18 BOARD OP AGRICULTURE. 



The Sheep-tick (Melophagus ovinus Linnaeus). Figure 21. 



This insect never acquires wings. It has a broad head, 

 wider than the thorax. The abdomen is roundish and hairy, 

 not showing distinct rings, and in the gravid female becomes 

 much enlarged. The legs are short and stout, and the claws 

 very strong. The proboscis is as long as the head. Like the 

 horse-tick, it is viviparous, producing a full-grown larva, en- 

 closed in an oval case, as shown in Figure 21. 



It is often very troublesome to sheep, especially lambs. 

 There have been numerous remedies proposed. In general, 

 when there are but few, they can easily Figure 21. 



be removed by hand when the sheep are 

 sheared ; but when numerous on lambs, 

 they may be destroyed by various washes 

 or baths. Snuff, or sulphur in powder, 

 rubbed thoroughly in to the wool, is some- 

 times used with good results. A bath 

 made by steeping tobacco in water, about 

 2 pounds to 10 gallons of water, in which the lambs are 

 entirely immersed, with the exception of the face, is said to 

 be effectual, but in some cases, has proved injurious to the 

 health of the lambs. Probably the same solutions recom- 

 mended for fleas would be equally effectual for these ; but 

 the strength of petroleum water, or naphtha water, or car- 

 bolic acid water, ought to be adapted to the age and strength 

 of the animals to which it is applied, young lambs having a 

 much more tender skin than dogs or old sheep. 



The Sot-flies of Horses, Cattle, and Sheep. 



The insects belonging to this family are much less degraded 

 than the other parasitic Diptera. But in reality these are not 

 parasites, except in the larval state. They pass the pupa state 

 in the soil, and in the winged state are powerful fliers, seek- 

 ing the quadrupeds only for the purpose of depositing their 



Figure 21. Sheep-tick (Melophagus ovinus Linnaeus), enlarged. The figure on 

 the left represents the puparium when first born. From Packard's Guide. 



