194 Maine Agricultural Experiment Station. 1917. 



ages given do not include the mortality of the eggs and larvae 

 in gooseberry drops and no accurate statement can be made of 

 the mortality in the fallen fruit. Our observations on mortality 

 were confined to the egg cavity and hence only dead larvae of 

 the first instar were found. We frequently observed that the 

 eggs of the currant fruit fly were covered with a fungus growth, 

 but this may have been secondarily developed after the eggs 

 failed to hatch. In opening one egg receptacle below a binoc- 

 ular microscope, two small mites were found near an egg. 

 Although natural enemies may attack some of the eggs, the 

 primary cause of the mortality of fertile eggs and larvae in 

 gooseberries is unknown. 



' ' Feeding Habits of Larvae. 



The minute larva, upon hatching from the egg in the egg 

 chamber, may either penetrate toward the interior of the fruit 

 leaving no external visible trail, or bore beneath the peel form- 

 ing a tiny winding tunnel which, at its maximum length, may 

 extend almost completely around a currant or half way around 

 a gooseberry (Fig. 14, D). At first the trail is light colored but 

 later it turns brown and becomes quite conspicous. A dissec- 

 tion under a binocular microscope of the tunnel leads to the 

 region where the larva is feeding. The recently hatched larva 

 may feed for a time in the pulp between the peel and seeds, but 

 later it may partly or entirely eat its way into a seed. 



As the larva grows the seeds become too small to hold the 

 maggot and the larger larva is commonly found partly within 

 or between the seeds or in the pulp. After a larva has devoured 

 the embryo of a currant seed, the posterior end of the body may 

 remain within the seed coats while the mandibles (Fig. 13, G) 

 of the protruding anterior end gnaw holes in the neighboring 

 seeds, or the body may be withdrawn from the seed coats and 

 the larva may then be found with the head region buried in a 

 seed and the caudal part protruding (Fig. 13, A). In other cases, 

 both ends of the body may be within two currant seeds, the 

 posterior portion being within the empty seed coats and the 

 anterior part within a hole of another partly devoured seed. 



An examination of currants after the exit of the larva 

 showed that in some cases the embryo of every seed was con- 



