External Parasites 



231 



The fleas are provided with very sharp piercing mouths. 

 They are what are termed 'partial parasites' — parasites 

 that only go to their hosts to feed. The fleas are not noticed 

 on the birds because they generally attack them at night ; 

 then, howe^-er, they do much harm, causing constant irri- 

 tation and loss of blood, and depriving them of rest. 



" Life-history of Hen Flea. — The^ female flea lays her eggs 

 (nits) chiefly in the nests amongst dust and dirt and in the 

 crevices of the walls 

 and floor. These nits 

 give rise to pearly 

 white maggots, with 

 brown horny heads, 

 which can often be 

 found in the bottom 

 of the nests amongst 

 the dust. These 

 larvae are mature in 

 2 or 3 weeks, then 

 they reach about ^ of 

 an inch in length. In 

 warm weather they 

 may be full fed in 



even 10 days. They then spin a pale cocoon amongst the 

 dirt, in which they pupate. The pupa is at first pale 

 brown, then dark chestnut brown. In this condition the 

 flea remains 10 to 21 days, when the pupa hatches into the 

 adult. They breed all the year round, but chiefly in warm 

 weather. It is well to remember that, whenever there are 

 dark and dirty hen roosts, there are sure to be a number of 

 Pulex gallincE." 



Treatment. — These parasites do not usually occur under 

 sanitary housing conditions. When they occur the houses 

 should be cleaned and sprayed as for red mites (p. 215). 



Fig. 51. — The chicken flea, Pulex gallinw 

 or avium. The mark above the head in- 

 dicates the actual size. (After Kaupp.) 



