Abstract
Population fluctuation of O. kashmirica benefica, a major natural enemy of citrus red mite (Panonychus citri), was surveyed from 1997 to 2000 in yuzu orchards in Goheung region and, developmental periods, developmental threshold temperature (DT) and effective cumulative temperature (ET) were estimated. Under four constant temperatures of 15, 20, 25 and 30$\^{C}$, developmental periods from egg to adult of the beetles were 67.3, 31.4, 19.4 and 15.3 days, respectively. The period of each stage was long in the order of pupa> egg > 3rd larva> 2nd larva> 1st larva. Mean numbers of eggs oviposited by a female per day were 3.3, 5.6, 7.3 and 7.7 under the temperatures, respectively. The highest hatchability (92%) and adult emergence (60%) were shown under 25$\^{C}$. Adult longevity was 54.3 days for females, and 58.6 days for males. In natural condition, the sex ratio of the beetle was 0.58. Developmental thresholds (DT) for egg, 1st, 2nd, 3rd larva, pupa, and egg to adult were 12.7, 10.0, 10.8, 7.9, 10.1 and 10.6$\^{C}$, respectively. The effective cumulative temperatures (ET) were 41.4, 22.9, 22.7, 46.6, 165.3, 292.9 day-degree at the same development stage, respectively. The beetle occurred from early April to early December in yuzu orchards. The population peak of the beetles was dependent on the amount of prey mite (Panonychus citri), and the ratio of the predator to prey mite was 1 to 100-200 at predator peak stage in the field.
전남 고흥지역의 유자과원에 발생하는 글응애와 그 우점천적인 O.kashmirica benefica의 발생소장과 온도별 발육특성, 발육영점온도 그리고 유효적산온도를 1997년부터 2000년까지 4년동안 조사하였다. 15, 20, 25, 3$0^{\circ}C$ 항온조건에서, 알부터 우화까지 발육기간은 각각 67.3, 31.4, 19.4, 15.3일이었고, 각 태별로는 번데기, 알, 3령 유충, 2령 유충, 1령 유충 순으로 발육기간이 길었으며, 암성충의 일평균산란수는 각각 3.3, 5.6, 7.3, 7.7개로 온도가 높을수록 산란수는 증가하였으나, 부화율과 우화율은 $25^{\circ}C$에서 각각 92%와 60%로 가장 높았다. 성충 수명은 암컷이 54.3일, 수컷이 58.6일로 숫성충이 약간 길었고, 자연발생 상태에서 성비는 0.58이었다. 알, 1령 ,2령, 3령 유충, 번데기 그리고 알에서 번데기까지의 발육영점온도는 각각 12.7, 10.0, 10.8, 7.9, 10.1, 10.6$^{\circ}C$였고, 유효적산온도는 41.4, 22.9, 22.7, 46.6, 165.3, 292.9일도였다. O.kashmirica benefica는 유자과원에서 4월 상순부터 12월 상순까지 발생하고, 발생최성기는 글응애 발생량에 의존하여 해에 따라 다르며 발생최성기에 글응애와의 비율은 100-200:1이었다.
