378 Annals Entomological Society of America [Vol. V, 
their fellows. The hard chitinous covering and the elytre are 
never completely devoured even by starving specimens. It is 
much more probable that they died in the larval stage and were 
later devoured by the other two larve; or they might have 
shrivelled up and darkened, and were thus easily overlooked. 
. That the two larve which were present four years later were two 
of the original six is highly probable. There are several larve 
in our laboratory which were obtained three years ago, when 
they were full grown, and they have apparently not changed 
‘any since. 
8. VARIATION IN SIZE. AMONG THE ADULTS. 
The adult male specimens are smaller, as a rule, than the 
female insects, but the small individuals are not necessarily 
always. males. There is an extemely wide variation in the 
sizes of both sexes which in the adult stage vary from 1.25 mm. 
to 4 mm. in length, the width also being proportionate. It is 
difficult to determine just what is the cause of such a pronounced 
difference. Although poor nutrition gives rise, in general, to 
smaller insects, very small individuals also appear among the 
large ones which have lived under very favorable conditions. 
A marked variation in size of the different larve of the same 
brood is apparent within a few days after they hatch. Obser- 
-vations show, however, that the small, slowly developing larve 
do not always give rise to small adults, as in some cases it is 
merely a matter of taking more time for development. 
9, PHOTOTACTIC REACTIONS AND DEATH FEIGNING. 
The larve immediately after hatching manifest a strong 
negative reaction to light, concealing themselves in any avail- 
able shaded area. If placed near a window they at once begin 
to crawl away from the light, and the reaction is even more 
pronounced when the specimens are taken into a dark room 
and a strong light is introduced at one end of the glass dish 
containing them. This negative phototaxis persists throughout 
the larval life, and just before the larve pass into the pupal 
stage the reaction becomes even more pronounced. Thus, the 
pupz are almost invariably found in dark places which afford 
them a favorable means of protection. 
_ The adults, both male and female, usually retain their 
negative response to light after emerging from their pupal skins. 
