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Psyche 
[Vol. 92 
Fig. 1 . Sphex ichneumoneus filling her nest. The wasp stands at the nest entrance 
(facing away) and scrapes soil between her legs, using the tarsal rakes on her prothor- 
acic legs. She starts close to the nest entrance and gradually works her way up the 
mound. This means that early in a bout of scraping, the soil is flung into the burrow, 
whereas later the soil lands close to the nest entrance, and is thrown into the burrow 
during the next bout of scraping. Scraping is accompanied by frequent biting at the 
substrate with the mandibles to loosen the soil. The same behavior was observed in 
Sphex pensylvanicus. 
Fig. 2. Sphex ichneumoneus nudges soil into her burrow. After scraping, the 
wasp turns around and walks down the mound toward her burrow. She often pauses 
at the nest entrance and nudges at the soil around the lip of the burrow. She pushes 
the soil ahead of her using the front of the mandibles and clypeus in quick, short, 
posterior to anterior motions of the head. Similar nudges were observed in S. 
pensylvanicus. 
