http://news.cqnews.net/html/2012-07/04/content_17139760.htm
国际在线专稿：据《每日邮报》7月3日报道，研究人员日前在泰国发现世界上最小的苍蝇，这种苍蝇通体只有0.4毫米长，大小同盐粒相当，甚至还要小。它们常常寄生在蚂蚁的脑袋内部，长到一定程度后再将寄主“斩首”。
　　这种叫做Euryplatea nanaknihali的极小苍蝇是蚤蝇（Phoridae）的一种，体型比普通家蝇要小15倍，比普通果蝇小5倍。
　　蚤蝇以斩杀蚂蚁著称，这种蝇科昆虫将卵产在蚂蚁体内，当卵变成幼虫之后，便以蚂蚁的脑袋为食，直到最后使蚂蚁的头颅落地。
　　这一发现证明即使是世界上最小的昆虫也可能成为寄生虫的猎物，研究人员称，Euryplatea nanaknihali能将头部仅有0.5毫米大的蚂蚁“斩首”。

Teeny Fly Likely Cuts Off Tiny Heads

Fruit flies are pretty small. But they laugh at a species of fly recently discovered in Thailand. Dubbed Euryplatea nanaknihali, this member of the phorid fly family is less than half a millimeter long—a fifth the size of a fruit fly.
But before you ooh and aah over the “cute widdle bug,” bear in mind that it probably makes its living cutting off the heads of tiny ants. The fly is described in the Annals of the Entomological Society of America. [brian v. brown, small size no protection for acrobat ants: world's smallest fly is a parasitic phorid (diptera: phoridae)]
Many phorid species lay their eggs in living ants. The newly hatched larvae move to the ants’ heads, feed on them and eventually decapitate them.
But some ants were considered immune to the parasitic threat because they were too small for any known fly species to fit into their heads. With the discovery of the littlest phorid fly, however, that size advantage—or rather, lack-of-size advantage—vanishes.
It’s not definite yet, but the new little fly probably is an ant eater: its pointy abdomen is well adapted to pierce an ant’s body for egg-laying purposes. How adorable is that?