70 



lice aiul many of tlic carniv(jrous insects (liul acceptable food in 

 these soft bodied insects. 



Among birds, perhaps the tit-mice are as sei-viceable as an\- in 

 destroying the plant lice. Insecticides of varions sorts have 

 proved more or less useful preventives of the ravages of plant lice. 

 Pyrethrum, especially it used mixed with water, is often very good. 

 Potato parings boiled in water produce a liquid which appears to 

 be iatal to many ir.sects. The kerosene or carbolic acid emulsions 

 mentioned in the early pages of this article are very useful against 

 many of the plant lice. Some years ago a solution was recom- 

 mended by the Lhiited States ^Vgricultural Department which i.> 

 'made as lollows : — 



'1 ounces Sulphur flour 

 "2 " Washing soda 

 ]/2 " tobacco 



A piece of quicklime the size of a duck's ^'J,)l,- Pour all the ingre- 

 dients into a pot or pan, boil for fifteen minutes stirring constantlv. 

 After this let the mixture stand quieth until it settles, when the 

 clear upper portion can be poured ofl from the sediment. The 

 jjortion poured otfwill keep indefinitely. In using it needs to i)e 

 diluted considerably, more or less as the tbliage is tough or tender. 

 The plant lice are grouped b}' entomologists in four subdi\i- 

 sions, or families. The first family includes the familiar scale 

 insects, bark lice, mealy bug, etc., and is called coccidie. It is a 

 group not easily defined because it includes many varied forms. 

 In many cases there is a remarkable di\'ersity between the males 

 and females and sometimes they are to all appearance about as un- 

 like as possible, certainly they are more unlike than many insects 

 placed in widely different zoological groups. This family includes 

 a large number of exceedingly troublesome insects, and no insects 

 are more readily carried from place to place since in some of their 

 stages of growth they are able to withstand great changes in the 

 suiTOunding conditions. Moreover some are protected b\ a scale 

 which completely covers them, others secrete a downy or wooly 

 covering which wholly changes their appearance and also affords 

 some degree of protection. Certain products of commercial \alue 

 as cochineal, and shellac are obtained from species of coccidie and 

 quite a number secrete wax sometimes in sufficient quantities to be 

 of value. As a rule the perfect males are active, two-wingeel in- 

 sects, while the temales are sluggish ami wingless. To this group 



