210 Annals Entomological Society of America [Vol. X, 



It will not be possible to estimate the ultimate effect of this 

 parasite upon the Anomala problem before the end of the present 

 year, but the prospects are good. As Scolia manilcE attacks 

 Adoretus as well as Anomala, we hope that it will be beneficial 

 in our gardens as well as in our cane fields. 



During the course of this work we have experimented 

 with several species of Tiphias, two species of Prosena, a Dexia, 

 and a Campylotheca, also with several predators. Up to the 

 present we have not succeeded in establishing any of these in 

 Hawaii. In Japan there is a species of Asilid fly which is 

 very active in the larval stage, attacking the larvae of Anomala, 

 and in the adult stage attacking the adult beetle, but we have 

 had to eliminate this from our work as it is also very active 

 against bees. 



Bacteria acting upon the grubs have been found in all the 

 countries in which we have carried on our work and it plays 

 an important part in keeping a check upon Lamellicorn grubs. 

 In Hawaii it has been noticed, and I have similar experience 

 elsewhere, that a field badly infected with Anomala grubs will 

 recover and be comparatively free for a period, and the writer 

 has reasons to suspect that in some cases this is due to the 

 accumulated bacteria in the soil making it too unhealthy for the 

 grubs. 



Fungus is also very effective in wet districts, and in dry^ 

 districts during the wetter season. 



Efforts were made to find an egg parasite and many thousand 

 of eggs were placed in various situations, but without results. 

 Ants and terminates attacked the eggs as well as the usual 

 coleopterous predators. 



After three years study of the death factors acting upon 

 these beetles in Japan, Formosa, Java and the Philippine 

 Islands the writer concludes that the problem is a complex one. 

 The death rate is far highest among the eggs and larvae and 

 natural selection has been a small percentage to act upon in 

 the adult stage, and the specific characters of these beetles 

 show little or no effect of natural selection. 



