408 Report of the Department or Entomology of the 



A NATIVE SPECIES OF ERMINE MOTH. 



There is one native species of the genus Yponomeuta which is 

 muliipunctellus Clem. Dyar records the Atlantic states as its range 

 of distribution; and according to Chambers it is very common in 

 Kentucky, while Gaumer has obtained specimens in Kansas. The 

 caterpillar feeds on the leaves of Evonymus atropurpureus Jacq. 

 and spins its webs over the plant as is characteristic of the insects 

 of this genus. This species differs from European forms by the 

 larger number of black dots on the front wings and the marked 

 difference in the hind wings of the sexes. All the wings of the male 

 are white while the female has the anterior wings white and the 

 posterior wings dark gray. 



natural ENEMIES. 



The ermine moths have a large number of natural enemies, the 

 most important of which belong to the orders Hymenoptera and 

 Diptera. Ratzeburg ^ has enumerated over thirty hymenopterous 

 species which are said to attack these insects. In southern Russia, 

 according to Mokshetsky ^ twelve species of hymenopterous and 

 three species of dipterous prey upon malinellus and during some 

 seasons they exert a marked regulatory and repressive action upon 

 the multiplication of this pest. A common and most efficient enemy 

 of both padelliis and malinellus is the remarkable chalcid, Encyrtus 

 (Ageniaspis) fiiscicollis Dalm., which presents the exceptional 

 phenomenon of polyembryony ^ and possesses immense reproductive 

 powers. 



Among collections of Yponomeuta moths received from Europe 

 there were included a number of unnamed parasites which, through 

 the courtesy of Dr. L. O. Howard have been identified'* as follows: 

 Herpestomus n. sp., Angitia sp. and Tetrastichiis sp. from malinellus 

 from France; Discochceta evonyniellce Ratz. from padellus from 

 France; Cnemedon vitripennis Meigen from padelhis from Holland; 

 and from malinellus from Japan, Herpestomus n. sp. which according 

 to Kuwana is the only parasite which attacks this lepidopteron in 

 this country. 



In spite of the large number of Yponomeuta caterpillars which 

 have been found in New York, it is worthy of record that we have 

 not reared any of the well known parasites which abound in the 

 normal range of distribution of these pests. The failure of the 

 more common and efficient species to accompany the ermine moths 



* Die Ichneumon, d Forstins. Bd. 3, p. 259. 



^ The Apple Moth, 1907. 



' Marchal, Paul. Reeherches sur la Biologie et le Developpement des Hym^noptSrea 

 Parasites — La Polyembryonie Sp^cifique ou Germinogonie, Arch. Zool. Exp., 4, 

 2:257-335, 1904. 



'' Identifications of Hymenoptera by Mr. J. C. Crawford, and of Diptera by Mr. 

 J. R. Malloch. 



