Attract,reward and disrupt: responses of pests and natural enemies to combinations of habitat manipulation and semiochemicals in organic apple

The widespread use of pesticides along with the simplification of the landscape has had undesirable effects on agroecosystems, such as the loss of biodiversity and the associated ecosystem service biological control. How current production systems can be remodelled to allow for a re-establishment of biological pest control, while preserving productivity, is a major challenge. Here, we tested whether a combination of tools could augment or synergize biological control of insect pests in apple (Malus domestica), comprised of a tortricid pest complex, a geometrid pest complex and the rosy apple aphid. The tools aimed at disrupting mating behaviour of multiple pest species (multispecies mating disruption, “Disrupt”, MMD), attracting natural enemies (a blend of herbivory-induced volatiles, “Attract”, A), or providing refuge and rewards for a diverse insect community (perennial flower strip, “Reward”, R) over a 3-year period. Suction samples were consistently richer in generalist predators but not in parasitoids when multiple tools including MMD?+?A?+?R or MMD?+?A were employed. In addition, lepidopteran pest levels were significantly lower in these plots than in MMD or MMD?+?R at the end of the 3-year experiment. This was, however, not reflected in survival of artificially established aphid colonies. Our data indicates that multiple, complementary tools can greatly enhance natural enemy level, but also that long-term implementation is needed to fully realize the augmentatory or synergistic potential of complementary components and restore biological control as an ecosystem service of practical relevance.

     

Combining banker plants to achieve long-term pest control in multi-pest and multi-natural enemy cropping systems

Banker plants increase biological pest control by supporting populations of non-pest arthropod species, used as alternative hosts or prey by natural enemies. Due to the specificity of trophic interactions, banker plants may not efficiently promote natural enemies with different ecologies. Yet in most cropping systems, different pest species are present together and require different biocontrol agents to efficiently control them. In the present study, we tested the combined use of two banker plants and their associated prey/host to enhance populations of the specialist parasitoid Encarsia formosa targeting the main tomato pest Bemisia tabaci, and a polyphagous ladybird Propylea japonica targeting the secondary pest Myzus persicae in tomato crops. In a laboratory and a greenhouse experiment, we measured the abundances of these four species using the Ricinus communis—Trialeurodes ricini banker plant system alone, in combination with the Glycines max—Megoura japonica system, or in absence of banker plants. We found that the first banker plant system enhanced populations of E. formosa, resulting in increased suppression of B. tabaci populations and the suppression of their outbreak in both our laboratory and greenhouse experiment. Conversely, abundances of P. japonica were not affected by this first system, but were significantly increased when the second was present. This resulted in increased control of M. persicae populations and the suppression of their early and late outbreaks. Our study demonstrates the potential for combined banker plants to provide long-term, sustainable control of multiple pests by their target natural enemies in complex agroecosystems.

     

Quantitative dynamics of larch caterpillar (Dendralimus superans [Buller]) and the biological control

The relationship between pest population and other factors is rather complex within the forest ecosystem. A number of environmental factors, such as extreme climatic conditions, infection of natural enemies, may cause the death of pest insects directly. The effect of these factors reflects basically the situation and cause of death of insects at different stages of entire process of growth and development, so that they may be employed as the basic records of the quantitative dynamic of the population, and are of important value to the study of population quantitative dynamics of pests. Since Morris and Miller (1954) applied the life table technique to study natural population of insects, the insect life table technique has becoming an important means for the study of quantitative dynamics of pest populations. In foreign countries, the study of the life table of forest pest began in 50 year’s already. Moreover, the results of investigation were applied to the productive practice, such as the spruce budworm (Chorisloneura fumiferana Clemens), winter moth (Opperophlera brumata Linnaeus), while in our country, the quantitative dynamics of many forest pests were not investigated. The larch caterpillar is one of the great pest of larch plantation in China. Every year, the outbreak of this pest occur in some places, causing large economic loss. Many studies were performed on the biological and chemical controls, but the investigation on quantitative dynamics of the natural population of larch caterpillar was lacking. Since 1980, we studied the quantitative dynamics of the natural population of larch caterpillar in Shangzhi County, Heilongjiang Province and worked out life tables of two generations.     

Host instar suitability of <Emphasis Type="Italic">Bemisia tabaci</Emphasis> (Genn.) (Hom.: Aleyrodidae) for the parasitoid <Emphasis Type="Italic">Eretmocerus mundus</Emphasis> (Hym.: Aphelinidae)

Efficient use of parasitoids in pest control depend on the knowledge of the biological relationships between host and parasitoid. Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) is one the most important natural enemies of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) that is found in fields and greenhouses in Adana, Turkey. Although more studies have been done to determine the relationships between E. mundus and B. tabaci, the differences among strains of E. mundus could have important biological concequences. In this study, biological characteristics of native population of E. mundus parasitization of B. tabaci (Q biotype) were determined using bean plants Phaseolus vulgaris (L.) at a constant temperature of 25 ± 1°C, relative humidity 70 ± 10% and 16:8 (L:D) photoperiod regimen. All B. tabaci nymphal instars were parasitized by E. mundus, but the mean number of daily-parasitized nymphs was highest in the second instars (15.3). In addition, second instar females had the shortest mean development time (15.2 days). Mean development times of parasitoids obtained from first, second, third and fourth B. tabaci instars varied from 15.2 to 16.2 days and 15.2 to 15.9 days for female and male, respectively. Proportion of female (♀/♂+♀) varied from first (0.53) to second (0.34) host instars. Impact of results on potential biological control of B. tabaci was discussed through conservation native natural enemies.     

Captive sentinel hosts efficiently measure the establishment,seasonality and dispersal of a parasitoid biological control agent

Introduced biological control agents are used to suppress populations and reduce the damage caused by many exotic herbivorous insects in New Zealand pasture. Understanding the dispersal behaviour of a recently introduced biocontrol agent in its new environment is important as it helps biocontrol practitioners make decisions on the number and location of future releases. In this study, a monitoring device which contained sentinel hosts was developed to monitor the establishment and dispersal of the Irish strain of Microctonus aethiopoides (Hymenoptera, Braconidae) into areas of the South Island of New Zealand where the clover pest Sitona obsoletus Gmelin (Coleoptera, Curculionidae) had recently become established. Field tests of the monitoring device at five sites in Marlborough confirmed that M. aethiopoides would enter the device through a 900 µm mesh and parasitise the sentinel weevils within. In a further trial conducted over 4 years at four sites in North Canterbury, monitoring devices successfully tracked the dispersal and establishment of M. aethiopoides at sites up to 27 km from the original release site. Monitoring devices containing sentinel hosts may help reduce the cost of classical biological control programmes as they enable rapid sampling of numerous sites and largely eliminate the time consuming practice of dissecting field collected hosts to determine the presence of the parasitoid.

     

Gegenwärtige Projekte der biologischen Bekämpfung verschleppter Forstschädlinge

Summary Current projects of biological control of introduced forest insects. (Third report on the activities of the European Station, Commonwealth Institute of Biological Control).The report covers the period of 1965 to 1970 dealing briefly with nine forest pests of European origin introduced into North America or East Africa. Research in Europe on the natural enemies of these pests is described and the present status of biological control operations is dicussed. The pest species dealt with are: the larch sawfly (Pristiphora erichsonii Htg.), the European pine sawfly (Neodiprion sertiferGeoff.), the birch leaf-mining sawfly (Fenusa pusilla Lep.), the birch case-bearer (Coleophora fuscedinella Hb.), the larch case-bearer (Coleophora laricella Zell.), the pine shoot moth (Rhyacionia buoliana Den. & Schiff.), the elm bark beetle (Scolytus multistriatus Marsh.) and the woolly aphidsDreyfusia piceae Ratz. andPineus spp.     

华山松尺蛾生物学特性及防治

本文对华山松尺蛾Biston sp.形态特征,生活史,生活习性和防治进行了研究.     

Insektenbekämpfung in West-Samoa unter besonderer Berücksichtigung des Standes biologischer und integrierter Verfahren

Zusammenfassung Wir geben einen Überblick über die in West-Samoa wichtigen Insektenarten der wichtigsten Kulturpflanzen und fassen den Stand der Kenntnisse zusammen, soweit sie die ökologischen Grundlagen von bereits laufenden biologischen bzw. integrierten Verfahren im Pflanzenschutz betreffen. Der Indische Nashornkäfer, Hauptschädling in Kokosplantagen, ist seit der Einbürgerung desBaculovirus oryctes unter Kontrolle. Sowohl Schadenserhebungen als auch die Überwachung der Virus-Verseuchung (1975/76–1983) zeigen, daß sich die Verhältnisse stabilisiert haben. Im August 1980 stellten wir den BlattkäferBrontispa longissima erstmals fest. Die Bekämpfung dieses neuen Schädlings kann die Kontrolle des Nashornkäfers beeinflussen, sofern Insektizide eingesetzt werden. Langfristig ist daher auch eine biologische Kontrolle vonBrontispa anzustreben. 1981 wurde die EulophideTetrastichus brontispae nach Samoa eingebürgert, seitdem läuft ein Massenfreilassungs-Programm. In Labor und Feldversuchen konnte außerdem gezeigt werden, daßMetarrhizium zur Bekämpfung vonBrontispa geeignet ist. Ein integriertes Bekämpfungsmodell der Taro-Eule wird vorgestellt. Die Kenntnis vorläufiger Schadensschwellen in Zusammenhang mit Schädlingsüberwachungen sowie Maßnahmen zur Schonung bzw. Förderung natürlicher Gegenspieler ermöglichen ein differenziertes Vorgehen gegenüber dem Schädling. Über andere Kulturen geben wir nur einen kurzen Überblick, da z.B. in Bananen wegen eines fest etablierten Spritzplanes kaum Möglichkeiten für biologische Verfahren gegeben sind. In Kakao sind Insekten-Probleme unbedeutend, in Gemüse liegen noch wenig Erfahrungen vor.

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Insect pest control in Western Samoa with special reference to present status of biological and integrated control measures

A report is given on the insect pest fauna of major crops and the ecological background of today's pest control strategies.The coconut rhinoceros beetle still is the most important pest associated with this plant, but is under fair control since the introduction of theBaculovirus oryctes in 1967. Both damage surveys, and monitoring of virus incidence over the past 8 years indicate stabilization of the plant-insect-virus system. The use of insecticides againstBrontispa longissima, a pest new to W. Samoa since 1980, could interfere with the biocontrol system of the rhinoceros beetle. It is the intention to get long-term control overBrontispa by the eulophid parasitoidTetrastichus brontispae, being mass-released since 1981. Suitability ofMetarrhizium spores application in protecting young coconut palms fromBrontispa was tested in the lab, and in the field.The staple crop taro suffers mostly from the taro cluster caterpillar. In taro where weedicides and insecticides are widely used in Samoa the well established predator-parasitoid-complex îs not giving sufficient natural control over this pest. Collecting information on crop injury levels, augmentation and preservation of anApanteles endoparasitoid, and monitoring techniques enabled us to develop an IPM model.Pest control problems in other crops are delt with in briefness only because there is either a conventional pesticide application sheme in use (bananas) leaving only little opportunity for purely biological control, or information is not sufficiently available yet on pest status like on insect-born losses in vegetables.

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Mit 2 Tabellen     

Targeting a coatomer protein complex-I gene via RNA interference results in effective lethality in the pollen beetle Brassicogethes aeneus

The pollen beetle Brassicogethes aeneus is a serious pest of oilseed rape (Brassica napus) in Europe. Management of this pest has grown difficult due to B. aeneus’s development of resistance to pyrethroid insecticides, as well as the pressure to establish control strategies that minimise the impact on nontarget organisms. RNA interference represents a nucleotide sequence-based, and thus potentially species-specific, approach to agricultural pest control. The present study examined the efficacy of targeting the coatomer gene coatomer subunit alpha (αCOP), via both microinjection and dietary exposure to exogenous complementary dsRNA, on αCOP-silencing and subsequent mortality in B. aeneus. Beetles injected with dsRNA targeting αCOP (at 0.14 µg/mg) showed 88% and 100% mortality at 6 and 10 days post-injection, respectively; where by the same time after dietary exposure, 43%–89% mortality was observed in the 3 µg dsRNA/µL treatment, though the effect was concentration-dependent. Thus, the effect was significant for both delivery routes. In working towards RNA-based management of B. aeneus, future studies should include αCOP as a target of interest.

     

日本松干蚧发生特点及治理对策

指出了日本松干蚧是我国重要的林业枝梢害虫,其发生密度大、防治难,对林业生态安全造成严重的影响。详细描述了其外部形态和生物学特性,初步分析了该虫发生特点,提出了相应的治理对策。     

我国双条杉天牛研究概况

双条杉天牛是国内森林植物检疫的重要害虫，是柏类树种的毁灭性害虫，近些年来，已对一些地区古柏保护构成威胁。本文系统综述了双条杉天牛在我国的分布与危害、生物学、生态学、预测预报及综合防治研究进展情况，对该虫今后在生物学和生态学等方面的进一步研究有一定参考价值，同时对制定该虫综合防治策略和方案也有实用意义。     

Synthetische Sexual-Pheromone und deren Inhibitoren für Choristoneura murinana Hbn. (Tannentriebwickler. Lepidoptera: Tortricidae)

In a specific field-screening test it could be shown that (Z)-11-tetradecenylacetate is an attractant for males ofCh. murinana. (Z)-11-tetradecenylacetate in combination with (Z)-11-tetradecenol, (Z)-11-tetradecenal or (E)-11-tetradecenal showed synergistic effects. (E)-11-tetradecenylacetate (and to some extent (E)-11-tetradecenylacetate. (Z)-11-tetradecenylacetate alone or in combination with its synergists could be used in integrated pest management programmes of European forests.

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Hoechst Aktiengesellschaft.     

Pathogens and Pests Threatening Plantation Forestry in Zimbabwe

The Zimbabwean forestry industry, which contributes significantly to the economy, was introduced in the 1940s and is dominated by Pinus spp., Eucalyptus spp. and Acacia mearnsii De Wild. This paper assembles and consolidates literature on diseases and pests of forest plantations to serve as a foundation for management and future studies. Most of the outlined diseases and pests have been known since the early days of forest plantations (i.e. the 1960s) whilst some are recent, signifying their increasing importance to the forest industry. Pinus spp., Eucalyptus spp. and A. mearnsii are affected by pathogens and pests originating from the native areas of the hosts while the origins of others are not known. Disease outbreaks resulted in discontinuous cultivation of Eucalyptus globulus Labill. and Pinus radiata D. Don. that were important species in eastern and southern Africa. Forest health issues impacting on forest production are poorly understood and there is an urgent need to implement a structured forest health survey program and appropriate support to identify current and emerging pest and disease issues. Additionally, this information is important to support the forestry seed and timber export program.     

Using flower strips to promote green lacewings to control cabbage insect pests

Habitat management improves biological control by increasing the abundance and fitness of natural enemies through the provision of floral resources along field edges or between crops. Among the natural enemies reliant on flower resources, green lacewings often stand out due to their abundance, predation capacity and polyphagy. We evaluated the impact of tailored flower strips on the enhancement of natural enemies, especially green lacewings, in three organic cabbage (Brassica oleracea) farms in Southern Sweden. Insects were sampled from the flower strips, and cabbage pests and predators were visually recorded in the crop. In a laboratory assay, the pollen feeding preferences of Chrysoperla carnea (Stephens, 1836) were evaluated in a dual-choice test. The pollen consumed by the Chrysopidae was extracted from laboratory and field specimens, then quantified and identified. Flower strips were found to attract predators and parasitoids, whose abundance increased as flowers bloomed. Cabbage plants next to the flower strips showed lower pest infestation as compared to cabbage plant control, although no significant differences were observed in the number of predators. Chrysopidae used flower strips as feeding, reproduction and shelter sites and mainly consumed pollen from Phacelia tanacetifolia Benth. Under laboratory conditions, C. carnea showed a preference for P. tanacetifolia and Coriandrum sativum L. pollen over Borago officinalis L. and Fagopyrum esculentum Moench. We show that tailored flower strips could be an efficient tool for enhancing beneficial arthropods and should be considered in integrated pest management for cabbage crops.

     

Parasitoids associated with Monochamus galloprovincialis (Oliv.) (Coleoptera: Cerambycidae) within the pine wilt nematode-affected zone in Portugal

Until recently, the pine sawyer Monochamus galloprovincialis (Olivier) (Coleoptera; Cerambycidae) was considered a secondary forest pest in Portugal. Its pest status changed when it was found to be the main vector of the recently introduced pine wood nematode (PWN) Bursaphelenchus xylophilus (Steiner and Bührer) Nickle (Nematoda; Aphelenchoididae). A survey in three locations within the PWN-affected zone was conducted in order to identify parasitoids associated with immature stages of the beetle and to evaluate their importance. No parasitoid was found associated with the insect eggs whereas 10% of the larvae were found parasitised by three Braconidae. Cyanopterus flavator Fabricius was the most numerous species; Iphiaulax impostor (Scopoli) and Coeloides sordidator Ratzeburg were the other species present. A review of the parasitoids associated with Monochamus in Europe, eastern Asia and North America was made, and the possibility of using the local species in future biological control programmes in Portugal is briefly discussed.     

巴东县森林病虫害防控工作现状及对策

森林病虫害是＂不冐烟＂的森林火灾,对于巴东县这样的以林业作为支柱产业的山区县来讲,森林病虫害的监测、研究和防治更具有举足轻重的地位。笔者通过对巴东独特地域的病虫害现状调查和防控对策的研究,拟从一个更高的认识高度和更有效的生物环保防范措施来防控森林病虫害,旨在为区域病虫灾害防控探寻出一条高效的新路。     

Bionomics ofBiston betularia (L.) in Daxing’an Mountains forest area

Observations on life cycle, habits and characteristics ofBiston betularia (L.), which is a major pest infecting birch, were made in Daxing’an Mountain forest area, Heilongjiang Province during 1997–1998. In this area, the pest has one generation per year and overwinters as eggs in cracks of the lower part of stem. Adults emerge from mid-July to late August, and the damage of larvae occurs mainly in May and June. Life cycle table ofBiston betularia was given and control suggestions were made in this paper. Foundation item: This paper is part of Key Subject of Birch in State 9th Five-Year Plan. Biography: Sun Fan (1971-), female, lecture in Northeast Forestry University, Harbin, China Responsible editor: Chai Ruihal     

Public attitudes about forest pest outbreaks and control: Case studies in two Canadian provinces

A public mail survey was sent to a sample of New Brunswick (NB) and Saskatchewan (SK) residents in 2007 to investigate their attitudes about controlling two very different forest pests: spruce budworm (SBW) (Choristoneura fumiferana) and forest tent caterpillar (FTC) (Malacosoma disstria). Participants were asked a series of questions related to their knowledge of these pests and their preferences over control options and program extents. SBW was the most widely known forest pest in NB, and FTC was most widely known in SK. Both groups largely supported (at over 80%) controlling future SBW and FTC outbreaks with biological control. They generally agreed that ecologically sensitive areas and wildlife habitat were the top priority that should be protected during the next outbreak of either pest. However, provincial differences in attitudes were found over the rank order of forest-type priorities that should be protected and the rank order of control options. Socio-demographic factors found to positively influence the preferred SBW and FTC control extent included those who had a high level of pest knowledge, those who had family members work in the forest industry, those who were residents in New Brunswick, those who were male, those who were aged 55 and over, those who had an education level beyond secondary school, and those who had household income of $50,000 or more. Results of this study can be used to assist policy makers and forest managers to arrive at publically acceptable pest control policies and make better informed decisions about future pest outbreaks.     

Performance of four <Emphasis Type="Italic">Trichogramma</Emphasis> species (Hymenoptera: Trichogrammatidae) as biocontrol agents of <Emphasis Type="Italic">Heliothis virescens</Emphasis> (Lepidoptera: Noctuidae) under various temperature regimes

Trichogramma spp. are major parasitoids of lepidopteran pest eggs, but there is large variation in efficacy toward a given pest among the numerous described Trichogramma species. It is important to select the Trichogramma species that most effectively parasitize and develop in target pest eggs for biological control. In this context, Trichogramma pretiosum, T. exiguum, T. atopovirilia and T. acacioi were studied in Heliothis virescens eggs under different thermal conditions. The parasitoids were reared at constant temperatures of 20, 25 and 30°C and tested at these respective temperatures, while parasitoids reared at 25°C were also tested at 20 and 30°C, for a total of 20 species–temperature combinations. About 30 H. virescens eggs were offered to the parasitoids for 24 h. Among the four species, parasitism rate by T. atopovirilia was highest at all temperature conditions, whereas T. acacioi had the lowest rates of parasitism at 25°C and 25/30°C. Parasitism ranged from 13.8 to 43.8% among all species–temperature combinations. Viability (emerged parasitoids) ranged from 80.8 to 98.4%, and was deemed satisfactory. The emergence rates of T. exiguum and T. acacioi were affected by temperature. Temperature also affected the sex ratio of T. exiguum at 25/30°C, whereas T. pretiosum and T. acacioi produced females predominantly independent of temperature. Overall, the parasitoid T. atopovirilia was the most efficient in parasitizing H. virescens eggs, though the levels of parasitism obtained might not ensure its successful use in biological control programs. The temperature-related differences in biological traits observed in the four Trichogramma species tested hint at the importance of making careful choices regarding climatic conditions where the parasitoid is going to be used when selecting a species for biological control programs.