REMEDIES. 245 



There are several other species of Eriosoma or downy lice 

 in this State, inhabiting various forest and ornamental trees, 

 some of which may also have been introduced from abroad. 

 The descriptions of foreign plant-lice are mostly so brief and 

 imperfect, that it is impossible to ascertain from them which 

 of our species are identical Avith those of Europe ; I shall 

 therefore omit any further account of these insects, and close 

 this part of the subject with a few remarks on the remedies 

 to be employed for their destruction generally, and some 

 notice of the natural enemies of plant-lice. 



Solutions of soap, or a mixture of soapsuds and tobacco- 

 water, used warm and applied with a watering-pot or with a 

 garden engine, may be employed for the destruction of these 

 insects. It is said that hot water may also be employed 

 for the same purpose with safety and success. The water, 

 tobacco-tea, or suds should be thrown upon the plants with 

 considerable force, and if they are of the cabbage or lettuce 

 kind, or other plants whose leaves are to be used as food, 

 they should subsequently be drenched thoroughly with pure 

 water. Professor Lindley recommends syringing plants, as 

 often as necessary to remove the lice, with a solution of half 

 an ounce of strong carbonate of ammonia in one quart of 

 water, which has the merit of being clean as well as effectual. 

 Lice on the extremities of branches may be killed by bend- 

 ing over the branches and holdino; them for several minvites 

 in warm and strong soapsuds, or in a solution of whale-oil 

 soap. 



Against the depredations of the plant-lice that sometimes 

 infest potato-fields, dusting the plants with lime has been 

 found a good remedy. Lice multiply much faster, and are 

 more injurious to plants, in a dry than in a wet atmosphere ; 

 hence in green-houses, attention should be paid to keep the 

 air sufficiently moist ; and the lice are readily killed by fumi- 

 gations with tobacco or with sulphur. To destroy subterra- 

 nean lice on the roots of plants, I have found that watering 

 with salt water was usefol, if the plants were hardy ; but 



