298 



THE AGRICULTURAL NEWS. 



Sepembee 9, 1916 



INSECT NOTES. 



THE CONTROL OF A WOOD-BORING 



LARVA. 



In view of the occurrence of the woud-boiing moth 

 Vuomitiai punctifer, Hamp. in the West Indian islands, and 

 the damage done by it to a wide range of shade and fruit trees 

 (see Agricultural News, Vol. XIII, p. ;<28) the following 

 details as to the methods of control available should be 

 useful. They are taken from an account of a closely related 

 species of similar habits given by L. O. Howard and F. H. 

 Chittenden inFannrn^' Jinlletin No. 708, of the United 

 States Deparniient of Agriculture: — 



'The protected and concealed manner of life of this 

 borer, as shown by the life-history, which will apply in the 

 main to borers in general, renders it very difficult of treat- 

 ment b}- means of insecticides or other direct manures. The 

 mo.st efficacious remedial measure consists iu cutting oti' and 

 destroying aflected branches, and in the injection of bisulphid 

 of carbon into the holes or burrows where the larvae are 

 at work. 



'Twigs or branches which, by their wilting or by 

 the presence of burrows showing accumulations <<( frass or 

 sawdust-like castings at their entrance.s, indicate the presence 

 of this borer, should be carefully searched out, the smaller 

 ones pruned away and the larger ones cut back, and the 

 amputated portions promptly burned. The stubs should be 

 coated, preferably with grafting wa.x, to prevent the entrance 

 c>f other insects or the spores of decay-producing fungi, 

 although coal-tar preparations containing mineral sub.stances 

 are in somewhat general use for this purpose. After wind- 

 storms the atiected branches which have fallen to the ground 

 and those which remain attacked to the tree should be 

 collGcted and burned. Wherever trees show that they are 

 past recovery it is best to take them out and promptly 

 destroy them. The word "promptly" is used adviseflly, 

 since tliis insect, as previously stated, frequently migrates 

 from one twig or branch to another. 



'In the case of young and rare trees and others which show 

 only a few larval burrows in the bark, bisulphid of 

 carbon is the best remedy and one which has been in 

 general use again.st the present species in the {xiblic paries (jf 

 New York City. It is injected into the openings of the 

 burrows, and the openings are innnediately afterwards closed 

 with various substances. For this injection a mechanic's 

 long spouted oil can of small size may be used on large trees, 

 but against a related species the writers have made very good 

 use of a small gla.ss syringe, such as may be purchased at drug 

 stores for about 10 cents. These glass syringes are most 

 serviceable, becau.sp the exact amount bisulphid may be 



seen when drawn into the syringe, and because there is no 

 threading to be injured by the reagent. Metal syringes may 

 also be used, but it is more difficult to measure the exact 

 amount, and the bisulphid acts on the leather packing. Rub- 

 ber .syringes are not .serviceable because of rapid corrosion. 

 About a teaspoonful of the liquid bisulphid is sufficient for 

 each borrow. 



'For stopping the holes after injecting the liquid, putty 

 and moist clay, advised by some, have been found practically 

 useless. Grafting wax, on the other hand, gives perfect 

 satisfaction. Coal-tar is less advisable but may be substi- 

 tuted for the latter, or the holes may be closed by inserting 

 a wooden plug and breaking or siwing it off even with the 

 trunk. In any case the stopper should be tight, to exclude 

 water from rains, which might tend to produce decomposition 

 of the surrounding wood or invite the entrance of other 

 insects, like carpenter and other ants and secondary borers, of 

 which there are many species, and injurious fungi. 



'It is possible to reach and destroy many larvae by forc- 

 ing a copper or other pliable wire into the channels. This is 

 a well-known borer remedy. It is impo.ssible, however, by 

 this means to kill the insects in all cases, owing to the length 

 or crookedness of the burrows. Bisulphid of carbon should 

 then be u.sed. 



'To what extent electric or other bright lights are service- 

 able as an agency in the destruction of the moths of this borer 

 has not been definitely determined, but they possess a certain 

 value. A method frequently advised consists in placing 

 shallow pans around electric-light poles in and about 

 parks to attract the moths. The pins are partially filled with 

 water, and a small quantity of kerosene is poured into them. 

 The moths Hying against the globes drop into the pans and 

 are promptly killed when they come in contact with the oil. 

 In this way man}' males can be destroyed. 



'In large parks the destruction wrought by this borer 

 annually is an important item, and it will be found profitable 

 to establish a system of inspection consisting iti the employ- 

 ment of park keepers and boys and others who may be 

 engaged at lower wages to keep a constant lookout for 

 evidences of borer attack on valuable trees. In 1893 a New 

 ^'ork entomologist spent two months in tighlinng this insect 

 alone in the city parks of New \ ork, collecting wagon loads 

 of limbs and branches and destroying the contained larvae 

 and pupae. 



'If valuable trees are to be pnaected, the in.sect should 

 not be allowed to breed in usele.ss growth. The borers in 

 sui'li trees should be destroyed or the trees i)romptly felled 

 and burned. Care should be exercised in transplanting trees 

 and fertilizers should be used in order that the trees may be 

 always thrifty, the better to withstand attick. This also 

 means protection from the attack nf aphides, scales and defol- 

 iators such as the white-marked tu.ssock moth and the fall 

 w^ebworm, and keeping them free from disease. 



'Finally, in the (control of this species promptness and 

 thoroughness cannot bo too strongly emphasized. The bisul- 

 phid of carbon remedy should always be used where applic- 

 able, and the inspection .system advised should be instituted 

 in all public parks and on city streets infestfd by this pest. 

 I'udividual owners of valuable trees should become acquainted 

 with the pernicious nature of this borer, and united action 

 should be secured with neighbours whose trees sutler from 

 the ravages of the pest.' 



