| The rice planthopper such as the whitebacked rice planthopper and the brown rice planthopper are major pests of rice in China and many other countries in Asia. To meet the demand of sustainable pest control strategy, the rice plant-whitebacked rice planthopper -natural enemy Microvelia horvathi Lundblad interactions are studied in this paper. The results are summarized as follows:1. There were obvious differences on the grown .development and survival of the whitebacked planthopper Sogatella furci fera (Horvath) after fed on the four rice varieties possessing different resistance levels to the whitebacked rice planthopper, namely, Xiangzaoxian31 (susceptible) ,Jiayu164(susceptible) Weiyou402 (moderately susceptible) and Zhuliangyou02(moderately resistant). Its nymph duration and pre-oviposition stages on Zhuliangyou02 was longer than those on the other three varieties; its adult lifespans on Jiayu164 was longer than other ones; the survival of its nymph on Jiayu164 was 77% and higher than other ones. The egg size of the whitebacked planthopper was also obviously different, the egg size on Xiangzaoxian31 was 0.0422 mm3 and more than others; the egg size on zhuliangyou02 was smaller and 0.0354 mm 3.2. There were obvious differences on math-morphological feature from images of the Whitebacked rice planthopper fed on the 4 rice varieties, besides the area of posterior wing. The antenna's distance of the whitebacked rice planthopper fed on Xiangzaoxian31 was longer than those on the other three varieties, the distance between head and proboscis and the distance between head and preclypeus on Xiangzaoxian were also longer; but the spinula length on Weiyou402 and the aea of primaries on it were longer than other ones. What's more, the math-morphological feature of whitebacked rice planthopper fed on Zhuliangyou02 was shorter than the other three varieties. These proved that rice varieties possessing different resistance levels had effects on the math-morphological feature of whitebacked rice planthopper.3. Statistical analyses of 17 math-morphological features(such as propedes length, primaries's area, etc. ) from images of whitebacked rice planthopper fed on 4 ricevarieties were used in this evaluation. The results indicated that the former two principal components were 81.36% in the total information, and it played an important role that the length of postpedes tibia and spinula, the distance between head and proboscis and the total propedes length. It evidenced that rice varieties had effects on whitebacked rice planthopper. In the course of preventing whitebacked rice planthopper, we make great efforts for impelling the grow of rice varieties possessing different resistance levels, so that the use of chemic pesticide was reduced.4. The indirect effect of four rice varieties possessing different resistance levels to whitebacked rice planthopper on the growth, development, survival Jind reproduction of predatory mirid Microvelia horoathi Lundlad after fed on nymph or adult of WBPH were investigated in laboratory. The results showed that there were obvious differences among the durations of egg and nymph of M. horoathi. Its egg durations and nymph on Zhuliangyou02 were longer than others. The survival of its egg and 1-3 instars on Weiyou402 were lower, but the survival of 4-5 instars on Zhuliangyou02 was lower, only about 24.8% of the eggs could develop into adults, than those on other three varieties. The results indicated the population dynamic; of Microvelia horoathi Lundlad was effected on rice vaieties possessing different levels to whitebacked rice planthopper.Therefore, cultivating resistant rice and making use of predatory insect were considered as two effective measures, the basic demand of IPM is bringing into play controlling pest to cooperate with the two measures. The abundant experiments showed that resistant rice had an adverse effect on pest the same as on predatory insect. Consequently, we should cultivate these resistant level rice that have an adverse effect on pest a... |
PDF Full Text Request