CONTROL OF THE CITROPHILUS MEALYBUG. v5 



able area in the northern part of the city. In 1916 over 100 acres of 

 citrus were found to be infested at Riverside, and at the present time 

 this infestation covers approximately 250 acres. Smaller infestations 

 are recorded at Cucamonga and Alhambra on citrus. It is reported 

 at Long Beach and Los Angeles on ornamentals and occurs in the 

 northern part of the State in the San Francisco Bay region. 



There is little probability of distribution by natural travel as the 

 insect remains close to its host. The more important means of dis- 

 tribution are the picking boxes, picking sacks, clothing of the pickers 

 and pruners, teams, wagons, and ladders ; of slightly less importance 

 is distribution by wind, birds, and insects. Several new infestations 

 have been definitely traced to distribution through picking boxes pre- 

 viously used to transport infested fruit. 



ECONOMIC IMPORTANCE. 



In a severe infestation the mealybug not only masses on the twigs 

 and foliage but also on the fruit. These masses may even cover from 

 one-half to two-thirds of the surface and hang down in cottony fes- 

 toons from the bud end. Such masses are common on severely in- 

 fested lemons and on navel oranges, in the case of the latter particu- 

 larly at the navel end. Where two fruits touch, a similar favored area 

 of infestation is formed, especially on grapefruit and lemons. On 

 young green fruit the immature forms crowd under the sepals, weak- 

 ening the supporting tissues and influencing premature drop. The 

 insects are also found in numbers on the young succulent new growth 

 and sucker growth. 



They secrete a honeydew which falls to the foliage or fruit below 

 and in this medium grows a black fungus commonly known as 

 " smut." The fruit and foliage become so black with this deposit as 

 greatly to retard their development and to necessitate a special wash- 

 ing before the fruit can be packed. 



The combination of the attack of the insects under the sepals and 

 the deposit of " smut " frequently causes a heavy dropping of young, 

 green fruit and also of the mature fruit, if held long on the trees. 

 The deposit on the foliage results in a heavy leaf drop, often an 

 almost complete defoliation of the tree. The feeding of the insects 

 on the fruit destroys its natural gloss and often causes deep brown 

 pittings in the rind which seriously affect the grading of the fruit. 

 One packing-house manager reported a lowering of the grades from 

 one severely infested orchard of from 30 to 40 per cent of the highest 

 classed fruit. The lower grades are also seriously affected and fre- 

 quently fall to culls, or unmarketable fruit. Severe infestations on 

 lemons have been known to result in an almost complete loss of the 

 crop, the fruit grading as culls. 



