PROC. ENT. soc. WASH., VOL. 22, xo. 6, JUNE, 1920 119 



is not usually the case in termites. The compound eyes in- this 

 apterous pigmented form are vestigial; the ocelli are as in the 

 winged adult. There are also differences in the antennae of the 

 reproductive forms. See Table I. 



y.orotypus lives under conditions closely similar to termites, in- 

 habiting runways under bark on dead standing trees or logs, 

 where it is moist. Often termites are present, and indeed Zoro- 

 typus at first was believed to be a "termitophile" or "inquiline.' 

 Both insects pass the greater portion of their lives in the dark, 

 (Caudell, 1918 and 1920). 



Mobility of the Reproductive Forms. 



Queens of all three types of reproductive forms of Nearctic 

 termites are more or less active at all periods of their life time, 

 are not imprisoned in a permanent cell and never lose their power 

 of locomotion as do the queens of tropical species which are im- 

 prisoned in a permanent, central "royal" cell in a stable colony. 

 The Xearctic queens do not attain the size they are less than 

 one inch in length nor is their rate of egg laying as great as that 

 of the queens of tropical species. This must be an advantage, 

 since certain species of Rcticulitcrmes, subterranean in habit, are 

 able to go below the frost line in winter and adapt themselves 

 to the most favorable conditions of temperature and moisture 

 when either above ground in wood or in subterranean galleries. 

 Probably in the prairie regions of southwestern United States 

 the reproductive forms are also below ground during long periods 

 of drought when the ground is dry and caked hard ; at any rate, 

 they have not been found above ground. 



The queens of tropical termites often reach very large dimen- 

 sions, several inches in length, and become immobile, egg-laying 

 machines. Adequate protection is afforded to these large queens 

 by the huge mounds of great hardness or, in the case of species 

 the queens of which do not attain such large size, but are over 

 one inch in length, by the large spherical tree nests of tough 

 texture. 



The queens of Nearctic termites that live in wood only i species 

 in genera of the family \\aloiermitidae Bks.) are more mobile and 

 their abdomens become relatively less distended than those of 

 subterranean species which are able to retreat to underground 

 galleries. 



In young or "incipient" colonies the young first form adults 

 must do all the excavating and forage for themselves. Later, 

 after they have reared broods of workers and soldiers, the former 

 feed them and gradually their rate of egg laying at first very 

 slow increases. Eventually the abdomens of mature queens 



