ENTOMOLOGIST AND BOTANIST. 



165 



It is ■well known that elm trees, as well as 

 apple trees, in certain localities in the United 

 States, are sometimes eaten almost bare by that 

 common looping caterpillar called the Canker- 

 worm ; and that these woians have been checked 

 and controlled by those who are acquainted 

 with their peculiar habits, by fastening leaden 

 troughs of oil round the butts of the trees. Like 

 the larvre of many other moths, this worm buries 

 itself under the ground to change into the pupa 

 state; but unlike the great majority of moths, 

 the perfect male has wings, and the perfect 

 female has no wings at all, and is therefore 

 compelled to crawl up the trunks of the trees to 

 deposit her eggs, instead of flying on to the 

 trees, as almost all other insects have the power 

 of doing when in the perfect state. Hence the 

 philosophy of the practice above alluded to, 

 which depends for its efficacy on this trait in the 

 natural history of the Canker-worm. Not very 

 long ago, the elm trees which ornament the city 

 of Baltimore were attacked by a larva that strip- 

 ped them bare. Supposing it to be the notorious 

 Canker-worm, the corporate authorities spent a 

 good many hundred dollars in fixing leaden 

 troughs filled with oil, after the most approved 

 fashion, round their trees. They might just as 

 well have built a tight board fence round a 

 corn-field to keep out the crows and blackbirds. 

 The insect that was afflicting their trees was 

 not the Canker-worm, but the larva of a beetle 

 {Galeruca calmariensis) imported by some 

 chance or other from Europe, where it often 

 strips the elm trees in the same way; and, un- 

 fortunately for the City Fathers of Baltimore, 

 the female of this beetle has wings, and was not 

 in the least inconvenienced by the oil-troughs. 

 A little time spent in investigating the habits of 

 this beetle would have saved them all their trouble. 



A similar instance of just such entomological 

 folly occurred a couple of year? ago in Southern 

 Illinois. A certain fruit-grower in Union county, 

 for lack of a proper knowledge of the habits of 

 that little pest the Curculio, took it into his head 

 that this insect had no wings and could not fly, 

 and that it could only reach the fruit, in conse- 

 quence, by climbing up the tree. Hence he 

 very sapieutly went to work and fixed a band 

 of wool around every tree in a large orchard 

 containing about 10,0U0. Now, as the Curculio 

 has ample wings, and can fly with the greatest 

 ease, this procedure was of no earthly use in 

 protecting this worthy fruit-grower's peaches. 

 He might just as well have wrapped the wool 

 round his stove-pipe under the delusive idea 

 that he could thereby keep the flics and mos- 

 quitoes out of his house. 



There is a small timber-boring beetle — called 

 Limexylon navale, or in English the Naval 

 Timber-pest — which is very common in the Oak 

 forests of the North of Europe, and occasionally 

 occurs in such numbers in the Swedish and 

 French dock-yards, as to do a prodigious amount 

 of damage. About one hundred years ago the 

 Swedish Government found out that this insect 

 was doing millions of dollars' worth of damage 

 in their dock-yards by boring the timber full of 

 holes, so that if it had been put into a ship, it 

 would have let the water in like a sieve. The 

 Swedish Government concluded that it wouldn't 

 answer to incur such a heavy annual loss ; and 

 they did the very wisest thing that they possibly 

 could have done. They applied to the celebrated 

 LinniEus — the father of the Science of Entomol- 

 ogy — though to many perhaps he is only known 

 as a great Botanist. Linna3us took the matter 

 in hand, and having investigated the habits of 

 the insect, discovered that it came out of the 

 timber in the perfect or winged state in one 

 particular month only (June) when it flew 

 around, paired, laid its eggs on any oak timber 

 to which it had access, and shortly afterwards 

 perished. So he said to the Swedish Govern- 

 ment: "Gentlemen, all you have to do is to sink 

 all your oak timber under water during the 

 mouth of June, so that the female beetle may 

 not be able to deposit her eggs on it; and you 

 will be no more troubled for a groat many years 

 to come with Liviexylon navale.'' The Govern- 

 ment did so ; and the result was just what Lin- 

 nieus had predicted. Dr. Harris informs us that 

 not very long afterwards the insect occurred in 

 similar profusion in a French dock-yard ; and 

 although a naval officer, who was also a good 

 entomologist, suggested the Linnajan remedy 

 to the authorities, they neglected to apply it — 

 having perhaps the common unfaith in Science, 

 and thinking with the vulgar, that the study of 

 bugs was all a humbug. As might have been 

 expected, they reaped the reward of their ignor- 

 ance, and suflered an immense amount of valu- 

 able timber to be destroyed by this insect, which 

 might just as well have been saved. 



Such instances might be multiplied ad inflni- 

 tum, but we forbear, and take consolation in 

 the fact that a new era is dawning. There were 

 men who had no faith in Fulton and liis Steam- 

 boat. There were men who had no faith in 

 Morse and his Electric Telegraph. There were 

 men who had no faith in Stephenson and his 

 Locomotive. But if Fulton, and Morse, and 

 Stephenson, had themselves had no faith, or 

 had suffered themselves to be laughed down by 

 the criticisms of the would-be wits and can't- 



