6 INSECTS AFFECTING THE ORANGE. 



chrysalis presents a still more striking example of the same protective 

 resemblance. 



Injurious insects. — First in importance are the Bark-lice (Coccidse). 

 These sap the life of the tree at its source. The vital j.uices are sucked 

 up, and probably also poisoned, as the blood of animals'sometimes is 

 by the sucking parasites which infest them. 



Of insects injuring the root, little is known. As has been shown, 

 " Wood-lice" (Termites) are very often injurious just beneath the surface 

 of the ground, and there are some as yet unknown larvse winch are 

 said to bore into the tap-root at a considerable depth. The trunk has 

 few enemies, except Bark-lice, some species "of which prefer to attack 

 that part. 



The leaves and twigs, being those portions which offer the greatest 

 extent of exposed surface and the greatest variety of food, support 

 also the largest number of depredating enemies. A large proportion 

 of the leaf eaters feed indiscriminately upon many plants. Such are 

 nearly all the locusts, grasshoppers, and crickets, many caterpillars, 

 and some true bugs which injure by suction. The latter, however, for 

 the most part confine their attentions to the tender shoots, blossom 

 buds and fruit. 



With many of these insects the injury is limited to the gnawing of a 

 few leaves, and their importance to the orange-grower is not great. 

 Others, on account of their large size and voracity, defoliate the trees 

 and do appreciable damage. 



The tender budding stalks furnish particular species of insects 

 with their especial food ; certain other species feed upon the budding 

 leaves in the earlier part of their lives, and, when adult, select them as 

 places of deposit for their eggs. These do especial harm in checking 

 the advancing growth, nipping it in the bud, and inflicting far greater 

 damage than those which confine their attacks to^ mature parts of the 

 plant. 



Injury to the blossom buds and young fruit is caused by certain suck- 

 ing-bugs (Hemiptera), and the fruit as it approaches maturity is attacked 

 by insects of the same family, whose punctures cause it to drop from the 

 trees and rot. 



A minute mite, which appears to be one of the few forms of insect 

 life peculiar to plants of the citrus family, infests the leaves and green 

 fruit, causing upon the rind of the latter a discoloration known as " rust." 



Beneficial insects. — Under this head are included a great variety 

 of predaceous insects and parasites, without whose aid in checking the 

 horde .of depredators, the cultivation, not only of the Orange, but of 

 most other plants, would be an impossibility. 



Every order of insects furnishes its predatory species, which are to a 

 greater or less extent beneficial in destroying the j)lant-eating kinds 

 upon orange trees. The paper wasps, which hang their nests to the 

 branches, are employed in seeking out spiders and leaf-rolling cater- 



