11 



dozen of such species — and the world possesses hundreds of them — 

 naturally must in time keep in check the scales destructive to fruit 

 and other trees, so as to effectually prevent injury. We can solve this 

 simple matter by introducing all insects preying upon eoccids as well 

 as upon other injurious insects, and protecting the same by discontin- 

 uing the process of spraying and fumigating, which, if continued as 

 at present, will have to be done until eternity. 



NOTES ON THE ENEMIES OF SCALE INSECTS IN CERTAIN COUNTKIES. 



HAWAII. 



In accordance with my commission from you, and letter of instruction 

 from the Entomologist, 1 left San Francisco for Honolulu with a lot of 

 beneficial insects on August 11, 1801, to spend a few days at this place 

 and to look into the general condition of scale insects and their enemies. 



The most injurious eoccids at these 1 islands are the various species of 

 Dactylopius, which are not only injurious to most plants and trees, but 

 are a great plague to the coffee industry, actually destroying whole fields 

 of these trees. Pulvinaria psitdi Mask, is another very prevalent coc- 

 cid infesting a great many shrubs and trees. The guava and coffee 

 trees were always found covered with this scale. Lecanium acuminatum 

 Sign.. L. depressum Sign., and L. lonyulitm Douglas are also found in 

 large numbers. The condition of the coffee industry has, according to 

 recent accounts, become somewhat more favorable, and natural enemies 

 have probably turned up to feed upon these scales. Yet from what 

 was seen at Honolulu it may positively be stated that no proper and 

 effective enemy has as yet begun to prey upon these particular eoccids. 



I would recommend as the most effective and easily introduced enemy 

 of these scales the Cryptolatmm montrouzieri Muls., of which the par- 

 ticulars are given below. Within a few yej«rs these beetles and their 

 larva- would become so numerous that practically the mealy bugs would 

 be reduced to small numbers. In addition a number of other and also 

 effective enemies could be introduced to the great benefit of coffee- 

 growing. The CryptoUvmus beetle would at the same time also feed 

 upon the various species of Pulvinaria and Lecanium, and here the 

 various species of RhizoMus would do good work. A number of our 

 Chilocorus bivulnerm Muls. were given to Mr. A. Yaeger, who turned 

 them loose in good condition. 



Internal parasites are present upon the Lecanuhe, and one of these 

 preying upon /,. depressum Sign, has been brought to California in con- 

 siderable numbers and liberated in an orange orchard infested with L. 

 oleee Bern, and /,. hesperidum Linn. A few species of Scymnids were 

 found upon these scales and Coccinclla abrfominalis Say. had been 

 found, especially upon L. depressum Douglas, with numerous eggs, larva?, 

 and imagoes; these and three species of Scymnids were sent to Cali- 

 fornia. 



