Inland floodwater mosquito 
Iridescent Bromeliad Fly 
Ischnotoma eburnea 
Iteomyia salicisverruca 
Jantia crassipalpis 
Jewelweed Gall Midge 
Jewelweed Vein Gall Midge 
Juriniopsis adusta 
Kite-tailed Robberfly 
Kribiodorum perpulchrum 
Ladder-backed Hover Fly 
Lagenosoma dispar 
Lamprolonchaea brouniana 
Laphria asturina 
Laphria divisor 
Laphria saffrana 
Laphria sericea complex 
Laphria virginica 
Large Bee-fly 
Large Marsh Horse Fly 
Large-tailed Aphideater 
Lasiopa villosa 
Lauxaniid Fly 
Lenophila achilles