TABLE 1.

Nitrogen fixation (C₂H₂ reduction) activity of termites examined in this study

Termite species	Termite family	Collection		Nitrogen fixation activitya (nmol of C2H4 formed/ h/g [wet wt])
		Originb	Date
Lower termites
R. speratus	Rhinotermitidae	Ogose	October 1996	16
C. formosanus	Rhinotermitidae	Okinawa	April 1997	79
N. koshunensis	Kalotermitidae	Okinawa	August 1996	210
C. domesticus	Kalotermitidae	Iriomote	April 1997	33
G. fuscus	Kalotermitidae	Okinawa	August 1996	31
H. sjoestedti	Termopsidae	Yakushima	July 1997	34
Higher termites
N. takasagoensis	Termitidae	Iriomote	October 1997	0.7
O. formosanus	Termitidae	Iriomote	April 1997	ND
P. nitobei	Termitidae	Iriomote	April 1997	2.5

^aThe activity was measured within 3 days after collection, except for G. fuscus, in which case it was 2 months after collection. Values are the averages of duplicate assays performed separately. ND, not detected. 

^bAll collection sites were in the Japan Archipelago. The Ogose district is in the Saitama prefecture at latitude 36°N. Yakushima Island is in the Kagoshima prefecture at latitude 30°N. Okinawa Island and the Iriomote Island are in the Okinawa prefecture at latitudes 26 and 24° N, respectively.