3. Establishing crossing between field and laboratory
mosquitoes.
Field-caught mosquitoes from Elende were crossed with the FANG An.
funestus colony to allow segregation of the resistance allele already
at a very high frequency in the population. F1 larvae
from the field mosquitoes and larvae from the FANG colony were reared
until the pupal stage, then individually placed in 15ml tubes with 2ml
of water and stoppered with cotton wool. This was done to obtain virgin
female mosquitoes for each strain. Female field-collected mosquitoes
were crossed with male FANG to generate a field x FANG line. A
reciprocal crossing with the female FANG and the male from the field was
also generated. Only the female FANG crossed with males for the field
was successfully established. This line was maintained until the
F3 generation when bioassays were performed.