342 INSECTS AFFECTING VEGETATION 



nary combing and brushing will not dislodge them. They are com- 

 monly known as nits, and are quite large enough to be seen on care- 

 ful examination. These nits are also quite resistant to any ordinary 

 insecticide applications, and where there is a large supply, infection 

 may continue for some little time after treatment is begun. 



As the breathing pores of these insects are not well protected, 

 they may be reached by greasy pomades or ointments, or even 

 plain lard, liberally applied. Pomade vaseline is the cleanest of 

 these materials, and should be liberally applied after the hair and 

 head have first been thoroughly combed and washed. Such para- 

 sites as have not been removed by the mechanical measures em- 

 ployed will become choked by moving among the greasy hair. This 

 application miust be repeated at intervals of three or four days for 

 ten days, by which time all the nits will have hatched. So long as 

 any eggs remain unhatched the danger of reinfestation remains. 



Another remedy, said to be very effective, is an infusion of 

 larkspur, with which the head is to be washed. This also must be 

 duplicated to reach the insects as they hatch, and has no advantage 

 over the simpler greasy applicants. 



A second species, much less common, is the body-louse, which 

 lives in the seams of clothing and after feeding retires into hiding. 

 This is essentially a pest of the camp, where the soldiers know 

 them as gray backs, and of all places where men and women are 

 crowded together with insufficient clothing or without due regard 

 to cleanliness. These lice lay their eggs in the seams in which they 

 hide and so tough are they that they will resist ordinary boiling 

 in water for a considerable period. 



Under normal household conditions these insects never become 

 numerous, but, as with bed-bugs, any member of the family using 

 a public conveyance may bring them in. When a garment has 

 become infested, the parasites should be located and destroyed, if 

 possible. If not possible, the clothing should be boiled or steamed 

 to destroy both insects and nits. If that also be impossible or in- 

 advisable, then smear the inside of the seams with mercurial oint- 

 ment. It does not require much, and it kills by clogging and poison- 

 ing. It may be necessary, if the garment is badly infested, to re- 

 new the application after a few days, until all the eggs have been 

 hatched. 



The third species is known as the crab-louse, from its broad 

 shape and sprawly legs, and this inhabits the coarse hair of the 

 body, on the breast, under the arm pits or in the pubic region. This 

 also lays its eggs on the hair, and the structures of its feet is such 

 that it can hold to a hair so tightly that this can be pulled out 

 more easily that the insect can be dislodged. These insects may be 

 picked up in the toilet rooms of hotels, railroad cars or other places 

 open to the public at large, and as the insects are hard biters they 

 often cause a great deal of irritation. 



Mercurial ointment, thoroughly and frequently applied at the 

 infested points, is the only reliable remedy, and it may require ten 

 days or two weeks before complete riddance can be obtained. Ordi- 



