June, '13] TIMBERLAKE: PARASITES COCCUS HESPERIDUM 301 



one undescribed, the other E. longipenne, Cheiloneurus sp. and Cer- 

 chysius sp. The undescribed species of Ayiicetus is most probably a 

 fifth species of this group, and has been found only at Sacramento. 



Cerchysius sp. 



Of these species the Cerchysius is by far the most common, although 

 in another connection as a parasite of ScuteUista cyanea and- Tomocera 

 calif ornica underneath the black scale (Saissetia oleoe Bern.). Al- 

 though it is nowhere abundant, it is rather frequently found under 

 the black scale near Santa Barbara and San Diego. In Los Angeles 

 County it has been rarely found in the last two years. Its presence 

 is at once made known by the characteristic puparium-like shell, 

 which it transforms out of the larval skin of its host, toward the end of 

 its own larval life. As a parasite of Microterys flavus on the soft scale 

 it is extremely rare, and has been found only twice, once at San Diego, 

 and once at Santa Barbara. In confinement, however, it reproduces 

 freely on the larvjB of Microterys. It is the only one of the Encyrtine 

 parasites of the soft scale that so far has been found to present a dis- 

 tinct tendency toward hibernation. 



The undescribed Eusemion and the Cheiloneurus are both rare 

 and are native species that presumably more or less by chance attack 

 Microterys flavus occasionally. Other species of Cheiloneurus of w^hich 

 there are many are probably similar in habits, although recorded as 

 primary parasites of various Coccid genera, such as Lecanium, Kermes 

 and Pseudococcus. One or two undescribed species have been reared 

 from Coccinellid larvae in which connection they may be hyperparasitic 

 on Homalotylus. The life history of the present species is nearly identi- 

 cal with that of Eusemion longipenne, which will be treated in some 

 detail. The habits of the other Eusemion have not been yet fully 

 studied. 



Eusemion longipenne (Ashmead) 



This species was described by Ashmead from Florida, and his single 

 specimen was reared from Lecanium on oak. In California the species 

 has been found at Santa Barbara and the neighboring town of Car- 

 penteria, and has been reared in small numbers from collected material 

 as a parasite of Microterys flavus. In captivity, however, it reproduces 

 with facility also on Aphycus flavus. 



The female is a most industrious worker and spends hour after 

 hour in puncturing the scales and in depositing her eggs. She is ap- 

 parently unable to determine by means of any tactile or other sense 

 residing in her antennse, whether a scale contains a primary larva or 

 not, for if supplied with unparasitized material she spends many hours 



