The Suitability of Korean Pine (Pinus koraiensis SIEB. et ZUCC.) and Japanese Red Pine (P. densiflora SIEB. et ZUCC.) as a Host of the Japanese Pine Sawyer, Monochamus alternatus HOPE (Coleoptera: Cerambycidae)

The suitability of two pine species, Pinus koraiensis and P. densiflora, as a host of the Japanese pine sawyer, Monochamus alternatus HOPE was compared. The larval entrance holes and overwintered larvae were distributed primarily around the middle section of the P. densiflora trunks, whereas in the case of P. koraiensis trunks, they were scattered in the middle to lower portions. These distribution patterns were similar to those of the oviposition slits in each of the pine species. The density of the entrance holes and of the overwintered larvae in P. koraiensis was higher than in P. densiflora, as was the survival rate over hibernation estimated from these two vales. Both in 1988 and in 1989, the beetles emerged somewhat earlier from P. densiflora than from P. koraiensis. The weight gain per feed unit among the beetles fed on one-year old P. densiflora shoots was greater than it was in beetles fed on shoots of P. koraiensis. During the first three days after emergence almost all beetles showed a preference for P. koraiensis when presented with the two pine species simultaneously. These results suggested that P. koraiensis is similarly suitable or rather superior as a host for the Japanese pine sawyer to P. densiflora.