KECOKL) OF TWO FIKLD COLON IKS OK IIKKTLES, 77 



late summer scoiitiii<j;, m whic-li woik il was necessary to employ 

 several assistants in order to cover tJie extensive territory which was 

 exammed, inchcated that tJie beetles liad spread over a much lari^er 

 area than had been anticipated, and this is sliown on the above- 

 mentioned map (PI. TX). Tn order to fj^ive an i(k'a of the i'e|)r()ckic- 

 tion anil cUspersion unckn- actual iield concUticms, a somewhat detailed 

 account will be given of two colonies, namely, Saugus and Wellesley, 

 Mass. 



RECORD OF TWO FIELD COLONIES OF CALOSOMA BEETLES. 



In -luly, 1907, Mr. Mosher liberated 331 beetles as soon as they were 

 recei\cd from Eur()])e m badly infested woodland near the old para- 

 site laboratory at North Saugus, Mass. Larva? of sycophanta were 

 found later in the month and during the followmg year they were 

 quite alnmdant. As there were plenty of gips}' moth cater})illars and 

 })upa? for them to feed upon, it seemed desirable to determuie the 

 extent of spread and the amount of increase of the Calosoma beetles 

 during the summer of 1908. In order to do tliis the woodland was 

 examuied thorough!}^ in August, and counts made of all the molted 

 skins found. All the trees were climbed, and the rough bark, which 

 was likely to harbor molted skins, was ins])ected, as were the masses 

 of gipsy moth pupa? and the burla])s. Ninety-three first-stage and 

 294 second-stage molted skins were found in an area of about six 

 acres, which seemed to represent the limit of s])read of the s})ecies. 

 That this w^as not the limit of spread, however, was defuiitely shown 

 the next summer when larva? and molted skms were found at inter- 

 vals for more than half a mile in every direction. 



In the fall of 1910 the colony was examined in the same manner 

 as in 190S, and in the territory inspected the latter year 733 first- 

 stage and 818 second-stage molted skins were found. Tliis indi- 

 cates that there had been an increase of the beetles in the center 

 of the colony as wxll as a general dispersion of the species. A small 

 block of trees adjoining this area was examined and molted sldns 

 were found in about the same relative numbers. A record of the 

 dispersion from this colony could not be secured, because in 1909 

 it had merged \\\X\\ other colonies planted a mile or more distant. 



In order to check up this data a careful scout was made, in the 

 fall of 1908, of a colony at Wellesley Farms, Wellesley, :Mass. The 

 beetles that were placed in this colony, 105 males and 110 females, 

 were received from Europe late in June, 190S, and were liberated 

 July 1 of that year. The timber growth, which was cliiefly oak, 

 ^\^th trees of from 4 to 10 inches in diameter, had been burlapped, 

 and two men were employed to desti'oy the gipsy moth catorjnllais. 

 as the infestation was l)a(l. The bcM^tlcs were lil)ei-ated in two spois 

 about 300 yards a[)arl. The scout iiig in this colony con^isUMJ in 



