Maskell. — On Parasites of Beetles and Woodlice. 199 



Art. XXV. — On some Mites parasitic on Beetles and Wood- 

 lice. 



By W. M. Maskell. 



[Read before the Wellington Philosophical Society, 26th October, 1892.] 



Parasites, as Thackeray says, exist always ; and there is 

 perhaps no portion of the great animal kingdom (excepting 

 man) which exhibits the truth of this saying more fully than 

 the various tribes and families of insects, and of the Crustacea. 

 These organisms, which are themselves commonly engaged in 

 preying upon their fellow-creatures, are subject to an infinite 

 variety of hostile attacks from beings smaller than they are, 

 and their lives (perhaps fortunately for the rest of creation) 

 must be by no means happy ones. It would be a very useful 

 thing if the study of the different insect parasites in New Zea- 

 land were seriously undertaken, and it is to be hoped that 

 some day, when a proper Agricultural Department exists here, 

 this will be done. Meanwhile every contribution to know- 

 ledge is valuable, and the following note is offered as a small 

 instalment. 



Parasites upon the smaller forms of animal life, such as 

 insects or Crustacea, may be of many kinds. Some are them- 

 selves insects, such as the minute Hymenoptera which prey 

 upon the so-called "blights"; others are Entozoa, internal 

 parasites preying upon the very intestines of their hosts ; 

 others, again, belong to the great order Arachnoidea, which 

 includes not only the spiders but also the different mites. 

 Mites feed on both animal and vegetable matter. Some are 

 harmless, some injurious, some useful, some even murderously 

 noxious. In the sheep-scab and human itch we have examples 

 of abominable nuisances ; in the almost invisible little animal 

 which swarms often in cabinets and boxes we have an annoying 

 and destructive enemy ; in the tree- or beetle-mites we have 

 frequently very useful scavengers ; in sugar or in biscuit, mites 

 are both injurious and offensive ; while we consider that the 

 presence of mites is not only harmless but even necessary to 

 the proper ripeness and flavour of certain kinds of cheese 

 which are inferior without them. Amongst all these varieties 

 of mites there is one family which has for its special object 

 the preying upon some species of animals which are them- 

 selves enemies to man ; and two of these I am introducing to 

 you this evening. If anybody here present has occupied him- 

 self with farming he will be only too well acquainted with 

 what are known as " wireworms " ; while anybody who grows 

 flowers in pots has had troubles with the little animals called 

 "woodlice." The mites which I now exhibit, none of which 



