FIGURES 27–33 in Nesting biology and immatures of the oligolectic bee Trachusa larreae (Apoidea: Megachilidae: Anthidiini)

FIGURES 27–33. Microphotographs of two cells from which closure had been removed before defecation had started. 27. With the cell maintained in a vertical position in the laboratory during defecation, the larva still applied most feces to the anterior end of the cell resulting in this display. It demonstrates that the stimulus to the larva as to where to place feces is obviously not gravitational in nature and suggests that cell shape and/ or texture of the inside of the cell closure (despite the fact the closure had been removed earlier) might be the stimulus (as had been suggested by Cooper, 1957). 28. Same cell, 3 days later, larva now adding abundant silk forming base of nipple; note outer cocoon layer, layer of pale anal discharge, and thick base of nipple. 29. Same cell, 2 hr later, showing white silk of outer dome. 30. Same cell, one day later, dome of nipple now complete with color mostly changed. 31. Same, four day later, final coloring; note conspicuous display of finegrained, pale-yellow discharge surrounding nipple. 32. On another cell (cell opening misshaped) dome partly constructed, still white. 33. Same cell, 12 hr later, fibers now reddish.