|Title:||穀象生活習性之觀察||Other Titles:||Bionomic Studies of Rice Weevil, Sitophilus Oryzae Linnaeus||Authors:||林欉
|Issue Date:||7-Mar-1959||Publisher:||農業試驗所||Journal Volume:||8||Journal Issue:||1||Start page/Pages:||44-54||Source:||農業研究||Abstract:||
Inrestation of rice weevil Sitophilus oryzae Linnaeus was the only inferior to rice bostrychid Rhizopertha dominica Fabricius in Taiwan. But due to its quick reproduc. tion and overlapped each stage was much injurions rice bostrychid. This observation was carried out at Taipei, Taiwan from June, 1951 to October, 1953. The results might be briefly summarized as follow:
1. Egg stage took 3-10 days, 4.7 days in average; percentages of egg hatching was more than 98%.
2. Each larval stadium took 3-21 days, 4.7 days in average; total larval stage took 15-29 days and 19.2 days in average.
3. Prepnpal stage toon 1-2 days and 1.3 days in averag.
4. Pupal stage took 3-13 days and 6.1 days in average; precentage of pupation was 98%.
5. Number of eggs laid by one female within 24 hrs was 2-7 usually; total number of eggs laid by one female was 4-356, and 186 in average.
6. Sex ratio female was 46.8% in average; adult duration of male wale longer than female, i. e. 9-139 days and 94.9 days in average of female and 12-230 days and 113.6 days in average of male respectively.
7. Rice weevil had 8 generations annually. End of February to mid of April was the 1st generation, end of April to mid of May was the 2nd generation, end of May to end of June was the 3rd generation, first to end of July was the 4th generation, August was the 5th generation, mid of September to first of October was the 6th generation, mid of October to end of November was the 7th generation, end of December to following end of January was the 8th generation respectively.
8. Period (or days) of one generation, the shortest was 20 days, the longest 50 days and 32.2 days in average.
9. Reproductivity of adult was much influenced with the seasonal and temperatue interference. According to rearing data one couple of rice weevil from September to its following 3 months gave 78-550 individua1s and 306.3 inaverage; from first of November to its following 3 months gave 138-246 and 184.1 in average; 678-2,904 and 2,171.2 in average following 6 monthe; 3,878-6,867 and 5,301.3 in average following 9 months and 6,596-1,1036 and 8,475.2 in average following 12 months or one year respectively. The dead individuals were not included in the above data.
10. Estimation of injuried loss was taken one couple of adults let them reproduce and feed freely over one year in given 720g. brown rice, the loss was 450g. i. e. 62.55 % 571g. or 79.39% and 500g. or 69.53%. If put 200 couples of rice weevil in brown rice, they will consume 100kg. of brown rice over one year and shown its injury was so severe.
|Appears in Collections:||1.台灣農業研究(1950～迄今)|
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