About 7,000 recombinant clones, derived from chromosomally-identified families of wild-caught females of Anopheles dirus species D, were screened. The most promising clone was totally specific to species D when tested against single F1 females of all four species of the complex. In fresh specimens the clone was positive for DNA levels 150 times less than the normal DNA content of single individuals. Fresh adult males and females, larvae, and dried specimens have been successfully identified. The clone was sequenced; it is 124 bp long and appears to be repeated in the genome about 1.8 × 104 times.