Thirty years of slug control using the parasitic nematode Phasmarhabditis hermaphrodita and beyond

Several slug species are highly pestiferous and threaten global sustainable agriculture. Current control methods rely heavily on metaldehyde pellets, which are often ineffective, harm nontarget organisms and have been banned in some countries. A viable alternative is the parasitic nematode Phasmarhabditis hermaphrodita (and recently P. californica), which has been formulated into a biological control agent (Nemaslug®) to control slugs across northern Europe. Nematodes are mixed with water and applied to soil where they seek out slugs, penetrate behind the mantle and kill them in 4–21 days. Phasmarhabditis hermaphrodita has been on the market since 1994 and since then there has been ample research on its use. Here we review the research carried out on P. hermaphrodita over the last 30 years since its development and release as a commercial product. We provide information on life cycle, worldwide distribution, history of commercialisation, gastropod immunity, host range, ecological and environmental factors that affect its success in the field, bacterial relationships, and summarise results of field trials. Finally, we suggest future directions for P. hermaphrodita research (and other Phasmarhabditis species) to enhance its use as a biological control agent to control slugs for the next 30 years. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

The Seismic Structure of the Sun

Global Oscillation Network Group data reveal that the internal structure of the sun can be well represented by a calibrated standard model. However, immediately beneath the convection zone and at the edge of the energy-generating core, the sound-speed variation is somewhat smoother in the sun than it is in the model. This could be a consequence of chemical inhomogeneity that is too severe in the model, perhaps owing to inaccurate modeling of gravitational settling or to neglected macroscopic motion that may be present in the sun. Accurate knowledge of the sun's structure enables inferences to be made about the physics that controls the sun; for example, through the opacity, the equation of state, or wave motion. Those inferences can then be used elsewhere in astrophysics.     

基于VAR模型的农村居民消费结构演进与经济增长关系分析

通过构造一个由消费结构、第二产业结构、第三产业结构和GDP四个变量组成的VAR模型,对中国农村居民的消费结构与经济增长相互作用的关系及其动态特征进行了实证研究.通过设定的模型、格兰杰因果检验、预测方差分解和协整检验,发现经济增长会影响农村居民消费结构演变,而经济增长对第二产业结构的影响存在双向因果关系.     

高温胁迫对杧果幼苗生理生化指标的影响

通过测定高温胁迫下四季杧与台农一号杧一年生嫁接苗叶片生理生化指标的变化,探讨其耐热的生理生化机制。结果表明:随着高温胁迫时间的延长,四季杧和台农一号杧的丙二醛(MDA)含量和相对电导率均明显上升,但四季杧的上升幅度和含量均明显高于台农一号杧。保护酶活性方面,高温胁迫处理后四季杧的SOD酶先下降后上升,而台农一号杧则是先上升后下降,且其含量明显高于四季杧;CAT酶的含量在高温胁迫后2个品种均减少,但四季杧CAT酶的含量明显高于台农一号杧。渗透调节物质游离脯氨酸在高温胁迫处理后含量明显高于处理前,但台农一号杧的上升程度明显高于四季杧。可溶性糖的含量在处理后12 h时,四季杧的含量明显高于台农一号杧,但在处理后72 h时,结果却相反。可溶性蛋白含量先下降后上升,并且四季杧的上升程度明显高于台农一号杧。胁迫处理后2个杧果品种的叶绿素含量和叶片相对含水量均下降,但四季杧的含量均明显低于台农一号杧。综合各项指标,初步推测台农一号杧比四季杧更耐热。     

Onion toxicosis in a herd of beef cows.

A herd consumed approximately 20 kg onions/cow/day for 6 weeks. Five cows died and two aborted. Onion toxicosis results in methemoglobinemia and hemolytic anemia. These changes can cause secondary organ damage and death, if enough onions are consumed.     

甘蔗与抗旱性相关差异蛋白质组分析

采用桶栽方式,对抗旱性强的F172和抗旱性弱的YL6甘蔗品种在苗期进行重度干旱胁迫处理后,应用蛋白质双向电泳技术进行差异蛋白质分析,分别找出差异显著的28和20个差异蛋白点,其中部分呈现上调表达,部分呈现下调表达,还有部分新增的蛋白点,因品种抗性不同而表现各异,F172叶片中的差异蛋白主要表现为上调表达,而YL6中大多表现为下调表达。在重度干旱胁迫下,抗旱性不同的甘蔗品种蛋白质丰度变化有显著差异。采用MALDI-TOF-TOF/MS鉴定所获得的差异蛋白,从YL6、F172中分别鉴定出18、14个蛋白的氨基酸序列,对所鉴定的蛋白质根据功能分为8类。YL6中参与自由基清除的2个,参与光合作用的6个,参与细胞生长和分裂的1个,参与基础代谢的6个,参与防卫反应的2个,未知功能蛋白1个。F172中参与自由基清除的1个,参与光合作用的2个,参与细胞生长和分裂的2个,参与基础代谢的4个,参与信号转导的2个,参与蛋白加工的1个,未知功能蛋白2个,其中22 k D干旱诱导蛋白的丰度明显提高,而在YL6中则检测不到此蛋白。这说明在干旱胁迫下抗旱性不同的甘蔗品种在蛋白质组成上有很大差异,推测这是不同甘蔗品种间抗旱性差异的重要分子基础。     

New 2-phenyl-4,5,6,7-tetrahydro-2H-indazole derivatives as paddy field herbicides

A series of 3-chloro-2-(4-chloro-2-fluorophenyl)-4,5,6,7-tetrahydro-2H-indazole derivatives containing various substituted isoxazolinylmethoxy groups at the 5-position of the benzene ring were synthesized and their herbicidal activities assessed under greenhouse and flooded paddy conditions. Among them, compounds having a phenyl or cyano substituent at the 3-position of the 5-methyl-isoxazolin-5-yl structure demonstrated good rice selectivity and potent herbicidal activity against annual weeds at 16-63 g AI ha(-1) under greenhouse conditions. Field trials indicated that these two compounds controlled a wide range of annual weeds rapidly with a good tolerance on transplanted rice seedlings by pre-emergence application. They showed a low mammalian and environmental toxicity in various toxicological tests.