192 ASSOCIATION OF ORGANISMS—THE WEB OF LIFE 
wingless blood-sucking Fleas are here included. The modifica- 
tions which they have undergone have no doubt been in relation 
to the parasitic habit. 
BretLes (COLEOPTERA) AS PARASITES AND BRooD-PaRASITES.— 
To this order possibly belongs a family of small insects (Stylopzd@) 
parasitic upon Bees, Wasps, and, to some extent, upon certain 
Bugs. Many zoologists, however, place them in a distinct order 
(Strepsiptera). The adult female is little more than a shapeless 
bag, living in the abdomen of a bee or other host, with one end 
projecting externally (fig. 1137). The adult male, on the other 
hand, is a very active creature, possessing 
large hind-wings, but only vestiges of fore- 
wings. His free life is short, three days 
being the maximum on record, while in some 
species (of Xezos) fifteen to twenty minutes 
is the limit, though during this brief period 
extraordinary energy is shown. The nu- 
merous eggs are developed internally, hatch- 
ing out into minute six-legged larve, which 
make their way into the bodies of bee-grubs 
or the like, though the way in which these 
hosts are found is in many cases but imper- 
fectly understood. Their presence in the 
Fig. 1137.—A Bee-Parasite (s- interior of the grubs does not cause death, 
Oo on eve toe 10F they jeed upon the fatty substance (fat- 
ae eee moment anand body) between the various organs. Having 
once become parasitic they lose their legs 
and assume the appearance of minute maggots. Later on, when 
the bee-grub passes into the pupa stage, the parasitic larva pushes 
out one end to the exterior, and, if a male, also passes into the 
pupa stage, but if a female, undergoes comparatively slight modi- 
fications. When the adult bees come out of the pupe the male 
parasites also emerge to lead their free existence, but the females 
remain fixed in their hosts. Individual bees harbour but one or 
a few of these curious parasites; in wasps they may be more 
numerous. 
The parasitic habits of some of the Oil-Beetles ((Ze/ozde) are 
both remarkable and highly interesting. Fabre has worked out 
the life-history of one species (Svtaris humeratis, fig. 1138), of 
which the larve feéd on the eggs and honey of certain bees 
BARGAIARRe 
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