Control Efficiency of Four Biological Pesticides against Pieris rapae Linne and Their Impacts on Yield and Benefit of Chinese Cabbage

[ Objective] The paper was to screen out ideal biological pesticides, in order to provide guidance for pollution-free control against Pieris rapae Linne. [Method] Taking Chinese cabbage variety Taiyuan Erqing as the test material, the field control efficiencies of four pesticides including PrGV · Bt WP 1 000 times dilution, NPV · Bt SC 750 times dilution, 0.5% azadirachtin EC 750 times dilution, and 0.3% matrine AS 500 times dilution against P. rapae were studied, and their impacts on yield and planting benefits of Chinese cabbage were also determined. Using foliar spray method, the pesticides were sprayed for the first time when the second or third instar larvae of P. rapae first occurred in fields, and sprayed for the second time with the interval of 15 d. The fields sprayed with beta-cypermethrin EC （organic chemical pesticide） and water were set as control. [ Result] NPV · Bt SC 750 times dilution had the best effect after spraying for two times： the control efficiency against P. rapae at 15 d after spraying was 90.11% ; the damage rate of Chinese cabbage was only 0.21%, while the commodity rate reached 100% ; compared with chemical pesticide spraying, the commodity yield （177 262.5 kg/hm2 ） and the income after deducting spraying cost （48 858.5 yuan/hm2 ） were increased by 14.7% and 13.75%, respectively. [ Conclusion] Although biological pesticides are more expensive, they have long persistence and good control effect, resulting in green and safe Chinese cabbage with high commodity rate and yield, and higher eventual economic benefit after deducting spraying cost.

上海地区蔬菜害虫研究 Ⅳ菜粉蝶Pieris rapae L.生物学特性观察

菜粉蝶每年发生多代,以往资料上海地区均以每年发生5～6代为依据。为模清实际发生世代数和田间虫口消长、为害情况,自1980～1982年经过田间观察圃内定点、定期系统调查和养虫笼内饲养的结果如下:

Developmental Response of <i>Pieris brassicae</i>(L.) (Lepidoptera: Pieridae) on Different Cauliflower Cultivars under Laboratory Conditions

Cauliflower is popular vegetable in Pakistan and it is severely attacked by Pieris brassicae (L). There are different cauliflower cultivars available in this area. The aim of this study was to determine the developmental response of Pieris brassicae on ten cauliflower cultivars. An experiment was conducted during 2012-13 at the Entomology section of the Agriculture Research Institute Tarnab Peshawar under laboratory conditions of 20&degC ± 2&degC, 50% ± 5% RH and 12:12h photoperiod. Pieris brassicae eggs were collected from a cauliflower field ARI Tarnab and the larvae placed after hatching on fresh leaves often cauliflower cultivars. The results showed that the larval development of P. brassicae was short (35 days), longer larval length (32.41 mm), larval mortality was low (6.6%) and pupal weight was high (0.50 g) on Clima cultivar. On the other hand, a longer larval developmental period (37 days), higher larval mortality (86.66%), shorter larval length (24.55 mm) and lower pupal weight (0.42 g) were recorded on cultivar AX-2034.

A Method for Preparing Insecticide of Cabbage Worm Pieris rapae and Its Control Effects

[Objective]The paper was to study the field control effects of different formulae of plant extracts against cabbage worm Pieris rapae,and to provide a basis for promotion and application of insecticides in production.[Method]With the leaching solution of radix anemones rivularis,Artemisia carvifolia and Nicotiana rustica,and lime and salt water as the materials,field efficacy test was conducted for consecutive two years.[Method]When the mass ratios of radix anemones rivularis mother liquid,A.carvifolia mother liquid,N.rustica mother liquid,lime water and salt water were 4:2:2:1:1:6,4:2:0:1:1:8,4:0:2:1:1:8 and 0:4:2:1:1:8,the control effects were 82.7%-89.8%,38.3%-42.0%,41.0%-45.4%and 52.9%-56.4%,respectively.The insecticide showed the best control effect when the mass ratio of radix anemones rivularis mother liquid,A.carvifolia mother liquid,N.rustica mother liquid,lime water and salt water was 4:2:2:1:1:6.[Conclusion]The optimal formula has good control effect against P.rapae,and the technology has obtained national invention patent.

Cloning and Sequence Analysis of lef-3 Gene from Pieris rapae Granulovirus

To better understand the origination and evolution of lef-3 gene from baculovirus genome and determine the relationships between various viruses at molecular level, late expression factor 3 gene （lef-3） fragments of Pieris rapae granulovirus were obtained through conventional PCR method and sequenced after cloned into T-vector. Then, bioinformatics analysis on lef-3 gene and its encoding sequences were conducted by using bid-softs. Four mutations were appeared in the ORF of cloned lef-3 gene, which did not alter the characteristics of amino acids. It was inferred that PiraGV LEF-3 protein contained 399 amino acids, the molecular weight of which was 3.99 kD. Prediction of the LEF-3 advanced structure and homology comparison between other LEF-3 from various baculoviruses showed that the lef-3 gene might encode the single-stranded DNA-binding protein. The result of BLAST revealed that the lef-3 gene only existed in Lepidoptera host for the baculovirus genome, and the evolution analysis illustrated that lef-3 gene could be divided into 3 groups including one granulovirus （GV） group and 2 nucleopolyhedrovirus （NPV） groups. The selection pressure analysis of GV lef-3 gene coding region showed that the majority of lef-3 genes performed negative selection, while the Ka/Ks differed from different lef-3 gene, to some extent, which also performed positive selection. The origination analysis revealed that lef-3 gene of baculovirus might derive from bacteria. The lef-3 gene of PiraGV was cloned successfully and the possible patterns of origination and evolution were speculated through bioinformatics analysis.

Field Efficacy Trials of Different Pesticides against Pieris rapae and Plutella xylostella

Field efficacy trials of different pesticides against Pieris rapae and Plutella xylostella showed that seven pesticides had certain control effects against P.rapae and P. xylostella. 240 g/L Chlorfenapyr SC had the most ideal control effect,with quick effect and long persistence,and the control effects against P. rapae and P. xylostella were 91. 96% and 95. 73% after application for 7 d,respectively. 25% Thiamethoxam WDG 3 000 times dilution had the poorest control effect,and quick effect and persistence were not ideal; the control effects against P. rapae and P. xylostella were 49. 21% and 57. 20% after application for 7 d,respectively. The remaining pesticides had good control effect against both P. rapae and P. xylostella,with certain persistence. Slight injury such as yellowing tender leaves appeared in the area treated with 50% thiocyclam SP,although the injury was reversible,it was still not recommended to use; no other treatments had adverse effects on growth of cabbage.

Molecular characterization of three Hsp90 from Pieris and expression patterns in response to cold and thermal stress in summer and winter diapause of Pieris melete

Heat shock proteins （Hsps） have been linked to stresses and winter diapause in insects, but whether they are components of summer diapause is still unknown. In this study, complementary DNAs of lisp90 from Pieris melete, Pieris rapae and Pieris canidia named PmHsp90, PrHsp90 and PcHsp90, respectively, were cloned and sequenced. The deduced amino acid sequence consisted of 718 amino acid residues with a putative molecular mass of 82.6, 82.6 and 82.7 kDa, respectively. The amino acid sequences contained all of the five conserved signature motifs in the Hsp90 family and a bHLH protein folding activity region. The differential expression pattern of PmHsp90 in response to summer diapause and winter diapause, which are related to heat/cold stress, was investigated. Cold stress induced Hsp90 up-regulation in summer and winter diapause pupae, but not in non-diapause individuals. Heat shock up-regulated PmHsp90 gradually with an increase in temperature in summer diapause, and PmHsp90 was rapidly up-regulated in winter diapause. After 30 min heat shock at 39℃, substantial up-regulation of PmHsp90 transcript levels were observed both in summer and winter diapause. However, in non-diapause a relatively stable expression was found under different durations of 39℃ heat shock. Compared to the optimal treatment of 18℃ for diapause development, a high temperature acclimation of 31 ℃ induced PmHsp90 up-regulation in summer diapause, whereas a low temperature acclimation of 4℃ induced up-regulation in winter diapause. The current results indicate that Hsp90 may play an important role in response to heat/cold stress both in summer and winter diapause.

Enzymatic properties of phenoloxidase from Pieris rapae （Lepidoptera） larvae

The kinetic parameters of partially purified phenoloxidase （PO, EC. 1.14.18.1） from the 5th instar larvae of Pieris rapae （Lepidoptera） were determined, using L-3, 4- dihydroxyphenylalanine （L-DOPA） as substrate. The optimal pH and temperature of the enzyme for the oxidation of L-DOPA were determined to be at pH 7.0 and at 42℃, respectively. The enzyme was stable between pH 6.5 and 7.4 and at temperatures lower than 37℃. At pH 6.8 and 37℃, the Michaelis constant （Kin） and maximal velocity （V） of the enzyme for the oxidation of L-DOPA were determined to be 0.80 mmol/L and 1.84 μmol/ L/min, respectively. Tetra-hexylresorcinol and 4-dodecylresorcinol effectively inhibited activity of phenoloxidase and this inhibition was reversible and competitive, with the IC50 of 1.50 and 1.12 μmol/L, respectively. The inhibition constants were estimated to be 0.50 and 0.47μmol/L, respectively.

Parasitism of Pieris rapae （Lepidoptera： Pieridae） by the endoparasitic wasp Pteromalus puparum （Hymenoptera： Pteromalidae）： Effects of parasitism on differential hemocyte counts, micro- and ultra-structures of host hemocytes

Parasitism by the endoparasitic wasp Pteromalus puparum （Hymenoptera： Pteromalidae） by using only its associated venom, can suppress the immunal responses of Pieris rapae （Lepidoptera： Pieridae）. However, up to now, current knowledge of the mech- anisms has been limited. The response of host hemocytes to parasitism was investigated using a combination of light and transmission electron microscopy （TEM）. Five hemocyte types, prohemocytes （PRs）, granulocytes （GRs）, plasmatocytes （PLs）, oenocytoids （OEs） and coagulocytes （COs）, were observed and characterized from both unparasitized and parasitized Pieris rapae pupae. Light microscopy showed that both GRs and PLs became more round and spread abnormally after parasitism, whereas the shape of other types of hemocytes remained unaffected. In addition, the size of PRs and PLs became larger while OEs became smaller. The proportion of PRs significantly increased after parasitism and that of PLs decreased by 43.9%, but there was no significant increase of GRs and OEs. TEM showed that all types of hemocytes except COs were damaged to various degrees after parasitism, especially resulting in electron opaque cytoplasm and nucleus, fewer cell organelles of rough endoplasmic reticulum, mitochondria and vesicles. Our results indicate that parasitism by P. puparum affects differential hemocyte counts and structures of host hemocytes, particularly for GRs and PLs, which may be the main cause of the parasitoid suppressing host cellular immune responses.

cDNA of an arylphorin-type storage protein from Pieris rapae with parasitism inducible expression by the endoparasitoid wasp Pteromalus puparum

This report presents the cDNA cloning of a storage protein, PraAry, from Pieris rapae and investigates its expression regulated by parasitism of an endoparasitoid wasp Pteromalus puparum. The full-length eDNA of PraAry is 2 270 nucleotides and contains a 2 121 nucleotide open reading frame encoding 707 amino acids with calculated molecular weights of approximately 83 kDa. Analysis of the primary protein sequence revealed that it possesses a signal peptide of 16 amino acids at the N-terminus and contains two highly conserved storage protein signature motifs. According to both phylogenetic analysis and the criteria for amino acid composition, PraAry belongs to the subfamily of arylphorin-type storage protein （1.42% methionine and 18.82% aromatic amino acids）. Reverse transcription- polymerase chain reaction analysis indicated that the transcriptional level of PraAry mRNA in P. rapae pupae fat body is inducible in response to parasitism by P. puparum.

Inhibitory Kinetics of p-Substituted Benzaldehydes on Polyphenol Oxidase from the Fifth Instar of Pieris Rapae L.

Polyphenol oxidase （PPO） is the enzyme responsible for enzymatic browning during the growth of insects. It is also involved in defense reactions and is related with immunities in insects. PPO a metalloenzyme oxidase, catalyzes the oxidation of o-diphenol to o-quinone. The present paper describes the effects of benzaldehyde and its p-substituted derivatives on the activity of PPO from the fifth instar of Pieris rapae L. PPO from the fifth instar of Pieris rapae L. was purified using ammonium sulfate fractionation and chromatography on Sephadex G-100. The enzyme kinetics was characterized using L-3,4-dihydroxyphenylalanine （L-DOPA） as substrate. The results show that benzaldehyde, phydroxybenzaldehyde, p-chlorobenzaldehyde, and p-cyanobenzaldehyde can inhibit the PPO activity for the oxidation of L-DOPA. The inhibitor concentration leading to 50% activity lost, IC50, was estimated to be 5.90, 5.62, 2.83, and 2.91 mmol/L for the four tested inhibitors, respectively. Kinetic analyses show that the inhibitory effects of these compounds are reversible. Benzaldehyde, phydroxybenzaldehyde, and p-chlorobenzaldehyde are noncompetitive inhibitors while p-cyanobenzaldehyde is a mixed-type inhibitor. The inhibition constants were determined for all four inhibitors. p-chlorobenzaldehyde and p-cyanobenzaldehyde were more potent inhibitors than the other compounds. These results provide a basis for developing PPO inhibition-based pesticides.

Proteome changes in the plasma of Pieris rapae parasitized by the endoparasitoid wasp Pteromalus puparum

Parasitism by the endoparasitoid wasp Pteromalus puparum causes alterations in the plasma proteins of Pieris rapae. Analysis of plasma proteins using a proteomic approach showed that seven proteins were differentially expressed in the host pupae after 24-h parasitism. They were masquerade-like serine proteinase homolog (MSPH), enolase (Eno), bilin-binding protein (BBP), imaginal disc growth factor (IDGF), ornithine decarboxylase (ODC), cellular retinoic acid binding protein (CRABP), and one unknown function protein. The full length cDNA sequences of MSPH, Eno, and BBP were successfully cloned using rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis indicated that the transcript levels of MSPH and BBP in the fat bodies of host pupae were inducible in response to the parasitism and their variations were consistent with translational changes of these genes after parasitism, while the transcript levels of Eno and IDGF were not affected by parasitism. This study will contribute to the better understanding of the molecular bases of parasitoid-induced host alterations associated with innate immune responses, detoxification, and energy metabolism.

Mobility affects copulation and oviposition dynamics in Pieris brassicae in seminatural cages

When, how often and for how long organisms mate can have strong consequences for individual fitness and are crucial aspects of evolutionary ecology. Such determinants are likely to be of even greater importance in monandrous species and species with short adult life stages. Previous work suggests that mobility, a key dispersal? related trait, may affect the dynamics of copulations, but few studies have investigated the impact of individual mobility on mating latency, copulation duration and oviposition latency simultaneously. In this paper, we monitored the copulation dynamics of 40 males and 40 females, as well as the oviposition dynamics of the females of the Large White butterfly Pieris brassicae, a facultative long-distance disperser butterfly. Individuals from a breeding were selected to create a uniform distribution of mobility and we recorded the timing, number and duration of all copulations in a semiexperimental system. We showed that mobility, measured as the time spent in flight under stressful conditions (a proxy of dispersal tendency), correlates with all aspects of copulation dynamics: mobile males and females mated earlier and for shorter periods than less mobile individuals. In turn, late mating females increased the time between copulation and oviposition. These results feed the previously described mobility syndrome of R brassicae, involving morphological and physiological characters, with life-history traits. We suggest that the reduction of mating latency and copulation duration has an adaptive value in dispersing individuals, as their life expectancy might be shorter than that of sedentary individuals.

番茄茎叶提取物对菜粉蝶的生物活性研究

以乙醇、乙醚、苯、石油醚和丙酮为溶剂对番茄(Lycopersicon esculentum Mill.)茎叶进行浸提,测试各溶剂提取物对菜粉蝶5龄幼虫的触杀、拒食和胃毒活性。结果表明,各溶剂提取物对菜粉蝶(Pieris rapae L.)主要表现为拒食活性和胃毒活性,其中乙醇提取物的拒食和胃毒活性最强。

青翅蚁形隐翅虫对菜粉蝶卵的捕食作用

研究了不同猎物虫态、不同猎物密度、不同捕食者密度、不同温度下青翅蚁形隐翅虫(Paederus fusci-pesCurtis)对菜粉蝶(Pieris rapaeLinnaeus)卵捕食作用的影响。结果表明:1)青翅蚁形隐翅虫对菜粉蝶卵的捕食能力显著高于其低龄幼虫;2)不同猎物密度下的捕食功能反应符合HollingⅡ型方程,其方程为Na=1.031 8N/(1+0.016 9N),寻找效应则随着猎物密度的增加而减少;3)青翅蚁形隐翅虫干扰反应模型为E=0.595 3P-0.690 2,随着捕食者密度的增大,平均捕食量逐渐减少;4)不同温度下的捕食量以25~30℃时最高。

一株苏云金芽孢杆菌防治菜粉蝶幼虫的研究

对引进的一株对鳞翅目害虫具有毒杀作用的生防菌株,苏云金杆菌库尔斯泰克变种(BacillusthurengiensisBerlinervar.kurstaki)A1.272,通过SDS-PAGE确定其伴孢晶体分子量为130kD,确定其对菜粉蝶(Pierisrapae)4-5龄幼虫的致死中浓度LC50=2.3×106cfuml。对分别不同浓度的菌悬液和伴孢晶体悬液进行了温室防效试验,和田间小区试验。结果表明施药后2d100倍稀释的菌悬液对菜粉蝶幼虫的温室防效可达90%以上,施药后5d,Bt菌悬液50倍和100倍稀释液防效达到100%。田间防效也可达到90%以上。

糠醛苯甲酰腙的合成及生物活性研究

以糠醛、苯甲酸甲酯、水合肼为原料,合成了糠醛苯甲酰腙。经元素分析、红外光谱对目标化合物进行了结构表征。研究了糠醛苯甲酰腙对菜粉蝶(Pieris rapae L.)的生物活性,结果表明,糠醛苯甲酰腙对菜粉蝶具有较强的触杀活性和胃毒活性,而拒食作用较弱。

运用模糊数学预测甘蓝生长期菜青虫的发生量

研究了降雨量、气温和风速与甘蓝生长期菜青虫(Pieris rapae)发生量之间的关系,运用模糊数学预测甘蓝生长期田间菜青虫的发生量。经检验,2014年预报与实测相符合,2003~2013年预测符合率达91%。

Purification, characterization and evaluation of insecticidal activity of trypsin inhibitor from Albizia lebbeck seeds

A Bowman-Birk inhibitor with activity against gut proteases of Helicoverpa armigera was extracted in 0.I M sodium phosphate buffer from defatted seed flour of Albizia lebbeck. It was purified to 29.62 folds with 51.43% recovery using ammonium sulfate precipitation, gel filtration chromatography on Sephadex G-100 column and ion ex- change chromatography on DEAE-Sephadex As0. The purified protein had a molecular weight of 12,303 daltons as determined by SDS-PAGE. It was found to be heat stable up to 60~C and had two pH optima of 7.5 and 9.0. The inhibitor exhibited non-competitive pattern of inhibition with a low Ki value of 0.2 ~tM. The inhibitoi- was found to be susceptible to varying concentrations of reducing agents like DTT and 2- mercaptoethanol, thereby indicating the role of disulphide bridges in maintaining its three dimensional structure and stability. The purified inhibitor caused mortality and suppressed larval growth ofPieris brassi- cae larvae. It was also found to be effective against gut trypsin extracted from Spodoptera littoralis. The sequence of the genes encoding for such inhibitors can be determined and the genes expressing protease inhibitors can be used in vegetable crops to confer resistance against insect pests and other plant pathogens.