ADDITIONAL DA'IA (tX TIIK Locrs'l' ]i iRKK. 33 



HABITS OF LARVJE AND ADULTS. 



W'lu'ii a larxa Ix'^iiis activity in the spi-iiii^- it inolt> and ))r(»c(»eds 

 to oxcuvate an iiulcju'iHlcnt food and oiitraiicc l»urro\v tlir()ii<ili the 

 dead an^a of l)ark suiroundinii' the liihernatiiii;" cell or tlir()u<;h the 

 livin<^ bark iinniediately surrouiidiiii;" tlie dead area, until it reaches 

 the cainl>iiim. It then excavates an irreoujar ^roovc or cavity in 

 the outer sapwood. retiiriiinn" fre(|uently to the outer cell or oi)enin<^ 

 to push out the l)()riii<;s and apparently to u;et relief fioni the 

 exudinji" sap. A lary;e per cent of the hirva' die before any further 

 progress is made, but survivors grow rapidly and soon succeed 

 in ovorconiing tht> many ()l)stacles, including natural enemies, 

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

 stiige on until tiie larva- have attained their full growth they 

 are very active and destructive. Their food consists principally of 

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

 licpiids (lowing 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. Tiie fact that the entire development often takes place 

 in a burrow scarcely more than twice th(^ length of a matured larva 

 indicate.s that food must be obtained from some source other than 

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

 returns to the inner and outer l)ark to enlarge the burrow, and push 

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

 throughout sufHcient to allow the passage l)ack and forth of the 

 full grown larva. \N'hen full grown the lar\ a eidarges the iiuicr end 

 of the burrow, plugs the outer portion with l)()iing chips, and in due 

 time ti'ansforms in succession to t\w \)x\\):i and adult. Wlien the adult 

 is fully matured it escapes through the exit ])re|)are(l by the larva. 

 Immediately after a female emerges she is joined by one or moi(^ 

 males, anrl within a few hours, or within twenty-four hours, she \)\o- 

 ceeds to deposit eggs. She runs altout ovei" the l)ark investigating 

 the crevices, l)y means of her o\ ipositor, to locate those most suitable 

 for an cv[*^. Sometimes as many as twenty places are critically 

 examined before one is selected, and it appears that but one v^j;^ is 

 depo8ite(l in a place by the same female, liut othei' females may tind 

 the same place and each deposit an i^^^^,:^. so that sometimes several 

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

 The faculty of the female in locating the mo-t •>uital)le place for an 

 QiTir bv means of the sensitive palpi on the tip of the ovipositor is 

 remarkal»l(\ 



The l»eetles feecl piincipally on pollen from the llowers of golden-rod, 

 l)Ut are vei-y fond of any sweet licpiid, such as sugar sirup placed on 

 the trunks of the trees, Thev an' found duritjg the dav on the trunks, 



