212 
HYMENOPTERA. 
in section. In making a cell, the wasp brings a pellet of mnd and 
spreads it out in a curve ; she brings more and more, working it all up 
into a wall rising from the base she builds on, and curving inwards till 
there is a small round aperture left; she then puts on a neat rim (Fig. 117) 
and the cell has just the appearance of the upper half of an ordinary 
Indian gylah (water-jar). Through the opening she slips paralysed 
caterpillars, usually green semiloopers (Plate X, Figs. 1, 2); if they are 
large, three to five is enough ; if not, as many as eight are put in. The 
egg is laid before the caterpillars are put in and hangs by a thread from 
the roof of the cell; when the cell is stocked the rim is demolished and 
the cell closed ; another is then begun above and when the full number 
are made, the whole is finished off with mud evenly. The wasp is very 
sensitive to disturbance and readily abandons the cells ; if the cell is 
more than half stocked, the transformation still takes place though the 
wasp is of a much smaller size. When a cell is partly demolished and 
left undisturbed, the wasp will often repair the damage and in this res¬ 
pect she shows a much less fixity of instinct than does Sceliphron for 
instance. The complete making, storing and closing of a cell usually 
occupies one day. 
The egg is a delicate white object, about 4 m.m. long and hanging 
by a stalk about 1*5 m.m. long. On hatching the larva puts out its 
head but does not leave the egg shell so long as it can feed from it; 
it attacks the nearest caterpillar and only when it has grown a little 
does it leave the egg shell completely. When it has eaten all the cater¬ 
pillars it spins a delicate cocoon, pupates and emerges. The imago then 
cuts through the cell and escapes. Chrysis orientalis, Guer., Stilbum 
cyanurum, Forst., Chrysis fuscipennis, Br., and a Tachinid parasitise this 
species, and in one case every cell of a nest of ten contained a Chrysid. 
Eumenes edwardsii has been reared from a clay cell, oval with rounded 
ends, found on a blade of grass. 
Rhynchium has similar habits, collecting caterpillars, and is found 
everywhere : the common species are R. hwmorrhoidale, Fabr., R. brun- 
neum, Fabr., R. abdominale, Ulig., and R. nitidulum, Fabr. The last 
makes a cluster of up to 25 oval cells coated with black gummy mate¬ 
rial in which are stored her prey. R. brunneum , F., stores her nest with 
