실내에서 작은뿌리파리(Bradysia difformis, Sciaridae, Diptera)의 대량사육시스템

Mass-rearing Method of the Fungus Gnat, Bradysia difformis (Sciaridae, Diptera) in Laboratory

작은뿌리파리는 넓은 기주 범위를 가지며 시설하우스에서 피해를 주는 주요 해충이다. 이를 해결하기 위한 방제 방법을 연구하기 위해 재현성 있는 사육방법을 개발보급시켜야 할 필요가 있다. 본 연구는 실내에서 작은뿌리파리에 대한 대량사육시스템을 구축하고 생태적 특성을 연구하였다. 작은뿌리파리의 온도별 발육을 조사한 결과, $20^{\circ}C$에서 부화율, 용화율, 우화율이 가장 높았으며, 성충을 제외한 발육기간이 20.8일로 가장 짧았다. 성충수명은 온도가 높아질수록 수명이 짧아졌으며, $20^{\circ}C$에서 평균 144개로 가장 많이 산란하였다. 작은뿌리파리 유충 사육배지 조성이 유충 발육에 미치는 영향을 알아본 결과, 물한천배지와 감자디스크배지가 부화율 84.7, 84.4%로 높았으며, 유충기간은 감자디스크배지가 14.7일로 가장 짧았다. 용화율, 우화율은 감자디스크배지가 85.2, 82.6%로 가장 높았고 산란수도 125.6개로 가장 높았다. 우화케이지에서 생육배지를 선발한 결과, 우화율은 원예용 상토 50% + 톱밥 25% + 잘게 간 감자 25% 배지가 접종 14일차의 우화율이 88.4%로 가장 높았다. 우화케이지의 생육배지 적정 접종밀도는 유충 1,000개 접종 시 84.7%로 가장 높았고, 유충 3,000, 5,000, 7,000개 접종시 81.4, 58.8, 38.7%로 유충 접종량이 많을수록 우화율이 낮았다. 위 실험 결과에 따라 작은뿌리파리의 대량사육시스템의 사육단계별 자세한 사항을 정리하였다.

The fungus gnat, Bradysia difformis, has been recognized as an important pest of greenhouse crops. There is a need for research on the control of the fungus gnat. However, it is difficult to obtain many generations of the fungus gnat for several kinds of research. Indoor propagation is a very useful method for obtaining enough individuals in cases where the need is for larvae in soil. This study was conducted to determine the optimum growing media and temperature conditions for rearing the fungus gnat in the laboratory. Under experimental temperature conditions, hatching, pupation, and eclosion rates were the highest at $20^{\circ}C$. The developmental period of the fungus gnat was shortened with higher temperatures. The greatest number of eggs was an average of 144 at $20^{\circ}C$. Using different types of larvae growth media, the highest hatching rates were 84.7 and 84.4% in water agar and potato disks, respectively. The larval period was the shortest, at 14.7 days, when grown on potato disks. The highest pupation and eclosion rates were 85.2 and 82.6% on potato disks, respectively. The highest number of eggs was an average of 125.6 on potato disks. Regarding the effects of different growth media on the eclosion rate of B. difformis, the highest eclosion rate was 88.4% on the soil mix, and was 50% on oatmeal, 25% on shredded potato. The results of four different inoculation levels of larvae on eclosion rate of B. difformis showed that the highest eclosion rate was 84.7% for 1,000 larvae. The eclosion rate was shortened with a higher number of larvae inoculated/cage. In the growth medium used, 3,000 eggs were better for the initial level of inoculation, showing a relatively high emergence rate and short developmental period. Mass rearing procedures were explained in detail.