Differential Effects of Pesticide Applications on Liriomyza huidobrensis (Diptera: Agromyzidae) and its Parasitoids on Pea in Central Kenya.

Three Liriomyza species [Liriomyza huidobrensis (Blanchard), Liriomyza trifolii (Burgess), and Liriomyza sativae Blanchard] have been reported as the most important leafminer pests in vegetable production systems in Africa. In Kenya, farmers rely on indiscriminate synthetic insecticides use. On-farm field investigations were set up at three different locations (Sagana, Kabaru, and Naromoru) in central Kenya to determine the effect of pesticide application on the abundance of leafminers and their parasitoids under three management practices, namely: farmer practice (FP), reduced pesticide use (RP), and a control with no use of pesticides (CO). In addition, laboratory experiments were designed to test the effect of commonly used pesticides in pea production systems in central Kenya--Dimethoate, Dynamec, Thunder, Cyclone, Bestox, Folicur, Milraz, and Bulldock--on L. huidobrensis and two of its parasitoids, Diglyphus isaea Walker and Phaedrotoma scabriventris Nixon. The mean numbers of leafminer flies in control treatment were higher than in RP and FP in both first and second seasons across all sites, but RP and FP did not differ significantly. Parasitoid numbers were very low and there was no much variation between treatments at each location in both first and second seasons. No significant differences were observed between the three management practices with regards to the yield measurements. In the laboratory, the estimated LD50 values for L. huidobrensis larvae were all more than two times higher than the recommended dosages, while the LD50 of adults were below the recommended dosages. The estimated LD50 values for the parasitoids were much lower than recommended dosages for all pesticides except Thunder. This study, therefore, demonstrates that the pesticides currently used do not control the Liriomyza leafminer larvae that constitute the most destructive stage of the pest, but are rather detrimental to their parasitoids. In addition, the current low level of parasitoids recorded under field conditions even where no pesticide was used during this study, warrants consideration of classical biological control programs.

Partner notification in the management of sexually transmitted infections in Nairobi, Kenya.

OBJECTIVE: To assess utilization of partner notification as a tool in prevention and control of Sexually transmitted infections in Nairobi City Council clinics. DESIGN: A cross-sectional study carried out between April and September 2000. SETTING: Nairobi City Council health clinics were stratified into eight administrative divisions and a total of 16 out of 54 primary health clinics with at least four STIs patients per day were selected. A standard questionnaire was administered to every fourth patient with clinical diagnosis of STIs who gave consent on exist. Sexual partners referred by index cases during the five day period from each clinic were also enrolled into the study. An additional questionnaire was administered to HCP who were managing STIs patients and their sex partners. RESULTS: Of 407 STIs patients recruited between April and September 2000, 20.6% were primary and 2% were secondary referrals giving an average referral rate of 23%. Respondents with multiple sex partners were less likely to refer their partners compared to those who had one partner (17.9% vs 82.1%, p < 0.005). Counseling of STI patients on the importance of partner referral was more effective than issuing referral cards alone (72.8% vs 56.8% % p = < 0.006). Barriers to partner notification included partners being out of town (44.6%) fear of quarrels and violence from partners (32.5%) and casual partners (15.1%) whose sex partners were unknown. CONCLUSION: Counseling and understanding of STIs patients on the need to treat all sexual partners is pivotal to the success of partner referral.

Effects of neem seed derivatives on behavioral and physiological responses of the Cosmopolites sordidus (Coleoptera: Curculionidae).

Both in a choice and multi-choice laboratory tests, fewer adults of the banana root borer, Cosmopolites sordidus (Germar), settled under the corms of the susceptible banana "Nakyetengu" treated with 5% aqueous extract of neem seed powder or cake or 2.5 and 5% emulsified neem oil than on water-treated corms. Feeding damage by larvae on banana pseudostem discs treated with 5% extract of powdered neem seed, kernel, or cake, or 5% emulsified neem oil was significantly less than on untreated discs. The larvae took much longer to locate feeding sites, initiate feeding and bore into pseudostem discs treated with extract of powdered neem seed or kernel. Few larvae survived when confined for 14 d on neem-treated banana pseudostems; the survivors weighed two to four times less than the larvae developing on untreated pseudostems. Females deposited up to 75% fewer eggs on neem-treated corms. In addition, egg hatching was reduced on neem-treated corms. The higher the concentration of neem materials the more severe the effect.