44 JAMES WATERSTON. 



About three years later Swezey (4) recorded a disconcerting departure from the 

 usual habit of Paraphelinus. In February 1908, P. xiphidii was bred as a hyper- 

 parasite from cocoons of a Dryinid, Haplogonatopus, Perk.* Experiment showed 

 that Paraphelinus reared from the Dryinid readily attacked Xiphidium eggs and the 

 resulting imagines quite as freely reverted back to Haplogonotopus, attacking the 

 larva just before it pupated. Whether the host was an egg or larva the number of 

 Paraphelinus was the same, viz., 12 or 13 commonly. 



Apparently P. xiphidii is a vigorous parasite, attacking whatever pabulum most 

 conveniently offers itself ; and the unfortunate feature of this particular case of 

 hyperparasitism lies in the fact that it was desirable to protect the Dryinid because 

 it destroyed leaf-hoppers. Xiphidium varipenne itself is partly a noxious insect, 

 in so far as it attacks tender shoots, flower stamens, etc., and partly useful as a 

 devourer of Aphids. 



The material which I have had Before me is as follows : — 



(a) A single female — •" St. Clair, Trinidad; 12.iv.16; swept from grass" 

 (C. B. Williams), which I have determined as P. tomaspidis, How. (see notes 

 p. 56) ; 



(b) two lots of a distinct new species from British Guiana : (i) Issororo, N.W. 

 Dist., 6.vii. 1916, Lot 7, "Emerged from base of grass, Imperata caudata, 

 containing Tomaspis ? carmodyi" (C. B. Williams), 2 (J (J, 8 ££ ; (ii) ib. et 

 id., Lot 8, during July 1916, 8<?<J, 26 $$ ; 



(c) a slide containing a " parasitised egg of Xiphidium $ and 6 $$ of 

 Paraphelinus, Perkins " — Lahaina, Maui, 28. ix. 1905 (0. H. Swezey) ; possi- 

 bly the seven examples referred to by Swezey (2, p. 215). This was generously 

 placed at my disposal by Dr. Perkins to treat as might seem best. The seven 

 examples have been remounted after careful potashing, the male and three 

 females being partly or completely dissected. These preparations with 

 others from Mr. Williams' material are deposited in the British Museum. 



Only the most careful manipulation will produce satisfactory preparations of 

 Paraphelinus. The wings may be detached from either dried or spirit material 

 and mounted in the way already suggested {Bull. Ent. Res. vii, p. 231-2) ; but after 

 potash and acetic acid, transference to oil should be gradually attempted. Three 

 or four graduated layers from oil to absolute alcohol in a narrow 1 inch tube are not 

 too many when dealing with such delicate organisms ; the actual transference to 

 absolute should be effected as quickly as possible, for even a momentary pause will 

 permit the acid to evaporate and the preparation will be ruined. The object of 

 having the specimen charged with acetic acid when passed into absolute is to regulate 

 transfusion and to prevent collapse. 



The slide of P. xiphidii was treated as follows : — The hard balsam at the edge 

 having been removed, a little xylol was run round the cover slip ; when the xylol 

 had acted on the balsam for a short time two needle points were inserted a little apart 

 and the cover broken by pressure between. In this way the cover was gradually 

 chipped off without at any time bringing pressure to bear upon the brittle mounts. 



* " H. vitiensis. ... No repetition of this hyperparasitism has since come to my 

 notice." — 0. H. Swezey, in litt., Dec. 1916. 



