Aug. 2i, 1916 Life-History Studies of Cirphis Unipuncta 



805 



the body of the dead female was examined many more eggs in all stages 

 of development were found in the ovaries. In some cases more than 800 

 developed and undeveloped eggs were contained in the body of a single 

 female. 



The newly hatched larvae first eat the eggshells, but apparently do not 

 eat the white substance by which the eggs were attached. Later they 

 feed on the tissues of the corn leaf on which they are resting, destroy the 

 parenchyma, and leave the other leaf surface as a transparent mem- 

 brane (PI. CVII, C) . Later, they feed from the edge of the leaf, devouring 

 all the leaf tissue. 



In the first instar the larvae, if slightly disturbed, give themselves a 

 compound twist, "humping" the body and drawing the head and 

 thoracic segments around, bringing the ventral surface forward, and 

 clinging by the pseudolegs and anal claspers. If further disturbed, they 

 drop on a silken thread, and in this twisted position resemble balls of 

 frass, losing all semblance of the larval form. Sometimes the larvae 

 contort themselves with a snap or fling, without the silken attachment, 

 which fact seemed to explain the loss of an occasional individual in the 

 experiments. 



Table II. — Eggs laid by individual females of Cirphis unipuncta at La Fayette, Ind., 



August to September, IQ14 



1 Abdomen of dead moth not examined. 



2 Died. 



The use of a silk thread by larvae when disturbed occurred with less 

 frequency in the second instar. After dropping, the first-instar larvae 

 remain inactive for a moment before attempting to crawl away; and in 

 later instars they swing the head or fore part of the body vigorously to 

 one side and feign death. During the fifth molt, a disturbed larva 

 feigned death for five minutes. 



During the first and second instars the larvae walk in a looping manner, 

 but this characteristic is lost in the third and succeeding instars. 



As the larva approaches a molt, the condition is recognizable by the 

 largeness of the body diameter as contrasted with that of the head. When 

 within a few hours of the molt, the larva habitually anchors its anal 



