40 THE FLORIDA BUGGIST 
but never in a single instance to Culex. As many as eight and 
ten have been counted attached to the thorax and abdomen of 
some individuals; but it is doubtful if any mosquitoes are killed 
by them. 
The larvae are more easily preyed upon and we have some 
enemies that are very effective in holding them in check. There 
are a few water beetles, especially in the sinks, that feed upon 
the larvae. This community is a regular paradise for dragon- 
flies and there are from fifty to seventy-five species found. Any- 
where around the grounds, on a quiet day, one can see scores of 
them. Their larvae feed upon mosquito larvae and bemg present 
in such large numbers devour many of them. Two well grown 
dragon-fly larvae have eaten thirty-five Culex larvae over night. 
Dragon-fly larvae have been found in the larger areas of water 
in all the marshes surrounding the University, but have not been 
found in the sink holes. 
The most active enemies* we have are the little top minnows 
(Gambusia affinis) (Fig. 22, p. 22) and the “goggle-eye” or a 
warmouth bass (Chaenobryttus gulosus) (Fig. 23, p. 28). The 
usefulness of the top minnows has been mentioned by other writ- 
ers (Howard 1902, Van Dine 1906). It is surprising how many 
mosquito larvae these little fellows will eat. A half dozen of them 
have eaten over a hundred Culex larvae in a couple of hours, and 
ten of them have eaten two hundred larvae (all that were fed 
them) for several days in succession. They are very active and 
one has only to stand quietly on the bank to see them as they 
patrol the water every few minutes. They have been found in 
the deeper portions of all the marshes, the sink holes, ditches, and 
wherever there is a permanent supply of water. Their small size 
enables them to go almost anywhere and to work their way in 
among the vegetation. Wherever they are found is a poor place 
to look for mosquitoes. They have been found in only one in- 
stance in the same pond with mosquitoes. This was in a circu- 
lar depression covering four or five acres, lying about a mile 
northwest of the University. The depression is shallow and the 
slope from the bank toward the center is very gradual. It is 
overgrown with water weeds and in some places the edges are 
surrounded with sphagnum moss. Anopheles larvae were found 
abundant in some places among these weeds and moss. In some 
cases, the weeds and moss were so thick that the water could not 
be seen at all and it looked as though the larvae were actually 
*Determined by Dr. H. S. Davis. 
