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Wednesday, May 9, 2007

ANIMAL TRACKER

Four-spot midget


* Japanese name: Hinuma itotombo
* Scientific name: Mortonagrion hirosei
* Description: "Four-spot midget" is an odd name for an insect, but in this case it is entirely accurate. This is a tiny animal, just 25-mm in length with four distinct spots on the top of the thorax. Males and females are the same color, a delicate jade green on the underside of the eyes and thorax. The abdomen is gray-brown, and the top of the thorax and eyes are dark brown. The four thoracic spots are jade.
* Where to find them: From Honshu to Kyushu, in reed beds in brackish waters. Discovered rather recently — in 1972 — it is thought to be the last new species of odonate (the collective name for dragonflies and damselflies) to be described in Japan. This is quite a distinction for the country known in ancient mythology as Akitsushima, which means "Land of the Dragonflies." It is a globally endangered species, and perhaps the rarest dragonfly in Japan, because its already rare habitat of saltwater reeds is disappearing. For this reason the IUCN Species Survival Commission Odonata Specialist Group recommend it as a priority species for protection. Reed cutting has caused the local extinction of the damselfly in some parts of Japan as this removes stems of reeds that the animal uses to lay eggs into. Its flying season spans from May to October
* Food: Small flying insects, with the emphasis on small. Adults catch midges and mosquitoes that live in reed swamps. The larvae of the four-spot midget are naturally small, but are voracious predators. They do us a favor by devouring the larvae of midges and mosquitoes. For this reason it has been considered a potentially good species to introduce into the southeastern United States, where mosquitoes living in brackish waters can be a health problem.
* Special features: This damselfly is highly unusual in that it's a halophile, which literally means "salt lover." Almost all other odonates prefer clean, freshwater, but this one likes salty water. The larvae are therefore adapted to the different conditions — such as lower oxygen content — found in brackish water.

PHOTO COURTESY OF BIO-IMAGE NET



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