Methods in Anopheles Research - MR4

Chapter 2 : Anopheles Laboratory Biology and Culture2.4 Anopheles Culture2.4.9 Anopheles Adult DietPage 1 of 22.4.9 Anopheles Adult DietMR4 StaffIntroduction6% glucose, 10% v/v corn syrup, 10% w/v sucrose, and dilute honey are common sugar sources for adultmale and female mosquitoes. These can be provided using soaked cotton balls lying on top of a cage ifthe mesh is non-absorbent (e.g. nylon rather than cotton). This requires ensuring that the cotton stays wetenough for the mosquitoes to drink the sugar. Sugar pads normally need to be changed no less thanevery week because mold spores and fungi grow well on exposed sugar pads. 0.2% methylparabenadded to a sugar source can extend the time before the sugar source begins to collect mold spores thatare harmful to mosquitoes without causing early mortality or reduced longevity (Benedict 2009). In thiscase, sugar sources can be left unchanged for 30 days as long as they stay wet.Cleanliness of sugar water and cotton balls is of the utmost importance.After a bag of cotton balls is opened, mold spores can settle on themimmediately. Cotton balls can be sterilized by autoclaving and should bestored in sealed containers.One way to avoid having to moisten sugar pads is to use a hangingfeeder that holds soaked cotton (Figure 2.4.9.1). This example consistsof an inverted sample vial (Fisherbrand Polystyrene Sample Vial (20ml)Cat. No. 03-341-13) hung in the cage. A hole has been punched in thecap (at the bottom) to allow mosquitoes access to the soaked sugar pad.The vial hangs from a bent wire inserted into the vial base by heating thewire and forcing it through the plastic. Two large cotton balls are soakedwith sterilized sugar solution and then placed in the vial. This orientationhas the advantage that Anopheles will seldom lay eggs in it, and it willremain moist for 1 week without attention. If using such a source, thesugar vials and covers should be bleached between use and stored in aclosed container to prevent mold spores from accumulating on them.Figure 2.4.9.1. Invertedhanging sugar vial.Another alternative is to fit theopening in the cap (as shown inFigure 2.4.9.2) of the invertedfeeder with a piece of porousplastic large enough for the mosquitoes to feed through but smallenough that water does not drip. The porous plastic center in thephotograph to the left was obtained from Small Parts Inc., catalogno. SPE-040-20. This modification allows for pouring the sugarwater directly into the feeder with no need for cotton. Using thishanger in combination with sugar water containing methylparabensolution should require no attention for about 30 days.Figure 2.4.9.2. Cap of feeder witha porous plastic insert.ReferencesBenedict MQ, Hood-Nowotny RC, Howell PI, Wilkins EE (2009) Methylparaben in Anopheles gambiae s.l.sugar meals increases longevity and malaria oocyst abundance but is not a preferred diet. J. Insect Phys.55: 197-204.