THE FALL WEB-WORM. 251 
Chickens, and even the omniverous ducks, do not eat them ; if offered to the former 
they pick at these morsels, but do not swallow them. 
The English sparrow has, in this case at least, not proven of any assistance what- 
ever. Indeed, as before stated, its introduction and multiplication has greatly 
favored the increase of the worms. 
The "pellets" of a Screech-owl (Scops asio) found in the vicinity of Baltimore, 
Md., and examined by Mr. Luggar, consisted apparently almost entirely of the hairs 
of these caterpillars, proving that this useful bird has done good service. 
Perhaps the statement maybe of interest, that this little owl is getting much more 
common in the vicinity of such cities in which the English sparrow has become 
numerous, and that the imported birds will find in this owl as bold an enemy as the 
Sparrow-hawk is to them in Europe, and even more dangerous, since its attacks are 
made towards dusk, at a time when the sparrow has retired for the night and is not 
as wide awake for ways and means to escape. 
If our two cuckoos, the black billed as well as the yellow-billed species, could be 
induced to build their nests within the city limits or in our parks, we should gain in 
them two very useful friends, since they feed upon hairy caterpillars. 
The common toad (Bufo americana) has eaten great numbers of these caterpillars, 
as shown by dissections made by Mr. Lugger, and it should be carefully protected 
instead of being tormented or killed by boys or even grown people. The toad is 
always a useful animal and ought to be introduced in all gardens and parks. 
The following species of spiders were observed to eat the caterpillars, viz, JSIarpessa 
undata Koch and Attus (Phydippus) tripunctatus. Neither species builds a web, but 
obtains its prey by boldly leaping upon it; they are, in consequence of such habits, 
frequently called tiger-spiders. The former was exceedingly common last year, 
more so than for many previous years, thus plainly indicating that the species did 
not suffer for lack of food. This species is usually found upon the trunks of trees, 
and is there well protected by its color, which is, like that of the bark. It hides in 
depressions and cracks of the bark, and, jumping upon the passing game, or, cat-like, 
approaching it from behind, it thrusts its poisonous fangs into the victim, which 
soon dies and is sucked dry. The Attus has similar habits, but is still more cautions ; 
it usually hides under loose bark. Both spiders are wonderfully active, and kill large 
numbers of caterpillars. Their large flat egg- masses can be found during the winter 
under dead bark and in cracks. Both species hibernate in silken nests in similar 
localities. 
Predaceous insect enemies.— The caterpillars of this moth have quite a number of 
external enemies, which slay large numbers of them. The well-known Rear-horse 
{Mantis Carolina, see Fig. 89) seems to be very fond of the caterpillars. The Wheel- 
bug, Prionidus cristatus (Fig. 104), has proved to be one of our best friends in re- 
ducing the numbers of the caterpillars. This insect was formerly by no means 
very common in cities, but of late years it has greatly increased in numbers, and is 
now a well-known feature in all our public parks and such streets as possess shade- 
trees. Outside of the city it is rarely met with; nor does it extend much farther 
north than Washington. It is, like the Mantis, in all its stages a voracious feeder 
upon insects, slaying alike beneficial and noxious ones. The bright red larvae and 
pupae, also carnivorous, are seen in numbers during the summer; they usually 
remain together until hunger forces them to scatter. They assist each other in kill- 
ing larger game, and are to this extent social. The Wheel bug could be observed 
almost anywhere last summer, usually motionless, stationed upon the trunk of trees, 
waiting for the approach of an insect. If one comes near, it quite leisurely inserts 
its very poisonous beak, and sucks the life-blood of its victim. When this becomes 
empty it is hoisted up in the air, as if to facilitate the flow of blood, until eventually 
it is thrown away as a mere shriveled skin. The appetite of the Wheel-bug is re- 
markable, whenever chances offer to appease it to the fullest extent. Frequently, 
however, times go hard with it, and notwithstanding it is very loath to change a posi- 
