Abstract
To obtain the useful informations for control of Anomala octiescostata Burmeister, flight behavior and food habit of this beetle were conducted by the field investigation in a golf course.
(1) This beetle was diurnal, and flied in a swarm over the turfgrass from 7: 00 to 11: 00 AM on a fine day, late in April. Researching the relation between the flight of this beetle and air temperature, illumination degree, it seemed that the illumination degree more than 30, 000lux was needed for the flight, and the air temperature more than 23°C inhibited their flight. The adults flying in a swarm over the turfgrass were almost all the males. It was guessed that the purpose of their flight was the search for the copulatory females.
(2) Sex ratio of the adults was examined by collecting from the turfgrass (40×40×20cm) of an infested fairway. The ratio of the females increased as soon as the adult swarming took place in the morning, because many adult males for the swarming emergenced from the turfgrass. But the sex ratio of this beetle showed about 1: 1 after the swarming.
(3) Copulatory behavior frequently took place on the turfgrass in the morning when this beetle flied in a swarm, and the phenomenon that many adult males gathered to only one female in crowds as a ball was observed at that time.
(4) The adult was a polyphagy insect, and fed 24 species of plants in 14 families in a golf course. Particulary, they gathered and fed on Rhododendron sp. (azalea), Artemisia vulgaris (nugwort), Symplocos chinensis, Quercus acutissima (a kind of oak) .
(5) It is to be desired that the optimum timing for control of this beetles is between 7: 00 and 11: 00 AM on a fine day from 20 to 30th April. Chemical insecticides should be applied to the infested fairway where the swarming was occuring.
