Life History.

The perfect insect, or beetle, is of a tawny brown colour, having stripes or lines upon the elytra or wing cases. The body has also lines upon it. In this state it is believed that the beetles do no harm to crops. They may be seen in May flying, especially in damp places, and resting upon weeds and plants page 28 Towards the end of June pairing takes place and the females helped by their long narrow shape place their nearly round, minute, white eggs on the stems of grasses, weeds, and the stalks of corn plants, close to the ground, as Curtis says, between the enveloping leaves or sheaths near the bases of the stalks. From the eggs larvæ are produced, of very small size, which grow slowly, and finally attain a length of about an inch. They are yellowish, having six thoracic legs, with their bodies divided into twelve segments, looking like coats of mail or the plates of an ironclad, under the microscope. There are dark coloured marks upon the terminal segment, characteristic of this species according to Westwood. The mandibles or jaws of the larvæ are perfectly adapted for gnawing roots and stems. Curtis states that these jaws are sometimes so worn at an advanced age that the apex is rounded, and the smaller teeth have entirely disappeared.

The larvæ remain in the ground, devouring what root, or stem, or bulb food may come in their way, for several years. Five years is the extreme limit according to some entomologists. Others say more. Miss Ormerod thinks that the limit is determined to some extent by the supply of food, and without doubt the quantity and quality of the available food much influence their life duration.

Before assuming the pupa state the wireworms go down deep into the earth for their transformation, which is accomplished in about a fortnight, and the perfect insects come from the ground. There is no cocoon enwrapping the pupa. Taschenberg is of opinion that some of the pupæ may remain in statu quo during the winter, but Bjerkander, the great authority upon these insects, does not support this, neither does Curtis.