1968] 
Leuthold — Crematogaster 
335 
togaster scutellaris that at least indicates the corresponding recruit- 
ment stimulus in that species. The subject of this paper is an analysis 
of the complex food recruitment behavior and its efficiency in C. 
ashmeadi. 
MATERIAL AND METHODS 
Crematogaster ashmeadi is an arboreal ant that dwells in dead 
hollow branches. Its range is the coastline from Virginia to Florida 
and the Eastern Gulf States (Creighton 1950). Our laboratory 
colonies were collected from red mangrove trees (Rhizophora 
mangle) on the Florida Keys and established in horizontally piled 
pieces of hollow mangrove branches on wooden frames measuring 
20 X 25 cm. These colonies, polygynous in nature, were kept at 
room temperature in plastic trays 30 X 45 X17 cm with the inside 
walls coated with talcum powder to prevent escape. Various shapes 
of 50-cm-long bridges were used to join the nest site with a food 
station located in another tray where water, honey and mashed 
shrimps or cockroaches were offered to the ants. To begin recruit- 
ment experiments the colonies were first starved for five days or 
longer, then a new food source was offered on a movable side bridge 
which was connected to the old pathway between the nest and the 
former feeding station. The patterns of movements and courses were 
analyzed by slow-motion cinematography (16 mm film, 64 frames 
per second ) . 
THE RECRUITMENT BEHAVIOR OF A FOOD FINDER ANT AND 
THE RESPONSES OF OTHER WORKERS 
On the pathway between nest site and feeding station of a 
Crematogaster laboratory colony, a basic back-and-forth traffic of 
workers continues even when no more food is available at the feed- 
ing place. Even in starved colonies the workers keep up running 
over the bridge. Most of them still strictly follow their well estab- 
lished trail pathway but a certain low percentage abandon the trail 
to explore neighboring areas. To begin food recruitment experi- 
ments, a 24-cm-long side bridge supplying a honey source at its end 
is connected to the main bridge of a starved colony. Usually within 
a few minutes the side bridge is discovered by a scout ant which 
starts searching the new area and quickly locates the food. In order 
to observe the recruitment behavior of one single explorer ant, the 
side bridge is removed and reconnected only for the passage of this 
particular ant. The explorer ant smells honey, diluted with water 
(1:1) already at a distance of about 4 cm. It may be attracted to 
