ADDITIONAL DATA ON THE LOCUST HORHR. 33 



HABITS OF LARV^l AND ADULTS. 



When a larva begins activity in the spring it molts and proceeds 

 to excavate an independent food and entrance burrow through the 

 dead area of bark surrounding the hibernating cell or through the 

 living bark immediately surrounding the dead area, until it reaches 

 the cambium. It then excavates an irregular groove or cavity in 

 the outer sapwood, returning frequently to the outer cell or opening 

 to push out the borings and apparently to get relief from the 

 exuding sap. A large per cent of the larvae die before any further 

 progress is made, but survivors grow rapidly and soon succeed 

 in overcoming the many obstacles, including natural enemies, 

 resistance of the tree, etc., and enter the sapwood. From this 

 stage on until the larva? have attained their full growth they 

 are very active and destructive. Their food consists principally of 

 the nutritious substances of the bark and wood, and probably of the 

 liquids flowing into the burrow, but they do not hesitate to kill and 

 feed upon each other when two or more come in contact within the 

 same burrow. The fact that the entire development often takes place 

 in a burrow scarcely more than twice the length of a matured larva 

 indicates that food must be obtained from some source other than 

 the wood and bark. Throughout its active life the larva frequently 

 returns to the inner and outer bark to enlarge the burrow, and push 

 out its borings, so that the burrow when completed is of a diameter 

 throughout sufficient to allow the passage back and forth of the 

 full-grown larva. When full grown the larva enlarges the inner end 

 of the burrow, plugs the outer portion with boring chips, and in due 

 time transforms in succession to the pupa and adult. When the adult 

 is fully matured it escapes through the exit prepared by the larva. 

 Immediately after a female emerges she is joined by one or more 

 males, and within a few hours, or within twenty-four hours, she pro- 

 ceeds to deposit eggs. She runs about over the bark investigating 

 the crevices, by means of her ovipositor, to locate those most suitable 

 for an egg. Sometimes as many as twenty places are critically 

 examined before one is selected, and it appears that but one egg is 

 deposited in a place by the same female, but other females may find 

 the same place and each deposit an egg, so that sometimes several 

 eggs are found in one crevice. As a rule, however, there is but one. 

 The faculty of the female in locating the most suitable place for an 

 egg by means of the sensitive palpi on the tip of the ovipositor is 

 remarkable. 



The beetles feed principally on pollen from the flowers of golden rod. 

 but are very fond of any sweet Liquid, such as sugar sirup placed on 

 the trunks of the trees. Thev are found during the dav on the trunks. 



