The Potency of Collecting Larvae of Otyctes rhinoceros L. (Coleoptera: Scarabaeidae) in the Oil Palm Plantation

The intensive and continuous collection of rhinoceros beetles, Oryctes
rhinoceros L. (Coleoptera: Scarabaeidae), is an extraordinary strategy
in IPM (Integrated Pest Management). This study was intended to
evaluate the potency of people in collecting larvae and to determine
the age structure of the beetle population. The study was conducted in
Asahan Regency, North Sumatera Province. Adult men, adult women,
adolescent girls, and adolescent boys collected beetles for 2 hours in
each breeding site. Results showed that the beetle was more significant
abundant in decomposed trunks at plots of immature and mature palms
than at heaps of the empty fruit bunches namely 236, 221 and 93
individuals/2 hours. The population age-structure showed significantly
predominant of 2 nd and 3rd instars in all breeding sites, i.e. eggs, 1 st instars,
2 nd instars, and 3 rd instars, pupae, adult males, and adult females were
2.02, 23.29, 21.39, 47.06, 3.17, 0.86, and 2.21%, respectively. Adult
men, adult women, and adolescent boys had similar potency in collecting
3 rd instar larvae while the least amount was collected by the adolescent
girls viz. 70, 85, 60, and 38 larvae/2 hours, respectively. It is suggested
that the study results support future efforts in the sustainable control of
rhinoceros beetle through collecting larvae for commercial utilization.