82 Psyche [June 



e. g., Nodonota piincticoUis is very destructive to the petals of the 

 rose. 



The frequency with which anthophilous Coleoptera ^'isit pollen 

 flowers led Knuth to infer that they exhibit a marked preference 

 for pollen.^ That carnivorous forms, like the Coccinellidse which 

 live largely on Aphides and insect eggs, find pollen a more agree- 

 able food than nectar is not improbable; but if this were generally 

 true of all anthophilous genera then Nemognatha and Gnathium 

 would not have become adapted to feeding on nectar alone. My 

 observations lead me to believe that Chauliognathus, Leptura, 

 Typocerus, Strangalia, the Mordellids and many others manifest a 

 preference for nectar. But genera, as among the leaf-chafers, 

 which occur in enormous numbers must as a necessity feed upon 

 pollen as well as nectar and also on the succulent parts of the plant. 



Coleoptera are occasionally taken on zygomorphic or bilabiate 

 flowers with the nectar deeply concealed, where they are either 

 searching for food or their presence is accidental. According to 

 Kerner beetles of the genera Anthobium, Dasytes, and Meligethes 

 find refuge and shelter in the interior of the gentians, while species 

 of Cetonia remain for several days in the partially expanded flowers 

 of Magnolia feeding on the sweet juices and pollen. ^ Carrion beetles 

 are found in the spathes of the aroids. The interior of flowers is 

 also used for nocturnal lodging, the temperature prevailing within 

 being several degrees warmer than that of the outer atmosphere. 



Color and odor are of little significance as allurements to the 

 anthophilous Coleoptera, for although beetles are most frequently 

 found on yellow and white flowers this is not an evidence of "a 

 color preference," as Mtiller supposed, but is a result incidental to 

 the flower characters previously described. Since, however, beetles 

 are strongly attracted by a bright light it is not unlikely that a 

 sharp contrast in luminosity between the inflorescence and the 

 foliage is noticed by them. It has been frequently asserted that 

 floral odors are very attractive to beetles, but we have met little 

 evidence to support this view, although carrion beetles detect 

 indoloid scents. The writer has exposed free honey for long 

 intervals which attracted Hymenoptera, Diptera and Lepidoptera, 

 but never any Coleoptera. But environment may be an important 



1 Knuth, Paul, "Handbuch der Blutenbiologie," Vol. 1, p. 223. 

 2Kemer, A., "The Natural Historj- of Plants," Vol. 2, p. 163. 



