FARMERS BULLETIN 862. 



IG. 1. — Lemon infested with the common mealybug. 



usually follows the washing of this rind-weakened fruit. A severe 

 infestation may result in partial or even complete defoliation of the- 

 trees. The lemon, grapefruit, and navel orange are preferred host 

 fruits, although other varieties may be attacked severely. 



CHARACTERISTICS AND LIFE HISTORY. 



An idea of the superficial appearance of the common mealybug 

 may be obtained from figure 2. The boch' of the insect is covered 

 with a white waxy secretion, which is most pronounced in a bordering 

 fringe of short filaments. The female retains the same general ap- 

 pearance through all stages of development from larva to adult. 

 The male in its early stages is ver}^ similar to the female, but about 

 four weeks after hatching it forms a cocoon, and from this it emerges, 

 from 10 d'Ajs to two weeks later, as a very small and delicate, light 

 olive-brown, winged, gnatlike adult. Reproduction takes place from 

 eggs deposited in a cottony sac secreted by the mature female. The 

 number deposited depends on the size of the insect and varies from 

 less than a hundred to more than a thousand, the average production 

 of a female mealybug on green fruit being between 300 and GOO eggs. 

 The length of a single generation on orange trees under the climatic 

 conditions of Pasadena, Cal., during 1914r-1916. varied from a mini- 

 mum of 36 days during the summer to approximately six months 

 during the winter. There are three more or less distinct generations 

 a year on the citrus trees of southern California. 



As a rule the infestations in the late winter and spring are so 

 light as to escape notice, but later the crowding of the young insects 

 on the small fruit, followed by the production of egg sacs in early 

 summer, readily reveals the presence of the pest, and the maximum 

 infestation and injury usually come in the early autumn with the 

 second generation of mealybugs. 



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