[in Japanese]

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(1) On February 12, 1980, Sphenophorus venatus vestitus Chittenden (Hunting billbug) that injures turfgrass was found at the Wajiro golf course of Fukuoka Country Club (in Higashi Ward, Fukuoka City) and the Koga golf course (Fukuoka Prefecture) .
(2) This insect was found in golf courses in Okinawa Prefecture in July, 1979. At some places, dense inhabitation of 18 adults per m² were found. In the Fukuoka district, presence of the insect was already observed in 1977, and 30 to 50 adults per m² were collected at places of dense inhabitation, and 10 to 20 at places less inhabitation.
(3) The insect seems to have been confounded with May beetle larvae. However, the discrimination between them is possible because the May beetle larvae has three pairs of legs and a large annular segment at the hinder part of the abdomen.
(4) This insect appears to have a shorter period of growth than that of May beetle. One generation of the insect seems to require approximately six weeks only, and two or more generations will develop in a year.
(5) In the Fukuoka district the insect mainly hibernates as adults, and partly as larvae. The larvae live 5 to 6 cm under the land surface, while adults live near the land surface, and dusky thrushes preying on them were observed.
(6) Although adults injure by crushing the plant with their mouth part, the more serious damage is that of subterranean parts of the plant by larvae. The injury by larvae is notable in the period from the end of summer through autumn. The injured turfgrass is blighted to yellow color, and become lifted easily by pulling up its stems or leaves.
(7) Invasion of fungi, bacteria, virus, nematodes and other organisms which may cause damage of the turfgrass can also be forecasted from the findings on many invading injurious insects, such as Bluegrass webworm, Rhodesgrass scale, and Hunting billbug. Studies and measures to cope with such situation are strongly desired to be taken promptly.

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The author studied ecology and course of the prevalence of a turfgrass injuring insect, Rhodesgrass scale (Antonina graminis MASKELL), in the Tokai district for the purpose of controlling this insect. The study is summarized below.
(1) Rhodesgrass scale inhabits in subtropical regions, such as Africa, Australia and the South of the U. S. A., and its habitats in Japan had been restricted in Okinawa Prefecture. This insect is supposed to have lately intruded into Japan along with turfgrass when it was imported.
(2) This insect clings to the proximals of erect branches and nodes of runners of turfgrass and suck the sap of the plant. The injured turfgrass changes its color to brown as it suffered from a drought injury, and withers. The damage is particularly notable at well-drained, sunny, and dry turfgrass-fields and in and after the end of August.
(3) This insect is parthenogenetic and multiplies by ovoviviparity. Embryos in the body of female are milk white, oval, and 0.45mm in length. The 1st-instar insect is not covered with shells and moves actively with 3 pairs of legs. Therfore, it is easy to distinguish the insect of this instar from that of other instars. The length of the insect was 0, 56mm.
(4) The insect of 2nd or higher instars is dark purple in color, takes shape of a bag, extrudes white nephridium outside the body, and inserts its suctorial mouth on the surface of abdomen into the plant, and clings to the plant. The three pairs of their degenerated legs have no locomotive function and serve only to cling to turfgrass. On the turfgrass, the insect excretes white waxy materials to make up the shell. The lengthes of 1st, 2nd, 3rd instars and adults were 0.40 to 0.90 mm, 0.6 to 1.2mm, 1.3 to 1.9mm, and2.0 to 4.0mm, respectively.
(5) As temperature becomes higher, the rate of delivery of larvae is increased. The number of the larvae delivered at the temperatures of 30°C and 26°C were 200 and 139, respectively, with distinct difference by temperature. It would be thought that temperatures higher than 25°C are necessary for delivering larvae.
(6) The time of occurrence of the 1st instar insect was the beginning of June to the middle of July in the 1st delivering stage, and the beginning of August to the middle of September in the 2nd delivering stage. The larvae of the 3rd delivering stage were produced only when the insect had been raised in a glass room, though they were small in number. In the natural state, this insect is considered to develop twice a year.
(7) In order to control the insect in the Tokai district, a desirable effect has been brought about by spraying 1000-time dilution of supracide emulsion in the beginning of June and the beginning of August.

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