MKTIlOns OK SKCrRING DATA KItOM Ci )IX)N 1 KS. 75 



were liberated diiiiiiu- the summer of l'.)l() as had hceii released in all 

 the previous yea r>. Tliis docs jiot hold true in repird to the niuidxT 

 of larva) liberated. 



Two years or uiore will be required before any accurate figures on 

 increase in the colonies ])lanted in 1910, or spread from them, can 

 reasonabh'- be expected. The information already ^'iven concerning 

 the reproduction of new and old beetles bears directly on the condi- 

 tions which exist m field colonies. If the beetles li})erated in 1906 

 and 1907 reproduced at the normal rate, the progeny from these col- 

 onies should show far greater mcrease and dispersion than the beetles 

 more recently liberated, and that this is the case will be brought out 

 in the followmg pages. On the other hand, colonies consisting of 

 larvae, or beetles reared from larvae, can not be expected to show any 

 great increase for the first year or so, because young beetles ordinarily 

 oviposit sparmgly. 



Owing to the fact that Calosoma sycojjhanta has been able to sur- 

 vive for a number of years under field conditions and that reproduc- 

 tion and dispersion have been going on at a satisfactoiy rate, as deter- 

 mined by observations made during the past four summers, it has been 

 considered madvisable to make further importations of tills species, 

 for the reason that if it is necessary to liberate more colonies aside 

 from those that can be supphed from the material now being held at 

 the laboratory, it should be possible to cohect sufficient quantities 

 m the field for the i)urpose. 



METHODS OF SECURING DATA FROM FIELD COLONIES. 



Smce the work began it has been of the utmost imi)ortance to 

 determine actual cimditions in the field and to find out whether each 

 introduced species was surviving and reproducing. Durmg 1907 

 mmierous visits were made to the colonies wliieh had been liberated, 

 but little of imi)ortanee was found until about the middle of July, 

 when Mr. L. S. Winchester, who had been employed for a few weeks to 

 take up this particular work, found Calosoma beetle larva^ under the 

 burlaps on trees whei-e a colony had been })lanted in Burlington, Mass. 

 Tins, of course, showed that the beetles had successfully liibernated 

 during the whiter and re|)ro(luced, and was a very encouraging sign. 

 Later in the month several larvie were found ui the Saugus (Mass.) 

 colony and a single larva was found in one of the colonies at Lynnfield, 

 Mass., so that at the end of the season it was known definitely that 

 three of the six colonies libei-ated in 1906 were well established hi the 

 field. 



Durmg the examhiatioii of the colon}' liberated by Mr. Moslier at 

 North Saugus, Mass., in July, 1907, it was discovered, contrary to 

 expectations, that the larvae of this species climb the trees antl feed 

 upon the caterpillars and pupae of the gipsy moth found on the trunks. 



