PSYCHE. 



OBSERVATIONS ON THE BREEDING HABITS OF THREE CHRYSO- 



MELID BEETLES, CALLIGRAPHA BIGSBYANA, C. MULTI- 



PUNCTATA AND C. LUNATA. 



BY ROBERT W. HEGNER, MADISON, WISCONSIN. 



During the summers of 1905-07 I was engaged in the hybridization of a number 

 of chrysomeHd beetles, chiefly three species of the genus Calligrapha, namely C. 

 multipunctata, C. bigsbyana and C. lunata. My experiments are not yet completed 

 but some points of interest have developed in regard to the breeding habits of these 

 species while kept in the laboratory under artificial conditions. 



The geographical distribvition of the Calligraphas cannot be given accurately 

 because of the fragmentary condition of the data concerning their occurrence. They 

 have been reported from eighteen states situated in boreal America and no doubt may 

 be found in-favorable localities anywhere in this region. 



The willow is the principal food plant of C. bigsbyana and C multipunctata; 

 all authors who have made observations on the subject include this plant, and all 

 specimens that have been collected for me or by me were found on its leaves. The 

 beetles prefer the long-leafed species, Salix longijolia, and, as far as I know, do not 

 occur in nature on any other form. They will live however on other willows if forced 

 to do so as adults and larvae will eat Salix amygdaloides in the laboratory. Hamilton 

 ('95) gives Alnus and x\cer as the food plant of C. bigsbyana in southwestern Pennsyl- 

 vania as does Smith ('99) also for New Jersey. 



C. lunata has been found only on the wild rose, Beutenmuller ('90), Lugger ('99) 

 and others having reported its capture on this plant. 



There are four methods that may be mentioned of keeping these beetles in the 

 laboratory — all of which have been used. First, the glass tank made in such a way 

 as to allow the experimenter to subject the insects to various degrees of moisture, 

 temperature, etc; second, the plaster of paris cage used by Janet ('93) for breeding 

 ants and later by Dimmock and Knab ('04) for raising carabid beetles; third, the 

 ordinary wire cage; and fourth, glass covered slender dishes. The last named was 

 found to be the easiest to manage. The dishes should be about 10 cm. in diameter, 

 if larger the food tends to become dry. 



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