亚洲玉米螟末龄幼虫促前胸腺激素与蜕皮甾类激素滴度的变化

用放射免疫分析法(Radioimmunoassay,RIA)以12小时间隔测定了亚洲玉米螟Ostrinia tfurnacalis末龄非滞育幼虫血淋巴中蜕皮甾类激素滴度.通过前胸腺体外培养,以12小时间隔测定了前胸腺体外分泌活性的变化.发现二者的变化在相同发育阶段是一致的.在亚洲玉米螟上建立了促前胸腺激素(PTTH)体外测定法,并用此法以24小时间隔测定了末龄幼虫脑和血淋巴中PTTH滴度.发现血淋巴中PTTH滴度在末龄第5和7天各有一高峰,脑中只在第5天有一高峰.

CHANGES OF PTTH AND ECDYSTEROID TITERS IN LAST INSTAR LARVAE OF THE ASIAN CORN BORER OSTRINIA FURNACALIS (GUENEE)

The haemolymph ecdysteroid titers of the last instar non-diapause larvae of Asian corn borer Ostrinia furnacalis (Guenee) were determined by radioimmunoassay. Two peaks were present on the fifth day and the seventh day respectively. The secretory activity of cultured prothoracic glands were determined at 12 hours intervals; it was found that two secretory aeti-vity peaks were also present. This means that the changes of haemolymph ecdysteroid titers coincided temporally with the changes of secretory activity of the prothoracic glands during the same developmental age o fthe larvae. An in vitro assay for the PTTH was established in Ostrinia furnacalis and titers of the total PTTH activity of the brain and haemolymph were determined at 24 hours intervals during the last larval stadium with this method. There were two peaks of haemolymph PTTH titers on the fifth day and seventh day respectively during the last larval stadium, but only one peak in the brain on the fifth day.