16 The 'Bulletin. 



At a is shown the adult beetle, the line to the right indicating 

 its actual length. Farmers often suppose that these Lady-beetles are 

 the parents of the louse, but in reality they are enemies to the louse 

 (and are, therefore, friends to the farmer), for the reason that they 

 feed on the lice. They lay their eggs on the leaf and these hatch to 

 the larva as shown at c, and this larva, when grown, changes to the 

 pupa, as shown at b, and from this pupa the adult beetle (a) emerges. 

 The larva (c) of the Lady-beetle also feeds actively on the cotton lice. 

 There are several other species of Lady-beetles that attack the Cotton- 

 louse, but the one here mentioned is the most abundant and beneficial 

 one. 



There are a number of other insects which help to keep down the 

 Cotton-louse, such as the Lace-wing Flies and Syrphus Flies, but 

 they do not require detailed mention here. On the other hand, cotton 

 (or any other plant) which is badly infested with lice is apt to be 

 frequented by many insects which go there, not to attack the lice, but 

 to get from the lice a sweetish substance called a honey-dew," which 

 the lice secrete from their bodies. Ants, flies and v\-asps are fond 

 of this substance and are frequently abundant on plants which are 

 badly infested with the lice. 



Summary.- — -The Cotton Leaf-louse is most abundant in cool, wet, 

 late seasons and is sometimes destructive, but usually disappears or 

 becomes much less evident when hot weather comes on, due prin- 

 cipally to the activity of the parasites and other natural enemies. 

 Parasitic four-winged Flies, the Convergent Lady-beetle, Lace-wing 

 Flies and the Syrphus Flies are the most active of the natural 

 enemies. Louse-infested cotton is also frequented by certain other 

 insects which go there for the honey-dew anel do not take part either in 

 destroying or aiding the lice. The Cotton-louse has no stage of 

 existence except that of a louse, though some are winged, as shown in 

 the illustration. 



REMEDIES. 



Since the Cotton Leaf-louse does most of its destructive work early 

 in the season, some of its injuries can be avoided by later planting so 

 that the young cotton will come on in hot weather when the natural 

 enemies of the louse are active and able to protect the crop. This is 

 a point worth consideration on plantations where the louse is a 

 serious pest every year, though perhaps not advisable for those who 

 do not usually suffer severe injury from the louse. Good fertiliza- 

 tion and frequent shallow cultivation will cause the crop to grow 

 vigorously and soon be beyond the stage of serious injury. 



When the Cotton-louse suddenly appears in great numbers in re- 

 stricted spots in the field and threatens to spread over the entire 

 . area, it may pay to use a spray pump and thoroughly spray all the 

 plants in the infested area. For this purpose use ordinary home- 

 made or laundry soap, dissolved in water at the rate of iy 2 pounds to 



