,140 PROTECTION OF PLANTS^ ,1516-17 



. ^ Control. ^(X) Oil of carraway (1 part to 5 parts white vaseline) rubbed 

 into leg and foot every few days; (2) bathing in warm soapy water and apply- 

 ing sulphur ointment or naphthaline mixed with 9 parts lard, or 5% creolin 

 or zenoleum or vaseline and zinc ointment. 



Itch- Mite of man. (Sarcoptes scabiei Latr.) 



This pest burrows under the skin where eggs are laid. In about a 

 week the eggs hatch and the young mites become mature in about four 

 weeks- The lesions and blisters formed are very irritating, and the disease 

 may spread rapidly. '?;?;?*;;: ^ 



Sheep Scab Mite. (Psoroptes communis var. ovis Furst) 



This mite burrows under the skin of sheep forming large areas of crust 

 called scabs. From these areas, commonly confined to the neck, back and 

 rump, the wool falls away. The disease is contagious. Each female lays 

 15-24 eggs which hatch in 2-3 days; the young mites mature in 15 days. 

 (See Farmers' Bui. 713, U.S. Dept. Agr.) 



Family — Ixodidae (Ticks) 



Cattle Tick. (Margaropus annulatus) 



In the Southern States this tick-causes large losses as the agent respon- 

 sible for the Texas Cattle Fever. It is a dark eight-legged creature. The 

 engorged female drops from cattle to the ground and lay its eggs. The 

 young ticks (seed ticks) on hatching crawl up nearby herbage and drop 

 on the backs of cattle as they brush by. Attached to the skin they feed 

 until they become mature. 



Rocky Mountain Spotted Fever Tick. (Dermacentor venustus) 



This tick, with others, is able to transmit the so-called "Spotted Fever" 

 of man in the Rocky Mountain states. It is possible that the ground 

 squirrel of the region serves as a reservoir of the virus. The disease is 

 probably transferred through the salivary secretion of the tick. Dr. 

 Hadwen reports cases of "tick paralysis" of man and sheep in British Col- 

 umbia due to the bites of this species. 



D' variabilis is a widespread form, occurring on dogs, cattle, horses 

 and man, but apparently is of little economical importance. 



