INSECT PESTS OF OHIO SHADE AND FOREST TREES 261 



Distribution. This species is distributed over nearly the entire 

 United States, occurring in greatest numbers in the western-central 

 section. 



Natural enemies. Lady beetles of several species are known to 

 destroy this insect in the earlier stages and particularly in the egg 

 stage. Species of Ichneumon and Chalcid flies are reported as para- 

 sitizing it, while tiger beetles and ground beetles are reported as 

 preying upon it. 



Control. Under Ohio conditions, when control measures become 

 necessary, spraying with arsenate of lead is the cheapest and most 

 effective method. Since the insects feed largely upon the lower 

 side of the leaves and since the leaves of Populus and willows are 

 so glossy that sprays do not adhere readily, the liquid should be 

 directed so as to cover the under leaf surfaces, and soap should be 

 added to the spray solution to facilitate spreading and sticking. 



In sections of New York, where basket willows are cultivated, 

 the growers use an ingenious beetle-collecting machine to good 

 effect. The machine is so arranged that when it is drawn or pushed 

 down the rows the beetles and their larvae are collected in a pan 

 filled partly with kerosene and are thus destroyed. This machine 

 is illustrated and described by Doctor Lowe (29). The field of use- 

 fulness of this apparatus is very limited, particularly in Ohio, since 

 little is done with the basket-willow enterprise in this State. 



THE SPOTTED WILLOW LEAF BEETLE 

 (Lina interrupta Fabr.) 



The preceding species seems more abundant than the spotted 

 willow leaf beetle in most states where these pests occur. Under 

 Ohio conditions, however, the latter is more abundant and destruc- 

 tive. In most 'accounts it is treated under the name of Lina 

 lapponica Linn, or Melasoma lapponica Linn., but according to 

 Blatchley (30) lapponica "is a European speciees with thorax 

 wholly metallic." With our species interrupta, as will be seen by 

 an examination of the accompanying illustration, Plate XL, Fig. 1, 

 the thorax is edged laterally with lighter bands. 



Description. The adult beetle resembles closely in size and 

 shape the preceding species, being a little less than three-eighths 

 of an inch in length and of elongate, rounded form. In coloration, 

 however, interrupta differs greatly from scripta. The present 

 species is deep black beneath showing a slight tinge of metallic. 

 Above the thorax is shiny black with a border of red or yellow at 

 the sides. The wing covers are deep yellow or red, variously 

 marked with black as is shown in Plate XL, Fig. 1. As a rule, the 



