Identification of Volicitin-related Compounds from the Regurgitant of Lepidopteran Caterpillars

Volicitin-related compounds were found in the oral secretion of the three noctuid species, Helicoverpa armigera, Mythimna separata and Spodoptera litura, and one sphingid species, Agrius convolvuli. Volicitin [N-(17-hydroxylinolenoyl)-L-glutamine], N-(17-hydroxy-linoleoyl)-glutamine, N-linolenoylglutamine and N-linoleoylglutamine were identified in the secretion from the noctuid larvae. In secretions from the sphingid larvae, N-linolenoylglutamine and N-linoleoylglutamine were the main components. Furthermore, there were significant differences in the amounts of the N-acylamino acid conjugates in the secretions from the three noctuid species. These results suggest that the proportion of volicitin-related compounds in the regurgitant was species-specific.     

Accumulation of oxacarbocyanine dyes with different alkyl chain length in bone marrow cells and hepatocytes

A study was made of the inclusion of fluorescent probe H-510 based on 3,3′-dialkyloxacarbocyanine bromide (where alkyl is ethyl, nonyl, or octadecyl) into cells of different types. Alkyl chain length (C2, C9, or C18) was found to largely determine the accumulation dynamics and mechanism. Similar spectral characteristics for all probe types in bone marrow cells were found by microfluorimetry, suggesting insertion of dye molecules irrespective of their lipophilicity into micelle-like structures formed probably by cell phospholipids. Spectroscopy data indicate interaction of 3,3′-diethyloxacarbocyanine bromide (H-510/C2) and 3,3-dinonyloxacarbocyanine bromide (H-510/C9) dyes in hepatocytes with a less polar microenvironment (nonpolar and low-polar lipids that constitute a significant part of the total content of cell lipids). The fluoresccence maximum of long-chain dye H-510/C18 in hepatocytes is shifted to the short-wavelength region and strictly coincides with the fluorescence maximum of the probe in an albumin solution. It is not excluded that inclusion of the probe into cells occurs via endocytosis upon its binding to surface proteins.     

灭幼脲引起两种幼虫表皮组织病变的显微观察

本文研究了灭幼脲引起黄粉(虫甲)(Tenebrio mclitor)和粘虫(Mythimna separata)幼虫的中毒征象和组织学病变.低剂量能引起幼虫蜕皮障碍,但看不到明显的组织学病变.高剂量处理,不仅引起了严重的中毒征象,而且伴有明显的组织学病变:内表皮生长停滞,真皮细胞排列异常,在内表皮和真皮细胞之间出现附加层和球状颗粒.对这些现象进行了较细致的讨论.     

粘虫棉铃虫对杀虫剂活性的相关性

研究了37种杀虫剂对粘虫、棉铃虫活性的相关性。结果表明,粘虫对杀虫剂的活性和棉铃虫是一致的,其直线回归式：Y＝164．36＋0．646X相关系数（R）为0．953。R值受棉铃虫对拟菊酯抗性的影响。     

粘虫的胚胎发育

粘虫(Mythimna separata)胚胎发育经过卵裂及胚盘形成、胚带及原肠发生、胚带分节及附肢形成、体壁形成及背向闭合、胚胎反转和器官发生与形成6个时期。粘虫卵在25℃,胚胎发育至12h,胚带呈新月形或“C”字形。随着原肠发生,首先出现口陷与肛陷,与此同时,胚带逐渐伸长并开始分节。胚胎发育至32h,胚带头尾相接并呈波浪形弯曲,在胚胎反转前,胚胎发育至42h,前肠、后肠及马氏管已经形成。胚胎发育至54h时,胚动完成之 后,中肠才明显可见。同时将大量卵黄包围起来。神经系统的发生与气管形成始于原肠发生之后,至胚胎反转之前,神经节索才出现,随着胚动发生,神经节体积不断增大,腹神经索逐渐形成,纵走气管明显可见。     

马桑内酯对粘虫体内蛋白质和消化酶的影响

用马桑内酯分别对粘虫采用注射和饲喂处理,48 h后测定粘虫不同部位消化酶活性及蛋白质含量,以探讨马桑有效成分的作用及其杀虫机理.结果显示:(1)注射羟基马桑毒素处理后粘虫组织中蛋白质含量(与丙酮处理比较)均降低,皮组织降低幅度最大为29.47%,饲喂处理后各组织中蛋白质含量均升高,其中皮组织的升高幅度最大为56.87%;但该毒素对粘虫体内蛋白酶和羧酸酯酶的影响不明显.(2)注射与饲喂马桑亭、马桑宁,粘虫体内蛋白质含量均明显比对照处理升高,蛋白酶活性增强,其中饲喂马桑亭处理的粘虫血淋巴中蛋白质含量升高最大为511.49%,蛋白酶活性增强幅度最大为4 640.26%.马桑亭和马桑宁均可使粘虫组织中羧酸酯酶活性降低,其中饲喂马桑宁处理降低幅度最大为82.94%.结果表明:羟基马桑毒素对粘虫体内蛋白质代谢的影响与用药方式有关,马桑亭和马桑宁处理后的粘虫体内蛋白质含量增高、蛋白酶活性增强及酯酶活性降低均达到显著水平.     

家蚕病原菌LZ10-1的分离鉴定及对鳞翅目害虫的致病性研究

家蚕是一种重要的经济昆虫,家蚕病原细菌造成的蚕病为蚕业生产带来巨大损失。本研究从自然感染病蚕组织中分离得到高致病力的家蚕病原细菌LZ10-1,结合16SrDNA分析和形态学观察结果,菌株LZ10-1为蜡样芽胞杆菌(Bacillus cereus)。对鳞翅目害虫棉铃虫和粘虫添食LZ10-1芽胞原液72h,供试昆虫的矫正死亡率分别为100%和95.7%,表明家蚕病原细菌具有防治农林害虫的潜力,作为杀虫资源具有开发利用的价值。发掘家蚕病原细菌的生防潜力,能提高蚕桑行业现有资源利用,是拓展行业发展新方向的有益探索。     

Sexual dimorphism in a dioecious population of the wind-pollinated herb Mercurialis annua: the interactive effects of resource availability and competition

Background and Aims

Male-biased sex allocation commonly occurs in wind-pollinated hermaphroditic plants, and is often positively associated with size, notably in terms of height. Currently, it is not well established whether a corresponding pattern holds for dioecious plants: do males of wind-pollinated species exhibit greater reproductive allocation than females? Here, sexual dimorphism is investigated in terms of life history trade-offs in a dioecious population of the wind-pollinated ruderal herb Mercurialis annua.

Methods

The allocation strategies of males and females grown under different soil nutrient availability and competitive (i.e. no, male or female competitor) regimes were compared.

Key Results

Male reproductive allocation increased disproportionately with biomass, and was greater than that of females when grown in rich soils. Sexual morphs differentially adjusted their reproductive allocation in response to local environmental conditions. In particular, males reduced their reproductive allocation in poor soils, whereas females increased theirs, especially when competing with another female rather than growing alone. Finally, males displayed smaller above-ground vegetative sizes than females, but neither nutrient availability nor competition had a strong independent effect on relative size disparities between the sexes.

Conclusions

Selection appears to favour plasticity in reproductive allocation in dioecious M. annua, thereby maintaining a relatively constant size hierarchy between sexual morphs. In common with other dioecious species, there seems to be little divergence in the niches occupied by males and females of M. annua.