92 
Psyche 
[June 
This may possibly be to orient to the sun in order to continue rolling 
in the same direction as before. 
Summary 
The natural behavior in the field of the common Eastern tumble- 
bug Canthon pilularius (L.) is discussed. Two types of dung balls 
are made: food balls and brood balls. The former are made, rolled, 
and buried by a single beetle of either sex to serve as food for itself, 
the latter are made, rolled, and buried by a male, accompanied by 
a female, to serve as food for a single larva. 
Both types of balls are made, rolled, and buried similarly and 
involve a succession of separate processes. Time intervals and meas- 
urements are given for each phase of the behavior sequence. The 
brood ball is shaped much more carefully than the food ball and is 
a more perfect sphere; it is rolled farther and buried deeper. 
The direction in which a ball is rolled away from the dropping 
was found to have some relationship to the slope of the ground, the 
wind direction, and the position of the sun, in that order of priority. 
Some discussion of sun orientation is presented. 
The male is always the active partner in relation to the brood ball 
— he initiates ball making before the female joins him, he rolls the 
ball entirely, defends it from other males, and buries it unaided. The 
female cooperates only in making the ball and is otherwise passive. 
The pair copulate soon after burial and the male seems to stay 
about 22 hours with the ball and female. The female stays several 
days longer to lay one egg in the ball and convert it into a brood pear, 
which is then abandoned and left unattended in the soil. 
References Cited 
Bragg, A. N. 
1957. Use of carrion by the beetle, Canthon laevis (Coleoptera, Scara- 
baeidae). Southwest. Nat., 2(4): 173. 
Cooper, R. H. 
1938. Tumble-bugs. Canadian Ent., 70 : 155 — 157. 
Geisler, M. 
1961. Untersuchungen zur Tagesperiodik des Mistkafers Geotrupes sil- 
vaticus Panz. Zeits. Tierpsych. 18(4) :389 — 420. 
Halffter, G. 
1959. Etologia y paleontologia de Scarabaeinae (Coleoptera, Scara- 
baeidae). Ciencia (Mex.), 19: 165 — 178. 
1961. Monografia de las especies norteamericanas del genero Canthon 
Hoffsg. (Coleoptera, Scarabaeidae) . Cinecia (Mex.), 20:225 — 
320. 
Hardenberg, C. B. 
1907. Comparative studies in the trophi of Scarabaeidae. Trans. Wis- 
consin Acad. Sci., 1 5 : 548 — 602. 
