BLUEBERRY INSECTS IN MAINE. 2/9 



found was June 22, 191 5, and, in the laboratory material, July 

 17 was the first date on which a caterpillar was recorded as 

 leaving the fruit that year, a period of about 25 days. About 

 12 days are required for the last 2 instars; this has been veri- 

 fied several times, as the berries have begun to ripen by the 

 time the larvae are half grown, and they can be raised easily. 

 As the instars are probably of about equal duration this is what 

 one would expect if the duration of larval life is 25 days. 



First instar larvae were common by June 25, and most were 

 still in this stage at the end of the month. The majority leave 

 the fruit about the twentieth of July in a normal season or 

 around the thirtieth in a backward season such as 191 5. A few 

 straggle along up to mid-August. Probably most of them pass 

 through the second instar in early July and nearly all have 

 m.olted to the third instar at least by the tenth, though a few 

 first instar larvae may be encountered even as late as July 7. 



In most cases the larva when it hatches enters the berry near 

 the calyx end usually on the outside of the berry at the base of 

 one of the sepals, but some enter by the calyx cup and a few 

 near the stem end. Most commonly the larva enters beneath a 

 sepal and tunnels around the circumference of the calyx cup in a 

 complete circle, just beneath the surface; then it burrows down 

 to the stem end, sometimes through the center and sometimes 

 close to the surface. Often the skin is discolored where the 

 trail runs beneath it. From this point on, the fruit is irregularly 

 eaten. Merely a shell of skin filled with dried pulp, the coat 

 of the seeds and fine brown frass all woven together with silk, 

 i) left when the larva is full grown. Frequently 2 berries are 

 webbed together. The first one is usually small and dry, full 

 of frass webbed together; the second is larger and fresher. 

 They are firmly attached together by silk and the larval trail 

 leads from one into the other, at the point of attachment, 

 usually on one side of the fruit. Rarely 3 or even 4 berries are 

 thus united. 



When full grown, the larvae leave the berries. In the labor- 

 atory they entered rotten wood in preference to sand, or earth. 

 They spin silken cocoons in which they pass the winter as 

 prepupae. A natural inference would be that they pupate in 

 the spring and emerge as adults after a short pupal period, but 

 there are no data at hand on this point. 



