16 STATE BOARD OF AGRICULTURE. 



this kind of loss I saw recently in a plum orchard of about 200 trees 

 which had been in bearing condition for six or seven years. Each 

 year the trees blossomed well, set their fruit well, and in July 

 dropped every plum, filled with Curculio larvae ! In five years not 

 five bushels of fruit were harvested from all the trees ! This is 

 an extreme case ; but similar ones are not rare, and the fruit grower 

 does not suffer alone. In 1898 and 1899 more than one grain farmer 

 failed to get even his seed back from his wheat fields, because of injury 

 done by the Hessian fly. 



All parts of a plant are subject to insect attack. Caterpillars, 

 slugs and grubs, beetles, bugs and lice attack and devour the leaves 

 or suck the plant juices. Borers infest the twigs, branches, trunks 

 or stems of tree and vegetable, and numerous types live in the soil 

 on or near the roots — like white grubs and wire-worms. Mandibu- 

 late or biting insects devour the plant tissue, while haustellate or 

 sucking forms drain the juices which nourished it. The distinction 

 is important, for the means adapted to destroy the one type are some- 

 times useless as against the other : Thus paris green applied on 

 potato leaves kills the beetle and its larvae when they feed on them ; 

 but it has not the slightest effect upon the plant lice that suck only 

 the juices. Therefore we must adapt our remedial measures to the 

 case especially in hand, and our first inquiry must always be just 

 how, just when and just where does the insect do its injury When 

 these questions are satisfactorily answered we can more intelligently 

 consider the best methods of preventing or checking further ravages. 

 Sometimes a modification of the ordinary farm practice will suffice 

 to secure exemption from further attack, while if insecticides must 

 be resorted to, the point or stage at which to strike is a matter of 

 great importance. 



On ordinary farm crops annually put in, the insect injury is 

 usually all crowded into the compass of a single year: i. e., the 

 melon crop is lessened from 50 % to 100 % over a given district, and 

 this loss is the measure of damage. There is nothing that prevents 

 putting in a similar crop the year following and no certainty that any 

 such disaster will again overtake it, even if no measures in avoid- 

 ance be taken. 



In orchards injury may be and often is progressive, as when 

 bearing trees are attacked by borers which first lessen the crop and 

 eventually destroy the tree. Here the measure of damage is the value 

 of the bearing tree for the period which is required to bring another 

 into similar condition, and the injury extends over a period of years. 



Briefly, then, all farm and orchard crops are subject to insect attack 



