豆大蓟马对12种杀虫剂的敏感性测定

室内采用叶管药膜法测定12种杀虫剂对豆大蓟马(Megalurothrips usitatus)成虫和若虫的毒力。结果表明,供试药剂中除杀虫环和拟除虫菊酯类杀虫剂对豆大蓟马各虫态的毒力较低外,其他药剂均对豆大蓟马具有较高的毒力。毒力测定分析结果表明,供试药剂对豆大蓟马若虫的毒力不同程度上均大于成虫,且对成虫的毒力又以对雄成虫的毒力大于雌成虫。综合来看,乙基多杀菌素、甲维盐、噻虫胺、啶虫脒、阿维菌素和噻虫啉等药剂对豆大蓟马毒力较大,可推荐作为田间防治药剂。     

温度对豆卷叶螟Lamprosema indicata(Fabricius)生长发育的影响

为探明温度对大豆主要害虫豆卷叶螟生长发育的影响,以大豆叶片为主要寄主饲料,研究了19,22,25,28,31℃共5个恒温处理对豆卷叶螟不同虫态的发育历期、发育速率和存活率的影响。结果表明:在19~31℃范围内,随着温度升高,各虫态的发育历期均缩短,发育速率与温度呈显著正相关。豆卷叶螟卵、幼虫、蛹、成虫和世代发育起点温度分别为9.89,10.90,11.18,19.57和13.49℃,有效积温依次为75.16,193.39,98.59,48.34和431.04 d·℃。豆卷叶螟种群存活曲线属于DeveyⅢ型,表现为卵期的高死亡率。这些结果为豆卷叶螟的预测预报提供了基础参考数据。     

几种杀虫剂对豆大蓟马的毒力测定及复配增效作用

豆大蓟马是海南冬种豇豆的重要害虫,严重影响豇豆产品质量和商品价值。本文采用离心管药膜法,测定了毒死蜱、阿维菌素、高效氯氰菊酯、甲氨基阿维菌素苯甲酸盐、吡虫啉和啶虫脒等6种杀虫剂对豆大蓟马的毒力,并测定了甲氨基阿维菌素苯甲酸盐与其它5种杀虫剂复配的增效作用及最佳配比。结果表明:供试药剂对豆大蓟马毒力(LC50)大小顺序为:甲维盐(0.000 5 g/L)阿维菌素(0.056 1 g/L)毒死蜱(0.125 3 g/L)高效氯氰菊酯(0.165 4 g/L)啶虫脒(0.228 3 g/L)吡虫啉(19.803 5 g/L);以甲氨基阿维菌素苯甲酸盐与毒死蜱复配的共毒系数为776;甲氨基阿维菌素苯甲酸盐与毒死蜱配比为1∶9时的共毒系数为1 733。本研究为开发豆大蓟马防治药剂和田间化学防治提供了基本资料。     

普通大蓟马产卵选择性初探

采用叶盘法对普通大蓟马的产卵选择性进行研究。二元选择性实验结果表明,该虫产卵时对豇豆嫩叶正面和反面的选择性没有差异,但喜欢在菜豆和花生嫩叶的正面产卵。以豇豆嫩叶反面、菜豆嫩叶正面和花生嫩叶正面供普通大蓟马产卵时,产卵选择性顺序为豇豆>菜豆=花生,近85%的卵产在豇豆嫩叶上。寄主植物叶表茸毛密度对普通大蓟马的产卵选择性有一定的影响。     

普通大蓟马在3种豆类作物上的实验种群生命表研究

普通大蓟马[Megalurothrips usitatus（Bagnall）]是各种豆类作物上的主要害虫之一。为了探求寄主植物对该虫的影响,在（26±1）℃,RH（60±5）％和光照L/D=14 h/10 h条件下,组建了普通大蓟马在豇豆[Vigna unguiculata（L.） Walp.]、菜豆（Phaseolus vulgaris L.）和花生（Arachis hypogaea L.）上的实验种群生命表。结果表明：净增殖率和周限增长率以豇豆上普通大蓟马种群最高,其值分别为12.68和1.150 5;在菜豆上这2个参数最低,分别为3.10和1.069 8。普通大蓟马的平均世代周期在豇豆上最长（19.22 d）,花生次之（18.76 d）,菜豆最短（17.20 d）。豇豆、菜豆和花生上普通大蓟马种群的内禀增长率分别为0.140 2、0.067 5和0.113 5。菜豆上普通大蓟马种群加倍时间为9.94 d,比豇豆和花生上的种群加倍时间分别长1.01倍和0.63倍。由此可见,3种豆类作物中,豇豆是普通大蓟马最适宜的寄主植物,而菜豆的适合度最低。     

桑小头木虱Paurocephala sauteri Enderlein生物学特性研究

近年在海南各植桑区均发现桑小头木虱（Paurocephala sauteri Enderlein）严重为害,桑园被害株率达100%。在我国,该木虱仅记录于台湾省,为我国大陆新入侵害虫。本研究在实验室条件下[(27±1)℃、RH (70±5)%、12L∶12D],采用45日龄桑树扦插苗和离体叶片饲养,对桑小头木虱的发育与繁殖特性及各虫态的形态特征开展观察。结果表明,桑小头木虱生活史包括卵、1~5龄若虫和成虫期。各龄期主要形态特征为：卵呈水滴形,带短的卵柄,端部具细长的端丝,初产时乳白色,待孵化时可见淡红色眼点;1龄若虫头、胸部乳白色,复眼和腹部橘黄色,无翅芽;2~5龄若虫黄绿色,随着龄期增加,体长增加,翅芽随之变化。2龄翅芽出现,稍突起;3龄翅芽较小,呈三角形;4龄和5龄翅芽长椭圆形,其中5龄超过腹部第1节。各龄若虫和初羽化成虫均可分泌白色球形蜡质。雌雄成虫以两性生殖方式繁殖后代,羽化3 d后体色由黄绿色逐渐变为黄褐色并开始交配,交配时间为0.5~3 h,结束交配18~21 h后开始产卵,产卵量为20~42粒。卵单个散产于叶片背面叶脉处,偶尔可见产于新抽嫩叶正面边缘,5~7 d后孵化,孵化率为98.19%,雌性百分率为70.44%。若虫期12~18 d,完成一代的时间为18~24 d。本研究将为桑小头木虱的准确识别与监测,以及防控策略的制定提供前提条件和理论依据。     

茶卷叶蛾发育起点温度与有效积温的研究

本文研究了茶卷叶蛾在不同温度下的发育历期、发育起点温度和有效积温,结果表明,在18～30℃范围内,茶卷叶蛾的发育历期随温度的升高而缩短,蛹、幼虫、卵的发育速率与温度呈极显著的正相关(P<0.01),茶卷叶蛾卵、幼虫、蛹的发育起点温度分别为9.48℃、6.13℃、7.95℃,有效积温分别为102.86日·度、492.32日·度、138.67日·度.     

温度对大豆蚜生长发育和繁殖的影响

在5种不同温度条件下研究了大豆蚜有效积温、发育起点温度、繁殖力等生物学特性。结果表明,大豆蚜各虫态的发育历期随着温度的升高而显著缩短,若虫发育明显受到低温抑制。10℃下发育历期最长为22.08d,15、20、25、30℃分别为14.04,10.67,9.92和6.71d。相对低温同时也抑制大豆蚜繁殖能力,10℃下平均产仔量和日产仔量均为最小,分别为15.73头和1.23头/d。 20和25℃下大豆蚜繁殖力较强,平均每天产仔量分别为27.87和27.36头。通过直线回归分析,得出大豆蚜1龄若虫发育起点温度最高为2.0268℃,有效积温为38.4216日度,大豆蚜世代发育的起点温度为1.6587℃,有效积温为202.7879日度。     

剑麻H.11648开花生物学特性研究

通过对剑麻H.11648的开花过程、花器形态发育规律及花粉粒形态的观测来研究其开花的生物学特性,并为龙舌兰科植物的植物学和系统繁育学研究提供理论依据。     

苦丁茶生物学特性研究

研究了苦丁茶的生物学特性,在杭州气候条件下,苦丁茶100％顶芽萌动期在4月20日～4月25日,5月30日后逐渐形成驻芽,在自然生长条件下,每年只长一轮新梢,从100％顶芽萌动到驻芽形成期间,新梢生长前速后缓,新稍长度的倒数(Y)与时间天数的倒数(X)呈极显著的正相关,顶芽的萌动期与生长速度主要受气温和日照条件的影响。100％顶芽萌动后20～25天为苦丁茶适采期。从其叶结构的切片观察,苦丁茶叶肉组织中未发现石细胞和单酸钙结晶等成份,海棉组织具有较大空腔。与茶叶(Tea)的结构有明显的不同。     

茶尺蠖发育历期的温度效应

观察研究结果表明,茶尺蠖(Ectropis Obliqua Prout)各虫态发育历期随着温度的上升而缩短,发育速率则随着温度的升高而加快,并探明了各虫态历期与期内均温之间的曲线关系模型。同时,用加权法和回归直线法分别计算了各虫态的发育起点温度和有效积温常数,结果表明两种方法计算的数据间差异不显著,表明两方法均可采用。验证结果表明,利用各虫态的发育起点和有效积温,推算茶尺蠖的发生代数及各虫态的发生期,与实际发生情况基本吻合。     

Resistance of Oryza spp. to thrips, Stenchaetothrips biformis (Bagnall) (Thysanoptera: Thripidae)

A method to evaluate rice cultivars for resistance to Stenchaetothrips biformis (Bagnall) in the greenhouse was developed. Eleven traditional cultivars of Oryza sativa and 12 wild rices were selected for resistance. Studies on the mechanisms of resistance indicated that resistant cultivars were non-preferred for feeding and oviposition. Larval survival was lower and adult life shorter on resistant compared with susceptible cultivars. Resistant cultivars had an adverse effect on fecundity and oviposition rate which resulted in a low population growth. Plant injury on susceptible cultivars reduced plant weight and height.     

木槿曼粉蚧生物学特征的初步研究

木槿曼粉蚧是我国南方大豆上的一种新害虫。为了明确其各个虫态识别特征及其在大豆上的生活史及主要生物学特征,在室内恒温条件下[温度(25±1)℃,相对湿度70%±5%,光周期为L∶D=12∶12],观察描述了雌雄不同虫态的形态特征及其个体生活史、各虫态主要习性和危害特征等。结果表明:木槿曼粉蚧具有典型的性二型现象。雌虫包括卵、1龄若虫、2龄若虫、3龄若虫和雌成虫。雄虫包括卵、1龄若虫、2龄若虫、预蛹、蛹和雄成虫。若虫期各龄期体长、体宽、触角节数等形态结构具有明显差异,可作为区分龄期的依据。在25℃条件下,以大豆为寄主的雌性个体若虫期为33.34 d,成虫期19.03 d,平均产卵269.6粒;雄性个体若虫期24.60 d,预蛹期2.27 d、蛹期3.33 d,成虫寿命仅3.83 d。     

An Evaluation of Frankliniella occidentalis (Thysanoptera: Thripidae) and Frankliniella intonsa (Thysanoptera: Thripidae) Performance on Different Plant Leaves Based on Life History Characteristics

To compare the performance of Frankliniella occidentalis (Pergande) and native Frankliniella intonsa (Trybom) on cucumber and tomato leaves in laboratory, life history characters were investigated, and life tables were constructed using the method of age-stage, two-sex table life. Compared with tomato leaf, there were shorter total preoviposition period (TPOP), higher fecundity, longer female longevity, and higher intrinsic rate of increase (r) of both F. occidentalis and F. intonsa on cucumber leaf. Meanwhile, on cucumber leaf, the shorter TPOP, higher fecundity, longer female longevity, and higher value of r were found on population of F. intonsa but on tomato leaf which were found on population of F. occidentalis. From above, cucumber leaf was the preference to population development of both F. occidentalis and F. intonsa compared with tomato leaf. Nevertheless, on cucumber leaf, population of F. intonsa would grow faster than that of F. occidentalis, which was the opposite on tomato leaf. As to the population development in fields, much more factors would be taken into account, such as pollen, insecticide resistance, and effects of natural enemies etc.     

海南异歧蔗蝗生物学习性及4种农药对其毒力测定

异歧蔗蝗Hieroglyphus tonkinensis I.Bol是竹子、甘蔗、水稻及其他禾本科作物的重要害虫,其自2006年首次在海南爆发成灾以来,危害逐年加重。为深入了解异歧蔗蝗在海南的发生与危害,寻找适宜且经济有效的测报及防控措施,近年来对其生物学习性进行了系统观察和研究,并对其有效的防治措施做了探究。结果表明:异歧蔗蝗在海南一年发生1代,为害期约150 d。以卵在土中越冬,若虫4月中旬孵化,根据气温高低可能提前或推后10 d左右,成虫羽化高峰期在6月上中旬,9月上旬陆续死亡。温度与异岐蔗蝗若虫和成虫生长发育关系的研究表明,28℃是异岐蔗蝗生长发育的最适温度,成虫产卵量最大,寿命最长。4种药剂对其毒力测定表明,锐劲特和阿维菌素具有较好的毒杀效果。防治异歧蔗蝗要以3龄前若虫为主,以阿维菌素烟雾剂防治竹林及蔗田异歧蔗蝗具有较好的效果。     

Field evaluation of selected botanicals and commercial synthetic insecticides against Thrips tabaci Lindeman (Thysanoptera: Thripidae) populations and predators in onion field plots

The effectiveness of three botanical insecticides (neem, datura and bitter apple), and three new chemistry synthetic insecticides (acephate, spirotetramat and spinetoram) against onion thrips (Thrips tabaci) was evaluated in experimental field plots at university of Sargodha, Pakistan. The influence of these botanical and chemical insecticides on natural predators and crop yield was simultaneously investigated. All the botanicals and chemical insecticides tested caused significant reductions (45–70%) in thrips populations; the botanicals gave more than 60% control of thrips, while among chemical insecticides, acephate was found to be the most effective followed by spirotetramat and spinetoram, respectively, and these insecticides gave better control than the botanicals. The adverse effects of the botanicals on predator populations were negligible compared to the chemical insecticides. All chemical treatments resulted in a significantly higher yield compared to the untreated control. The botanicals and chemical insecticides became less effective by 7 days after treatment. Therefore, it is recommended that treatment with botanical or chemical insecticides should be repeated weekly consecutively at least three times to keep thrips populations below economic injury levels until crop maturity.     

Natural Enemies of the Frankliniella Complex Species (Thysanoptera: Thripidae) in Ataulfo Mango Agroecosystems

A field survey was conducted in Ataulfo mango (Mangifera indica L.) orchards in Chiapas, Mexico, with the objective of determining the natural enemies of the Frankliniella complex species (Thysanoptera: Thripidae). Seven species of this genus feed and reproduce in large numbers during the mango flowering. Two representative orchards were selected: the orchard “Tres A” characterized by an intensive use of agrochemicals directed against thrips, and the orchard “La Escondida” that did not spray insecticides. During mango flowering, five inflorescences were randomly collected every 5 d in both orchards, for a total of 18 sampling dates. Results revealed the presence of 18 species of arthropods that were found predating on Frankliniella. There were 11 species in the families Aeolothripidae, Phlaeothripidae, Formicidae, Anthocoridae and Chrysopidae; and seven species of spiders in the families Araneidae, Tetragnathidae, and Uloboridae. Over 88% of predators were anthocorids, including, Paratriphleps sp. (Champion), Orius insidiosus (Say), Orius tristicolor (White), and O. perpunctatus (Reuter). The orchard that did not spray insecticides had a significantly higher number of predators suggesting a negative effect of the insecticides on the abundance of these organisms.     

Development,Survival, and Reproduction of Orius insidiosus (Hemiptera: Anthocoridae) Reared on Frankliniella invasor (Thysanoptera: Thripidae)

The minute pirate bug Orius insidiosus (Say) is an important predator in mango agroecosystems. It attacks several species of thrips, particularly Frankliniella invasor Sakimura, which is considered a species of economic importance in mango. We investigated the effect of six diets on the development, survival, and reproduction of O. insidiosus: 1) first instars of F. invasor, 2) second instars, 3) adults, 4) pollen, 5) pollen plus thrips larvae, and 6) water. Individuals fed on thrips larvae, with or without pollen, completed their immature development significantly faster. Nymphs of O. insidiosus were able to complete their development feeding on pollen only, while individuals that received water as a diet were unable to reach the adult stage. The highest intrinsic growth rate was obtained when O. insidiosus were fed on pollen plus thrips larvae, and the lowest when individuals were fed on thrips adults. Our studies show that a diet of pollen plus F. invasor larvae is optimal for O. insidiosus development and population growth.