关键词：
灭幼脲;小地老虎;粘虫;黄粉(虫甲);组织病理变化;低剂量效应
摘 要：
小地老虎[Agrotis ypsilop (Rottemberg)]、粘虫[Mythimna separata (Walker)]及黄粉(虫甲)(Tembrio molitor L.)的幼虫经灭幼脲处理后,含几丁质组分的体壁表皮层、气管壁内膜和中肠围食膜等组织,分泌激素的咽侧体、前胸腺等内分泌腺体,以及代谢器科管脂肪体,都分别出现明显可辨的组织学改变和病理症状,同是地表现一些差异程度并不显著的现象。根据中毒症状和组织学的改变,本文详细分析和讨论了死幼脲处理后对上述两种夜蛾幼虫和一种拟步(虫甲)幼虫的毒理学基础。
译 名：
EFFECTS OF DIFLUBENZURON ON INTERNAL ORGANS AND TISSUES IN SLACK CUTWORM, ARMYWORM AND YELLOW MEALWORM
作 者：
GONG GUO-JI WANG YING-CHANG You(Department of Plant Protection, Nanjing Agricultural University, Nanjing)
关键词：
diflubenzuron——black cutworm——armyworm——yellow meal worm ——histopathological change——sublethal effect
摘 要：
The toxic or stimulating effects of diflubenzuron on the internal organs and tissues of the black cutworm, Agroth ypsilon (Rottem.), the armyworm, Mythimna separata (Walker), and the yellow mealworm, Tenebrio molitor L, in the last larval instar were tested and examined with microscopy. The larvae at 24 to -18 hours after the moult were injected with diflubenzuron in different concentrtioas. In group 1 the larvae were injected with the median lethal doses (LD50) for observing the serial symptoms produced and the changes in micro-strurtures of the internal organs. In group 2 they were injected with the median effective doses (ED50) for observing the stimulating effect, The internal organs and tissues examined after the Treatment include integument, trachea, midgut, fat body, corpora allala, prothoracic gland, oenocytes and. pericardial cells. The tesults are .summarized as follows.1. The larvae injected with the median lethal doses exhibited "positive responses", grew abnormally and became deformed or dies before transformation into prepupae. All the structures containing chitin as the major component were severely affected or even destroyed and disappeared. The epidermal cells in the integument became strongly acidophil, flattened and smaller in size, without nuclei, intercellular boundaries indistinct, with very thin endocuticle, chitinous lamellae in procuticle disordered, or no procuticle secreted. The trachea contains very thin intima and disarranged tacnidia, and the size of the wall cells decreased, without nuclei. Whole layer of the mid-gut epithelium was detached from the muscular layer of me-senteron and suspended in the haemolymph; and peritrophic membrane disappeared. The fat bodies underwent the most conspicuous histological change, their general shape deformed, and the cells were reduced to 1/5 to 1/10 of the normal size, or even completely lysed and disappeared. The fat bodies seem to be. the direct target for the action of diflubenzuron m lethal dose. The corpora allata could not be distinguished; perhaps they had undergone lysis. The tonofibrillae connecting the muscles to the cuticle were damaged; sometimes they disappeared so that the muscles were detached from the cuticle and suspended in the haemocoel.2. The larvae injected with diflubenzuron below the median effective doses exhibited "negative reponses" grew and developed normally and showed no overt signs of poisoning. All internal organs and tissues were normal as compared with the control except the corpora allata, prothoracic glands, fat bodies, the oenocytes, pericardial cell and haemocytes which might show some excessive growth.3. Based on the observation on the microstructural changes of the internal organs and the serial symptoms produced, it is suggested the toxicity of diflubenzuron might be due to the interference of the normal functioning of the fat bodies and the endocrine glands in addition to the inhibition of chitin synthesis so as to upset normal metabolism and hormonal regulation within the insect body.
