131 
is practically rid of the moult skin, though it has not yet reached 
its final form. The full-formed pupa (Fig. 66) is delicate, espe- 
cially so at the waist, and hardly mobile; it is dirty yellow, with 
the appendages somewhat glassy and well provided with knobs 
and spines. It measures 27 mim. long. The lateral processes of 
the abdomen probably assist in keeping the tender creature in 
position. I was in hopes of hatching this pupa, and although it 
got pretty far along in dev elopment, - it could not survive the at- 
tacks of the numerous mites of which I freed it daily. Unlike 
some of the stouter-skinned pupae, its movements were infre- 
quent and very slight. 
The wasp is much troubled by ants. One of the commoner 
Polyrhachis, a silk-spinning tree-ant represented in the Philip- 
pines by many species, happened to tumble into a_half-filled 
Ammobia burrows; the ant, not of an aggressive kind outside the 
domain of her nest, was much frightened and the wasp quite con- 
cerned, since, like most Fossores, she had a decided aversion to 
ants. Finally the Polyrhachis was gingerly seized in the wasp’s 
jaws and thrown out unhurt. Another Polyrhachis falling into 
this burrow was, after several half-hearted attempts on the part 
of the proprietress to eject her, allowed to crawl out. 
The heavy rains force the Pheidolegiton ants out of their bur- 
rows, and their obnoxious armies frequently traverse an Ammo- 
bia burrow. The wasp cannot cope with these myriad small but 
vicious creatures and so must abandon her work. If the burrow 
be but temporarily filled or partly exposed to rain, the ants are 
likely to raid it and destroy the contents. 
Larrinae. 
The members of this subfamily are smaller and usually more 
thick-set wasps than the Sphecinae and exceedingly active. The 
typical Larrinae prey on Orthoptera ( (crickets, grasshoppers, 
locusts, mantis, etc.), and many of the smaller species capture 
bugs. In Africa, Bridwell took Nitela, one of the smaller Larri- 
nae, that was carrying Psocidae to its nest. Some, as 7achytes 
and Liris, have deep, many-celled nest burrows, while Tach ysphex 
is noted for her shallow, one-celled tunnels. A few (Hylo- 
liris) nest in the forests, in decayed wood, but most like the 
hot sunshine. The eggs of the Larrinae are fixed transversely 
to the underside of the thorax of the paralyzed victim. The grubs, 
as far as known, have moderately large heads and the lateral 
tubercles of the thorax better developed than usual. The cocoon 
is a firm oval affair formed of agglutinized soil, wood dust, etc. 
The interesting manner in which the larva fashions this cocoon 
