104 ' Tlte Preparation of Coccldae 



4. Preservation of Unmounted Specimens. 



A few hints for the preservation and storing of unmounted material 

 may be of use. 



Desiccation is the method usually adopted and — for a general 

 collection — is certainly the most convenient ; though, where it is desired 

 to retain the exact form of the fresh insects, it may be advisable to 

 preserve duplicates in alcohol or dilute formalin. 



A very large number of species, e.g. all the Diaspidinae and the flatter 

 forms of Lecanium, may be treated like botanical specimens, i.e. dried, 

 together with the leaves to which they are attached, between absorbent 

 paper. But the pressure employed should be light — merely sufficient 

 to keep the leaves flat. I frequently have material submitted to me 

 for determination, where no pressure at all has been employed, with 

 the natural consequence that the leaves are so curled or shrivelled that 

 the task of examination is greatly aggravated. In such cases it is 

 necessary to break up the whole material and to examine it very closely 

 or valuable specimens may be overlooked. A leaf that has been dried 

 flat may be completely examined with the maximum of convenience 

 in the minimum of time. Thin slices of bark, or rind of fruits, may be 

 treated in the same way. Twigs bearing specimens ma}^ be cut up into 

 convenient lengths and dried without pressure. In any case, super- 

 fluous and useless parts should first be removed, to facilitate subsequent 

 examination and save space. Leaves bearing hemispherical or highly 

 convex species may be dried flat without pressure by pinning down the 

 edges. Species that are not habitually attached to their host plant, 

 such as many species of Pseudococcns, Orthezia, etc., are best removed 

 and dried separately, after which they may be kept in small glass tubes 

 plugged with cotton wool, or, better still, in the small gelatine capsules 

 supplied by chemists for the reception of various drugs. Specimens 

 dried in sifv should be wrapped in soft paper and placed in small envelopes 

 upon which the full data should be written. Capsules or tubes should 

 be placed in similar envelopes. The envelopes themselves may be 

 conveniently stored in white cardboard boxes which should be made 

 to order and should be of various sizes which must be multiples of the 

 smallest unit. The sizes that I have adopted in my own collection are : 



]|x2|x^ ; l|x2|xl; 

 ]|X2-^X2- lix2fxi. 



