关于稻水象甲形态的几个问题

 稻水象甲是半水生昆虫，其幼虫和蛹具有拒水的外表皮及发达的气管系统，能直接从体表包裹的空气中获得所需要的氧，在水稻根部营外寄生生活。幼虫第 2 至 7 腹节背面各有一对脊状突起和稍向前倾的羊角状的呼吸管，形成特化气门，可伸出体外或缩入体内。这 6 对可以伸缩的脊状突起和前倾的羊角状呼吸管是稻水象甲幼虫重要的形态特征。稻水象甲的蛹期是在膨大的、充满空气的土茧中度过的。这些土茧总是附着在稻根上，与稻的输气组织相通。

Notes on the Morphology of the Rice Water Weevil, Lissorhoptrus oryzophilus

According to the investigation, the rice water weevil, Lissorhoptrus oryzophilus, falls into semi aquatic species. The larvae and pupae are parasites on rice roots. They have hydrophobic exocuticle and a well developed tracheal system, surrounded by air bubbles in mud, therefore they can secure an adequate supply of oxygen directly from the air bubbles. There are six pairs of modified spiracles on each abdominal segment from the 2nd to the 7th inclusive. The modified spiracles are shaped as a hook curved forward and partially retractile, which is the most striking characteristic of the larvae of the rice water weevil. Pupal stage of the rice water weevil is passed in a water tight, inflated cocoon. The cocoons are always found attached to rice roots.