60 MANUAL OF TROPICAL AND SUBTROPICAL FRUITS 



lime, and distillate emulsion. These may all prove to be 

 effective with the avocado as well. 



Among the scale insects which commonly attack the avocado, 

 the most important are the black scale (Saissetia olea? Bern.), 

 and a soft white scale (Pulwnaria pyriformis CklL), the latter 

 being a serious pest in Florida. Severe infestations of the black 

 scale are occasionally found on old seedling trees in California, 

 but this insect has not yet become a pest in the young avocado 

 groves of that state. The wax scale (Ceroplastes floridensis 

 Comst.) is occasionally found on avocados in Florida, but rarely 

 requires combative measures. All of these scale insects, as 

 well as a white fly ( Trialeurodes floridensis Quaint.), which has 

 become troublesome on some of the Florida Keys, can probably 

 be controlled by the use of oil sprays. 



The citrus mealy-bug (Pseudococcus citri Risso) has been 

 reported on the avocado in Ventura County, California, but it 

 is not known to have caused extensive damage. The avocado 

 mealy-bug (Pseudococcus nipce Mask.), which is a serious pest 

 in Hawaii, has been found in southern Florida groves. It 

 sometimes becomes very troublesome. D. F. Fullaway of 

 Hawaii recommends that it be controlled by spraying with oil- 

 emulsions. 



The presence of the avocado weevil (Heilipus lauri Boh.) 

 in California, where it was probably introduced from Mexico in 

 avocado seeds, caused the Federal Horticultural Board to 

 prohibit the importation of seeds of the Mexican race from 

 Mexico and Central America. This insect is a small black 

 beetle which tunnels in the seeds, and is said to do considerable 

 damage. 



Other seed weevils attack the avocado in various parts of 

 the tropics. H. S. Barber describes the more important ones, 

 so far as they are known, in the Proceedings of the Entomological 

 Society of Washington, March, 1919. Heilipus pittieri Barber, 

 from Costa Rica, is similar to H. lauri. Conotrachelus persece 



