I think you should go ahead to perform the test. I believe that blood fed mosquitoes will give you best results since fed mosquitoes tend to rest more compared to unfed ones thereby enabling high exposure to the treated surface during the standard 3 minute duration of the test. the objective is to test mosquito susceptibility to the insecticide, whether fed or unfed.

Hi Hania, If I'm right the official WHO guidelines strongly suggest using non blood-fed mosquitoes. It makes sense because you need to test the efficacy of insecticides on mosquitoes before they feed on a host, as a good insecticide should be a form of control that prevent mosquito bites. Also, some chemicals may not directly kill the mosquito but impair their feeding or reproductive capabilities.

Anyway I think that if you're only testing the "direct" lethality of a compound, you can use BF mosquitoes (as Moses said). You should just be aware that if you publish your results a reviewer could potentially argue about the use of BF mosquitoes.

If you are using lab reared mosquito adults it is better to use unfed mosquitoes, However, this may not be feasible in case of field collected resting mosquitoes. One is likely to get all mosquitoes in all stages of gonotropic cycle in field resting collection...in that scenario one has no other option but to use even blood fed or even gravid mosquitoes depending on the mosquitoes collected

The ideal WHO assay will be on unfed mosquitoes, if not available in the field then lba reared female can be used, In field collected mosquitoes separate different gonotropjic cycle so that you may also find out different rate of susceptibility. Good luck

Preferably non-fed mosquitoes might be used for insecticidal bio-assays but if not available [in case of field collections] blood fed mosquitoes can also be used. We are maintaining Ae. aegypti colony in Lahore. If you are interested we can provide unfed mosquitoes to you as well.

If lab reared colony, Better to use nonfed 3-5 days old mosquitos.

In exceptional cases when lab rearing facility is not available then you can use field collected female mosquitos.

AS per WHO protocol we cannot use blood-fed mosquitoes. With blood, mosquitoes enzymatic profile changes which has a great impact on their response to insecticides

However, under certain conditions when you are doing trials in the field where mosquito rearing labs are not available, blood fed mosquitos can be used for WHO susceptibility and cone bioassays. Whereever possible nonblood fed 2-3 days old female mosquitos should be used for IR monitoring.

Best is to use unfed 2-3 days old female mosquitoes.

WHO guidelines recommend against the use of bloodfed mosquitoes and you don't know how this blood meal or what it contains might affect the outcomes of your insecticidal bioassays thus your results wouldn't be that reliable. Therefore, regardless of you are doing this for operational evaluation or scientific research it's better to rear these mosquitoes let them lay eggs and perform your bioassays accordingly to the WHO guidelines!

U can u unfed animal only use for any experiments and insect means u can use 2nd /3rd instar larvae.

The WHO bioassay guidelines categorically discourage the use of bloodfed mosquitoes for the bioassay. This is due to the fact that the bloodmeal might affect your result and also they (the mosquitoes) possess varying profiles (fitness, enzymatic) which can also affect your results. If you most use them, clearly state that you used bloodfed mosquitoes for the assay and this will greatly discourage the acceptability of the results.