102 



BULLETIN ill, U. S. DEPARTMENT OF AGEICULTURE. 



arranged the same as in C.frigidum; the color, however, is black. Legs small and 

 spiny, tarsi bearing two claws. The anal proleg is stout and covered with numerous 

 short hairs. The imder siu'face is of a pm-er white than in C. frigidum, but bears 

 similar markings. The'Tatter resemble those of the preceding species in form and 

 arrangement, but are slightly darker in color. The spots composing the fii'st lateral 

 row are more elongated and all the ventral spots are somewhat larger than in the pre- 

 ceding species. The time spent in this stage is about one month, of which about 

 three weeks are passed in feeding. \Mien full gi-own the larva biuTows into the 

 groimd to a depth of several inches, and after preparing a cavity throws off its skin- 

 and goes into the pupal stage. 



LENGTH OF TIME REQUIRED TO COMPLETE LARVAL STAGE. 



From several feeding records kept of larvae that hatched between 

 June 20 and 24, 1909, it was possible to secure information on the 

 length ol time required to complete the different larval stages. It 

 was found at that time of year that an average of 3 days was required 

 to pass the &st stage, 5 days for the second, and 12 days for the third, 

 or a total of about 20 days between hatching and cessation of feedmg. 

 No notes were secured with this series of larvae as to the time when 

 feeding ceased and pupation began, but observations on larvae in 1911 

 showed that 6 days were spent in the prepupal stage. 



Some data secured in 1912 show that from 3 to 5 days were required 

 for larvae to complete the fii'st stage, 4 to 6 days for the second, and 

 12 to 17 days for the third. A fair average for these would be 4 

 days for the first stage, 5 for the second, and 15 for the third, or a 

 total of 24 days for the active feeding period. These larvae hatched 

 May 20 to May 28 — much earlier in the season than those referred to 

 under 1909 when the weather was cooler, and this wholly or in part 

 explains the longer time required to complete the growth in 1912. 



FOOD CONSUMED BY LARV^. 



The most natural food of these beetles and their larvae is cutworms 

 but it was not always convenient to collect these in sufficient num- 

 bers for the feeding experiments, so caterpillars of Porthetria dis'par 

 and Malacosoma amencana were used. A series of individual 

 records was kept in 1909 and 1910 with caterpillars of these species 

 as a source of food supply. In 1911 a series was kept, feeding pupae 

 of 21. americana only, after the cocoons had been removed. 



Table 24. — Food eaten by larvae of Calosoma calidum, 1909-10. 







Malaco- 











Malaco- 











soma 



Porthe- 









soma 



Porthe- 









ameri- 



tria . 









ameri- 



tria 





Date 

 hatched. 



Date 

 ceased 



cana 

 cater- 



dispar 

 cater- 



Total. 



Date 



hatched. 



Date 

 ceased 



cana 



cater- 



dispar 

 cater- 



Total. 



feeding. 



pillars, 



pillars, 





feeding. 



pillars. 



pillars. 









fifth and 



sixth 









filth and 



sixth 









sixth 



stage. 









sixth 



stage. 









stages. 











stages. 







1909. 











1910. 











June 20 



July S 



1 10 



13 



23 



May 29 



June 22 



9 



1 



10 



23 



12 



4 



13 



17 



June 2 



24 



10 







1.5 



23 



12 



3 



16 



19 



2 



22 



9 







9 



24 



13 



1 



21 



• 22 



7 



30 



( 



4 



11 



24 



16 



3 



20 



23 



7 



28 



7 



3 



10 



■ 24 



17 



1 



13 



14 



7 



28 



13 



5 



IS 













7 



30 



6 



8 



14 



' Two of these caterpillars were in the third stage. 



