Hi D.Calvo, I used to work in an Aedes insectary, which is very similar to Anopheles in terms of maintenance. We had several problems in the beginning, including water choice. We used to use tap water (although we tried distilled water iwhen we started) and they developed very well. If the water has chlorine (as ours had) or other chemicals added, you may let the water aside for a few days before transferring your larvae into it. We also started using fish food, but we switched to turtle food and we noticed that they grew more and faster (adding 2 pellets once a day). They filter water and even if they are well fed, they are going to continue ingesting food, which can be harmful to them and may be the problem here.

Of course, you should change the water at least twice a week, carefully transferring them into a clean water pan, avoid dense populations in a single pan and make sure that the room has a fairly constant temperature around 25, 26 degrees. Hope it helps :)

Hi T, Souza. Thank you so much for your answer, it has been very helpful.

We had also problems with the water, and we are also using now tap water which it is open 24 hour before to use it for the larvae. We will check what you say about the food, it is probably that they are ingesting to much food in this stadium.

Thanks

Hallo D. Calvo possibility can also be caused by food. we also rearing Anopheles in our lab, but Anopheles sundaicus. we get a lesson from the research and development vector centers in Indonesia that for food we using a mixture of Dog food + meat + yeast  with 5 : 3 : 10 ratio. For the water, we also use a tap water, but we replace it every three days, indeed necessary adaptation of larvae in the water that we use.

Hope its usefull :)

If you feed the larvae twice a day this may be reason for L4 mortality probably due to the fatty and dirty debris. If you cannot reduce feeding rate, transfer the L3 larvae into a clean water, making sure that there is no old food debris and fat starting from L3. Good luck.

Thank you Renam and Thiery for you inputs. Indeed I am thiking to that an acumulation of fatty and dirty debris. I am planning to make a cleaning of the water at L3  and let see.

Dear Calvo,

Depending on your tray size and larval density, It seem to me that you are using high quantity of food. Anopheles are sensitive to food quantity. Please use 2-3 drops of  2% slurry of your diet. For more precise diet quantity  please read Khan etal 2013. Development of inexpensive and globally available larval diet for rearing Anopheles stephensi (Diptera: Culicidae) mosquitoes. Parasites and Vectors 2013, 6: 90. and 

Khan et al 2014. Effect of drying eggs, and eggs storage on hatchability and development of Anopheles arabiansis Malaria Journal 12: 318 

Hi Calvo;

I suggest you to use the Protocol of MR4 for rearing Anopheles, the title is Methods in Anopheles Research, there you can found the diet to prevent the over feeding, because most of the time that could be the cause. I work rearing Aedes aegypti.

The link below will take you to the document.

http://www.mr4.org/Publications/MethodsinAnophelesResearch.aspx