THE GOPHER-TORTOISE TICK. 123 
ARTIFICIAL CONTROL. 
The methods applicable in the control of annulatus proper apply 
in a general way to australis. Our observations indicate that the 
longevity of the larve may be somewhat shorter than that of annu- 
latus. The long periods of warm weather in the Tropics should 
greatly assist in its eradication through starvation. If, however, 
the larve attach to small animals, as has been reported by Newstead 
(1909), and these develop to adults in any numbers, its eradication 
will be much more difficult. 
Genus AMBLYOMMA Koch. 
The five species of the genus Amblyomma which occur in the United 
States, namely, americanum, cajennense, dissimile, maculatum, and 
tuberculatum, have been studied and are considered in the following 
pages. The other species of this genus whose biology has been 
studied are variegatum by Barber (1894-95), in Antigua, goldii and 
varium by Rohr (1909), in Brazil, and hebreum (1899), marmoreum, and 
variegatum (1905), by Lounsbury, in South Africa. All five species 
which occur in this country and the three species studied in South Africa 
dropto pass thetwomolts. This also appears to be the case with the 
Brazilian species studied. Aside from the species which as adults 
attach to cold-blooded hosts only (dissimile, goldii, marmoreum, 
tuberculatum), the host relationship is not closely restricted. The 
species are able to withstand long periods of fasting while waiting 
fora host. While americanum is widely distributed, occurring in the 
Boreal and Austral regions, the other four species have only been 
found in the Tropical and Lower Austral Zones, three of these 
occurring only in the Gulf strip of the Austral Zone. The species 
are very hardy, yet require some protection, such as timber or 
underbrush; maculatum, however, exists on the prairie. 
Only one species is known to transmit disease, namely, hebreum, 
which conveys the infection of heartwater of sheep, goats, and 
cattle in South Africa. Experiments to determine the possibility 
of americanum acting as a transmitter of splenetic fever of cattle 
have been conducted by two investigators. In both cases the results 
were negative. 
THE GOPHER-TORTOISE TICK. 
Amblyomma tuberculatum Marx. 
The common name of the species is taken from the host of the 
adult. 
DESCRIPTIVE. 
Adult (Pl. IX, figs. 4-8).—Males from 7 by 4.5 mm. to 8 by 5 mm. 
Females, unengorged, 7 by 5 mm. to 10 by 6 mm.; engorged, 19 by 
13.5 by 8 mm. to 24 by 18.5 by 11 mm. Males, scutum reddish 
