158 
She is one of the slowest and most steady of flyers, and may 
thus be distinguished on the wing from the large black Eumenes 
curvata, of similar size, which has a rather jerky flight and which 
she very superficially resembles. 
Z. cyanopterus in Java has certainly been wrongly consid- 
ered a social insect by Forbes (’85), and doubtless the ample 
proportions of its beautifully-fashioned nest of leaf-bits lend 
to this view. The nest is normally a structure of several 
months’ occupation, but is often appropriated by tree-inhabiting 
ants, as certain species of Crematogaster and Dolichoderinae, 
before its completion, and almost invariably after its abandon- 






Fig. 88. Zethus cyanopterus, @, X 2. 
ment by the mother wasp and her brood. It consists of from 
one to four cells, each bent at the neck and enlarged at the 
bottom. The oldest or uppermost cell is strongly secured to a 
twig, palm leaflet, rattan flagellum, vine, etc., as the case may 
be, and from its underside the second cell and then those follow- 
ing depend. A well-defined roof, likewise of leaf-bits and always 
characterized by a tail-like extension of variable length, shelters 
this group, which is finally covered over by layers “of leaf-bits 
until the whole affair assumes a shapely and ‘rounded aspect, 
(Fig. 89) 
For some time I was unable to locate the tree from whose 
foliage Zethus secured her leaf-bits, for she appears to patron- 
ize but a single species of tree. The wasp, in this case building 
in a hibiscus bush very conveniently situated on a lawn, would 
