SPECIES INJUKING THE FRUIT. 35 



can not interfere seriously with the production of forage. It is of 

 greatest importance in Mexico, where the fruit of the Opuntia plant 

 is a very common article of diet for the natives. 



Instances of curious deformations of the plant result from the 

 work of this fly. The infested fruit, instead of developing as such, 

 is transformed into a very short joint, which gives rise to a larger 

 or nearly normal joint. The remarkable change in the appearance 

 of the plant caused in this way is sometimes very conspicuous. The 

 result of the work of the same or a similar species was described as 

 an abnormal fruit of Opuntia ficus-indica from Caracas by A. Ernst. 1 



Three additional species of Cecidomyiida3 have been reared from 

 Opuntia. They are included in the list at the end of this bulletin, 

 but need not be considered in this connection on account of their 

 very rare appearance. 



Cornifrons elautalis Grote. 2 



C omifrons elautalis Grote is a small grayish moth infesting the 

 green fruits of Opuntia. It was first collected by Mr. J. D. Mitchell 

 in Majr, 1908, at Hondo, Tex. Later it was taken at Tucson, Ariz., 

 but on the whole seems to be of rare occurrence. The larvae bore into 

 the fruit to a depth of 1 inch and eject a reddish-colored excrement 

 on the crown of the fruit, causing its death. At Tucson, Ariz., in 

 May, Mr. F. C. Pratt noticed that many fruits were injured by these 

 larva?. On some plants practically all of the fruits were injured, and 

 it was found that the larva? traveled from one fruit to another. In 

 that vicinity fully 10 per cent of the fruits were injured. 



The larva? are generally to be found just beneath the corolla, which 

 remains on the crown longer than when the fruit is uninjured. 

 When the corolla falls the larva? web over the orifice made in the 

 fruit, and the protection is augmented by the addition of the reddish 

 excrement. They also occur in the blooms, but leave them as soon 

 as the flower parts become dry. 



It is evident that eggs are generally deposited in the blooms, 

 although this is not by any means invariable. Many fruits were 

 observed in which entry had been gained from the side. 



The larva? are blackish, with a shining black head and narrow, 

 lateral crimson bands. 



Allorhlna mutabilis Gory. 3 



Mr. E. A. Schwa rz informs us that AllorMna mutahilh (lory is a 

 common enemy of the fruit of Cereus in Arizona. It i< well known 

 for its damage to fruits of various kinds. 



1 Nature. November S-\. 1882, p. 77. 

 - Order Lepidoptera, Family Pyralidse. 



3 Order Coleoptera, Family Scaralneida?. 



