Insect Pathogen – U.l.v. Combination for Crop Pest Control

Abstract

Two commercial preparations of Bacillus thuringiensis; Thuricide 16B and Thuricide HPC, four nuclear polyhedrosis viruses of; Trichoplusia ni, Spodoptera exigua, Heliothis zea and Autographa californica, and an entomogenous fungus, Paeceliomyces farinosus were tested. They were applied using; a Micro-Gen super model MS2W-15 Unit, on cotton, grapes and pears and a handgun on pears. The use of a u.l.v. sprayer reduces the cost of applying insect pathogens and makes spot treatments practical.     

Use of some plant extracts to control Biomphalaria alexandrina snails with emphasis on some biological effects

The present work was carried out to evaluate, the molluscicidal activity of cold water, boiled water, methanol, ethanol, acetone and chloroform extracts of some plant species against Biomphalaria alexandrina snails. Preliminary screening tests on 10 plant species showed that the highest molluscicidal potency was recorded for Euphorbia splendens, Atriplex stylosa and Guayacum officinalis. Exposure of B. alexandrina snails to plant’s methanol extracts led to a significant reduction in their survival and growth rates. In addition, newly hatched snails were susceptible to plant’s methanol extracts than elder ones. LC₂₅ of methanol extract from these plants caused a considerable reduction in the infectivity of Schistosoma mansoni miracidia to the snails. It caused a reduction in number of cercariae per snail during the patent period and in the period of cercarial shedding. The results, also, revealed that the glucose concentration in treated snails was increased in haemolymph, while soft tissue glycogen decreased. The activities of glycogen phosphorylase, succinate dehydrogenase (SDH), glucose-6-phosphatase and acetylcholinesterase (AchE) in homogenate of snail’s tissues were reduced (P < 0.001) in response to treatment with plants methanol extract, while glucose-6-phosphate dehydrogenase (G-6-PD) activity increased (P < 0.001). It was concluded that the application of LC₂₅ of methanol extracts of E. splendens, A. stylosa and G. officinalis may be helpful in snail control as it interferes with the snails’ biology and physiology.     

间作大蒜对茄子截形叶螨的防控效果

为明确间作大蒜对茄子截形叶螨Tetranychus truncatus Ehara种群的防控效果,于室内测定了大蒜提取液对截形叶螨卵的毒杀活性及对雌成螨的驱避和产卵选择性影响,并研究了田间不同比例间作大蒜对茄子截形叶螨自然种群的影响。结果表明,用0.05 g/mL和0.10 g/mL大蒜提取液处理后,截形叶螨卵死亡率分别为44.53%和63.53%,均显著高于空白对照;大蒜提取液处理蔬菜叶片72h后,截形叶螨雌成螨和卵的数量分别为16头和141粒,均显著低于空白对照组的23头和236粒;田间茄子和大蒜按1∶1、2∶1或4∶1间作均可降低截形叶螨自然发生数量,其中1∶1和2∶1间作对截形叶螨种群控制显著升高。研究表明,大蒜提取液对截形叶螨雌成螨取食及产卵具有显著的驱避活性;且间作大蒜可以对截形叶螨种群起到明显的抑制作用。     

联肼·乙螨唑对蔬菜优势叶螨产卵发育的影响及其田间防效

为明确新型复配杀螨剂联肼·乙螨唑对目前蔬菜田常发生的2种优势叶螨二斑叶螨Tetranychus urticae和截形叶螨T. truncatus的杀螨活性,于室内采用离体叶碟法测定其对这2种叶螨产卵及发育的影响,于室外采用活体植株评价该药剂对2种叶螨的田间防效。结果表明,经复配杀螨剂联肼·乙螨唑及其单剂处理2种叶螨雌成螨24 h后,死亡率为20.50%～54.98%,均显著高于清水对照;联肼·乙螨唑处理较清水对照显著降低了2种叶螨卵发育至若螨期的比率,联肼·乙螨唑处理后二斑叶螨和截形叶螨的若螨率分别为4.91%和1.63%。田间试验中联肼·乙螨唑对2种叶螨具有一定的速效性,药后3 d对二斑叶螨和截形叶螨的防效分别达95.74%和89.83%,药后7 d防效分别为98.03%和99.44%,显示了优良的防控效果及持效性。表明复配杀螨剂联肼·乙螨唑可用于田间蔬菜优势叶螨种群的高效防控。     

Ecological Studies on the Larger Grain Borer, Prostephanus truncatus (Horn) (Col.: Bostrichidae) and their Implications for Integrated Pest Management

In this article, we review studies of the ecology of the larger grain borer, Protephanus truncatus, both outside and within the maize storage systems. Laboratory studies have shown that P. truncatus can breed on a wide range of woody substrates (branches, roots, and seeds). Pheromone trap catches in different habitats strongly suggest that P. truncatus is well-established in certain non-agricultural environments, presumably breeding in dead or dying wood. In Meso-America, West and East Africa, P. truncatus reproduction in the field has been documented in branches ring-barked by cerambycid beetles. Within a maize store, P. truncatus densities can increase from very small initial colonies of probably less than 200 individuals to densities in excess of 1000 beetles per kg after about 4–6 months of storage. Insect parasitoids are very often found in smallholders' grain stores attacked by P. truncatus, but they do not contribute significantly to population regulation. Declines in maize store population levels in Benin from 1993 to 1996, and in adult abundance in pheromone traps in the natural environment in Kenya, have been attributed to predation by the introduced predator, Teretrius nigrescens, but in recent years pheromone trap catches in West Africa suggest that the situation may be complex. Several environmental factors, notably temperature, humidity, and daylength, and their interactions, have been correlated with P. truncatus flight activity, as well as, in West Africa, the emptying of maize stores. Laboratory experiments have shown food quality also affects flight activity. Factors terminating dispersal and flight are most likely attraction to the male-released aggregation pheromone. Short range attraction to plant volatiles has also been recorded. In Africa the highest densities of P. truncatus tend to occur in humid lowlands, which contrasts with the situation in meso-America where P. truncatus tend to occur in greatest numbers in cooler upland regions. Pheromone trap catches can be significant predictors of the risk of stores becoming infested. Coupled with the development of a rule-based model of flight activity, these studies may offer the prospect of predicting the risk of store infestation based upon temperature and humidity measurements.     

2-吡啶酰氨基环己烷基磺酰胺的合成与杀菌活性

为了进一步研究环烷基磺酰胺类化合物的杀菌活性与构效关系,在前期工作基础上,对先导化合物进一步展开研究,合成了15个未见文献报道的2-吡啶酰氨基环己烷基磺酰胺类化合物。首先以2-氧代环己烷基磺酰胺为原料,经过还原胺化后得到2-氨基环己烷基磺酰胺;再与取代吡啶甲酰氯反应,得到目标化合物。分别通过菌丝生长速率法与黄瓜活体叶片法测定了目标化合物对番茄灰霉病菌Botrytis cinerea及其他5种植物病原菌的杀菌活性。结果表明:目标化合物对番茄灰霉病菌表现出较好的抑制活性,其中化合物V-8在离体条件下对番茄灰霉病菌的EC50值为1.41 mg/L,在500 mg/L下的活体防效为79.17%;此外,部分目标化合物在50 mg/L下,对水稻纹枯病菌、水稻稻瘟病菌、大豆根腐病菌、黄瓜绵腐病菌和辣椒疫霉的抑制率高于60%,其中,化合物V-7对黄瓜绵腐病菌的EC50值为2.7 mg/L,其活性高于对照药剂多菌灵（EC50值为4.4 mg/L）,有进一步研究的价值。     

7-(1-酰基哌嗪-4-基)甲基喜树碱衍生物的合成及杀虫活性

以(20S)-喜树碱(CPT)为原料,根据类同合成法和亚结构连接法原理,对CPT的7-C位进行修饰,得到了系列新型7-(1-酰基哌嗪-4-基)甲基喜树碱衍生物(4a~4m),所有衍生物的结构均通过核磁共振氢谱(1H NM R)和液-质联用(LC-M S)等方法确证;并初步测定了其对朱砂叶螨Tetranychus cinnabarinus和松材线虫Bursaphelenchu xylophilus的室内杀虫活性。结果表明:与喜树碱相比,各衍生物均表现出不同程度的杀虫活性,其中化合物7-[1-(4-甲氧基苯酰基)哌嗪-4-基]-甲基喜树碱(4g)和7-(1-环戊酰基哌嗪-4-基)-甲基喜树碱(4j)对朱砂叶螨24 h的半数致死浓度(LC50值)分别为8.10和9.05 mg/L,对松材线虫的LC50值分别为6.34和6.68 mg/L。研究结果可为喜树碱衍生物杀虫活性构效关系研究奠定基础。     

米尔贝霉素类似物的合成及杀螨杀蚜活性

为寻找高活性的米尔贝霉素衍生物,以伊维菌素为原料,经脱糖、羟基保护、氧化、还原胺化、脱保护等将其转变为13-氨基米尔贝霉素类似物,通过三组分反应设计合成了一系列米尔贝霉素磺酰脒类化合物(7a~7i),并初步测定了其对朱砂叶螨Tetranychus cinnabarinus和豆蚜Aphis craccivora的室内活性。结果表明:各衍生物对朱砂叶螨和豆蚜均有较好的触杀活性,其中7f、7h和7i对朱砂叶螨24 h的LC50值分别为1.04×10–2、9.60×10–4和1.44×10–2 mg/L;7i对豆蚜24 h的LC50值为7.81 mg/L。米尔贝霉素13位氨基上磺酰化的结构修饰有助于提高米尔贝霉素类化合物的杀螨、杀蚜活性。     

Influence of Atrazine and Roundup pesticides on biochemical and molecular aspects of Biomphalaria alexandrina snails

The excessive use of pesticides in agriculture has sparkled the interest of scientists in investigating the harmful effects of these compounds. The present study evaluates the pesticides Atrazine and Roundup (glyphosate) on biochemical and molecular aspects of Biomphalaria alexandrina snails. The results showed that LC₁₀ of these two pesticides caused considerable reduction in survival rates and egg production of treated snails. Additionally, Atrazine proved to be more toxic to B. alexandrina snails than Roundup. In treated snails, glucose concentration (GL) in the hemolymph as well as lactate (LT) and free amino acid (FAA) in soft tissues of treated snails increased while glycogen (GN), pyruvate (PV), total protein (TP), nucleic acids (DNA and RNA) levels in snail’s tissues decreased. The activities of glycogen phosphorylase (GP), superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR), succinic dehydrogenase (SDH), acetylcholinesterase (AChE), lactic dehydrogenase (LDH) and phosphatases (ACP and ALP) enzymes in homogenate of snail’s tissues were reduced in response to the treatment with the two pesticides while lipid peroxide (LP) and transaminases (GOT and GPT) activity increased (P < 0.001). The changes in the number, position and intensity of DNA bands induced by pesticides may be attributed to the fact that pesticide can induce genotoxicity through DNA damage. It was concluded that the pollution of the aquatic environment by Atrazine and Roundup pesticides, would adversely affect the metabolism of the B. alexandrina snails, and have adverse effects on its reproduction.     

香豆素类化合物对朱砂叶螨的触杀活性及定量构效关系研究

采用玻片浸渍法,测定并筛选了25种具有代表性的香豆素类化合物对朱砂叶螨Tetranychus cinnabarinus雌成螨的触杀活性,并构建了一个预测能力较强的定量构效关系(QSAR)模型。结果表明:所有供试化合物对朱砂叶螨均具有触杀活性,且随着处理时间的延长活性升高。处理48 h后,LC50值低于1000 mg/L的化合物有8个,分别是3-(2-苯并咪唑)-7-(二乙氨基)香豆素(1)、3-(2-苯并噻唑)-7-(二乙氨基)香豆素(2)、3-氨基香豆素(3)、3-乙酰基香豆素(4)、4-甲氧基香豆素(5)、6-硝基香豆素(8)、6,7-二甲氧基香豆素(13)和7,8-二羟基香豆素(21),其中化合物1、2、3、5和13的杀螨活性优于药剂对照螺螨酯或与其活性相当;活性最好的化合物为13,处理48 h和72 h后LC50值分别为284.8和122.2 mg/L,其毒力约为螺螨酯的2倍。通过计算得到25种香豆素类化合物的34种物化参数,以此为描述子,经过SPSS相关性剔除、逐步回归分析和校正,得到一个以扭转力、取向力、总能量和分子半径为自变量的QSAR模型,该模型复相关系数R达到0.987,复判定系数R2也达到0.967,通过F检验证明上述模型具有较高的预测能力。     

基于转录组测序解析草地贪夜蛾对溴氰虫酰胺的解毒代谢分子机制

为阐明草地贪夜蛾Spodoptera frugiperda对溴氰虫酰胺的解毒代谢分子机制,通过LC₅₀的溴氰虫酰胺诱导草地贪夜蛾3龄幼虫后,利用酶活测定和转录组测序鉴定解毒代谢相关基因,并采用实时荧光定量PCR技术对细胞色素P450单加氧酶(cytochrome P450 monooxygenase,P450)基因进行验证分析。结果表明,经LC₅₀的溴氰虫酰胺处理后,草地贪夜蛾3龄幼虫体内3种解毒代谢酶活性较对照均有所升高,但仅P450活性较对照显著升高,而谷胱甘肽S-转移酶和羧酸酯酶与对照无显著差异。经LC₅₀的溴氰虫酰胺处理后草地贪夜蛾3龄幼虫转录组中共筛选到1 408个差异表达基因,其中上调表达的基因有935个,下调表达的基因有473个。药物代谢-细胞色素P450通路、药物代谢-其他酶通路及细胞色素P450对异生物质的代谢通路中有超过20个基因存在差异表达。在草地贪夜蛾转录组中筛选鉴定到121个P450基因,其中,属于CYP2、CYP3、CYP4以及Mito家簇的基因分别有9、45、58和9个,而经LC_5...     

Studies on granular formulations of Bacillus thuringiensis berliner

Survival of the spores of Bacillus thuringiensis in granular formulations has been tested under storage conditions in the laboratory and also outdoor conditions exposed to weather. The granular formulations were prepared with attapulgite and aqueous and non-aqueous carriers. The virulence of the spore formulation was tested on Bombyx mori larvae. A 0.4% spore concentration, with an initial count of 64 × 10⁶, gave ultimately 0.3 to 0.4 × 10⁶ viable spores/g of the granule after 248 days of storage in the room. The viable count of spores in the granules exposed to outdoor weather conditions fell rapidly within two days; at the end of 65 days, it was maintained at between 3 × 10⁴ and 12 × 10⁴/g of the granules. Optimum concentrations required in granules for 100% mortality of the test insect was found to be 0.4 × 10⁶ spores/g, at the rate of 50 mg of granules per 85 cm² of leaf surface. The granular formulation of B. thuringiensis was found to be more virulent than “Thuricide” formulation on B. mori larva.     

杠柳杀虫活性成分的分离

采用柱层析分离、高效液相色谱切分和生物活性追踪法,从杠柳 Periploca sepium 根皮甲醇提取物中分离出2个具有杀虫活性的化合物(G1和G2),经鉴定其分别为已知物杠柳新苷D和F。生物活性测定结果表明,化合物G1和G2 对3龄粘虫 Mythimna separata 48 h的胃毒致死中浓度(LC50)分别为0.39和0.34 mg/mL, 对小菜蛾 Plutella xyllostella 48 h的胃毒LC50值分别为1.21和1.39 mg/mL。     

吉林省截形叶螨与二斑叶螨卵的发育起点温度和有效积温

在自动控制温度和光照长度的实验室内 ,采用直线回归法对截形叶螨与二斑叶螨卵的发育起点温度和有效积温进行了研究和分析 ,结果表明:在18～30℃范围内 ,截形叶螨与二斑叶螨的发育起点温度分别是14.86℃和10.78℃ ;有效积温分别是48.84、76.45日度。当温度在发育起点温度至22℃范围内二斑叶螨卵的发育速率大于截形叶螨 ,而当温度高于22℃时截形叶螨卵的发育速率大于二斑叶螨     

Effectiveness of cyfluthrin dust treatment for control and protection of shelled maize against infestation by the larger grain borer,Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) in Tanzania

Abstract

Knockdown, mortality and residual activity of pyrethrins and cyfluthrin were studied on the larger grain borer (LGB), Prostephanus truncatus (Horn). Pyrethrum marc with 0.4% pyrethrins and cyfluthrin dust (0.1% a.i.) when applied on filter paper at 0.72 mg/cm² gave 98.6% and 100% knockdown (KD) respectively after 6 h. Cyfluthrin dust had a faster KD effect with 100% KD compared to 93.1% for pyrethrum marc, ½1/2>h after treatment. After 24 h there was no recovery from KD in both treatments. After 72 h, 23.2% of the LGB had recovered from KD while mortality was 76.8% in the pyrethrum marc treatment. After the same period, cyfluthrin resulted in 100% mortality. Mortality of P. truncatus exposed to different dosages of cyfluthrin dust in shelled maize was less than 100% at dosages lower than 1 part per million (ppm) but was 100% at 1 ppm and higher dosages 3 days after treatment. Progeny emergence was suppressed at all dosage levels above 0.25 ppm compared to a mean progeny of 68.8 in the check after 45 days. Cyfluthrin dust was more residually toxic at 0.5 ppm and higher dosages, with mortality of >90% at 5 months after treatment. This suggests that cyfluthrin dust at 0.1% a.i. mixed with shelled maize at 1 ppm will give protection and control of LGB infestation.     

基于丁香酚的异(口恶)唑啉类化合物的设计合成及抑菌活性

为了探索新型异齅唑啉类化合物作为杀菌剂候选化合物开发的潜力,本研究以廉价易得的芳香醛类化合物为原料制备了32个氯代肟类化合物,通过其与天然产物丁香酚的1,3-偶极环加成反应和后期官能团化反应,制备了35个异齅唑啉类化合物 ( D1 ~ D32 , E1 ~ E3 ),其中34个为新化合物。所有化合物的结构均经过液相色谱-电喷雾质谱 (LC-ESI-MS)、核磁共振氢谱 (1H NMR) 及元素分析确认。初步抑菌活性测试结果表明:多数目标化合物对油菜菌核病菌、水稻纹枯病菌、番茄早疫病菌和辣椒疫霉病菌具有较好的抑菌活性,其中化合物 D26 对油菜菌核病菌的活性最高,有效抑制中浓度 (EC₅₀) 为14.3 mg/L,具有进一步研究的价值。     

山蒟中脂肪链酰胺类化合物的分离及杀虫活性

采用提取、萃取及柱层析等方法,从山蒟Piper hancei Maxim甲醇提取物的石油醚和氯仿萃取相中分离到6个脂肪链酰胺类化合物,通过核磁共振、质谱并结合相关文献比对,其结构被分别鉴定为已知化合物chingchengenamide A( C1 )、N-异丁基-反-2-反-4-癸二烯酰胺( C2 )、假荜拨酰胺A( C3 )、荜茇宁( C4 )、N-p-香豆酰酪胺( C5 )和N-反式-阿魏酰酪胺( C6 ),其中 C1 为首次从山蒟中获得。利用幼虫浸液法测试了各化合物对白纹伊蚊Aedes albopictus和致倦库蚊Culex pipiens quinquefasciatus幼虫的12 h杀虫活性。结果表明:在20 mg/L下,化合物 C1 对白纹伊蚊的杀虫活性较高,其校正死亡率为100%,LC₅₀值为5.37 mg/L;化合物 C1 、 C2 、 C3 和 C4 对致倦库蚊的杀虫活性较高,20 mg/L下的校正死亡率分别为100%、88.5%、100%和100%,LC₅₀值分别为1.03、9.68、3.08和2.87 mg/L。     

21种化学药剂对新疆棉田主要害虫毒力及对多异瓢虫的安全性

为明确现阶段棉田常用化学杀虫剂对新疆维吾尔自治区（简称新疆）棉花主要害虫的毒力以及对新疆本地优势天敌多异瓢虫Hippodamia variegata的安全性,于室内分别测定当前21种棉田常用化学药剂对新疆棉田3种主要害虫棉蚜Aphis gossypii、截形叶螨Etranychus truncatus和棉铃虫Helicoverpa armigera以及优势天敌多异瓢虫的毒力,比较不同药剂对各种害虫和天敌的相对毒力指数以及益害毒性比。结果表明,药剂处理24 h后,10种蚜虫防治药剂对棉蚜成蚜的半致死浓度LC₅₀由高到低依次为氟啶虫胺腈、啶虫脒、吡虫啉、环氧虫啶、噻虫嗪、丁硫克百威、烯啶虫胺、呋虫胺、螺虫乙酯和吡蚜酮,其中益害毒性比较高的药剂主要有氟啶虫胺腈和螺虫乙酯;5种叶螨防治药剂对截形叶螨成螨的LC₅₀从高到低依次为阿维菌素、哒螨灵、四螨嗪、噻螨酮和炔螨特,其中益害毒性比较高的药剂主要有四螨嗪、噻螨酮和阿维菌素;6种鳞翅目害虫幼虫防治药剂对棉铃虫3龄幼虫的LC₅₀由高到低顺次为甲氨基阿维菌素苯甲酸盐（简称甲维盐）、氯虫苯甲酰胺、茚虫威、灭多威、毒死蜱和高效氯氰菊酯,其中益害毒性比较高的药剂主要有甲维盐和氯虫苯甲酰胺。综合上述2个方面结果,氟啶虫胺腈、阿维菌素、甲维盐和氯虫苯甲酰胺不仅对棉花害虫毒力效果强,而且对有益天敌安全性高。     

Photostabilization of biocontrol agents by berberine

We studied the photostabilizing effect of the isoquinoline alkaloid berberine on the following three model photounstable biocontrol agents: the bacterium Bacillus thuringiensis ( Bt ), the baculovirus Spodoptera littoralis nucleopolyhedrosis virus ( SlNPV ), and the entomopathogenic fungus Beauveria bassiana . The photoprotection provided by berberine was evaluated following various periods of simulated sunlight-UV irradiation. Insecticidal activity of Bt and SlNPV , as well as the rate of B. bassiana spore germination served as parameters for the photostabilizing effects. Only a berberine- Bt complex is effective, as practically no photostabilization was evident by just mixing the two components. The UV-sensitive SlNPV and B. bassiana spores were considerably photostabilzed by berberine. The role of the cationic nature of the berberine molecule and the importance of its absorbance spectrum in photostabilization of biocontrol agents are discussed.     

Larger Grain Borer in Africa; A History of Efforts to Limit its Impact

The story of Prostephanus truncatus in Africa is described from its original outbreak in Tanzania in the late 1970s to the present day. Information is given on the differing control methods put in place by infested countries and how co-ordination of local programmes and inputs from technical assistance agencies was approached by an agencies. The influence of changes in development thinking on the management of storage pests is considered. The current status of P. truncatus is addressed, inlcuding its impact on the international maize trade, particularly that provided for famine relief. The introduction of Teretrius nigrescens as a biological control agent is described. We also provide some milestones in efforts to manage the pest, describe the effectiveness of pest management in terms of cost benefit and suggest some new avenues that may lead to a sustainable reductioning in P. truncatus in Africa.