A Fixed-Precision Sequential Sampling Plan for the Potato Tuberworm Moth, <Emphasis Type="Italic">Phthorimaea operculella</Emphasis> Zeller (Lepidoptera: Gelechidae), on Potato Cultivars

Phthorimaea operculella Zeller is an important pest of potato in Iran. Spatial distribution and fixed-precision sequential sampling for population estimation of the pest on two potato cultivars, Arinda^® and Sante^®, were studied in two separate potato fields during two growing seasons (2013–2014 and 2014–2015). Spatial distribution was investigated by Taylor’s power law and Iwao’s patchiness. Results showed that the spatial distribution of eggs and larvae was random. In contrast to Iwao’s patchiness, Taylor’s power law provided a highly significant relationship between variance and mean density. Therefore, fixed-precision sequential sampling plan was developed by Green’s model at two precision levels of 0.25 and 0.1. The optimum sample size on Arinda^® and Sante^® cultivars at precision level of 0.25 ranged from 151 to 813 and 149 to 802 leaves, respectively. At 0.1 precision level, the sample sizes varied from 5083 to 1054 and 5100 to 1050 leaves for Arinda^® and Sante^® cultivars, respectively. Therefore, the optimum sample sizes for the cultivars, with different resistance levels, were not significantly different. According to the calculated stop lines, the sampling must be continued until cumulative number of eggs + larvae reached to 15–16 or 96–101 individuals at precision levels of 0.25 or 0.1, respectively. The performance of the sampling plan was validated by resampling analysis using resampling for validation of sampling plans software. The sampling plant provided in this study can be used to obtain a rapid estimate of the pest density with minimal effort.     

杨树上云斑天牛种群的空间格局及抽样技术

云斑天牛Batocera horsfieldi是我国南方杨树的重要蛀干害虫, 研究云斑天牛种群的空间格局和抽样技术, 可为该虫的危害调查与防治提供理论依据。应用Taylor的幂法则、Iwao m*-m回归分析法及6个聚集指标, 对云斑天牛种群的卵、幼虫、蛹或成虫的空间分布型和抽样技术进行了研究, 并做了影响因素分析。结果表明: 云斑天牛的卵、幼虫、蛹或成虫在杨树上均呈聚集分布, 分布的基本成分是个体群, 其聚集性随密度的增加而增大。运用Iwao m*-m回归中的两个参数α和β值, 计算出了在不同精度下以刻槽、排粪孔和羽化孔为防治指标时的理论抽样数据表及序贯抽样数据表,生产中可查阅使用。     

A comparison of the larval overwintering biology of the striped stem borer, Chilo suppressalis (Lepidoptera: Crambidae), in rice and water-oat fields

It has been suggested that the striped stem borer, Chilo suppressalis (Walker), has developed distinct populations inhabiting rice Oryza sativa (Linnaeus) and water-oats Zizania latifolia (Turcz). In this study, we compared several biological traits between overwintering larvae from rice and water-oat fields during the winter of 2010. The parasitism rate was significantly higher in the larvae that overwintered in the rice field than in those that overwintered in the water-oat field. The average body weight of overwintering larvae and the weight of 3-day-old pupae, as well as the number of eggs carried by adult females, were all significantly greater in the samples from the water-oat field. The diapause intensity, defined as the number of days required until pupation by overwintering larvae transferred to 25 °C and L:D 16:8 h, decreased progressively from January to March but decreased more rapidly in the water-oat field. Our results demonstrate differences in the overwintering biology of C. suppressalis larvae from rice and water-oat fields. These differences may contribute to the differentiation and reproductive isolation between host-plant populations in this species.     

荒漠景观下柠条豆象的空间分布及其对景观斑块格局的反应

柠条豆象Kytorhinus immixtus Motschulsky是危害柠条种子的主要种实害虫之一。本文应用了多个聚集度指标和回归分析方法,研究探讨了柠条豆象卵、幼虫在宁夏盐池、灵武、银川等荒漠景观中11个生境斑块中的空间分布型及种群对景观斑块格局的反应情况。结果表明:在11个景观样地中,柠条豆象卵和幼虫在各种生境斑块中均呈聚集型的负二项分布;卵和幼虫空间分布的Iwao回归方程分别为m*=2.23695+1.64742m(r=0.8273)和m*=2.24418+1.42084m(r=0.8889)、Taylor幂模型分别为logS2=0.51292+1.41118logm(r=0.9344)和logS2=0.59645+1.14736logm(r=0.9786),种群分布的基本成分为个体群,个体间相互吸引,有密度依赖性,聚集主要由环境因素和种间竞争引起的,聚集强度随种群密度的升高而增加。在荒漠景观下,柠条豆象的种群发生与寄主植物的种类、在斑块内的分布格局有着密切的关系,与斑块面积相关性较低(R2=0.1995)。主成分分析显示柠条林生长的土壤类型、生长方式是影响柠条豆象寄生的主要因素。     

稻茎毛眼水蝇幼虫田间分布型及抽样技术

根据14丘稻田稻茎毛眼水蝇幼虫调查资料．对其幼虫分布型进行了分析。结果表明;用I、CAm／m、Iσ四种聚集指标法测定,64．3％的田块呈随机分布．28．4%为均匀分布．7．3%为聚集分布。用Iwao平均拥挤度和Taylor幂法则测定．其田间分布型符合随机分布。用频次拟合法测验,50%的田块同时符合渡松、奈曼和负二项分布三种分布型;35．7%的田块同时符合2种分布型。根据该虫田间分布型的特点．制定了相应的序贯抽样技术。     

Role of membrane transport of water and glycerol in the freeze tolerance of the rice stem borer, Chilo suppressalis Walker (Lepidoptera: Pyralidae)

Overwintering larvae of the rice stem borer, Chilo suppressalis accumulate glycerol and are freezing tolerant to about -25 degrees C. However, non-diapausing larvae cannot accumulate glycerol and are killed by freezing. We compared the extent of tissue damage, the effects of glycerol concentration, and the transport of glycerol and water in fat body tissues from these larvae at selected freezing temperatures. Tissues from overwintering larvae, but not non-diapausing larvae, survive when frozen at -20 degrees C with 0.25 M glycerol, but the protection afforded by glycerol is offset by the water-channel inhibitor mercuric chloride. Glycerol in higher concentration (0.75 M) affords some protection even to the fat body of non-diapausing larvae. Radiotracer assays of overwintering larvae show that water leaves the tissues during freezing while glycerol enters, and that mercuric chloride disrupts this process. Transport is also disrupted after lethal freezing at -35 degrees C. Therefore, membrane transport of water and glycerol is involved in the avoidance of freezing injury to fat body cells of the rice stem borer, apparently by mediating the replacement of water with glycerol in freezing-tolerant tissues.     

刺槐叶瘿蚊越冬幼虫空间格局及抽样调查技术

本文采用聚集指标法分析了刺槐叶瘿蚊Obolodiplosis robiniae(Haldemann)越冬幼虫的空间分布格局,结果表明:刺槐叶瘿蚊越冬幼虫在林间呈聚集分布;其聚集的原因与刺槐叶瘿蚊自身的行为习性有关或由刺槐叶瘿蚊本身与环境的异质性共同作用所造成。采用"z"字型、平行线、棋盘式、大五点、对角线5种抽样方法估计林间刺槐叶瘿蚊越冬幼虫虫口密度,确定对角线法调查15样方为最佳抽样方法。对土壤不同深度土层中越冬幼虫数量调查,明确最适取样深度为3cm。同时利用Iwao回归建立了理论抽样数量模型:n=t2/D2(1.1957/x珋+0.8905)。利用过筛手检和过筛水漂2种方法检数土中幼虫,对检出刺槐叶瘿蚊越冬幼虫虫量及检虫时间进行了对比分析,结果表明过筛水漂法检虫较为可取。     

红棕象甲幼虫空间格局研究

【背景】红棕象甲是外来危险I生有害生物,近十年来在我国南方严重危害棕榈科植物。[方法】为了确定其调查抽样方法、准确获得虫情,应用聚集度指标法和回归模型分析法等,对红棕象甲幼虫的空间格局进行了研究。【结果】在lwao模型中,α=0．4208〉0,β=1.5133〉1,这说明了红棕象甲幼虫的种群空间格局的分布图式为聚集型;用马占山重新解释的Taylor幂法则分析表明,红棕象甲幼虫的空间格局归属于聚集型,个体之间相互吸引。【结论与意义】红棕象甲幼虫在林内呈聚集型分布,分布的基本成分为个体群;运用1wao法确定了林间最适理论抽样数和序贯抽样模型,为该虫的监测与防治提供了依据。     

西花蓟马在黄瓜和架豆上的空间分布型及理论抽样数

西花蓟马Frankliniella occidentalis（Pergande）已在北京部分蔬菜园区成功定居,对蔬菜生产造成危害。为了解该虫在蔬菜田的种群空间分布型,指导田间取样,本文应用几种聚集度指标的计算公式以及Taylor、Iwao的回归方程式,分析和测定了西花蓟马的种群空间分布格局。结果表明：在黄瓜和架豆上西花蓟马的空间分布型一致,均为聚集分布型;该虫的空间分布型不受种群密度的影响,并且也不随取样时间的变化而变化。种群数量动态研究显示西花蓟马成虫和若虫在黄瓜植株的中部叶片分布较多（从顶部向下数第4叶至第17叶片上成、若虫的分布数量多于其他叶片上的数量）,未展开的叶片、嫩叶和下部老叶危害较轻。用Iwao回归法中α、β参数计算出在允许误差范围内的理论抽样数。     

Relationships between body weight of overwintering larvae and supercooling capacity; diapause intensity and post-diapause reproductive potential in Chilo suppressalis Walker

The rice stem borer, Chilo suppressalis Walker, overwinters in China as a larva in facultative diapause. The instars and body weights of overwintering larvae vary widely. In this paper, the relationships between body weight and supercooling capacity, diapause intensity and post-diapause reproductive potential of overwintering larvae collected in late-stage rice field were examined. There was a significant positive correlation between body weight, instar, and head capsule width, thus the overwintering larvae were divided into five groups based on body weight (I, up to 35.0 mg; II, 35.1-57.0 mg; III, 57.1-79.0 mg; IV, 79.1-101.0 mg; and V, over 101.1 mg) for further analysis. The body water content of the lighter group (I) was significantly higher than that of the heavier groups (IV-V). However, the mean supercooling point decreased with an increase of the mean larval body weight in five groups; mean supercooling point of group I was significantly lower than that of group V, except in January 2009. After transfer of overwintering larvae to 15, 20 and 25 °C on different dates, smaller individuals pupated slightly faster than larger ones at the same temperature, suggesting that diapause was less intense in smaller overwintering larvae. On 19 March 2009 there was a strong positive correlation between larval body weight and the weight of 3 day-old pupae, and the number of eggs carried by 2 day-old adult females at 15, 20 and 25 °C. The average number of eggs carried by 2 day-old adult females differed significantly among different groups. The average number of eggs carried by 2 day-old adult females in group V was significantly greater than those of other groups, and that of group I was significantly lower than those of other groups, suggesting that post-diapause reproductive potential was determined, to a certain extent, by body weight of the overwintering larvae.     

Screen of Bacillus thuringiensis toxins for transgenic rice to control Sesamia inferens and Chilo suppressalis

Transgenic rice to control stem borer damage is under development in China. To assess the potential of Bacillus thuringiensis (Bt) transgenes in stem borer control, the toxicity of five Bt protoxins (Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ba and Cry1Ca) against two rice stem borers, Sesamia inferens (pink stem borer) and Chilo suppressalis (striped stem borer), was evaluated in the laboratory by feeding neonate larvae on artificial diets containing Bt protoxins. The results indicated that Cry1Ca exhibited the highest level of toxicity to both stem borers, with an LC₅₀ of 0.24 and 0.30 μg/g for C. suppressalis and S. inferens, respectively. However, S. inferens was 4-fold lower in susceptibility to Cry1Aa, and 6- and 47-fold less susceptible to Cry1Ab and Cry1Ba, respectively, compared to C. suppressalis. To evaluate interactions among Bt protoxins in stem borer larvae, toxicity assays were performed with mixtures of Cry1Aa/Cry1Ab, Cry1Aa/Cry1Ca, Cry1Ac/Cry1Ca, Cry1Ac/Cry1Ba, Cry1Ab/Cry1Ac, Cry1Ab/Cry1Ba, and Cry1Ab/Cry1Ca at 1:1 (w/w) ratios. All protoxin mixtures demonstrated significant synergistic toxicity activity against C. suppressalis, with values of 1.6- to 11-fold higher toxicity than the theoretical additive effect. Surprisingly, all but one of the Bt protoxin mixtures were antagonistic in toxicity to S. inferens. In mortality-time response experiments, S. inferens demonstrated increased tolerance to Cry1Ab and Cry1Ac compared to C. suppressalis when treated with low or high protoxin concentrations. The data indicate the utility of Cry1Ca protoxin and a Cry1Ac/Cry1Ca mixture to control both stem borer populations.     

扬州地区水稻二化螟寄生蜂种类及主要寄生蜂发生动态

本文报道了江苏扬州地区水稻二化螟Chilo suppressalis(Walker)寄生蜂主要有10种,即中华钝唇姬蜂Eriborus sinicus(Holmgren)、二化螟盘绒茧蜂Cotesia chilonis(Munakata)、稻螟小腹茧蜂Microgaster russata Haliday、螟甲腹茧蜂Chelonus munakatae Munakata、中华茧蜂Amyosoma chinensis(Szepligeti)、螟黄足盘绒茧蜂Cotesia flavipes(Cameron)、夹色姬蜂Auberteterus alternecoloratus(Cushman)、桑蟥聚瘤姬蜂Iseropus(Gregopimpla)kuwanae(Viereck)、螟蛉瘤姬蜂Itoplectis naranyae(Ashmead)以及二化螟盘绒茧蜂的重寄生蜂绒茧灿金小蜂Trichomalopsis apanteloctena(Crawford)。田间系统调查表明:扬州地区7-9月水稻二化螟寄生蜂的主要种类为二化螟盘绒茧蜂、中华钝唇姬蜂、螟甲腹茧蜂、稻螟小腹茧蜂、螟蛉瘤姬蜂、桑蟥聚瘤姬蜂,但这些寄生蜂对一代水稻二化螟幼虫的寄生率较低,对二代水稻二化螟幼虫的寄生率高。水稻二化螟越冬期的系统调查表明:扬州地区二化螟越冬幼虫的寄生蜂主要有3种,即二化螟盘绒茧蜂、中华钝唇姬蜂和稻螟小腹茧蜂,其中二化螟盘绒茧蜂和中华钝唇姬蜂是寄生水稻二化螟越冬幼虫的优势种。水稻二化螟越冬幼虫的寄生率调查表明,扬州地区水稻二化螟越冬幼虫的寄生率在不同年份间有一定的波动,但一般都在15%以上,有的甚至高达89.88%,因此寄生蜂对二化螟越冬幼虫具有很好的控制作用,能有效压低来年水稻二化螟的田间越冬基数。此外,3种寄生蜂出茧时间在1月和2月之间达到最长,分别达到19.79 d、17.26 d和27.00 d,该结果表明,在扬州地区这3种寄生蜂可能都存在滞育现象。     

Spatial and temporal correspondence of sunn pest oviposition and egg parasitism by Trissolcus spp. in Iran

The sunn pest, Eurygaster integriceps Puton, is a serious pest of wheat and other cereals in the Firouzabad region of Ardabil Province, Iran. In this study, we examined the spatial distribution of sunn pest eggs and their parasitism by Trissolcus spp., primarily Trissolcus grandis Thomson, during the growing seasons of 2008 and 2009. Ten quadrats of 1 m² were established in each of the ten experimental fields and sampled every 3 days beginning at Feekes growth stage 6 (beginning of stem elongation) through stage 11 (ripening). The numbers of sunn pest eggs, both parasitized and unparasitized, were tallied in each quadrat on each sampling date. Sunn pest oviposition peaked during the onset of flowering in both years, while parasitism peaked at the completion of anthesis in 2008, and at anthesis complete to early milk stage in 2009. Iwao’s regression provided a better fit to the data than did Taylor’s power law. Both models indicated an aggregated distribution of eggs and parasitism. Temporally, there was a negative overlap between egg density and parasitism from inflorescence emergence until the beginning of anthesis, and positive overlap from anthesis complete until the soft dough stage, such that parasitism ranged from 0% of eggs laid early, to virtually 100% of eggs laid late. Thus, despite good spatial correspondence between egg density and egg parasitism, the time lag between peak bug oviposition and peak parasitism enabled large numbers of early‐laid host eggs to hatch and diminished the potential efficacy of biological control by Trissolcus spp. The implications of these results are discussed in the context of integrated management of sunn pest in wheat fields and the possible benefits of early season augmentation of the parasitoid population.     

柑桔爆皮虫羽化孔的空间分布

通过调查柑桔爆皮虫成虫羽化孔的分布,经空间分布型检验和聚集度指标的测定以及Taylor幂法则和m*- m（Iwao）回归分析,结果表明,柑桔爆皮虫的羽化孔在柑桔树树体内和桔园内均呈聚集分布: 在枯树内呈负二项分布,在半枯树内呈负二项分布或奈曼A型分布,在桔园内呈负二项分布,在树体内和桔园内分布的基本成分均为为个体群,个体间相互吸引。树势较差的柑桔树容易受柑桔爆皮虫危害,在树势强的树体内不能完成世代发育。因此,柑桔爆皮虫采用多次聚集攻击的策略攻击寄主。在桔园内聚集危害部分寄主,在树体内聚集危害寄主主枝的中下部,主枝的死亡导致整株树势下降,下一代虫源进而再次攻击寄主,在树势下降的树体内柑桔爆皮虫完成世代发育并羽化出孔,成虫继续为害健康的柑桔树。     

Effects of Bt transgenic rice line on stripe stem borer,Chilo suppressalis and its consequences on egg parasitoid,Trichogramma brassicae Bezdenko (Hymenoptera: Trichogrammatidae) in the laboratory

Interactions among Chilo suppressalis (Walker), its larval parasitoid Trichogramma brassicae Bezdenko and insect-resistant transgenic rice lines were evaluated under laboratory conditions. The results showed that all neonates and second larvae of stem borer were dead regardless of being fed rotationally or permanently on Bt rice, but 18% and 28% of the third and fourth instar larvae could complete development and turned to adults, respectively, when fed rotationally. In the second year of project, third instar larvae of stem borer were used to evaluate Bt rice impact on T. brassicae. The result showed that emergence rate was lower, the abnormal female rate increased and adult female longevity of the wasp decreased significantly in comparison with the conventional variety. There was no significant difference in gender ratio and parasitism rate under Bt rice treatment in comparison with conventional variety.     

不同抗性小麦品种上麦红吸浆虫幼虫的空间分布型与理论抽样数

【目的】为了解小麦品种抗性对麦红吸浆虫Sitodiplosis mosellana(Géhin)幼虫在麦穗上空间分布型的影响,为科学调查提供合理的抽样依据。【方法】2015年5月采用剥穗调查法对陕西省周至县试验田种植的4个抗虫和4个感虫小麦品种麦红吸浆虫幼虫危害进行调查,应用6种聚集度指标和Iwao M*?m回归法综合分析了幼虫在抗性不同小麦品种上的的空间分布结构。【结果】幼虫在抗、感小麦品种整穗及麦穗上、中、下部位上空间分布型一致,均呈聚集分布,但在抗虫品种上聚集强度大于感虫品种;抗、感小麦品种上分布的基本成分均为个体群,个体间相互吸引。聚集均数λ分析表明,幼虫在抗性较强品种上的聚集主要由小麦穗部化学物质和形态结构等环境因素引起,感虫品种上则由环境因素和成虫的产卵习性共同作用所致。幼虫在抗、感小麦品种上的发生趋势一致,均是上部发生最重,中部次之,下部最轻。根据Iwao回归法中的分布型参数,确立了幼虫在不同虫口密度和允许误差条件下的理论抽样数。【结论】麦红吸浆虫幼虫在抗性不同小麦品种上均呈聚集分布,调查时应根据当地栽培品种平均虫口密度选择适宜的抽样数量。     

云南元阳梯田水稻田白背飞虱若虫空间分布型及理论抽样数

采用Taylor幂法扩散法和Iwao回归法分析了云南元阳哈尼梯田1400～2000m海拔16个哈尼族传统水稻品种田白背飞虱Sogatella furcifera(Horvath)1～3龄若虫的空间分布特征。结果表明,白背飞虱1～3龄若虫在不同海拔、不同水稻品种田均呈聚集分布中的负二项分布,其负二项分布的公共K值为3.53,聚集原因主要是由白背飞虱生物学特性和环境因素引起。Iwao直线回归方程拟合公式为m*=3.96+1.09m(R=0.97),Taylor幂拟合公式为lg(V)=0.28+1.34×lg(m)(R=0.85)。其中,在1400～1500、1501～1600、1601～1700、1701～1800、1801～1900和1901～2000m海拔梯田稻田中,白背飞虱若虫平均拥挤度分别为10.74±0.83、23.67±3.50、21.64±6.02、47.10±5.71、52.59±12.75、13.72±3.14,差异显著(F=5.77,P<0.01),其中在1701～1800和1801～1900m海拔稻田中白背飞虱平均拥挤度最高,表明在该海拔处白背飞虱在稻丛上分布较为集中,而在1400～1500和1901～2000m海拔稻田中平均拥挤度最低。根据空间分布型参数,建立了精度分别为0.1和0.2时的理论抽样数模型,分别为n=1905.43x+34.57,n=476x.36+8.64,该模型适用于不同虫口密度下的田间抽样。当白背飞虱虫口密度为5、10、20头/丛时,分别取样30、20和15个样方。     

Inhibition of midgut protease of yellow stem borer (<Emphasis Type="Italic">Scirpophaga incertulas</Emphasis>) by cysteine protease-like inhibitor from mature jackfruit (<Emphasis Type="Italic">Artocarpus heterophyllus</Emphasis>) seed

A novel protease inhibitor was isolated and purified from the mature seeds of jackfruit (Artocarpus heterophyllus) by precipitation with ammonium sulphate, followed by DEAE-cellulose and gel filtration (Sephadex G-100) chromatography. The isolated protease inhibitor strongly inhibited papain and midgut proteases of yellow stem borer (Scipophaga incertulas) larvae, as seen by in vitro assay. The purified protease inhibitor was active over a wide range of pH with the maximum activity between pH 4 and 10. This protein was also stable up to 80°C, but the retained activity was lost at 100°C, when heated for 30 min. The molecular mass of the purified cysteine-like protease inhibitor is to be 14.50 kDa as determined by SDS-PAGE. Significant reduction in larval weight and mortality was observed, when fresh rice culms with protease inhibitor was feeded to the yellow stem borer larvae. These results may provide important information to control the yellow stem borer in rice with respect to naturally occurring insecticidal proteins. The observed differences would potentially translate into reductions in population growth of yellow stem borer, indicating a potential value of using jackfruit protease inhibitor for protecting rice plants against damage by the yellow stem borer.     

Overview on current status of biotechnological interventions on yellow stem borer Scirpophaga incertulas (Lepidoptera: Crambidae) resistance in rice

Yellow stem borer (YSB), Scirpophaga incertulas (Lepidoptera: Crambidae), a monophagous pest of paddy is considered as most important pest of rain fed low land and flood prone rice eco-systems. Breeding of yellow stem borer resistance in rice is difficult owing to the complex genetics of the trait, inherent difficulties in screening and poor understanding of the genetics of resistance. On the other hand, a good level of resistance against the widespread yellow stem borer has been rare in the rice germplasm. Resistance to insects has been demonstrated in transgenic plants expressing genes for δ-endotoxins from Bacillus thuringiensis (Bt), protease inhibitors, enzymes and plant lectins. The performance of insect resistant GM rice in trials in China has been quite impressive. The present review is an attempt to assess the current state of development in biotechnological intervention for yellow stem borer resistance in rice.     

砂生槐种子蜂危害空间格局及理论抽样研究

应用6种聚集度指标、Taylor和Iwao回归分析法对砂生槐种子蜂幼虫的空间分布格局进行了分析,得出砂生槐种子蜂幼虫的空间分布型为聚集分布,田间调查抽样方法为分行取样法,并得出田间幼虫不同密度时的理论抽样数。