THE MOSQUITOES OF THE SOUTHEASTERN STATES Dif 
also have breathing tubes specially modified for penetrating the soft 
tissues of the plants, to which they remain attached until ready to 
transform to the adult stage, when they rise to the surface. 
Because of their habits, which are unique among mosquitoes, the 
larvae cannot be reached by ordinary surface larvicides such as oil. 
In experiments carried out by the writers in Florida, partial control 
has been obtained with common salt and with soap emulsions of 
pyrethrum extract in oil, but the results have been variable and the 
methods were not sufficiently economical to be feasible. In limited 
areas practical control can be obtained by destroying the host plants 
or by draining the ponds for a short per'od during the winter or early 
in the spring before the adults emerge. 
As Mansonia larvae are often difficult to locate, the following notes 
are given on the methods found by the writers to be successful in 
collecting them (723). Since the larvae of WM. perturbans have the 
habit of detaching themselves when their host plants are disturbed, 
they are likely to be missed if only the roots of such plants are 
examined. It is therefore necessary to search for the larvae in the 
bottom muck and trash of a pond area from which the host plants 
have been uprooted. This material may be scooped up with a large 
strainer and then examined in small quantities in shallow pans of 
clear water. As the larvae usually stay on the bottom of the pans, a 
careful search must be made. The white color of the larvae and their 
continuous movements aid in locating them among the trash. The 
collection of the larvae of J. titi/lans, which attach themselves to the 
roots of a floating plant (waterlettuce), 1s much simpler. These lar- 
vae are readily taken by lifting the host plants quickly into a pan of 
water for examination, or the plants may be lifted from the water 
by bringing the dish up under them. Some larvae usually remain 
attached to the roots, while others are found moving about in the 
dish. Specimens of J/. perturbans are also found at times on the 
same plant. 
Mansonia adults have very broad wing scales, mixed brown and 
white, and the proboscis and tarsi are banded. ‘The abdomen is blunt 
at the tip and lacks the longitudinal stripe of white scales found in 
Aedes sollicitans.. The two species found in this region are placed 
in separate subgenera, ¢7¢2//ans in subgenus Mansonia and perturbans 
in Coquillettidia. : 
MANSONIA PERTURBANS (Walk.) 
This speckled brown and white mosquito is widely distributed in 
the Eastern and Southern States. The adults are strong fliers and 
severe biters, and in many localities become a serious pest. The eggs 
are laid gn the surface of the water in rafts similar to those of Culex. 
Breeding takes place in marshes and lakes having a thick growth of 
aquatic vegetation, to the roots of which the larvae and pupae at- 
tach themselves. Larval development is extremely slow, and the 
winter is spent in this stage. The pupal period is also long for 
mosquitoes, lasting 5 or 6 days. | 
Throughout most of its range this species is believed to have a 
single generation each year, a large proportion of the adults emerg- 
ing over a comparatively short period late in the spring or early in 
