솔잎혹파리가 소나무생장에 미치는 영향에 관한 연구 (Ⅰ) - 충영형성률의 변동 - = Studies on the Effects of the Pine Needle Gall Midge , Thecodiplosis japonensis Uchida et Inouye , on the Growth of the Red Pine , Pinus densiflora Siebold et Zuccarini (Ⅰ) - Changes in Gall Formation Rate -

다국어 초록 (Multilingual Abstract)

Some aspects of the change in the rate of gall formation on the red pine, Pinus densiflora Siebold et Zuccarini, by the pine needle gall midge, Thecodiplosis japonensis Uchida et Inouye, were investigated at the coastal area in Chung Nam-Do from 1977 to 1982, and were analyzed with the nationwide survey data for 2 years from 1980 to 1981. The results obtained were as follows; the gall formation rate in several areas was compared between two consecutive generations. Four regression equations were established, with X as the gall formation rate in N year and Y as that in (N+1) year: 1) Y=11.2+1.15X (r=0.833) for the stands facing north on the phase of insect population increase, 2) Y=14.3+0.82X (r=0.739) for the stands facing south on the phase of population increase, 3) Y=7.3+0.46X (r=0.478) for stands facing north on the phase of population decrease and 4) Y=11.4+0.19X (r=0.086) for stands facing south on the phase of population decrease. After invasion of the pine needle gall midge into a red pine forest, gall formation rate increased for 6 consecutive generations and then decreased to low level within a period of another 6 years.