38 U.S. NATIONAL MUSEUM BULLETIN 255 



the fruit of Y. brevifolia. The writer has also collected this species 

 in the flowers of Y. schottii, as well as to rear it from the fruits. 



The young blastobasid larva, perhaps, enters a pod via the exit 

 burrow of Tegeticula or some other borer and commences to feed on 

 the seed residue left by the original occupant. Mature larvae fre- 

 quently can be detected externally by the presence of a silken, frass- 

 covered tube which protrudes about one-half to three-quarters of an 

 inch from the entrance of the burrow. Prior to pupation, the larva 

 leaves the fruit pod and constructs a whitish, silken cocoon in some 

 protective crevice, probably located most frequently near the base of 

 the yucca plant. The length of the pupal period is about two weeks. 

 Other blastobasids probably will be discovered in association with 

 yucca moths, for the habit as a scavenger in plant burrows of other 

 insects is a tendency typical of the family. 



Another group of insects that are encountered occasionally in the 

 flowers of Yucca are beetles of the family Nitidulidae. The author 

 found larvae of one species, identified by Dr. Anderson as belonging 

 to the genus Carpophilus, very abundant in the flowers of Yucca 

 schottii (figs. 38-39). The larvae of this unidentified species were 

 first noticed mining the flower petals. The mines are produced in the 

 shape of a Unear blotch and usuaUy extend the fuU depth of the petal. 

 At first the larvae are solitary miners, but as adjacent anthonomes 

 coalesce, several larvae may come to inhabit one large blotch which 

 eventually may occupy the enthe petal. An individual larva is not 

 restricted to a single mine; instead, it may leave the original mine to 

 initiate new ones in other parts of the flower at will. As the petals 

 are mined, a gradual decay of these parts commences that often 

 results in a premature dehiscence of the coroUa. The larvae may 

 continue to feed in the decaying petals after the flower has fallen, 

 for in this regard they seem very resistant to the adverse presence of 

 decay causing organisms. UsuaUy by this late stage, however, the 

 larvae abandon the petals and commence to burrow in the young 

 fruit. EspeciaUy in respect to this latter habit, it is very likely that 

 the larvae of Carpophilus and Tegeticula are involved in some com- 

 petition for food. 



The larvae of several species of Carpophilus, as well as other genera 

 of Nitidulidae, have been reported from the flowers of Yucca, particu- 

 larly Y. jilamentosa. These records, along with biological notes of 

 the larvae, are summarized by Connell (1956). 



Key to the Species of Tegeticula 



la. Fore wing white or mostly so. 



2a. Forewing entirely white (figs. 86-87) T. yuccasella 



2b. Forewing white, spotted with fuscous (fig. 84) . . . T. maculata maculata 



