REACTIONS OF BEETLES TO LIGHT 63 



A similar process was repeated in the spring of 191 2. This 

 time, however, the beetles were not as numerous on the flowers 

 of Spiraea as they were the previous season, a fact probably 

 due to the cool, rainy weather. About sixty female insects 

 were dissected and over two hundred specimens of both sexes 

 were kept alive for further observations. Again no eggs were 

 procured. Not a single case of copulation was observed during 

 the process of collecting about a thousand individuals in the 

 two successive seasons. In the laboratory where the collected 

 beetles were kept with an abundance of food and where most 

 of them lived from five to fifteen days, again no evidence of 

 sexual excitement was observed. 



The same season I succeeded in getting a number of almost 

 full grown larvae and also a number which were about half 

 grown. The large specimens pupated and metamorphosed the 

 first part of June and produced a new generation, the larvae of 

 which were kept for further experimentation. The smaller 

 larvae matured and reproduced in fall. 



Experiments on light reactions were performed and, as in 

 the case of T. tarsale, it was found that A. scrophulariae larvae 

 are decidedly negative to light in all stages of their larval his- 

 "tory. Also both sexes of this species manifested a decidedly 

 negative reaction to light immediately after their emergence 

 from the pupal skins. This response persisted through the 

 period of fertilization and egg-laying. Very shortly after laying 

 their eggs the female insects reversed their reaction to light, 

 becoming decidedly positive. The males, too, completely re- 

 versed their phototaxis during the latter part of their lives. 

 When the beetles were placed near a window they made frantic 

 efforts to get outside. The same reversal was observed in ex- 

 periments with an electric light in the dark room. Similar 

 results were obtained with the specimens of the second annual 

 generation which metamorphosed in fall. 



L. O. Howard, 1 in his paper on the Carpet Beetle or "Buffalo 

 Moth, ' ' says that it is probable that the migration of this beetle 

 from the house takes place, under ordinary circumstances, after 

 the eggs have been laid. The foregoing facts show conclusively 



1 Howard, L. O. The Carpet Beetle or "Buffalo Moth" (.Anthrenus scrophu- 

 lariae). Circular no. 5, revised edition, U. S. Dept. of Agric, Bureau of Entomology. 



This circular suggests some remedies for the checking of the pest which may 

 also be applied to T. tarsale. 



