1981] 
Tepedino & Parker — Flower-Visiting Insects 
329 
Waddington, K. D. 
1976. Foraging patterns of halictid bees at flowers of Convulvulus arvensis. 
Psyche, 83:112-119. 
Zar, J. H. 
1974. Biostatistical Analysis. Englewood Cliffs, N. J.: Prentice-Hall. 
Zimmerman, M. 
1981. Patchiness in the dispersion of nectar resources: Probable causes. 
Oecologia, 49:154-157. 
