Lucie M. Rogo

Biochemical identification of Phlebotomus (larroussius) pedifer and Phlebotomous (larroussius) elegonensis

Abstract Females of the vector of Leishmania aethiopica, Phlebotomus pedifer , have previously been morphologically indistinguishable from the non-vector, P. elegonensis . The present studies have biochemically separated these two species. Differences were observed in the mobility of four enzymes, GPI, HK, ICD and PGM on thin-layer starch gel electrophoresis. Using the isoelectric focusing technique, the two species could be differentiated by one enzyme, GPI.

A Study of the Mononychellus (Acari: Tetranychidae) Species Complex from Selected Cassava Growing Areas of Africa Using Principal Component Analysis

A study of several populations of the cassava green mites from eleven African countries representing wide ranging ecological zones were studied using a Principal Component Analysis. This study revealed that there is only one species of the Mononychellus present on cassava in Africa and is here designated M. tanajoa.RésuméUne etude de plusier populations des acariens vertes du manioc de onze pays africains représentant une zone écologique variée a été faite en utilisant l’analyse de la composante principale. Cette etude a démontré qu’il a qu’une seule espèce de mites du genus Mononychellus présente sur le manioc en Afrique et cette espèce est appellee Mononychellus tanajoa.

Salinity relationships of mosquitoes breeding in a brackish pond on the Kenya coast

A large pond, up to 2000 m2 area, adjacent to the sea at Jimbo, near Vanga, on the south coast of Kenya was studied for salinity and the presence of mosquito larvae 1980–1981. Rainfall peaked in November-December 1980 and again in March-May 1981, while salinity of the pond-water fluctuated inversely from dryness in February, more than 100% seawater equivalent in months before main rains, to below 13% seawater after the onset of rain in March.Five types of mosquito larvae occurred in the pond: Aedes albocephalus mostly at 21–30% salinity (range 13–30%); Culex sitiens mostly at 31–40% salinity (range 13–54%); Culex tritaeniorhynchus and Culex thalassius mostly at 41–50% salinity (range 13–50%) and the Anopheles gambiae complex from 13 to 54% salinity, at least those at higher salinities being Anopheles merus. No larvae were present when salinity surpassed 54% through evaporation, or fell below 13% after rain. The most reliable way to limit or control these pest and vector mosquitoes at Jimbo would be to drain the pond into the sea after rainfall, so that mosquito populations could not increase by breeding sequentially, while salination proceeds.

A Discriminant Function for the Short- and Long-Setaed Forms of the Mononychellus (Acari: Tetranchidae) Species Complex

A function for distinguishing between the long, intermediate and short-setaed forms of Mononychellus species complex is described. The results show that the dorsal-central body setae, variable D3, with a discriminant correlation coefficient of 0.99, was the most important variable. Five other variables, lengths of dorso-central body setae D1, D2, laterals L1, L2 and propodosomal P2, which had significant discriminant correlations (0.28 to 0.35) with the function were, however, included in the discriminant function.RésuméLa fonction décrite permet la distinction des formes à soies longues courtes ou intermédiaires des espèces du complexe Mononychellus. Les résultats prouvent que la soie dorso-médiane (variable D3) est de loin la plus importante, avec un coefficient de correlation discrimante de 0,99. Cinq autres variables-D1, D2, Latérales L1 et L2 et propodosomale P2-présentant des coefficients de correlation discriminante significatifs (0,28 à 0,35) n’ont néanmoins pas été inclus dans la fonction.