452 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



kotinskyi, Adelencyrtus odonaspidis. Scutellista cyanea, Tomocera 

 calif ornica, Toinocera ceroplastis, Aneristus ceroplastce, Coccophagus 

 orientalis, Coccophagus lecanii, Aphelinus diaspidis and Aspidiotiphagus 

 citrinus. 



The usual sequence of beginning, increase and decline of an out- 

 break of mealybugs or plant-lice is often to be seen. The pest may 

 get a start at a time or in some place where there are none of its 

 enemies, and may increase considerably before being found by any lady- 

 beetles or parasites. These latter, having arrived in small numbers, 

 begin to reproduce, and after a few generations increase sufficiently 

 to become effective in checking the increase of the pest; then, after 

 still further increase in numbers, finally exterminate the pest entirely. 

 After such an outbreak of mealybugs, the adults and larvae of the 

 lady-beetle, Cryptolcenms montrouzieri, may be seen in thousands, and 

 their pupae also in large numbers where the larvae have congregated in 

 some sheltered place for pupation. 



An occasional occurrence of this kind serves to illustrate the useful- 

 ness of the parasites and lady-beetles, and also shows what conditions 

 might prevail continuously if these pests were not kept pretty well in 

 check for most of the time. More of these lady-beetles and parasites 

 would be useful, and the entomologists of Hawaii avail themselves of 

 every opportunity of securing them. 



, Leaf-roller Parasites 



In 1895, among other parasites that Mr. Koebele introduced from 

 Japan were Chalcis ohscurata and Macrodyctium omiodivorum, which 

 attack the pupae and caterpillars of the leaf-rollers on sugar cane and 

 coconut palms. These two parasites do a great deal of good in 

 killing off these leaf-rollers. Chalcis ohscurata also parasitizes the 

 pupae of several other leaf-rollers of fruit trees and garden plants, 

 among them Ar chips postvittanus and Amorhia ernigratella, once very 

 abundant but now not very injurious. 



Macrodyctium omiodivorum is a small Braconid and chieflj' attacks 

 the larvae of the sugar cane leaf-roller, Omiodes accepta. This is a 

 native moth whose larvae normally feed on grass and are always to be 

 found in grassy regions, especially at elevations of 1,000 to 3,000 feet. 

 Sugar cane fields in the vicinity of such regions are often subject to 

 severe attack and considerable injury by these caterpillars. Since the 

 introduction of the Braconid, the leaf-rollers have been held in check 

 in the cane fields, or if outbreaks occur at any place they are soon 

 found by the parasites, which, having a very short life-cycle, are soon 

 able to increase sufficiently to check the pest. 



