Phytoseiulus persimilis is an important biological control agent, commercially produced worldwide. To increase understandings of its reproduction, herein we provided quantitative descriptions of the inflation and defl...Phytoseiulus persimilis is an important biological control agent, commercially produced worldwide. To increase understandings of its reproduction, herein we provided quantitative descriptions of the inflation and deflation of its spermathecae as a function of time and copulation duration, and the quantitative impact of copulation termination on volume of spermatheca vesicle, fecundity, and offspring sex ratio. After mating started, at least one spermatheca started to inflate immediately, but no egg was produced until spermatheca volume reached 1 021 μm3. Beyond this size, cumulative fecundity was linearly correlated with vesicle volume. Producing one egg required 36 μm3 volume increase of the vesicle. Each spermatheca vesicle reached its peak size at the end of mating duration(ca. 2.38 h after mating started), and started to shrink immediately. In 24 h, ca. 71% individuals had one completely shriveled spermatheca, while in 72 h all individuals had at least one shriveled spermatheca. The estimated maximum cumulative fecundity per female after a single mating is(69.4±7.7) eggs. No significant impact of mating termination on offspring sex ratio was observed after mating duration reached 60 min, while higher proportion of male offspring was observed when mating duration is 15 or 30 min. This study is the first step to investigate possible male impact on offspring sex ratio in P. persimilis. Our results suggested the number of sperms received during mating be a restriction factor of P. persimilis offspring sex ratio regulation.展开更多
Invited by the Japanese Niigata Prefectural Government and the Japan Economic Research Institute for Northeast Asia, Song Jian, president of the China-Japan Friendship Association (CJFA), attended the Northeast Asia E...Invited by the Japanese Niigata Prefectural Government and the Japan Economic Research Institute for Northeast Asia, Song Jian, president of the China-Japan Friendship Association (CJFA), attended the Northeast Asia Economic Conference in Niigata and visited Tokyo and Akita Prefecture from January 31 to February 7, 2004.展开更多
An agreement was signed on December 19th,2007 at Tokyo between Japanese Toray Fine Chemicals Co.,Ltd.(Toray)and CangzhouCoastal-port Chemical Industry Zone(CCCIZ),in Hebei province of northern China.According to.the a...An agreement was signed on December 19th,2007 at Tokyo between Japanese Toray Fine Chemicals Co.,Ltd.(Toray)and CangzhouCoastal-port Chemical Industry Zone(CCCIZ),in Hebei province of northern China.According to.the agreement,Toray Fine Chemicals Co.,Ltd.will purchase some 2.展开更多
基金supported by the National Key R&D Program of China(2017YFD0200400)the National Natural Science Foundation of China(31701850)the Basal Research Fund of Chinese Academy of Agricultural Sciences(Y2016PT13)
文摘Phytoseiulus persimilis is an important biological control agent, commercially produced worldwide. To increase understandings of its reproduction, herein we provided quantitative descriptions of the inflation and deflation of its spermathecae as a function of time and copulation duration, and the quantitative impact of copulation termination on volume of spermatheca vesicle, fecundity, and offspring sex ratio. After mating started, at least one spermatheca started to inflate immediately, but no egg was produced until spermatheca volume reached 1 021 μm3. Beyond this size, cumulative fecundity was linearly correlated with vesicle volume. Producing one egg required 36 μm3 volume increase of the vesicle. Each spermatheca vesicle reached its peak size at the end of mating duration(ca. 2.38 h after mating started), and started to shrink immediately. In 24 h, ca. 71% individuals had one completely shriveled spermatheca, while in 72 h all individuals had at least one shriveled spermatheca. The estimated maximum cumulative fecundity per female after a single mating is(69.4±7.7) eggs. No significant impact of mating termination on offspring sex ratio was observed after mating duration reached 60 min, while higher proportion of male offspring was observed when mating duration is 15 or 30 min. This study is the first step to investigate possible male impact on offspring sex ratio in P. persimilis. Our results suggested the number of sperms received during mating be a restriction factor of P. persimilis offspring sex ratio regulation.
文摘Invited by the Japanese Niigata Prefectural Government and the Japan Economic Research Institute for Northeast Asia, Song Jian, president of the China-Japan Friendship Association (CJFA), attended the Northeast Asia Economic Conference in Niigata and visited Tokyo and Akita Prefecture from January 31 to February 7, 2004.
文摘An agreement was signed on December 19th,2007 at Tokyo between Japanese Toray Fine Chemicals Co.,Ltd.(Toray)and CangzhouCoastal-port Chemical Industry Zone(CCCIZ),in Hebei province of northern China.According to.the agreement,Toray Fine Chemicals Co.,Ltd.will purchase some 2.