231 



NOTES ON COCCID-INFESTING CHALCIDOIDEA— II. 



By James Waterston, B.D.. B.Sc, 

 Imperial Bureau of Entomology, London. 



In the following descriptions I have dealt mainly with part of a small but valuable 

 collection of Coccid Chalcids, sent by Mr. W. H. Patterson from Aburi, Gold Coast. 

 The excellent condition in wliich the insects were received may be due to some extent 

 to the fact they were bred specimens, but it also owes something, I think, to the method 

 of packing employed. Into each tube (If in. X | in.) a little melted naphthalene 

 had been run wdth a piece of moderately thick paper on the top ; above this again 

 the Chalcids were loosely enclosed in screws, or (in the case of minute Eulophids and 

 Aphelinines) in small triangles of tissue paper, and the tube coated and sealed with 

 paraffhi wax. 



Some notes on the methods adopted for the preparation of the specimens for 

 descriptive purposes may be given. 



The material was sorted into species and two examples of each sex were selected 

 when available. The first example was relaxed for twenty-four hours, brushed out 

 and set in a drop of water, and when the liquid had nearly dried off, a touch of thick 

 gum tragacanth was placed on the tarsi and tips of the antennae and \\'ings. The 

 second specimen, after the wings had been broken off and transferred to clove oil 

 direct, was heated in 10 per cent, caustic potash until a few minutes after it had sunk ; 

 next transferred to glacial acetic acid, without washing, and when thoroughly cleared, 

 passed quickly into clove oil direct. In the case of species with, a thick, dark, heavily- 

 chitinised integument, which it is desired to study, the opaque sclerites may be treated 

 by Mayer's chlorine method (Arch. Anat. Phys., 1874, p. 321), as follows : — Place a 

 few crystals of potassium chlorate (KCIO4) in a watch-glass, and add one or two drops 

 of strong hydrochloric acid (HCl) ; when the action has taken place (which should 

 be immediately) and the green tinge of nascent chlorine is apparent, dilute with a drop 

 of distilled water, and imxRierse the sclerites in the liquid. When the chitiu is thin, 

 the bleaching will take place quickly ; the action should be carefully watched and 

 checked at the point desired by transferring again to the acetic acid and rinsing 

 there. Place next in clove oil ; if the integument is very dark and heavily-chitinised 

 do not add any water to the bleaching fluid. Dissections may be eftected either in the 

 acetic acid, which is easier, but a little unpleasant to work over, or in oil. From oil 

 the dissections may be mounted in balsam in the usual way, the head and thorax 

 being protected by fragments of cover glass to prevent crushing. By using circular 

 cover slips of | in. diameter (No. 1 for preference) the whole of the insect may be 

 conveniently mounted on two 3 in. X 1 in. slides. The following order of dissection 

 and mounting greatly facilitates descriptions : — antennae and mandibles ; first and 

 second maxillae ; labrum, hypo- and epi-pharynx ; prothorax (sclerites separated 

 and flattened) ; mesothorax, separated only into notal and sterno-pleural parts ; 

 propodeon ; abdomen, tergites, sternites, parts of ovipositor, or male genitaha ; 



