244 Transactions of the Academy of Science of St. Louis 
instar has a decidedly different appearance, the appendages are 
all reduced and the chitin becomes much thinner. There is no 
further change during the third instar. The one fly pupa is 
sufficient food to allow the beetle to complete its development 
and in nitida and bilineata Wadsworth found that pupation 
occurred inside the puparium of the prey. Exit of the adult is 
made by breaking a new hole in the wall of the puparium. 
Reports indicate that the behavior of the er so-called parasites 
of the cabbage root maggot (see previous af aitee to nitida, bipustulata, 
a = anthomyiae) is very similar to that of B. bilineata. Nor 
is behavior confined to this group. Scott (16206) reports Aleochara 
orate sia in the ees of Orygma reais Meig.; Scott 
eich A. algarum in the puparia of Coelopa ote Hal., and 
satietereiaable fly pu pari um, tk single beetle s: 16 id in a tube in 
which ei been placed a fly pupa. The tube Rast Seer with cotton 
and was not disturbed until after the beetle was found.) Bier cine rees 
(15:2) sites an instance where Aleochara lata was found in a breeding 
jar containing cocoons of saw flies but as this ehigacaiic behavior 
was not as yet suspected a thorough investigation was no 
behavior is slightly different in the case of Mesochara valida 
ie (Cone 91:318). The beetle lar rva gnaws its way into the pupar- 
rphid fly Copestylum marginalium Say) and remains until 
10 
studied by Reintes (26: "133-170). In pees work Kemne cues the eae 
of Wadsworth and obtains similar results. He then sees further and 
compares the behavior of bilineata with Aleochara curtula Goeze and 
Baryodma itv icata Manne hein: In the latter forms he finds that 
msnoed of the larva penaketng in the empty puparium to pupate it 
nd pupates in a nest-like cavity in the earth. (In Europe 
bilinenta Gyll., is considered to belong to the genus eel dls which 
is beatae as-4 subdivision of Bwcdas by Leng ). In comparing 
t ehavior of European genera ome has compared 
ie of three sieueke: elated groups.) 
The preceding feeding behaviors oe clearly that among 
the Staphylinidae there is in a number of cases, a trend toward 
parasitism. In these known cases Bie apparent host selection 
and the derived form of the larva during the second and thir 
instars also points toward the development of a parasitic be- 
havior. There has been no experimental work done on the 
choice of food by these larvae as all the — has begun with 
the attack on the fly pupa and not upon t a of the beetle. 
There is no apparent selection of larval ood on the part of 
the adults for they are near the infected cabbage in order ie 
for t 
larvae. The eggs are deposited in the soil near the infected 
v hich would be the case in a true soca behavink: The 
