Of the beetles, those which feed on leaves now become specially active. The Squash beetle (Diabrotica vittata, Fig. 231, and Fig. 230, D. 12-punctata) now attacks the squash plants before they are fairly up; and the Plum weevil (Conotrachelus nenuphar, Fig. 232) will sting the newly formed fruit, late in the month, or early in June. Many other weevils now abound, stinging the seeds and fruit, and depositing their eggs just under the skin. So immense are the numbers of insects which fill the air and enliven the fields and woodlands just as summer comes in, that a bare enumeration of them would overcrowd our pages, and tire the reader.
A word, however, about our water insects. Late in the month the May fly (Ephemera, Fig. 233) appears, often rising in immense numbers, from the surface of pools and sluggish brooks. In Europe, whole clouds of these delicate forms, with their thin white wings, have been known to fall like snow upon the ground, when the peasants gather them up in heaps to enrich their gardens and farms.
The Case worms, or Caddis flies (Fig. 234), begin now to leave their portable houses, formed of pieces of leaves, or sticks and fine gravel, or even of shells, as in an European species, and fly over the water, resting on the overhanging trees.
A few busy Mosquito Hawks, or Dragon flies (Libellula), herald the coming of the summer brood of these indefatigable friends of the agriculturist. During their whole life below the waters, these entomological Herods have slain and sucked the blood of myriads of infant mosquitoes and other insects; and now in their new world above the waters, with still more intensified powers of doing mischief, happily, however, to flies mostly obnoxious to man, they riot in bloodshed and carnage.
234. Different Forms of Case Worms.
This is the season to stock the fresh-water aquarium. Go to the nearest brook, gather a sprig or two of the water cress, which spreads so rapidly, a root of the eel grass, and plant them in a glass dish or deep jar. Pour in your water, let the sand and sediment settle, and then put in a few Tadpoles, a Newt (Salamander), Snails (Limnæa, Planorbis and Valvata), Caddis flies and Water beetles, together with the gatherings from a thicket of eel grass, or other submerged plants, being rich in the young of various flies, Ephemeras, Dragon flies and Water fleas (Entomostraca, Fig. 235), which last are beautiful objects for the microscope, and in a few days the occupants will feel at home, and the aquarium will be swarming with life, affording amusement and occupation for many a dull hour, by day or at night, in watching the marvels of insect transformations, and plant-growth.
235. Water Flea.
