BOSTRICHIDjE. 



At firrta straight groove is perceived There are few of the large German forests which 



have not, at one period or another, suffered from the 

 epidemic produced by the swarms of these insects, 

 and which is there termed wurm-troekniss, and in 

 the old liturgies these insects were mentioned under 



570 



confirmation. 



in the bark, on each side of which they burrow lateral 

 channels, in which the female deposits sixty or eighty 

 eggs ; each egg being placed separately 'in a small 

 rounded cavity, which is then covered with saw-dust. 

 After completing their labours, the parent-insects 

 make their way again through the bark to the outside 

 of the tree. At the end of fifteen days the larvae are 

 hatched, and immediately commence their work of 

 destruction. They are small, soft, fleshy grubs, with 

 short pointed legs, their body being divided into 

 segments. Each of these grubs, starting from the 

 place of its birth, constructs for itself a serpentine 

 tubular gallery gnawed between the bark and the 

 wood, and which, from the fanciful resemblance of 

 these galleries to the letters of the alphabet, has given 

 rise to the specific names of these insects, typogra- 

 p/iux, wicroftraphus, polygraphus, <ic. 



Track of the Typographer Beetle. 



These galleries never cross each other, but, by a re- 

 markable instinct in the larva, run in diverging lines 

 from the principal gallery, in which the eggs were de- 

 posited. Each gallery also increases in size, as it in- 

 creases in distance from the centre, which is owing to 

 the increased size of the grub. At the end of several 

 weeks the larva attains its full growth, and changes 

 into a pupa, in which state it is very tender and sen- 

 sitive ; so that an unfavourable season destroys vast 

 numbers in this state. And it is owing to the difference 

 in the weather, that the duration of time passed in 

 this state is increased or diminished. If the period 

 of the full growth of the grub occur in summer, the 

 insect passes through its various stages in the course 

 of eight weeks ; but if the eggs are deposited in 

 autumn, as many months are required for this pur- 

 pose. Arrived at its perfect beetle state, it devours 

 all the portion of the tree which remains between 

 the wood and the outer bark, and finally escapes 

 through the latter by boring a small circular orifice. 

 If, therefore, a tree exhibits a number of these small 

 holes, it is evident that the insects have escaped in 

 their perfect state. Wilhelm states, that often times 

 as many as 80,000 larvae are engaged in the destruc- 

 tion of a single tree. The number seems immense, 

 but when the minute size of the insects is considered 

 (and they are much beneath a quarter of an inch 

 in length), the statement may readily be credited. 

 Another thing is equally surprising: even if the trees 

 infested by these insects be cut down, floated in 

 water, kept for a length of time immersed either in 

 water or snow, or even placed upon ice, still the 

 insects remain alive and unhurt. 



their vulgar name of the turc. At the commence- 

 ment of the eighteenth century, the Hartz forests 

 were attacked, it reappeared in 1757, redoubled in 

 fury in 1769, and increased until 1777 ; in the two 

 following years it seemed to abate, but in the follow- 

 ing year, after a hot summer, it increased to a most 

 alarming extent ; the inhabitants were thereby me- 

 naced with entire ruin, by a total suspension of the 

 working of the mines. The mischief arrived at its 

 height in 1788, when it was calculated that on the 

 Hartz alone, a million and a half of trees were 

 I destroyed by it. As the evil increased, the impossi- 

 { bility of applying remedies was augmented, since at 

 this period the insects migrated in swarms, like bees, 

 to Suabia and Franconia. A succession of cold seasons 

 gave it a check ; but it re-appeared in 1790, and even 

 in 1796 there was cause to fear for the few situations 

 which had previously escaped. From these observa- 

 tions it was evident that the insects would not unwil- 

 lingly attack sound and healthy trees, and Wilhelm 

 observes, that the misplaced confidence which many 

 persons entertained that the insects attack only trees 

 already injured, and that their ravages are put an end 

 to by the insects themselves, have cost many hun- 

 dreds of trees. A small number of the bostrichi 

 would not be sufficient to destroy a healthy tree, nor 

 would they, except in favourable seasons, increase to 

 an alarming extent ; but it is always prudent, nay, 

 absolutely necessary, to remove felled timber without 

 delay, as the flowing sap is most attractive to insects. 

 Carpenters also, for the like reason, should be pre- 

 vented from erecting their sheds in or near forests. 

 The trees once attacked, should be immediately cut 

 down and barked, and tire bark burned. Indeed, it 

 is certain, that trees allowed to stand for a consider- 

 able time after they are dead, are neither fit for 

 building, nor for fuel, nor for the manufacture of 

 charcoal. The Bostrichus ligniperda instead of placing 

 its eggs at each side of the principal gallery, deposits 

 them all together, so that the larvae work from a 

 common centre, whence their burrows form a kind 

 of star. 



The second sub-family, Bostrichides, have the antennre 

 terminated by three large distinct joints, the palpi are of 

 the ordinary shape, neither being minute nor conical. 

 The tarsi have always the articulations entire ; here be- 

 long the genera Sinoxylon, Apate, Boslrichut and some 

 others, to which Latreille adds the genus Cis, which 

 Mr. Stephens places amongst the death-watches. 

 The habits of these insects are somewhat similar to 

 those of the other family, since they are constantly 



