390 DIPTERA. 



Duges, the}' are external. Kirby describes a gigantic species two 

 lines long, from British America. As a preventive measure in 

 ridding dogs of fleas we would suggest the frequent sweeping 

 and cleansing of the floors of their kennels, and renewing of 

 the straw or chips composing their beds chips being the best 

 material for them to sleep upon. Flea-afflicted dogs should be 

 washed every few da}-s in strong soapsuds, or weak tobacco, or 

 petroleum water. A writer in the "Science-Gossip" recom- 

 mends the use of Persian Insect Powder, one package of 

 which suffices for a good sized dog. The powder should be 

 well rubbed in all over the skin ; or the dog, if small, can be 

 put into a bag previously dusted with the powder ; in either 

 case the dog should be washed soon after." 



One of the most serious insect torments of the tropics of 

 America is the Sarco2)syUa (Rynchoprion of Oken) penetrans 

 Linn., called by the natives, the Jigger, Chigoe, Bicho, Chique, 



or Pique. (Fig. 311 much en- 

 larged ; , the gravid female, 

 natural size). The female during 

 the dry season, bores into the 

 feet of the natives (though it also 

 lives in dogs and mice, which 



accounts for its presence in houses), the operation requir- 

 ing but a quarter of an hour, usually penetrating under the 

 nails, and lives there until her body becomes distended with 

 eggs ; the abdomen swelling out to the size of a pea. The 

 presence of the insect often causes distressing sores. The 

 Chigoe lays about sixty eggs, according to Karsten, deposit- 

 ing them in a sort of sac on each side of the external opening 

 of the oviduct. The larvne do not live in the body of the 

 parent, or of its host, but, like those of Pulex, live free on 

 the ground. The best preventives against its attacks are 

 cleanliness and the constant wearing of shoes or slippers when 

 in the house, and of boots when out of doors. 



SIMULIDJE Loew. Simxlium molest um (Fig. 312 ; , larva 

 of this or an allied species, magnified), the Black-fly, represents 

 this family. Its antennjB are eleven-jointed ; the palpi are 

 four-jointed, with long, fine terminal joints, and the ocelli are 



