An inoculation trap for the auto dissemination of spores of Metarhizium anisopliae for the management of Oryctes rhinoceros in the field was designed and tested. The efficiency of the inoculation trap in capturing the adult rhinoceros beetles was found to be as good as the commercial pail type trap. The trap capture rate was 2.5 adults per trap per night (a/t/n), no different (at P>0.05) from the capture rate by the pail type trap (2.4 a/t/n). A performance test showed that 66.7% of the trapped adults that escaped from the inoculation trap were subsequently confirmed dead due to infection by the fungus. Laboratory tests also found that the infected adults had disseminated the spores to the breeding site, killing 91.7% of the larvae by fungal infection. The mortalities of the released inoculated adults were between 63% and 69%, due to infection by M. anisopliae. A field test showed that the percentage of trapped adults leaving the trap was between 85% and 95%. Both rates of spore solution (at 2 and 4 g litre^-1) caused high mortality to adults within the period of 15-30 days after trapping (DAT), and complete mortality was recorded at 45 DAT. Some 75% to 90% of the dead adults were confirmed to be infected by M. anisopliae. The density of viable spores collected from the soil in the trapping region showed an increase, suggesting that the M. anisopliae had been established in the breeding sites of the beetle.