MITES ON MOSQUITOES 173 



larval, pupal and adult condition. He showed that when the larva of Anopheles 

 molts in its transformation to pupa, the mite passes to the pupa, and when the 

 perfect insect is given out the hydrachnid leaves the skin of the pupa to attach 

 itself to the adult. 



Dr. Aubrey Hodges, in the " Journal of Tropical Medicine " (1902, p. 300), 

 gives an interesting account of mites found upon Mansonioides and upon Anoph- 

 eles paludis in Uganda. He states that in certain places quite 50 per cent of 

 the mosquitoes were attacked and he found as many as nine parasites upon 

 one mosquito. He asserts that the color of the parasite depends upon the 

 nourishment of the host, and that they are red when attached to a mosquito 

 which has sucked blood. He thought that the mites injure the mosquitoes, the 

 latter becoming weakened and living only a few days in captivity. 



It would seem from this statement by Doctor Hodges, as well as from the fact 

 that so many mosquitoes coming from Madagascar were found by Blanchard 

 to have mites attached to them, that in Africa there must be some genus or 

 genera, of hydrachnid mites, that more commonly attach themselves in the 

 larval condition to the larvae of mosquitoes than is the case in temperate regions. 

 This is the opinion of Mr. Banks, who thinks that the northern forms more com- 

 monly attach themselves to other aquatic insects. 



In the course of his interesting observations on mosquitoes at Scott, Arkansas, 

 Mr. James K. Thibault, Jr., has studied this question of parasitic mites. He 

 writes as follows : 



" More or less every adult specimen of certain species is found to be infested 

 by a red mite very similar in general appearance to those occasionally found on 

 house flies, though for the most part such will be the case only early in the 

 season — spring. The proportion of infested individuals among the various 

 species is very striking, Anopheles and Mansonia showing the greatest number 

 of infested individuals, likewise the greatest number of mites per mosquito. 

 The first Anopheles and Mansonia to hatch out show over ninety-five per cent of 

 infested specimens, and indeed it is well-nigh impossible to find a single speci- 

 men that is not parasitized. Culex ahominator D. & K. probably comes next, 

 but in this case the mite is bluish-green — about the same shade as that seen in 

 Culex ahominator itself when first hatched. This probably accounts for the 

 blue-green color of the otherwise red mite. 



" I list the various species which I have found to be infested, placing those 

 showing the greatest percentage of infested individuals first in the list, and 

 so on in order : 



"Anopheles crucians Wied. ; Anopheles quadrimaculatus Say; Anopheles 

 punctipennis Say; Mansonia perturhans Walk.; Culex ahominator D. & K. ; 

 Culex territans Walk, (rarely) ; Aedes triseriatus Say (only once) ; Megarhinus 

 septentrionalis D. & K. (rarely) . 



" Nearly all of the above-named species hibernate as adults, and one might 

 be led to believe that there was some connection between this and the fact that 

 they are so often parasitized, but I do not think this is the case. I believe that 

 it is more probable that the mites attach themselves to the mosquitoes when the 

 latter are in the larval or pupal stage, perhaps both. I once found three larvoe 

 of Culex ahominator all having mites upon them. These mites were of the 

 typical red color, whereas those found upon adult Culex ahominator are in- 

 variably bluish green. This difference in color is, I believe, to be explained by 



