HYMENOPTEROOS PARASITES OF RHYNCHOTA. 347 



four direct parasites, two of which must be considered doubtfully 

 ascribed to this host, and two secondary (and consequently in- 

 jurious) parasites. Marshall bred both sexes of his Aphidins 

 fabarum from it in England (Bracon. d'Europ. ii. GOO) ; Gaulle 

 (Cat. 87) gives Trioxys keraclei, Hal., as preying upon it. It 

 can hardly be considered proved that Haliday's T. angelica 

 destroys it, since he says simply, " Hab. inter Aphidis Angelica 

 sylvestris autumno parum frequens " (Ent. Mag. 1833, p. 490) ; 

 and his Praon abject am is no more reliable with "Hab. inter 

 Aphides Angelica sylvestris autumno passim " (/. c. 485). I 

 simply place these here because the common Aphis of Angelica — 

 a plant not mentioned by Buckton — seems to me hardly distinct 

 from A. rumicis. However that may be, I consider it compara- 

 tively certain that some species of Praon attacks A. rumicis, 

 since Buckton states (Mon. Aph. ii. 155) that he has bred Coryna 

 clarata from "its silken tent" beneath the dried larval skin of 

 this species ; it is extremely improbable that this Chalcid con- 

 structs a cocoon of its own, and Praon is the only genus of 

 direct parasites known to do so outside the host's body. Buckton 

 further gives a capital account (I. c. 85, pi. lxiv.) of his Chalcid, 

 Pachycrepis {Coryna) dubia, which he (probably erroneously) 

 considered a direct parasite, and he states that it is sometimes 

 destroyed by a much smaller parasite — (?) of the third degree — 

 several of which find sustenance in the former's body and pupate 

 within the external cocoon, which is said {I. c. 156) to resemble 

 a tilting casque, beneath the body of the either winged or 

 apterous aphis. 



94. Aphis atriplicis, Linn. 



I have found this species abundantly upon Aster tripolium in 

 the salt-marshes at Southwold, in Suffolk. Haliday records his 

 still exclusively British Aphidins asteris (Ent. Mag. 1835, p. 101), 

 "Habitat in Aphidibus Asteris Tripolii copiose." Gaulle says 

 (Cat. 106) that the Chalcid, Aphelinus tibialis, Nees, has been 

 bred from the probably synonymous Aphis chcnopodii. 



(To be continued.) 



