76 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



parasites have been obtained from codling moth larvae which were 

 collected in windfallen fruit and confined in cages. At the time the 

 parasitized codling moth larvae leave the fruit they may readily be 

 recognized by their inferior size and the absence of the pink color, 

 which is characteristic of the full-grown codling moth larvae. In the 

 orchard on the grounds of the station, where numerous adult parasites 

 had been liberated in the course of the season of 1911, fully 40 per 

 cent of the band-record larva? were parasitized in the late fall. The 

 average measurement of the head of full-grown codling moth larvae 

 is 1.5 mm. : the parasitized larva at the time of leaving the fruit has 

 an average head measurement of only 1.3 mm. In the spring of 

 1911, 15 undersized larvae, lacking the pink color, were confined in a 

 separate cage; of these, 10 proved later to be parasitized, while the 

 rest died from other causes. 



The parasite passes the winter in the larval stage within the host. 

 The following spring feeding is terminated, and the host larva is 

 completely devoured, except for the skin and the ehitinous parts 

 of the head. Within the cocoon of the host the parasite larva makes 

 a small oval cocoon, white in color, within which it pupates shortly 

 after. In 1911 one parasite pupated May 21 and issued as adult May 

 28, having remained 7 days in the pupal stage. So far as has been 

 observed, only a single parasite develops in each host larva. 



The parasitized codling moth larvae that winter do not modify the 

 cocoon in the spring as does the normal larva, which provides an exit 

 for the issuing moth. The parasite fly is therefore forced to gnaw its 

 way out through the walls of the cocoon. 



NEMATODE WORMS. 



On September 1, 1910, the writer collected a windfallen apple with 

 a full-grown codling moth larva which was found to be infested with 

 minute, white-colored nematode worms (species not determined). 

 The entire body cavity of the larva was filled with the worms and 

 quite a number of worms were also found in the burrows in the apple, 

 where the mass of worms had the general appearance of mildew 

 growth. 



MISCELLANEOUS OBSERVATIONS. 



NUMBER OF LARVAL INSTARS AND MOLTS OF THE CODLING MOTH. 



The codling moth, like all arthropods possessing an exoskclcton, 

 must shed the skin from time to time in the course of its growth. 

 The process of casting the skin is called "molting" (ecdysis) and 

 (he stages between the molls are termed "instars." 



The determination of the number of insfnrs of the codling moth 

 1' scomes difficult because <>l the small size of the larva in (lie early 



