262 OHIO EXPERIMENT STATION: BULLETIN 332 



beetles are much more plentiful which show a generous amount of 

 black on the wing covers. The ground color of the wing covers 

 referred to as deep yellow or red is, under field conditions more 

 frequently yellow than red, although occasionally infested areas are 

 found in which the red form of the beetle predominates. The eggs 

 are deposited in masses of about fifty on the leaves of the host, each 

 egg placed on end. They are greenish yellow, oval and about one- 

 eighth of an inch long. ,The larva at first is black, later becoming 

 lighter in color, and possesses the same arrangement of warts or 

 spines for the secretion of the white, pungent, milky material as 

 described for the preceding species. Some writers state in com- 

 paring the larvae of the two species that they cannot be distin- 

 guished apart unless it be that the milk secretion is a little more 

 profuse and pungent in the present than in the preceding. These 

 larvae likewise have the power to expel and retract the secretion. 

 The pupae of the two species are much the same and are found in 

 similar situations. 



Life history and habits. The insects winter over in the adult 

 stage in trash or in any sheltered place. In April they emerge and 

 begin feeding upon buds or foliage, depositing their eggs soon after 

 the leaves appear. The larvae upon hatching feed gregariously and 

 maintain to a certain extent this habit throughout their existence. 

 When mature they pupate after first securing the tip of the body 

 to some convenient surface. Frequently the pupae occur in clusters 

 of a pendent nature on the drooping twig tips of willow, as shown 

 in the illustration, Plate XL, Fig. 3. Since the insects have been 

 observed by the writer to be abroad as early as April 27 in southern 

 Ohio, there are in all likelihood two broods per season and probably 

 more, regardless of the fact that the adults are known to select their 

 winter quarters as early as the latter part of August. 



Nature of work. Both larvae and adults are foliage eaters and 

 the adults sometimes do much harm by eating out the developing 

 spring buds before the foliage starts. This type of injury was 

 observed April 27, 1916, at Rock Bridge, Ohio, where alder buds 

 were quite destroyed. Sometimes many as four or five beetles were 

 observed feeding upon a single bud. Similar injury to willows at 

 Wooster was observed May 5, 1916. 



The injury inflicted by the feeding insects in early summer is 

 quite extended in some sections of the State. For several years 

 past the willows about Wooster have been attacked in a serious 

 manner, as indicated by Plate XL, Fig. 4. Usually the lower grow- 



