Early biting rhythm in the afro‐tropical vector of malaria, Anopheles arabiensis, and challenges for its control in Ethiopia

Abstract

The biting cycle of the malaria vector Anopheles arabiensis Patton (Diptera: Culicidae) was assessed by hourly light trap collections in three villages in Tigray, northern Ethiopia. Hourly catches were conducted in two houses in each village, for four consecutive nights. Light traps were set from 18.00 hours to 07.00 hours in houses in which people slept under untreated bednets. Anopheles arabiensis showed early biting activities, which peaked between 19.00 hours and 20.00 hours in the three villages; over 70% of biting activity occurred before 22.00 hours, when people typically retire to bed. This early biting activity may have a negative impact on the efficiency of bednets to control malaria.

Do Long Lasting Insecticidal Treated Nets Alone and Long Lasting Insecticidal Treated Nets plus Indoor Residual Spraying combination have an effects on Anopheles arabiensis Patton (Diptera: Culicidae) population densities, biting cycle, biting places and biting rate; A randomised Control Trial in central and eastern, Sudan.

“…[25] [4] [26] [27] In this study the biting activity of Anopheles arabiensis was found to extend throughout the night with the peak commencing in the early hours of the night (first quarter 1900 -2200) before the inhabitants go to bed. Similar results were reported in a previous study in Northern Ethiopia which reported that the peak time initiated at early time of the night 1900 hrs after 40 years of DDT IRS [28] Over 64% of biting activity occurred before 24.00 hours, when people typically retire to bed. This early biting activity may have a negative impact on the efficiency of bed nets to control malaria.…”

Early biting of the Anopheles gambiae s.s. and its challenges to vector control using insecticide treated nets in western Kenya highlands

“…Human biting by malaria vectors has been shown to occur well before the house occupants slept under ITNs as was observed in Ethiopia where 70% of females Anopheles arabiensis were biting before 2200 h (Yohannes and Boelee, 2012). A similar scenario for the species was reported in Dar es Salaam Tanzania (Geissbühler et al, 2007).…”

Variation in the effectiveness of insecticide treated nets against malaria and outdoor biting by vectors in Kilifi, Kenya

“…species complex, An. arabiensis was more prevalent, which is known to be capable of feeding extensively on humans early in the evenings, before humans go indoors 54 . This shift in sibling species composition has previously been reported 6, 19 .…”