乌翅麦茎蜂发生与防治研究初报

<正> 乌翅麦茎蜂(Cephus sp.)是兰州市小麦生产上一种新发生的害虫。经过几年试验观察,基本搞清了它的发生规律,初步找到了比较有效的防治措施。 一、生活史与习性 乌翅麦茎蜂在兰州地区每年发生一代。7月以老熟幼虫在小麦根茬中造薄茧越冬。翌年4月下旬开始化蛹,5月上旬进入盛期,5月中旬为化蛹末期。成虫羽化自5月中旬开始,5月下旬达盛期,羽化期长约20天。成虫飞翔能     

二种脊漠甲的室内生物学特性观察

在宁夏银川利用室内自然条件比较观察了莱氏脊漠甲Pterocoma reitteri Frivaldszky和洛氏脊漠甲Pterocoma loczyi Frivaldszky的生物学特性。莱氏脊漠甲2年发生1代,以成虫和幼虫越冬,越冬幼虫于翌年6月下旬至9月上旬化蛹,羽化成虫7月上旬开始出现;洛氏脊漠甲2年发生1代,以成虫和幼虫越冬,越冬幼虫于翌年3月中、下旬出土活动,并在5月下旬至7月下旬化蛹,羽化成虫6月上旬出现。2种脊漠甲的幼虫在室内饲养条件下均有自相残杀的习性。     

胡麻短纹卷蛾生物学特性观察

胡麻短纹卷蛾见”euncaria切S。切已见。’h幼虫俗称胡麻漏油虫,是胡麻重要害虫。在北方胡麻产区的甘肃、宁夏、内蒙、山西等省均有发生,特别是六盘山西麓静宁、庄浪发生猖撅。1990～1992年,笔者对该虫的生物学特性进行了观察,现报道如下。回生活史胡麻短纹卷蛾1年发生1代,以老熟幼虫在胡麻地土壤中作茧越冬,越冬期长达10．5个月。5月下旬越冬幼虫开始出土化蛹,6月中下旬为化蛹盛期,7月下旬为化蛹末期。蛹期8～13天,平均10．6天。6月上旬田间最早发现成虫,中旬成虫大量出现,6月下旬至7月中旬为成虫羽化盛期,6月底至7月初往往出…     

甘南地区小红珠绢蝶生物学特性研究初报

小红珠绢蝶Parnassius nomion Fischer von Waldheim在甘肃甘南1年发生1代。翌年5月上旬幼虫孵化,6月下旬开始化蛹,7月下旬至8月上旬,成虫开始羽化,8月中旬至9月上旬成虫开始产卵,该虫以卵越冬。     

沙柳木蠹蛾的研究

沙柳木蠹蛾Holcocerus arenicola(Staudinger)是沙柳根部一种钻蛀性害虫.亦为害踏郎、酸刺、毛乌柳、柠条等.国内分布于内蒙、新疆、宁夏、陕西、甘肃等省(区). 该虫四年1代, 以幼虫在寄主蛀道内越冬.老熟幼虫5月上旬入沙化蛹;成虫6月初开始羽化, 中旬达盛期;7月上旬幼虫初孵, 取食、为害至10月下旬越冬.成虫白天静伏于沙柳丛, 傍晚8时半至10时半活动、交配、产卵, 趋光性强.雌蛾对雄蛾性诱力较强.成虫寿命2.9—4.1天, 产卵量平均265.4粒, 性比0.67—0.68:1.     

脐腹小蠹虫的生物学特性

白榆是河南省安阳县主要用材树种,近几年来,白输受脐腹小蠹台虫ScolytusschevyrewiSemenov危害,日趋严重。由于目前国内对该虫的发生发展规律未有报道,给我们的防治工作造成了很大困难。为摸清其发生危害规律,在中国科学院动物研究所昆虫组的指导下,我们对该虫进行了生物学特性研究。1生活史揭3年林间观察,脐腹小蜜虫在安阳县世代重叠,以老熟幼虫为主要越冬虫态,也有不同龄期幼虫、蛹和卵越冬,都能发育完成。3月中旬越冬蛹开始现化,3月下旬至4月上旬出现第一次羽化盛期,以后每隔35～42天完成一代,共6代。10月中下旬是最后一次…     

夹竹桃天蛾的生物学特性

夹竹桃天蛾Daphnis nerii(Linnaeus)是夹竹桃上的重要害虫,具有间歇性爆发的特点。该虫在湖南省衡阳地区1年发生2～3代,以蛹在寄主附近的枯枝落叶层、表层松土及土壤缝穴中越冬。越冬代成虫于6月上旬出现,6月中下旬产卵。6月下旬第1代幼虫孵化;第1代成虫于7月中旬出现,7月下旬产卵。第2代幼虫8月上旬孵化,8月下旬至9月上旬幼虫危害最历害,9月中旬开始化蛹,化蛹持续到10月中旬。第2代蛹发生分化,一部分成为越冬蛹,另一部分则羽化为成虫。第2代成虫于10月上旬开始产下第3代卵。10月上旬第3代幼虫开始孵化,11月中旬第3代幼虫开始化蛹、越冬。     

核桃小吉丁虫研究初报

核桃小吉丁虫足陕西省核桃主要害虫。一年发生一代,以老熟幼虫在受害枯枝中过冬,极少数在活枝上越冬。4月中旬至6月底为化蛹期,盛期为4月底至5月初。蛹期平均27.7天,最短16天,最长39天。成虫羽化后在蛹室中停留4—20天才咬破皮层钻出枝外。5月上旬至7月上旬为成虫出现期,盛期为5月下旬至6月上旬。幼虫化蛹结束时亦即成虫出现高峰。成虫出枝后取食核桃叶,约经半个月补充营养期开始产卵。产卵需要较高的温度和强光,卵多产在伸出树冠外围的长枝条上叶痕附近。成虫生活期平均35.3天,最长可达83天。6月上旬至7月下旬为卵出现期。卵期多为10天。6月中旬至8月上旬为幼虫孵化期,7月上旬为孵化盛期。幼虫多在二、三年生枝条皮层中串圈为害。受害严重时树叶变黄、脱落,枝条干枯。8月下旬幼虫老熟后开始钻入木质部,做一蛹室,在蛹室中过冬,至10月底大部幼虫进入了越冬阶段。     

李实蜂的生物学特性及其涂环防治

李实蜂Hoplocampa sp.在山东省枣庄地区是严重危害李树果实的主要害虫之一。据作者于2000～2004年间对山东省枣庄地区该害虫的调查,李树的被害果率达80%。李实蜂在枣庄地区1年发生1代,3月中旬开始化蛹,3月下旬至4月上旬成虫羽化,4月上、中旬幼虫孵化,4月下旬至5月上旬老熟幼虫越夏和越冬。建议采用涂环防治方法,防治率达95%以上。     

沙蒿尖翅吉丁生物学特性的研究

沙蒿尖翅吉丁Sphenoptera sp.是黑沙蒿上主要的钻蛀性害虫,引起沙蒿长势下降甚至死亡。对其形态特征及生物学特征的观察和研究结果表明:该虫在宁夏1年发生1代,以各龄幼虫在被害沙蒿根部越冬。老熟幼虫于4月中下旬开始化蛹,成虫始见于5月上旬,羽化期有两个高峰,分别是5、6月下旬。成虫羽化后并不马上离开蛹室,2～3d后咬出羽化孔,钻出蛹室。成虫需取食沙蒿叶片补充营养,2～7d后开始交尾,集中在13:00-16:30,雌雄成虫均可多次交尾。幼虫常多头聚集危害同一株沙蒿。大多数老熟幼虫在距坑道端部5mm处的根部化蛹,少数在直径为5～8mm的较粗的枝条内化蛹。沙蒿尖翅吉丁幼虫期有2种寄生性天敌,蛹期和成虫期各有1种寄生性天敌。     

Biology and bionomics in Scotland of Anthocoris gallarum-ulmi

Abstract. 1. Observations were made on the biology of Anthocoris gallarumulmi De Geer (Hemiptera - Heteroptera: Anthocoridae) in West Central Scotland from 1973 until 1975. The life cycle was intimately linked with those of its principal prey species Schizoneura ulmi and S.patchae , leaf roll-gall aphids, and elm, their primary host ( Ulmus sp.).
2. Overwintered adults emerged in late April/May and could be found on a number of early flowering tree species, before congregating on elm in late May/June. This population was univoltine and exhibited obligatory female reproductive diapause.
3. Overwintered females emerged already mated but the subsequent pre-oviposition period was 25 days and oviposition period 27 days. Ova were deposited only in close association with galls of S.ulmi and Spatchae , and behavioural variations were shown between sites. Fecundity was c . 16 ova per female.
4. The incubation period was c . 8 days with the subsequent period of larval development 38–53 days, during which time the diet was almost exclusively either S.ulmi or S.patchae . Intergall migration was characteristic of post second instar larvae, which resulted in the concentration of fifth instar larvae and adults in a limited number of galls. It was during this period of local high population density that mating occurred.
5. Adults left elm within 14 days of imaginal ecdysis and thereafter, until overwintering, were recorded in only very low numbers from a range of tree, shrub and herb species.
6. Overwintering adults selected as hibernacula the bark of four tree species but principally Acer pseudoplatanus and Quercus robor . Females required a period of at least 75 days of cold 'shock' to terminate reproductive diapause.
7. Mortality among males surviving to spring emergence was 67%.     

Susceptibility of 32 elm species and hybrids (Ulmus spp.) to the elm leaf beetle (Coleoptera: Chrysomelidae) under field conditions in Arizona

We evaluated elm leaf beetle, Pyrhalta luteola (Müller) (Coleoptera: Chrysomelidae), defoliation of 32 elm species or hybrids (taxa) established under field conditions in Holbrook, AZ. Percentage of defoliation, number of eggs, and number of larvae were estimated on randomly selected 15-cm shoot lengths annually in July, from 1996 to 2001. The following nine taxa consistently sustained 15-46% mean overall defoliation: 1) Siberian elm, U. pumila L.; 2) 'Dropmore' elm, U. pumila; 3) 'Camperdownii' elm, U. glabra Huds.; 4) 'Regal' elm, U. glabra x U. carpinifolia Gledisch x U. pumila); 5) 'Sapporo Autumn Gold' elm (U. pumila x U. japonica Sang.); 6) 'New Horizon' elm (U. pumila x U. japonica); 7) 'Charisma' elm [(U. japonica x U. wilsoniana Schneid.) x (U. japonica x U. pumila)]; 8) 'W2115-1' elm (U. parvifolia Jacq. x U. procera Salisb.); and 9) 'Homestead' elm [(U. hollandica Mill. x U. carpinifolia) x (U. pumila-racemosa Dieck x U. carpinifolia)]. Percentage of defoliation was significantly low on four Chinese elm (U. parvifolia) cultivars ('Allee', 'Athena', 'Glory'/lace bark, and 'Kings Choice'). Percentage of defoliation was also low on seven Asian elms (including U. chemnoui Cheng, U. bergmaniana Sneid., U. szechuanica Fang, and species of the U. davidiana Planch. complex [U. davidiana, U. japonica, U. wilsoniana, and U. propinqua Koidz.]) and the American elm (U. americana L.) 'Valley Forge'. Percentage of defoliation and the number of eggs or larvae per plant were highly correlated. The results of this study are generally consistent with results of past laboratory screening trials.     

榆跳象生物学特性及防治

榆跳象是榆树重要食叶害虫之一,在甘肃省张掖地区１年发生１代,以成虫越冬。成虫取食叶肉,幼虫潜叶危害。成虫期根施３％呋喃丹颗粒剂或２５％溴氰菊酯乳油２０００倍稀释液树冠喷雾,防治效果可达９０％。     

Dendrosoter protuberans (Hymenoptera: Braconidae), An Important Elm Bark Beetle Parasitoid

The most favourable period for Dendrosoter protuberans development occurred when wasps were introduced 16 days after the beginning of Scolytus multistriatus development (the greatest number of emerged wasps per a single parasitoid female with a very positive sexual index and high percentage of parasitised elm bark beetle larvae). No significant differences were observed in parasitoid efficiency between the 11^th and the 21^st day. The most unfavourable period for elm bark beetle parasitisation was six days after the beginning of S. multistriatus development (a low reproduction of D. protuberans, a negative sexual index and a low number of destroyed S. multistriatus larvae). The reproduction of both the elm bark beetle and D. protuberans was greater in the first, than in the second generation. The developmental period of D. protuberans in the first generation was approximately two days longer than in the second generation. Furthermore, the development of females was 1-2 days longer than the development of males. D. protuberans developed most successfully on S. multistriatus (the most abundant parasitoid reproduction with the longest developmental period and a very positive sexual index that resulted in a high percentage of parasitised larvae) and then on S. ensifer, S. pygmaeus and Pteleobius kraatzi. On the other hand, S. scolytus larvae were the poorest host of all elm species - the reproduction of D. protuberans in this species was the scarcest with the shortest period of development and a negative sexual index, hence larval parasitisation was the lowest.     

Comparative laboratory studies on three fungal pathogens of the elm bark beetle Scolytus scolytus: Pathogenicity of Beauveria bassiana,metarhizium anisopliae, and Paecilomyces farinosus to larvae and adults of S. scolytus

The entomogenous fungi Beauveria bassiana (nine isolates), Metarhizium anisopliae (seven isolates), and Paecilomyces farinosus (four isolates) were tested as pathogens of larvae of the elm bark beetle, Scolytus scolytus. Single isolates of B. bassiana and M. anisopliae were also tested against adult beetles. Of the 21 isolates tested as conidial suspensions against larvae, all proved pathogenic. The three most and least virulent isolates were, respectively, isolates of B. bassiana and M. anisopliae. The other isolates fell between these two extremes, with the four P. farinosus isolates all moderately virulent. Spore retention on larvae following inoculation was estimated by washing conidia off the larvae. From the results it was possible to relate larval mortality to the approximate spore dose causing infection at different spore concentrations. Thus, application of spores of the three pathogens at a concentration of 10³ spores/ml resulted in limited mortality. At this concentration, an average of only a single spore was recovered from the inoculated larva. Adult bark beetles also proved susceptible to infection by isolates of B. bassiana and M. anisopliae. They were exposed to discs of elm bark dipped in a conidial suspension. It was estimated that a dose of less than 100 spores could cause infection of beetles following feeding on the elm bark discs.     

Resistance of temperate Chinese elms (Ulmus spp.) to feeding by the adult elm leaf beetle (Coleoptera: Chrysomelidae)

Newly acquired Ulmus species from the temperate regions of China growing at The Morton Arboretum, Lisle, IL, were evaluated in laboratory bioassays for feeding preference and suitability for larvae and adults of the elm leaf beetle, Pyrrhalta luteola (Müller). Larval and adult no-choice and adult multiple-choice feeding studies revealed that U changii, U. lanceaefolia, U. prunifolia, U. pseudopropinqua, and U. taihangshanensis were the least suitable for feeding and reproduction by the elm leaf beetle. Ulmus wallichiana and the highly preferred U pumila were more suitable for feeding and reproduction. Suitability had no significant effect on male and female longevity. The least suitable species of U. changii, U. lanceaefolia, U. prunifolia, U. pseudopropinqua, and U. taihangshanensis show promise for future elm breeding programs.     

Effect of nutrition of parasites with nectar of melliferous plants on parasitism of the elm bark beetles (Col., Scolytidae)

In the forest of Kljestevica, the elm is attacked by four species of elm bark beetles: Scolytus multistriatus (Marsh.), Scolytus scolytus (Fab.), Scolytus pygmaeus (Fab.) and Scolytus ensifer (Rich.) (Col., Scolytidae). Scolytus multistriatus and S. pygmaeus are the most numerous species. Elm bark beetle is parasitized by four species of parasites: Dendrosoter protuberans (Nees), Ecphylus silesiacus (Ratz.), Coeloides scolyticida (Wesm.) (Hym., Braconidae) and Entedon leucogramma (Ratz.) (Hym., Eulophidae). Ecphylus silesiacus and D. protuberans are the most numerous species. The nectar of mustard ( Sinapis alba L., Brassicaceae) flowers, sweet basil ( Stachys recta L., Lamiaceae) flowers and of wild carrot ( Daucus carota L., Umbelliferae), has an important effect on the number of parasites and on the parasitism of the elm bark beetles. Wild carrot is the most attractive plant to the parasites for additional nutrition, especially for D. protuberans . Mustard and sweet basil flowers are suitable for additional nutrition of E. silesiacus imagos. On meadow flowers growing spontaneously in forest clearings, the lowest number of parasite imagos was collected by an entomological catcher, and the lowest percentage of parasitized larvae and eggs of the elm bark beetle was recorded in elm control catch trunks that were not near the cultivated melliferous plants.     

Development of the Dutch elm disease epidemic in southern England, 1971-6

The current epidemic of Dutch elm disease was studied by recording the fate of individual hedgerow elms (Ulmus procera) in five plots in the West Midlands, and by analysing data from successive Forestry Commission surveys of non-woodland elms in 234 plots in southern England. Ninty-five percent of the individual trees died between May 1972 and September 1975. The average infection rate (r) was found to be 1 -35 during the period when the proportion of disease, x, increased from 0–16 to 0–42. In the plots of the main survey the average infection rate was 0–65 and the cumulative loss increased from 6 to 62% between 1971 and 1976, with little evidence that the course of the epidemic was influenced by variations in the weather from year to year. These infection rates are as high as those recorded in Dutch elm disease epidemics elsewhere in the world. The infection rate in English elm was higher than in either the wych elm or the heterogeneous ‘smooth-leaved elm’. The study of English elm in four geographical areas of southern Britain showed that there was an initial drop in infection rate until x = 0–12, when a steady infection rate obtained in all four areas, ranging from 0–56 in the Midlands to 0–76 in the south-east. It is concluded that the epidemic is likely to continue at a high rate until most non-woodland elm have died. Most trees which survive are likely to be smooth-leaved elm in East Anglia. Few communities in southern England have been able to practice vigorous sanitation control programmes, but data from two, in East Sussex and Brighton, are analysed and the effect on disease progress discussed.     

Biological control of Dutch elm disease: Bacillus thuringiensis as a potential control agent for Scolytus scolytus and S. multistriatus

J assim , H.K., F oster , H.A. & F airhurst , C.P. 1990. Biological control of Dutch elm disease: Bacillus thuringiensis as a potential control agent for Scolytus scolytus and S. multistriatus. Journal of Applied Bacteriology 69 , 563–568.
The effects of exposing fifth instar larvae of Scolytus scolytus and S. multistriatus to spore suspensions of Bacillus spp. were investigated. Bacillus thuringiensis ser 3a, 3b increased the mortality of larvae cultured on an artificial medium from approximately 20% in control cultures to over 80% in cultures exposed to the bacteria. The mortality was dose-dependent for S. multistriatus and the approximate LC₅₀ value was 2.2 times 10³ spores/ml. Different serotypes of B. thuringiensis caused different levels of mortality: H6 produced the highest mortality and H1 the lowest. Bacillus alvei and B. cereus were also pathogenic but B. megaterium was not. The results are discussed in relation to the mechanism of pathogenicity and the potential for the use of B. thuringiensis for the control of the vectors of Dutch elm disease.     

Growth inhibitory activity of Daphne gnidium L. (Thymelaeaceae) extracts on the elm leaf beetle (Col., Chrysomelidae)

Abstract:  An investigation has been performed on the activity of spurge flax ( Daphne gnidium L., Thymelaeaceae), a typical component of the Mediterranean vegetation, on the development of the elm leaf beetle ( Xanthogaleruca luteola Muller; Col., Chrysomelidae), one of the most serious defoliators of urban forests. Different concentrations of ethanolic extracts of D. gnidium leaves were added to the natural diet (elm leaf discs) of X. luteola , starting with L2 larvae, and the effects induced on the vitality, growth and phase duration of the different stages have been evaluated. A significant reduction of larval survival and adult emergence, together with an increased length of the larval period, heavy reduction of weight gain and appearance of malformations in emerged imagines were observed in presence of spurge flax extracts. These findings agree to ascribe to D. gnidium leaf extracts a growth inhibitory activity and allowed identifying what should be the optimal concentration to be applied on elm leaves to prevent heavy damages by X. luteola .