345 



these pests ; the use of carbon bisulphide or naphthaline and the 

 collection of the adult beetles are the only ones yet recommended. 



Recently the attention of economic entomologists has been directed 

 towards a search for their enemies, both parasitic and predaceous, 

 such as those of Anomala orientalis in Hawaii. The insect enemies 

 of these beetle larvae include a number of Scoliidae. Thus in 

 North America Elis quinquecincta and Tiphia inornata are parasitic 

 on Lachnosterna ; in Europe, TipJiia femorata on Aynphimallus 

 {Rhizotrogus) solstitialis, Scolia hifasciata on Cetonia, and S. inter- 

 rupta on Anoxia villosa ; in Java, Elis fhoracica and E. luctuosa on 

 Anomala ; and finally, the species that is parasitic on the Japanese 

 Anomala orientalis, which was discovered by Muir of the Hawaiian 

 Sugar Experiment Station and is said to belong to the same genus, Elis. 

 Though many beetles are kno-svn to prey upon other insects, none have 

 hitherto been discovered that attack subterranean white grubs. 

 Recently a beetle was sent to the author which was said to be preda- 

 ceous upon them. It proves to be a species of Hister and, as this 

 beetle generally lives under decayed leaves or rotten bark, though it 

 may eat the grub under observation in confinement, whether it really 

 preys on them underground requires further confirmation. 



As regards Dipterous parasites, according to Davis, in North America 

 Micro jMialma disjimcta, M. pruinosa and Ptilodexia tibialis are said 

 to infest Lachnosterna grubs ; the author has not yet, however, found 

 any such species in Japan. In May 1914 the author received an 

 Asihd larva from the Nagasaki Prefecture, and reared from it an 

 adult that proved to be Promaclius yesonicus, Big. (P. ater, Coq.). 

 In 1916 further Asihd larvae were received from the Prefecture of 

 Nagano that were stated to be numerous among the beetle grubs 

 in seed-beds for forest trees. These, as well as the one found by the 

 author himself in a seed-bed of the Tokyo Forestrv' Experiment 

 Station, produced adults of the same species in July and August^of the 

 following year. Several lots of specimens of this species were subse- 

 quently obtained from forestry seed-beds in the Prefecture of 

 Kagoshima. From the study of these examples, the author is of 

 opinion that this Asihd larva is an important enemy of Lamellicorn 

 grubs in Japan. Recently Da\'is has also recorded the fact that 

 Promachus vertebratus and P.fitchi prey upon the larvae of Lachnosterna 

 in the United States [see this Revieiv, Ser. A, iv, p. 285]. 



The adult fly of Promachus yesonicus appears in the month of June 

 and is predaceous on a great variety of insects, including the adults 

 of white grubs. It oviposits in August, on grasses, weeds or even 

 on telegraph poles ; the eggs are white and are laid in masses. As 

 soon as the young larvae hatch they immediately bury themselves 

 in the soil and begin to feed on the beetle grubs. It was not possible 

 to ascertain how many grubs the fly larva destroys during its life- 

 time, but just before pupation two medium-sized grubs were required 

 to keep it alive for a week. The author was unable to rear the adult 

 from the egg, so that the exact duration of the hfe-cycle could not be 

 ascertained ; but in all probability pupation occurs in the early 

 summer of the second year, and the adult flies appear from June 

 to the beginning of August. Further investigation is still required 

 as to the practical utilisation of these Asihd larvae. As they are 

 usually found mixed up \vith the injurious grubs, when measures 



