Good Progress in the Control

Control of the Rhinoceros Beetle

OF interest to all coconut planters is the information issued recently by the Public Relations Office, Fiji. It is stated that; There is reason to hope that the rhinoceros beetle, a pest which seriously affects the coconut industry of Western Samoa, may be considerably reduced by a parasite introduced from Zanzibar by Mr. H. W. Simmonds, OBE, formerly Fiji Government Entomologist.

Mr. Simmonds has been informed by the General Manager of the Reparation Estates in Western Samoa that the para site, Scolia ruficornis, has been success fully established in the territory.

The rhinoceros beetle has hitherto re sisted all attempts at control. Mr, Simmonds has been at work on the problem since 1939. It was then known that, although no true parasite of the beetle had ever been recorded, Scolia oryctophaga of Madagascar would prob ably attack it. Soon after this, the Dutch in Java proved that it would do so, but they met with great difficulties in trying to breed the parasite.

Mr. Simmonds visited Java and he quickly concluded that the breeding difficulties were due to the absence of any cool season. Subsequent investigations strongly endorsed this view. As Samoa has no cold season it was felt that the same difficulty would be experienced there, but, in the absence of any other known parasite, a strong colony of Scolia

oryctophaga Was successfully shipped in 1939.

Mr. Simmonds’ attention was, mean while, drawn to a species in the Zanzibar Museum which was said to be a parasite of another Rhinoceros beetle. This species was Scolia ruficornis, and tests carried out showed that it would prob ably attack the Samoan beetle. The tests, however, furnished only an indi cation and not a proof. Mr. Simmonds recommended the introduction of rufi cornis and, in 1945, successfully landed 450 adult females in Apia. It was, how ever, still doubtful whether the parasite could use the Samoan beetle as its host and reports of its having been seen by natives were discontinued.

The report now received from Apia shows that the work of establishing the parasite has been a success. If para sitism is successful, the danger of the pest reaching other groups, such as Fiji and Tonga, will be reduced, as will the damage in Samoa.

A point of additional interest is that the journeys from Zanzibar and Mada gascar to Samoa are probably the longest ever successfully accomplished by adult parasites of this group. The method employed in transporting ruficornis should have further useful application.

Mr. Simmonds has had a long and successful career in the control of major insect pests of economic crops, and is master of the special technique involved in such work. The control of the rhinoceros beetle will, if successful, be one of his greatest achievements in a scientific field in' which entomologists associated with the Department of Agri culture, Fiji, have taken a prominent place.