86 DECIDUOUS FEUIT INSECTS AND INSECTICIDES. 



generation. Temperature conditions undoubtedly influence greatly 

 the lengths of the various life periods. 



HABITS. 



Late in May or in the early part of June the oyer-^yintering pupa 

 makes a narrow slit in one end of the cocoon and exposes a small 

 part of the anterior portion. The piij)a case then splits and the 

 moth emerges, the operation reCJiiiring from about 15 to 20 minutes. 

 Sometimes the wings become their normal size in a short time, but 

 in other cases 24 hours elapsed before the moth Avas perfect. The 

 moths mate on the next day, or second day following. One pair un- 

 der observation, having emerged on July 22, in the night, mated early 

 July 23, and was observed in copnlation from 7.30 until 11.30, a 

 period of 4 hours. This was probably near the normal period, as the 

 pair had not been out of the cocoon long. Oviposition usually fol- 

 lows soon after. In the pair mentioned above, one cluster of 69 

 eggs was deposited during the night of July 23, During oviposition, 

 which took place early in the morning, or more often in the late after- 

 noon or evening, the moth was observed to be on the underside of a 

 leaf with the wings at right angles to the body. The abdomen was 

 slightly bent, and the moth seemed to be depositing the eggs in rows. 

 The period required for the oviposition of a cluster is several hours, 

 depending upon the size of the cluster deposited. The flight of the 

 moths appeared to be feeble, and they were sluggish, especially on 

 cloudy days, the period of greatest activity being on clear days at 

 midday. The length of life of the moth is from 2 to 5 days without 

 food, although in the case of one pair under observation the male 

 lived from 3 to 3^ days and the female from 6 to 6^ days. 



The eggs are deposited on the underside of the leaf. Upon 

 hatching, the larva? start feeding from a common center, moving 

 l)ackward, and in a short time are side by side in a soldierlike forma- 

 tion, the feeding line usually being a curve. Although the larva? 

 may feed for a short time uj^on the lower surface, they are more fre- 

 quently^ found upon the upper, as this is better adapted to their style of 

 feeding — namely, skeletonizing or removing the outer epidermal layer 

 of the leaf. This manner of feeding is usually followed until the 

 larvie reach the fifth instar, when some begin to eat holes through 

 ilie leaf. From now on the larva^ gradually cease skeletonizing the 

 leaf and eat the Avhole tissue, leaving only the larger veins. 



Preparatory to molting, the larva^ crawl to the underside of the 

 leaf and molt in a group, with their heads in the center. After molt- 

 ing they feed, moving backward, and gradually form a curved line. 

 This was observed a number of times, although the larva^ had been 

 feeding before in difi'erent groups on the upper surface of difierent 

 leaves. 



