584 MEDICAL ENTOMOLOGY 



pigeons, ducks, geese, turkeys and canaries ; it causes serious loss to 



farmers, either by ' tick worry ' (massive infection) or by transmitting 



spirochaetes. Bishop gives some data regarding its 



Life history of Argas Hfe history j n a recent rep ort. The eggs hatch after 



persicus miniatus -' 



10 to 100 days according to the temperature. The larvae 



attach themselves to their hosts and remain fixed from three and a half 

 to ten days, when they drop off at night and hide in the cracks and 

 crevices in the fowl house. After an interval of from four to seven days 

 the larva moults and the first nymph emerges. The two nymphal stages 

 behave in the same way as those of persicus, dropping off immediately 

 they become replete with blood. The female feeds about seven times 

 and is capable of laying as many as 537 eggs ; the tick can complete 

 its life history in about forty days. 



The senior author has studied the complete life history of Argas 

 vespertilionis, and has bred a large number from eggs and from larvae. 



This tick is parasitic on the yellow bat, Scotophilus 

 Life history of Argas k M . The are j id in the resti kce of the 



vespertilionis 



bat ; the larvae hatch m from ten to twelve days, remain 



attached to the wing of the bat for ten days, and about twenty-four 

 hours before leaving the host become flat like the adult. The following 

 data give the life history of this tick : 



2110 12 .... Replete larva dropped during the day. 



26 1012 .... Changed into first nymph. 



30 10 12 .... Fed to repletion, taking twenty-five minutes to 



become full. 



6 11 12 .... Changed into second nymph. 

 1011 12 .... Fed to repletion, remaining attached for fifty 



minutes. 

 2311 12 .... Changed into female; placed with male, when 



copulation immediately took place, lasting five 



minutes. 

 15 1 13 .... Fed to repletion, having refused to do so several 



times before. 



21 1 13 .... Egg laying began (first batch). 

 30 1 13 .... Egg laying completed. 

 1 2 13 .,11 First larvae hatched. 



GENUS ORNITHODORUS, KOCH, C. L. 



Body flat when starving and convex when replete, and may be nearly 

 as broad anteriorly as posteriorly, or pointed and beak-like anteriorly. 

 The margin of the body is not distinct as in the genus Argas, but is of a 

 similar structure to the rest of the integument, which is generally mam- 

 milated. On the ventral surface there are two marked folds, one internal 



