柳毒蛾繁殖生物学的初步观察

【目的】为了明确柳毒蛾Leucoma salicis(Linnaeus)交配的日节律高峰,温度和不同交配持续时间处理对成虫寿命、产卵量和孵化率等繁殖生物学的影响。【方法】将新羽化的柳毒蛾成虫置于养虫笼中,观察交配的日节律高峰,并统计不同温度和不同交配持续时间处理下的成虫寿命、产卵量和孵化率。【结果】成虫在羽化当晚的后半夜凌晨开始交尾,次日晚上开始产卵。成虫交配集中在羽化翌日凌晨3:00—5:00之间,高峰为4:00。产卵高峰都出现在2日龄成虫,但是,25℃下成虫交配持续时间(9.2 h)显著短于28℃(11.8 h)。交配持续时间为30、60和300 min的处理,雌成虫平均寿命显著长于对照(对照9.2 h),雄虫仅60 min的处理显著长于对照。同时,极短的交配持续时间(30 min)显著降低雌虫的产卵量和孵化率。【结论】试验明确了成虫交配的日节律高峰,在适宜的温度范围内(25~28℃),雌雄成虫的寿命、单雌总产卵量无显著差异,交配持续时间明显影响成虫寿命、产卵量和卵孵化率。     

大豆荚发育程度对点蜂缘蝽成虫寿命及生殖力的影响

【目的】为明确大豆荚发育程度对点蜂缘蝽Riptortus pedestris成虫存活及生殖力的影响。【方法】在室内24℃±1℃恒温下,用不同日龄(5, 15, 25, 35和45日龄)离体鲜豆荚饲喂点蜂缘蝽,测定成虫寿命、产卵前期、产卵期、单雌产卵量等生物学参数和不同日龄豆荚籽粒中脂肪、总蛋白和总糖含量,分析点蜂缘蝽成虫的生物学参数与不同日龄豆荚籽粒中主要营养成分含量之间的相关性。【结果】随着所取食豆荚日龄的增加,点蜂缘蝽成虫的平均寿命、产卵期、单雌产卵量呈先增加然后下降的趋势,而产卵前期的变化趋势则相反。当饲喂35日龄豆荚时,点蜂缘蝽成虫寿命最长(56.90±9.47 d),产卵前期最短(6.00±0.58 d),产卵期最长(29.67±6.61 d),单雌产卵量最高(129.56±36.53粒),且与取食其他日龄豆荚的成虫之间存在显著差异。点蜂缘蝽成虫寿命、产卵期、单雌产卵量均与豆荚籽粒脂肪和总蛋白含量呈显著正相关,产卵前期与豆荚籽粒脂肪和总蛋白含量呈显著负相关。【结论】大豆荚发育程度对点蜂缘蝽成虫寿命及生殖力等生物学参数具有显著的影响,35日龄豆荚对点蜂缘蝽成虫存活和繁殖最为有利。     

广聚萤叶甲成虫交配时长对产卵量与孵化率的影响

【目的】明确不同交配时长对广聚萤叶甲雌虫产卵量和卵的孵化率的影响。【方法】在室内条件下,对不同交配时长下广聚萤叶甲的雌虫产卵量和卵的孵化率进行观察:(1)选取羽化第3d的广聚萤叶甲雌雄虫随机配对,观察24 h,记录交配情况和时长;(2)在交配开始1、5、15、30、60 min时,强行分开雌雄成虫,然后将不同交配时长的雌虫进行单独饲养,以正常交配一次的雌虫作为对照,每个处理选取23组;(3)将15～30 cm健壮豚草小苗插入注满水的塑料小瓶内,将配对的一组雌雄成虫和豚草小苗放入养虫盒中饲养,每天更换带卵的小苗并记录叶片上的产卵量;(4)将上述带卵的小苗至于适宜条件下培养,记录5～7 d内卵块孵化的情况。【结果】广聚萤叶甲正常交配一次的对照组的产卵水平显著高于各处理组,单雌产卵为889粒,交配时间15 min以下各组雌虫的产卵量明显低于交配30 min以上的各组雌虫。同时交配时长5 min以下雌虫产的卵基本不能孵化,而交配时间达到30 min以上的各组卵块的孵化率明显提高。【结论】雄虫转移雌虫受精所需精子量需要耗费的时间为30 min左右,且雄虫有延长交配时间的趋性。该结果为研究广聚萤叶甲的生态特性以及优化种群繁殖提供科学依据。     

落叶松尺蠖Erannis ankeraria Staudinger的生物学特性

【目的】明确落叶松尺蠖Erannis ankeraria Staudinger的发生规律及生物学特性。【方法】野外调查和室内饲养。【结果】在集宁市落叶松尺蠖1年1代,以卵越冬,越冬卵在翌年4月下旬、5月上旬孵化,6月中下旬开始入土化蛹,成虫于9月初羽化、产卵。在温度为20℃,RH=70%的条件下,落叶松尺蠖幼虫期(19.96±0.86)d,预蛹期(3.93±0.95)d,蛹期(108.4±13.17)d。蛹分布于树干基部30~90cm范围内,深度4~8 cm。雄虫在6:00—8:00及12:00—16:00羽化,早于雌性,雌虫在20:00—24:00羽化,羽化若干小时后可交尾,交配持续时间20~260 min,可多次交尾。20℃下交尾雌虫寿命为(5.56±1.47)d,雄虫为(3.95±0.95)d,产卵量为(162.2±69.9)粒;不交尾雌性为(8.03±2.90)d,雄性为(4.38±1.59)d,产卵量为(164.1±81.3)粒,但卵不能孵化;15℃条件下不交尾雌雄寿命分别为(14.48±6.67)d,(6.64±1.76)d,产卵量为(145.7±76.8)粒。【结论】落叶松尺蠖危害期短,蛹期较长,雌雄成虫羽化时间有差异;温度和交尾对寿命和产卵量都有显著影响。     

交配对广聚萤叶甲成虫耐饥与耐热能力的影响

昆虫交配是一个消耗能量的过程,因此交配后可能对其抗逆能力造成一定的影响。广聚萤叶甲是恶性杂草-豚草的专一性天敌,正常情况下,成虫耐饥饿和耐热能力较强。为明确交配对广聚萤叶甲成虫抗逆能力的影响,本研究观察在一次交配处理后,广聚萤叶甲在饥饿条件下或高温条件下继续存活时间。结果发现,在不提供食物的情况下,交配对雄虫的寿命影响不大,但雌虫的寿命(8.4 d±0.1 d)显著短于对照雌虫(10.8 d±0.1 d)。在高温状态下,无论取食与否,交配都会显著增加广聚萤叶甲雌雄成虫的耐热能力,尤其以雌虫表现更为明显(处理雌虫和对照雌虫存活时间分别为:取食(6.15 d±0.14 d,4.95 d±0.13 d)、不取食(5.55 d±0.13 d,4.81 d±0.11 d)。可见,交配降低广聚叶甲雌虫的饥饿能力,但成虫的耐热能力显著加强。     

梨小食心虫蛹重对成虫繁殖力和寿命及下一代幼虫发育的影响

【目的】本文旨在明确营养状况不同造成的梨小食心虫Grapholitha molesta(Busck)雌、雄蛹重量差异对其羽化的成虫产卵量、产卵期、寿命及下一代(F1)幼虫发育的影响。【方法】室内条件下,通过不同的饲养方法,获得个体重量不同的梨小食心虫雌、雄蛹,待其羽化交配后,记录其产卵量、产卵时间和成虫寿命;卵孵化前后,分别测量卵和初孵幼虫大小,计算卵孵化率,统计幼虫发育历期。【结果】雌蛹重量对梨小食心虫的成虫产卵量影响显著,其重量与产卵量呈正相关(y=15.505x-59.292);同一条件下,雌蛹与雄蛹重量也呈正相关(y=0.823x-0.538)。同时,雌蛹重量对成虫产卵期影响也较大,蛹重大的个体羽化的雌虫比蛹重小的个体羽化的雌虫产卵高峰期提前1 d;较重、中等和较轻蛹羽化出的雌虫个体每天产卵量高于10粒/雌的时间分别为9~10,7和5~6 d;产卵量高于5粒/雌的时间分别为12~13,9和6~7 d。而雄蛹重量对产卵量、雄成虫寿命影响没有明显影响。较轻的蛹羽化的雌成虫寿命比较重蛹羽化的雌成虫短2~3 d;而雄蛹重量对其羽化的雄成虫寿命影响没有明显规律。雌、雄蛹重量对其羽化成虫的卵孵化率、卵和初孵幼虫的大小影响均不显著,对F_1幼虫发育历期影响也不显著。【结论】梨小食心虫雌蛹重对羽化成虫的产卵量和产卵期等影响显著,田间防治时应注意在不同条件下完成发育的个体,尤其是雌虫,由于营养差异引起的个体大小对随后种群增长的影响。     

外源保幼激素对中华通草蛉滞育解除及滞育后发育的影响

【目的】本研究旨在明确外源保幼激素(juvenile hormone, JH)在中华通草蛉Chrysoperla sinica滞育快速解除过程中的使用剂量及最佳使用时期。【方法】测定点滴不同剂量(0, 5, 15, 25和35 μg/成虫)外源JH后中华通草蛉滞育成虫的产卵前期、产卵历期、雌虫寿命及单雌产卵量,以及15 μg/成虫外源JH处理对不同日龄(0, 5, 10, 20, 30和40日龄)滞育成虫处理后这4个指标的变化。【结果】在不同点滴剂量处理中,15和25 μg/成虫外源JH处理的中华通草蛉滞育成虫的产卵前期分别为6.82和6.29 d,显著短于点滴丙酮的对照组(10.55 d),且15 μg/成虫外源JH处理组产卵历期、雌虫寿命及单雌产卵量均最大,均显著大于对照组。不同日龄的中华通草蛉滞育成虫点滴15 μg/成虫外源JH,0, 5, 10和20日龄处理的成虫产卵前期均显著短于未经外源JH处理的对照组。10, 20和30日龄处理的成虫产卵历期和雌虫寿命均与未经外源JH处理的对照组无显著差异,但10, 20和30日龄处理的成虫生殖力显著降低,而20日龄处理时对照组和外源JH处理组均有较高的生殖力。【结论】综合考虑产卵前期、产卵历期、产卵量和雌虫寿命4个指标,15 μg/成虫的外源JH剂量是中华通草蛉快速解除滞育的最佳剂量;最佳使用时期为滞育20 d的成虫,此时对中华通草蛉成虫滞育解除后的生殖能力影响最小。本研究解决了中华通草蛉滞育解除耗费时间长的瓶颈问题,为成虫滞育天敌的高效存储利用与滞育的快速解除提供了新思路。     

眉斑并脊天牛生物学特性研究

眉斑并脊天牛Glenea cantor Fabricius是我国华南地区园林绿化植物木棉树的重要蛀干害虫。本试验通过室内饲养观察和野外调查,对该虫的生物学特性进行了研究。结果表明该虫在南宁一年发生4代,平均世代历期为70 d,主要以4龄幼虫在受害枝干内越冬。成虫羽化后出木前期为5.97±1.11 d。雄虫较雌虫提早羽化2-3 d,成虫期需补充营养,且具弱趋光性和假死习性。在日节律中,9∶00-11∶00和14∶00-16∶00为产卵高峰期,16∶00-19∶00为交配高峰期。雌虫出木后2 d开始交配,雄虫出木后4 d开始交配。雌雄虫一生可交配15.12±7.02次,每次交配时长为3.23±0.97 h,一天内仅交配一次。成虫主要趋向长势较弱的木棉树及枝条上产卵。产卵前期为13.50±3.15 d,平均产卵量为117.31±33.25粒。雌雄寿命分别为72.34±15.60 d和46.22±14.38 d。     

黄褐幕枯叶蛾生殖行为研究和林间引诱试验

【目的】为探索一种高效、无污染的防治黄褐幕枯叶蛾Malacosoma neustria testacea Motschulsky(Lepidoptera:Lasiocampidae)的方法,本文对其生殖生物学特征进行了研究。【方法】本试验于2013年和2014年期间通过室外笼内人工饲养和野外调查相结合,观察黄褐幕枯叶蛾的生殖行为学特征。【结果】黄褐幕枯叶蛾羽化期40 d左右,羽化高峰在6月19日―7月03日,日羽化高峰期在17:00―19:00,雌雄平均性比为1︰(1.19±0.07),未交配雌雄成虫的平均寿命分别为(4.13±0.142)d和(4.57±0.035)d,雄蛾的寿命高于雌蛾。在凌晨0:00―3:00均能观察到雌蛾有明显的求偶行为。成虫交尾高峰在凌晨2:30左右,1日龄的成虫交尾率最高(61.67%±2.89%),随着日龄的增加成虫的交尾行为逐渐减弱。交尾持续时间最短为20 min,最长可达135 min。林间诱蛾实验中,未交配雄蛾和空白对照都没有引诱到成虫,1~6日龄未交配雌蛾均能引诱到雄虫,且1日龄未交配雌蛾诱蛾量最大,凌晨2:00―3:00是诱蛾高峰期;凌晨1:30未交配雌蛾性腺提取物的引诱量最大,1日龄未交配雌蛾性腺提取物对雄蛾的引诱效果最佳。【结论】本试验的研究结果为利用昆虫性信息素防治黄褐幕枯叶蛾奠定了基础。     

广聚萤叶甲成虫的繁殖习性和活动规律初步观察

广聚萤叶甲Ophraella communa是豚草Ambrosia artemisiifoliaL.的一种重要专一性天敌昆虫,对豚草抑制作用显著。本文在室内对广聚萤叶甲成虫交配和产卵活动进行观察,结果表明广聚萤叶甲成虫一生多次交配多次产卵,雄虫交配前期为2.7d,明显长于雌虫的0.9d。交配雌虫有产卵前期,然后开始产卵。成虫交配活动主要在8:00-21:00,一般产卵高峰在12:00-16:00,在交配后的前16天,雌虫产卵处在高峰期,随后产卵逐渐减少。本论文为进一步开展广聚萤叶甲繁殖生物学研究和大量繁殖提供基础。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.