1985] 
Brockmann — Digger wasps 
311 
(Brockmann, 1980). Unlike other members of the family, all Sphe- 
cinae gather up the loosened soil into a ball and carry it out of their 
burrow, holding the bolus up under the head with their front legs, 
while walking on the middle and hind legs (Olberg, 1959; Evans and 
West Eberhard, 1970; Brockmann, 1980). In most species the wasp 
drops her load immediately outside the nest entrance, which results 
in a mound or tumulus. This accumulated soil is later used for filling 
the burrow after the provisioning is complete. In contrast with this, 
Ammophila usually flies up with the armload of soil and drops it 
some distance from the nest entrance (Table 1A; Evans, 1959). 
Some Ammophila walk out of the nest carrying armloads of soil, 
but then drop them away from the nest entrance, usually in different 
directions (Table 1A). The effect of this is that the Ammophila do 
not usually have a distinct mound from which they can fill their nest 
during the final closure, as do other ground-nesting Sphecinae. 
There are four stages to nest-closure and each involves different 
kinds of behavior (Table 1 A; Evans, 1959). (1) The wasp closes off 
the chamber or blocks the bottom of her burrow, and then (2) fills 
in the main tunnel. (3) When the tunnel is nearly filled, she blocks 
off or levels the soil in the entrance and then (4) disguises the loca- 
tion of her nest. Most species of Sphecinae do not show a distinct 
closure at the bottom of the burrow, but rather begin immediately 
by filling the side and main tunnels with soil (Table 1A). Ammo- 
phila, on the other hand, does not usually fill the short side-tunnel 
but blocks the bottom of the main tunnel by adding a single large or 
several small stones, clods of soil, sticks or other debris. Sphecinae 
fill the main shaft of the burrow by adding soil, by alternating soil 
and stones or by adding just stones (a few species use mud) (Table 
IB). In nearly all species these materials are alternately added and 
packed. Most wasps remove some objects such as large stones, 
sticks and leaves, as they scrape and pack. They do this by pushing 
the object aside with their mandibles, by picking it up with the 
mandibles and depositing it to one side of the nest entrance or flying 
up and releasing it at some distance (Frisch, 1937, 1940; Evans, 
1959; personal observation). 
There are four different kinds of filling behavior used by the 
Sphecinae (most species use some combination of these four 
methods). (1) Standing at the nest entrance, the wasp scrapes soil 
underneath her and into the burrow with her front legs “dog- 
