The temporal distribution of Orthotomicus erosus (Woll.) beetles within a Pinus radiata plantation near Grabouw was recorded from weekly trap logs over a period of five years. O. erosus is summer active. The number of eggs and larvae produced by these beetles was monitored for two years and showed that colonization is followed immediately by brood production.
In a survey of Somalicus species in the main maize growing area of South Africa (the Maize Triangle) 15 species were found. The geographical distribution of false wireworms, Somaticus species, pests of maize, are determined.
The blood-meals of bedbugs (Cimex lectularius) were examined for serum protein haptoglobins (HP) in order to detect potential multiple feeding by these insects. If natural multiple feeds in bugs which have fed on human hosts with different Hp types can be detected this would indicate the likelihood of hepatitis B virus being transmitted mechanically between humans by interrupted feeding.
Culex univittalus Theobald was infected by intrathoracic inoculation with Sindbis virus and West Nile virus respectively. Salivary glands were dissected out after 7 and 20 days extrinsic incubation and studied by transmission electron microscopy. How the superior vector capability of Cx. univittalus with West Nile virus over Sindbis virus could be explained by these ultrastructural observations is discussed.
Fruit on orange trees Citrus sinensis (L). Osbeck adjacent to silky oak Grevillea robusla A. Cunn. windbreaks in the eastern Cape Province had more severe scarring due to citrus thrips Scirtothrips aurantii Faure than fruit on trees in the middle of the orchards or on trees in adjacent orchards with different windbreak species. The objective of this research was to verify these observations, especially as a general increase in the severity of citrus thrips damage in the eastern Cape appears to have coincided with an increase in the popularity of silky oaks as windbreaks.
Diafenthiuron (CGAI06630) is a new type of acaricide/insecticide (thio-urea) for the control of mites and sucking insects on cotton. In contrast to other acaricides applied on cotton, diafenthiuron exhibits good activity against homopterous pests. The residual activity of a single application of diafenthiuron was determined as well as the efficacy of the compound in a spray programme. The compound was also tested using commercial application methods (aerial sprays).
A revision of the Palparini (Neuroptera: Myrmeleontidae) is commenced with an introduction to the tribe and descriptionption of Pamares gen. nov., with four new species, P. parvus, P. nephele, P. damarus and P. deru, from the Namib Desert of southwestern Africa.
The possible use of Klugeana philoxalis as a biological control agent of Oxalis pes-caprae L. was investigated. The phenology of the insect coincides with that of O. pes-caprae. The effectiveness of the insect for biological control could be influenced by factors such as its univoltinism, the timing of larval feeding and the vulnerability of the pupae to agricultural activity.