69 



The whirligigs {Gyrinidce) must he familiar to every one. They are those litttle black 

 beetles that one sees so often in groups on the surface of water, whirling and circling about 

 in every direction with great rapidity. " When thus occupied their motions are so exceed- 

 ingly quick that the eye is perplexed in following them, and dazzled by the brilliancy of tiieir 

 wiug-cases, which glitter like bits of polished silver or burnished pearl. On approaching 

 them they instantly take alarm and dive beneath the surface, carrying with them a little 

 bubble of air, which glitters like a drop of quicksilver, and is attached to the posterior por- 

 tion of their bodies. Sometimes they may be taken flying, their large wings enabling them 

 to change their abode without difiSculty, when the drying up of their native pool compels 

 them to migrate. This enables us to account for the occasional discovery (f these insects in 

 small puddles of newly-fallen rain water. The structure of the short hind legs, and espe- 

 cially of the curious branched tarsi, must be examined in endeavouring to account for the 

 singular motions of these insects ; the a.ssembling together of which has been regarded by 

 some writers as resulting purely from a strong social influence, and by others as indicating 

 no closer bond than that of animals congregating round their common food. That the food 

 of the GyrinidsD consists of small dead floating insects, I have ascertained ; but I would fur- 

 ther suggest that, being produced on the same spot, as is the case with the swarms of midges, 

 they are influenced in some degree by the common desire of continuing their species. I have 

 often ob.servcd that, in their gyrations, they hit against one another. In dull and inclement 

 weather they betake themselves to quiet places, under bridge.-*, or beneath the roots of trees 

 growing at the water's edge. When touched they emit a disagreeable odour, arising from a 

 milky fluid, which is discharged from the pores of different parts of the body. The remark- 

 able structuieof the eyes, which, unlike those of most insects, consist of two distinct pairs, 

 one on the upper and the other on the lower surface of the head, must be greatly service- 

 able to the insect in the peculiar situation iu which it is generally observed, and whereby it 

 is enabled to see objects beneath it in the water, and above it in the air.'' (Westwood). They 

 are all of a broad, oval form, generally of polished black colour, with broad oar like hind 

 tarsi, and long slender fore-feet, used in seizing their prey. They vary in size from about 

 one-fifth to half an inch in length. 



Besides the Diving beetles and the "WTiirligigs, there is yet another great family of 

 aquatic beetles, which belong to a different sub-tribe of this order of iuBCCts; its members are 

 termed "Water l,over.s," {Ui/drophilido') from their habits. 



The members of this family live either in the water, or on the damp margins and shores 

 of .'Streams and ponds ; they are carnivorous in the larval state, but as beetles they feed upon 

 refuse and decaying vegetable matter, thus uniting the qualities of the two families already 

 noticed, and those of the scavenger beetles, which we purpose bringing before the reader by 

 and by. A considerable number of these "W^ater Lovers" are found in Canada; some of 

 the species attain a very large size, while others are quite minute, and not to be discerned 

 witiiout close observation. As these creatures are not of any very general interest, we may 

 dismiss them from our notice and pass on to the more coQspicaous and note-worthy Carrion 

 Beetlea 



4. Burying and Carrion Beetles. {Silphida). 



These curious and interesting creatures belong to the family SUphidm ; they are dis- 

 tinguished by the flattened form of their bodies, iheu- knobbed antennse, their habits, and 

 the bliick nauseous fluid they discharge when handled. Their grand duty is to remove 

 from the surface of the earth all dead or putrefying animal matter, which would other- 

 wise become noxious and offensive. They are usually found in or close to carrion of all 

 sorts, though sometimes they devour putrid fungus ; occasionally we liave taken tiieni on 

 the wing, and have even found them attracted by light into our rooms in summer. The 

 SUphidm are divided into several genera, the chief of which are Necrophnnis, including the 

 Sexton or Burying Beetles, and Silpha, the Carrion Beetles ; botli of these genera are well 

 represented in Canada. 



The Sexton Beetles (Necrophorus), in spite of their loathsome occupation, are decid- 

 edly handsome insects. Their usual colour is deep shining black, variegated with rich 

 orange-red spots ; beneath they are frequently ornamented with yellowish silken hair like 

 that of a Humble-bee ; their antennie are very remarkable, consisting of a jointed stem 

 terminated by a rose-coloured or orange knob composed of four little cups or plates piled 



