THE CODLING MOTH IN MASSACHUSETTS 57 



The Larva. (See Plate I.). The newly-liatched larva is about one- 

 sixteenth of an inch long, pale greenish-white in color, with a shining black 

 head much wider than the rest of the body. Upon emerging from the egg, 

 the young worm crawls about over the leaf surface or fruit, in search of 

 food and also protection from bright sunlight. If fruit is not immediately 

 at hand, it usually crawls to the lower side of the leaf close to one of the 

 main veins and either burrows into the vein or feeds on the leaf tissue close 

 by, covering itself with a covering of silk. Here it may remain for some 

 days. Once it reaches a fruit, however, it quickly enters. 



The first worms to hatch usually enter the fruit at the blossom or 

 calyx end. At this time the apples are very small, and the closed calyx 

 cup offers the best shelter. Later in the season, when the fruit is larger 

 and the rapidly growing apples often touch leaves, twigs or other apples, 

 thus offering good chances for concealment, many of the larvae enter the 

 fruit through the side. When fruit has been scarred by mechanical injury, 

 the attack of insects or by sprays, the roughened surface also offers good 

 opportunity for the young larvae with their small jaws to bite through the 

 skin. 



Experiments with larvae fed upon foliage alone, showed that very often 

 they can survive for a week or ten days, and in some instances for fifteen 

 to twenty-one days. It was found, however, that these larvae made very 

 slow growth and there is little likelihood, therefore, that the insect could 

 carry through to the pupal stage in the absence of fruit. 



After feeding for about three weeks, the larvae become full-grown 

 and eat their way out through tlie side of the fruit. These mature larvae 

 measure about three-fourths of an inch in length and are white or pinkish- 

 white in color. This stage of the insect is the one most often seen and most 

 familiar to the fruit growers. Upon leaving the fruit, the larvae immedi- 

 ately crawl away in search of a suitable hiding place in which to spin their 

 cocoons. 



Cocoon. (See Plate I.). The cocoons of the overwintering larvae are 

 very tough, being formed of closely woven silk threads with bits of bark or 

 trash attached to give added protection. In the spring, when ready to 

 pupate, the larva usually remodels the cocoon, lengthening it somewhat, or 

 forming a tube-like passageway to the outside of its hiding place to aid in 

 the escape of the moth. The summer cocoons are much lighter, more 

 loosely woven, and somewhat longer than those in which the larvae winter 

 over. Occasionally cocoons are spun in wormy apples and in the soil near 

 the base of the tree. 



Pupa. (Plate I.). The pupa is formed within the cocoon and is about 

 one-half inch in length. It is at first light brown in color, but rapidly 

 darkens. When transformation is completed and the moth is ready to 

 emerge, the pupa wriggles out through the end of the cocoon, protruding 

 far enough to allow the moth to escape. 



Seasonal History 



Overwintering Larvae 



The insect passes the winter as a full-grown larva within a tightly- 

 woven cocoon. In the orchard these are found beneath rough bark and 

 in crevices or pruning scars on the trees. The larvae also find shelter in 



