philonomon luminans (Karsch.) predominate among imaginal forms. The range of physico-chemical conditions under which nymphs were found is recorded and the probable breeding success of certain species in these pools is discussed. Comparison with previous records of Odonata from temporary rainpools in Africa suggests that species are highly adapted to such habitats by the dispersal mechanisms of the imago which ensure efficient colonisation of such habitats, by the rapid nymphal growth rates which enable the life history to be completed before the pools dry up, and by the nymphal tolerance of rapid fluctuations and wide ranges in environmental conditions.
Chlorotettix parabolatus is transferred to the genus Tetartostylus Wagner and the new genera Renosteria and Hiltus are erected for C. spadix and C. africanus respectively. Thamnolettix angulata is transferred to the genus Neoaliturus Distant and T. rugulans to Recilia Edwards; T. decimnotatus could not be placed as no males are available. Scaphoideus cuprescens is transferred to a new genus Capoideus and Selenocephalus planescens is transferred to the genus Distaneia Signoret. Two new species are also descriptionbed, i.e. Hiltus gilvus and Bonsapeia ceresi.
The status and identity of the cochineal insects currently assigned to the genus Dactylopius O. Costa, 1835 are discussed. Altogether nine species, five old and four new, are dealt with: D. austrinus spec. nov.; ceylonicus (Green, 1896); coccus O. Costa, 1835; confertus spec. nov.; confusus (Cockerell, 1893); opuntiae (Cockerell, 1896); salmianus spec. nov.; tomentosus (Lamark, 1801) and zimmermanni spec. nov.
The larvae of Spodoptera spp. are of varying economic importance in the spheres of agriculture and horticulture in southern Africa. They include the African armyworm, S. exempta (Walk.), the lesser armyworm, S. exigua (Hubn.), the lawn caterpillars, S. capicola H.-S. cilium Cuen.), and S. triturata (Walk.), and the cotton leaf worm, S. littoralis Boisd. It is well known that there are phase variations in the armyworms S. exempta and S. exigua (Faure, 1943a and I 943b), and one of the main reasons for constructing a key is to enable identification of the passive phase of S. exempta. The latter is very similar in colour and markings to the non-phasing species, particularly S. capicola and S. triturata.