FORAGING PATTERNS OF HALICTID BEES 
AT FLOWERS OF CONVOLVULUS ARVENSIS' 
By Keith D. Waddington 
Department of Entomology, University of Kansas, 
Lawrence, Kansas 66045 
Introduction 
An animal may acquire food in one of three general ways: 1) it 
may move through the environment in search of food, independently 
of other animals utilizing the same resource; 2) it may avoid other 
animals, resulting in an evenly spaced distribution of animals 
(Ricklefs, 1973; Chapter 18); or 3) it may forage with other animals 
in single or mixed species groups. Group foraging has recently been 
described for a variety of animals: ants (Bernstein, 1975), bats 
(Heithaus, Opler, and Baker, 1974), and birds (Cody, 1971; Ward, 
1965). Since the acquisition of food is a likely determinant of an 
animal’s ability to survive and reproduce, the strategy used is prob- 
ably a result of natural selection for individuals which forage most 
efficiently. 
Few studies have been conducted to investigate the foraging 
strategies of bees. This information is essential to understanding 
pollen flow and the general pollination biology of natural vegetation 
and agricultural crops. Kalmus (1953) found that visual and olfac- 
tory cues are important in the mutual attraction of honeybees at 
dishes of sugar syrup, resulting in non-independent foraging. 
Frankie, Opler, and Bawa (1974) reported that males of Centris sp. 
commonly forage over the forest canopy in Costa Rica in groups 
of up to 300 bees. Charles D. Michener (pers. comm.) has observed 
bees (families Colletidae and Anthophoridae) foraging on flowers 
of the bush Chrysothamnus sp. in apparent aggregations. He has 
observed that while one or two bees might be at a clump of bushes 
at any time, large numbers seemed to appear, more or less simulta- 
neously, at the bushes, and after a time most of them left more or less 
suddenly. These bees seemed to be foraging in groups, not independ- 
ently from one another. In this paper quadrat censusing techniques 
Contribution number 1610 from the Department of Entomology, University of 
Kansas, Lawrence, Kansas 66045, U.S.A. 
Manuscript received by the editor February 16, 1976. 
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