INSECT PESTS AFFECTING THE CITRUS. 245 



INSECT PESTS AFFECTING THE 

 CITRUS. 



The insect pests that affect the citrus are numerous, but are 

 now easily kept in subjection by artificial means, aided largely 

 by their natural enemies parasitical and predaceous. 



In combating insect pests California has taken the lead over 

 every State and country in the world, and it is to be hoped that 

 through the fostering care accorded by the people the State will 

 not revert to primitive methods of allowing injurious insect 

 pests and tree and plant diseases to be introduced and obtain a 

 foothold in our orchards. 



The life of insects is divided into four periods: First, the ovum 

 (egg), which is motionless, and apparently lifeless; Second, the 

 larva (grub), which is active, voracious, and grows rapidly, 

 but without wings; Third, the pupa (chrysalis), which is 

 incapable of locomotion, and is in color and outward form 

 entirely unlike the larva from which it proceeds; Fourth, the 

 imago (perfect insect), which is active, has wings, does not 

 increase in size, and which lays eggs for future generations, 

 thus perpetuating its kind. The mode in which the life of an 

 insect is passed and the different species of trees it infests 

 differ very widely in the' various stages of its existence. 



The fructification of citrus trees in particular is mostly 

 accomplished by different species of insects, which convey the 

 pollen from tree to tree, and also from the stamens to the stigma 

 of the same tree. On the other hand there are multitudes of 

 baneful ones, which injure tree, fruit, etc., and are only checked 

 in their progress by other insects that prey upon them, or by 

 artificial means. 



SCALE INSECTS. 



Family COCCIDID^. 



"Male and female larvae similar, apterous, naked or covered, active. 

 Females in all stages apterous, metamorphosis semi-complete, naked or 

 covered, active or stationary ; rostrum usually present in all stages, some- 

 times absent in adult; feet sometimes absent after larval stage; tarsi, where 

 present, monomerous; feet, where present, ending in a single claw, eyes 

 somewhat absent. 



