Effect of Temperature on Development and Reproduction of the Cotton Caterpillar, Palpita indica(Lepidoptera: Pyralidae)

목화바둑명나방(나비목:명나방과)의 발육과 생식에 미치는 온도의 영향

Development and reproduction of the cotton caterpillar, Palpita indica, were investigatedunder different temperatures (15 .O, 17.5, 20.0, 22.5, 25 .O, 27.5, 30.0, 32.5, and 35 .O$^{\circ}$C). Duration fromegg to pre-adult of the cotton caterpillar were ranged from 68.6 days at 175$^{\circ}$C to 19.7 days at 35.0% (3.5times shorter growth period compared with that at 17S$^{\circ}$C). At 15.0$^{\circ}$C, cotton caterpillar eggs developedto the last larval instar but were not able to go through the pupal stage. The lower developmentalthreshold temperatures and degree-days of egg, larva, pupa, and complete development were 13.4, 10.6,11.6, and 11.5"C and 55.3,251.5, 138.3, and 479.8 degree days, respectively. The hatching, pupation andemergence rates were higher at 25.0eC and 27.5"C compared with other temperatures. The survival ratefrom the hatched larva to adult was the highest at 27.5"C. The preoviposition and the adult longevity were11.5 and 30.6 days at 17.5"C and 1.5 and 9.2 days at 35.0$^{\circ}$C, respectively. The mean fecundity perfemales was greater at 25.0$^{\circ}$C and 27.5"C compared with other temperatures. Mean generation time indays (T) was shorter on higher temperature. Net reproductive rate per generation (R,) was the lowest atthe highest temperature as well as at the lowest, and it was 199.1 which was the highest at 27.5"C. Theintrinsic rate of natural increase (r,) was highest at 30.0$^{\circ}$C as 0.148. As a result, optimum ranges oftemperature for P. indica growth were between 25.0-32.5"C .emperature for P. indica growth were between 25.0-32.5"C .t;C .

목화바둑명나방의 온도별(15.0, 17.5, 20.0, 22.5, 30.0, 32.5, $35.0^{\circ}C$) 발육과 생식에 미치는 영향을 조사하였다. 알에서 성충까지의 발육기간은 $17.5^{\circ}C$에서 68.6일이었고, $35.0^{\circ}C$에서는 19.7일로 온도가 높아질수록 그 기간이 짧았으며, $35.0^{\circ}C$에서는 $17.5^{\circ}C$보다 불육기간이 3.5배나 짧았다. 그리고 $15.0^{\circ}C$에서는 알에서 번데기 전단계까지는 발육하였으나 번데기에서 우화하지 않았다. 알, 유충, 번데기, 그리고 알에서 성충까지의 발육영점온도는 각각 $13.4^{\circ}C$, 10.6$^{\circ}C$, $11.6^{\circ}C$, $11.5^{\circ}C$였고, 유효적산온도는 각각 55.3, 251.5, 138.3, 479.8일도였다. 부화율, 용화율 그리고 우화율은 $25.0^{\circ}C$와 27.5$^{\circ}C$에서 높았다. 부화유충에서 성충까지의 생존율은$ 27.5^{\circ}C$에서 가장 높았다. 산란전기와 성충수명은 17.5$^{\circ}C$에서 각각 11.5일, 30.6일이었고, $35.0^{\circ}C$에서는 각각 1.5일, 9.2일로 온도가 높을수록 짧았다. 그리고 암컷한마리당 평균 총산란수는$ 25.0^{\circ}C$와 $27.5^{\circ}C$에서 많았다. 1세대당 순 증식율(${R}_{o}$)은 $27.5^{\circ}C$에서 199.1로 가장 높았다. 그리고 내적자연증가율(${r}_{m}$)은 온도가 높아 갈수록 컷으며 $30.0^{\circ}C$에서 0.148로 가장 크게 나타났다. 이상의 결과로 목화바둑명나방의 성장에 적합한 온도범위는 25.0~$32.5^{\circ}C$이었다.