Possible Clues:

• Mosquito of a genus of the same name
• There's a seal around the phone for this fly-by-night with a bite (9)
• Mosquito disturbing sleep on a hammock initially
• Germ-bearing mosquito
• Ha! No sleep? Swat the mosquitoes
• With a work he, Leslie, is the sort of 9 down to make one 1 across