J. T. Wads WORTH 103 



Parasites. 



Three species of Chalcids and one Braconid emerged from the 

 flower-heads in May 1912 and 1913, bnt in very small numbers ; pre- 

 sumably some of these were parasitic in the Uwphora larvae. The 

 Chalcids have not as yet been identified ; Mr Claude Morley, however, 

 has kindly named the Braconid, it is Bracovi mmutator Fab., and probably 

 parasitic on the lepidopteron Parasia metzneriella Stt. Brischke (1882) 

 records this parasite from the larvae of Sesia (Bembecia) hylaeijormis 

 Lasp. (not a British species) ; Marshall (1885) states that Elisha bred 

 two females of this Braconid from the lepidopteron Argyrolepia zephy- 

 rana Tr. It therefore appears probable that Bracon minutator is 

 parasitic on lepidopterous hosts. Under the description of Bracon 

 variator Nels., Marshall says " It is doubtful whether this Bracon is 

 a parasite of certain small curculios {Cionidae) or of flies of the genus 

 Trypeta " and further on he states that " Giraud records B. nigripedator 

 Nees, from Urophora solstitialis L. ; and Fitch once obtained a Bracon, 

 now lost, from galls of Centaurea inhabited by the same fly." 



With regard to these records of parasitic hymenoptera obtained 

 from flower-heads of C. nigra and other composite plants, 1 would 

 remark that unless it is proved that dipterous larvae and pupae alone 

 are present therein, it is incorrect to state definitely that they are 

 the hosts of the parasites obtained, inasmuch as a single flower-head 

 may contain the larva or pupa of a lepidopteron in addition to those 

 of diptera. 



Kaltenbach states that Eurytoma aterrima Schr. (verticillata) is 

 parasitic on U. solstitialis, and probably also Trigonoderus amahilis Walk, 

 and Semiotellus (Semiotus) diversus Walk. Walker (1833-37) records 

 these three Chalcids from near London but does not give their hosts. 



Mr C. Morley (1908), from a quantity of dried heads of Centaurea 

 nigra gathered in March, 1907, beneath fir-trees, obtained both sexes of 

 a Pteromalus in May, and numerous Bracon minutator cT in April ; he 

 also obtained one specimen of Pimpla sagax Htg. on April 26th, and 

 of this specimen he says (p. 81) " Its host was undoubtedly Urophora 

 solstitialis, many of which emerged during the following June ; unless, 

 of course, its presence there were purely accidental and its true associa- 

 tion were with the overhanging conifers, in which case it would surely 

 have shown itself in the jar in the course of the preceding month." 

 In view of the fact that with one exception, viz. Anthonomus pomorum L. 

 all the recorded hosts of this ichneumon are lepidopterous, and as the 



