Artificial Feeding and Laboratory Rearing of Endangered Saproxylic Beetles as a Tool for Insect Conservation

Conservation of threatened animals is frequently limited by lack of knowledge about their ecological preferences, and often artificial feeding is one of the few chances to save endangered species. We investigated the possibility to artificially feed two endangered flat bark beetles dependent on dead wood for their diet—namely, Cucujus cinnaberinus (Scopoli, 1763) and Cucujus haematodes Erichson, 1845—by examining their dietary preferences, life cycle duration, and survival in laboratory conditions. Individuals of the two species were caught in the wild and larvae and adults were fed in laboratory conditions by live or dead prey. Three species of saproxylic beetles: two cerambycids (Acanthocinus griseus Fabricius, 1793 and Rhagium inquisitor Linnaeus, 1758), one scolytid (Ips sexdentatus Börner, 1776) one tenebrionid (Tenebrio molitor (Linnaeus, 1758)) one dipteran (Lucilia sericata (Meigen, 1826)) and one ant (Lasius sp. Fabricius, 1804) were used as prey, with minced meat as a control. Our results indicated high survival and no difference in prey choice between the two flat beetle species. Larvae and adults preferred dead prey, but no significant preference was detected among dead prey taxa, supporting the hypothesis that the two species are opportunistic scavengers. Comparing data with previous results, both species and their developmental stages should be classified as obligate saproxylic organisms with preference to the dead and decaying organic material. Successful artificial feeding and rearing of these endangered species, followed by the release in the wild through rescue or reintroduction programs, therefore appear relevant for their protection and future conservation.     

Artificial Diet Influences Population Growth of the Root Maggot Bradysia impatiens (Diptera: Sciaridae)

In order to investigate the effects of artificial diets on the population growth of root maggot Bradysia impatiens, its population growth parameters were assayed on eight artificial diets (Diet 1, D2, D3, D4, D5, D6, D7, and D8). Results showed that developmental duration from egg to pupa was successfully completed on all eight artificial diets. However, the egg to pupal duration was shortest, while the survival rate of four insect stages was lowest when B. impatiens was reared on D1. When B. impatiens was reared on D7 and D8, the survival rate, female longevity, and female oviposition were higher than those reared on other diets. When B. impatiens was reared on D7, the intrinsic rate of increase (r_m = 0.19/d), net reproductive rate (R₀ = 39.88 offspring per individual), and finite rate of increase (λ = 1.21/d) were higher for its population growth with shorter generation time (T = 19.49 d) and doubling time (Dt = 3.67 d). The findings indicate that the D7 artificial diet is more appropriate for the biological parameters of B. impatiens and can be used an indoor breeding food for population expansion as well as further research. We propose that vitamin C supplement added to the D7 is critical for the improvement of the B. impatiens growth.     

Evaluation on the fitness and population projection of Nilaparvata lugens in response to elevated CO2 using two-sex life table

Abstract

The life history and fitness of Nilaparvata lugens being reared under ambient level (current CO₂ concentration), medially elevated (550?µL/L) and highly elevated (750?µL/L) CO₂ concentration for long-term generation were compared using two-sex life table instead of traditional age-specific life table. The results showed that significantly longer larval duration and lower fecundity of N. lugens were observed in 750?µL/L relative to 550?µL/L treatment (P?<?0.05). Accordingly, 550?µL/L CO₂ significantly enhanced population parameters of N. lugens, including significantly higher intrinsic rate of increase (r), finite rate (λ) and net reproductive rate (R_O), but not for 750?µL/L CO₂. Taken together, N. lugens performs enhanced development rate, fecundity and survival in individual life history and higher potential in population multiplication under 550?µL/L CO₂ level, while only indicates the less enhanced development rate and survival without significant increased capacity of population expansion under 750?µL/L CO₂ level. These results should facilitate predicting the fitness and potential population damage of N. lugens, which is valuable for the integrated control of N. lugens in the future increasing CO₂ concentration.     

大渡河上游鱼类资源现状

2017-2019年,对大渡河上游鱼类种类组成、优势种和多样性指数等进行了调查.结果显示:大渡河上游采集到鱼类2目6科24种,其中包括了四川省级保护鱼类2种、长江上游特有鱼类8种以及外来物种3种.大渡河上游现有分布鱼类以齐口裂腹鱼(Schizothorax prenanti)和重口裂腹鱼(S.davidi)等为优势种群...     

茶让生活更美好

茶作为中华民族的举国之饮,是中华传统文化的集中体现,也是彰显健康生活的民生产业。如今,中国茶在新时代的脉络中展现了蓬勃的生机与活力,迎来了发展的黄金时代。本文从茶产业、茶文化、茶科技和茶健康等角度全方位论述了中国茶的影响、地位、贡献和前景,解读茶让人民生活更美好的时代愿景。     

现代生活中的楚雄彝族烤罐茶习俗

彝族的茶文化有着悠久的历史,“烤罐茶”习俗是彝族人在漫长的历史进程中创造出来的文化传统,是彝族火塘茶艺与地域特色文化的有机结合。在彝族人的观念中,“茶”作为生活中的必需品也蕴含着他们图腾崇拜意识、待人接物的礼仪文化和民族之间凝聚力的表达等多种文化因素。新时代背景下,彝族的烤罐茶在历史的发展过程中得到传承,也蕴含着现代人的养生观念。本文以楚雄彝族烤罐茶习俗为研究对象,探索现代生活中的彝族烤罐茶习俗的传承发展及其丰富的文化内涵。     

基于RGB颜色空间的早稻氮素营养监测研究

针对双季稻区水稻过量施肥带来环境污染和成本提高问题,设计不同品种氮肥梯度大田试验,应用数码相机获取早稻冠层数字图像,研究不同色彩参数及早稻氮素营养指标的时空变化特征,以期确立双季早稻氮素营养预测模型。结果表明:不同品种同一氮肥处理下图像色彩参数差异不大;拔节期数字图像参数对氮素营养指标敏感;模型构建结果显示,图像参数INT与水稻氮素营养指标构建的模型决定系数(R2)最大,模型预测效果最佳,R2分别为0.895 7和0.924 7;进一步采用多元回归分析和BP神经网络分析法进行预测,预测效果均较好。对预测结果进行检验,发现品种对于模型的构建影响不大,以BP神经网络分析法构建的叶片氮浓度(LNC)模型和以INT为敏感色彩参数构建的叶片氮积累量(LNA)回归模型效果最优,而多元回归分析方法则效果不佳。早稻冠层RGB颜色空间敏感参数与氮素营养指标间相关性较好,可以实现氮素营养的无损监测诊断。     

微生物对鱼粉中组胺含量的影响研究

我国鱼粉产品质量参差不齐,由于原料问题组胺含量普遍高于国际先进水平,过高的鱼粉含量易造成食品安全问题。为了降低过高的组胺含量对鱼粉品质的影响,本实验通过使用微生物参与降解鱼粉产品中的组胺。实验将降解时间与微生物添加比例作为变量,测试出较为适宜微生物降级组胺的条件,以及该条件下的实际效果。实验结果表明在设置的6个时间中(以6小时为时间梯),24h为较适宜的降解时间;在较适宜的降解时间中(24h)较适宜的微生物添加比例为10:1。此时鱼粉组胺含量为1622mg/kg,相较未加入微生物处理的鱼粉组胺含量(5298 mg/kg)降低69%。实验结果证明了微生物处理鱼粉中组胺具有显著的效果,为鱼粉生产、储存技术的改良提供了参考依据。     

海底管道腐蚀缺陷处阴极保护数值模拟

海底管道表面很容易因为腐蚀形成缺陷点,具有深度大、传播快且检测困难的特点,对管道安全运行产生很大隐患。通过数值模拟方法研究了X80海底管道钢表面存在腐蚀缺陷时缺陷点内部对阴极保护产生的屏蔽作用,利用有限元方法模拟缺陷处的局部电位和阳极/阴极反应电流密度。结果表明:在腐蚀缺陷处阴极保护电流被部分屏蔽,特别是在缺陷的底部位置;缺陷处对阴极保护的屏蔽作用随着缺陷深度的增加和宽度的减小而越来越强。研究结果可为现场海底管道腐蚀状况和剩余寿命的评估提供指导。     

珠三角地区杂交鳢（乌鳢♂ × 斑鳢♀）弹状病毒感染状况调查

【目的】杂交鳢（ Hybrid snakehead）为我国重要的特种水产鱼类,为摸清杂交鳢弹状病毒 (Hybrid snakehead rhabdovirus, HSHRV) 的感染状况,2021 年 3 月至 2022 年 2 月对珠三角地区养殖的杂交鳢弹状病毒病展开调查。【方法】对繁育阶段的杂交鳢 亲本、鱼苗、水样进行随机采样;养殖阶段则选择固定时间进行随机采样,并在病害暴发时采样。监测周期内共采集 333 份样品,每尾鱼经无菌解剖后,取绿豆大小肝脏、脾脏和肾脏组织混样,保存于液氮中,用于提取 RNA;以反转录的 cDNA 为模板,采用 qPCR 技术进行 HSHRV 检测。【结果】感染 HSHRV 的鱼体主要临床症状为不规则游动、打转,体表无明显症状,解剖可见肝脏、脾脏、肾脏、肠道和鱼鳔充血发红或肿大;qPCR 检测结果显示,333 份样品的 HSHRV 平均阳性率为 13.21%,阳性样品主要集中在4 － 11 月,其中,8 月份的样品阳性率高达 23.91% ;养殖阶段的 HSHRV 平均阳性率（17.01%）显著高于繁育阶段的平均阳性率（3.26%）;从鱼体规格来看,HSHRV 最易感 10 cm 以内的鱼,阳性率高达 32.20%,主要在 3 －9 月检出;HSHRV 最不易感 20 cm 以上的鱼,阳性率低至 9.52%。【结论】明确了繁育阶段和养殖阶段以及不同养殖规格杂交鳢的 HSHRV 阳性率,为深入了解杂交鳢弹状病毒病的流行规律提供参考,以期为养殖过程中杂交鳢弹状病毒病的预防与控制提供数据支撑。