THE ELM-BARK BEETLE 47 



same way the grub of the hive-bee, which lives upon a ready- 

 made store of honeys and the maggot, of the blow-fly, which 

 finds all the food it requires in the mass of putrid flesh 

 selected by the parent, can manage perfectly well without 

 organs of locomotion, and these larvae are footless like those 

 of weevils. 



The garden-weevil is a most intractable pest. Perhaps, 

 there is no better remedy known than sifting all the earth 

 of the greenhouses, down to a depth of three to four inches, , 

 through fine sieves, thoroughly exploring at the same time 

 all crevices, or stopping them up. When building or fitting 

 up. greenhouses, it will save much loss to avoid narrow chinks,, 

 and to arrange for sweeping out or lime-washing every part 

 easily and completely. Repeated applications of soot and- 

 lime, worked up in water to the consistence of whitewash and 

 used fresh, have proved useful in the field. 



11. THE ELM-BARK BEETLE (Scolytus destructor) 



If in our rambles we come across a felled elm-tree, which 

 has lain some months on the ground, we shall be pretty sure 

 to find that its bark is mined by a small beetle. Nearly all 

 round the year the larvae can be discovered in such a tree by 

 stripping off a sheet of bark and searching the galleries thus 

 exposed to view, or (in winter) by examining the young wood. 

 Towards the end of May a vernal swarm of bark-beetles 

 appears, and an autumnal swarm in the end of August, but 

 the bark-beetles are so small (4-5 mm. long) and show them- 

 selves so rarely, that they may abound in places where even the 

 naturalist hardly ever remarks them. The elm-bark beetle is not 

 found in Scotland nor Ireland, and it is more plentiful in the 

 southern and midland counties of England than in the north. 



To become acquainted with the mode of hfe of this beetle 

 we must examine a sheet of infected elm-bark. The parts 

 which have'been mined are indicated by small holes like shot- 

 holes, which are usually situated here and there in the bottom of 

 deep cracks. In June,, when the female beetle is at work, there 

 rnay be a little heap of bark-dust. close to the hole, but very 

 often only the holes show where the bark has been mined. 



On a sheet of bark detached, from such a tree may be seen 



