CONTROL OF ARGENTINE ANT IN CALIFORNIA. 7 
sion of the colony usually occurs in the early spring and summer 
months. In the late fall (November) the outpost communities are 
usually abandoned and large central winter colonies are formed in 
more favorable locations having better drainage and sun exposures. 
The activities in these communities are limited, fewer workers are 
sent out in search of food, the male form disappears, reproduction 
almost ceases, and the number of ants is reduced. Several colonies 
dug up in December, 1919, and January, 1920, showed a large num- 
ber of workers in the colony with only a light trail going out in search 
of food, a number of females, no males, few if any eggs, a few matured 
larvae, and numbers of pupae. Renewed activities in these colonies 
and the division of the central colony usually occur in early April, 
though the time may vary somewhat with the season. 
As stated, the summer colony is composed of three distinct forms 
of adults — workers, males, and queens. (See fig. 3.) The workers 
gather the food and attend to the labors of the community and are 
simply imperfect females with no reproductive capacity. They 
greatly outnumber the other forms and are the ones most commonly 
met with. The males, always winged, are the drones of the colony 
and have only one function, that of fertilizing the queen. The queens 
are the reproducing females and for a short time during the mating 
period are winged. They remain in the nest most of the time, but 
occasionally may be found out in the trails — a characteristic of this 
species (fig. 4) . It is absolutely necessary that a fertilized queen ac- 
company a number of workers if a new colony is to be established, as 
the workers alone have no means of reproduction. 
The winters in southern California, though occasionally wet enough 
to retard the development of the ant colonies and force them to win- 
ter quarters, are so often broken by short, warm spells and the aver- 
age rainfall is so light that trap nesting has proved ineffective and 
seldom are any of the colonies destroyed by excessive moisture. 
The preferred food of the ants in orchards is the honeydew secreted 
by certain scales and aphids, the honeydew from blossoms, and the 
bodies of certain soft-bodied insects. The workers are very active in 
collecting this food and may be observed returning along the trail 
from a foraging expedition, their abdomens greatly distended with 
liquid food, or their strong mandibles securely clasping their prey. 
About residences the ants are more or less scavengers, feeding on bits 
of food wherever they can find it, but frequently invading pantries 
and even ice chests in search of meats, sugar, sirups, fruit, etc. Their 
trails may be extended to any part of the building in search of food 
and often during the first few hot days of summer the ants storm 
the house. 
An interesting feature in the distribution of this ant is that it has 
completely replaced all native species, with possibly two exceptions, 
