Kimalaste õietolmu korje sõltuvalt aedmaasika kasvatustehnoloogiast

Strawberry is a fruit crop grown worldwide. There are two main strawberry production systems: open fields and protected cultures (greenhouses or high tunnels). Growing strawberries under high tunnels has many advantages such as protection from different weather conditions, but also disadvantages such as lack of pollinators. The aim of this study was to investigate whether additional pollinators (bumble bees) visit strawberry flowers at different rate under high tunnels compared to open fields. Field experiment was performed to collect and analyze bumble bee corbicular pollen from hives located under high tunnels and open fields. We found that bumble bees under high tunnels gathered more pollen from plant species (strawberry and white clover) present there. By bringing additional pollinators under high tunnels attention should be paid, what kind of other plant species and how abundantly they are flowering there besides strawberry. Under high tunnels the weather conditions are somewhat different which also may affect bumble bee foraging behaviour

Kimalaste efektiivsus biotõrjepreparaatide siirutamisel sõltub konkureerivatest toidutaimedest

Sünteetiliste taimekaitsevahendite laialdane kasutamine ning nendega kaasnev võimalik negatiivne mõju keskkonnale ja inimeste tervisele on tänapäeva põllumajanduses üks kõige rohkem muret tekitav teema. Aedmaasika (Fragaria x ananassa Duch.) kui ühe maailmas enim kasvatatud marjakultuuri suurima kahjustaja, seene Botrytis cinerea Pers. põhjustatava hahkhallituse tõrjumisel kasutatakse praeguseni kõige sagedamini sünteetilisi fungitsiide. Arvestades nende kasutamisega seotud võimalikke probleeme, näiteks pestitsiidijääkide kogunemist viljadesse ja resistentsuse teket seenhaiguste suhtes (Diánez jt., 2002; Mommaerts jt., 2011), püütakse järjest enam leida võimalusi, kuidas asendada keemiline tõrje biotõrjega. Biopreparaadid on sageli kallid ja nende taimedele kandmine tavameetoditega töömahukas ning preparaadi kadu suur. Üheks alternatiivseks võimaluseks on rakendada uudset meetodit – vektortehnoloogiat, milles tolmeldajad siirutavad biotõrjepreparaate taimede õiteni. Tehnoloogia väljatöötamine on eriti olulise tähtsusega mahepõllumajanduse jaoks, et täiendada olemasolevat vähest tõrjemeetodite valikut. Eestis võivad vektortehnoloogia edukal kasutamisel avamaastikus osutuda probleemiks aedmaasikaga samal ajal õitsevad tolmeldajate toidutaimed, mis on kimalastele samuti atraktiivsed ja vähendavad seega biopreparaadi siirutamise tõhusust. Antud uurimistöö eesmärgiks oli selgitada, kas kimalaste efektiivsus biopreparaatide kandmisel sõltub teiste, aedmaasikaga samal ajal õitsevate toidutaimede esinemisest

1.13 Using respiratory physiology techniques in assessments of pesticide effects

The determination of sub-lethal effects of pesticides on beneficial insects is challenging topic because the vast number of different possible endpoints. Traditionally measured endpoints reflect the basic outcome but do not give any information about the mode of actions or the real non-harming dosages of the studied toxicants. Physiological changes, however, reflect even small deviations from normal state. The gas exchange patterns are sensitive cues to determine the sub-lethal toxicosis in insects. Methods of respiratory physiology have been used to detect sub-lethal toxic effects of many chemicals, but information for biological preparations is also needed, especially when bees are used in entomovectoring task. The aims of this study were i) to clarify which are the effects of three microbiological preparations on two bee species, honey bees Apis mellifera L. and bumble bees Bombus terrestris L. and ii) could we compare the effects of the same preparations on different bee species. We saw that honey bees and bumble bees react similarly on microbiological preparations, however the reaction strength differed. We found that kaolin affects the survival of bumble bees and honey bees as much as did entomopathogenic preparations, whereas pure spores of a non-hazardous fungus and wheat flour did not. Bumble bees seem to be more tolerant to microbiological preparations than honey bees.The determination of sub-lethal effects of pesticides on beneficial insects is challenging topic because the vast number of different possible endpoints. Traditionally measured endpoints reflect the basic outcome but do not give any information about the mode of actions or the real non-harming dosages of the studied toxicants. Physiological changes, however, reflect even small deviations from normal state. The gas exchange patterns are sensitive cues to determine the sub-lethal toxicosis in insects. Methods of respiratory physiology have been used to detect sub-lethal toxic effects of many chemicals, but information for biological preparations is also needed, especially when bees are used in entomovectoring task. The aims of this study were i) to clarify which are the effects of three microbiological preparations on two bee species, honey bees Apis mellifera L. and bumble bees Bombus terrestris L. and ii) could we compare the effects of the same preparations on different bee species. We saw that honey bees and bumble bees react similarly on microbiological preparations, however the reaction strength differed. We found that kaolin affects the survival of bumble bees and honey bees as much as did entomopathogenic preparations, whereas pure spores of a non-hazardous fungus and wheat flour did not. Bumble bees seem to be more tolerant to microbiological preparations than honey bees

Reliability of the entomovector technology using Prestop-Mix and Bombus terrestris L. as a fungal disease biocontrol method in open field

Botrytis cinerea Pers.: Fr. is a major plant pathogen, and a new approach is needed for its control in strawberry to minimise the increasing use of synthetic fungicides. The biofungicide Prestop-Mix, which contains Gliocladium catenulatum, is effective against Botrytis infections; however, the need for frequent applications increases the costs for farmers. Here, we demonstrate that bumble bees, Bombus terrestris L., effectively disseminate the preparation onto flowers in open field conditions. Over the course of three years, we found a highly significant decrease in the rate of Botrytis infection. Pathogen control was achieved with relatively low numbers of G. catenulatum spores per flower, even using flowers that are not highly attractive to bumble bees. An even distribution of spores was detected up to 100 m from the hives, either due to primary inoculation by bumble bees or secondary distribution by other flower visitors such as honey bees and solitary bees. We showed that the application of a biocontrol agent by bumble bees is reliable for the use of environmentally friendly pest control strategies in northern climatic conditions. This low cost technology is especially relevant for organic farming. This study provides valuable information for introducing this method into practice in open strawberry fields

Sublethal effects of kaolin and the biopesticides Prestop-Mix and BotaniGard on metabolic rate, water loss and longevity in bumble bees (Bombus terrestris)

Kaolin is an inert material with a broad range of applications, e.g. as an insecticide and as a filling substance in the formulation of biopesticides. Hence, bees that dispense biopesticides to the field in the context of entomovectoring are exposed to elevated risks because of sideeffects of those products. Here, we investigated with use of bumble bee workers of Bombus terrestris L. the lethal and sublethal effects of (i) pure kaolin, (ii) the biofungicide Prestop-Mix containing the parasitic fungus Gliocladium catenulatum and kaolin and (iii) the bioinsecticide BotaniGard containing the entomopathogenic fungus Beauveria bassiana and compared with wheat flour powder that we considered safe for bumble bees. As the most important result, treatment with kaolin increased the cuticular water loss and reduced the survival of treated bumble bees, while Prestop-Mix had no negative effect on longevity. BotaniGard caused mortality in the bumble bees because of the entomopathogenic spores it contained. In conclusion, our data indicated that substances used as ‘inert materials’ and in biocontrol agents which are used in IPM and organic farming systems may bring higher risks to bumble bees used in entomovector technology

Impact of Competitive Food Plants in Biocontrol of Strawberry (Fragaria x ananassa Duch.) Grey Mould (Botrytis cinerea Pers.) in the Example of Bumble Bees (Bombus terrestris L.) and Honey Bees (Apis mellifera L.)

Sünteetiliste taimekaitsevahendite laialdane kasutamine ning nendega kaasnev võimalik negatiivne mõju keskkonnale ja inimeste tervisele on tänapäeval üks kõige rohkem muret tekitav teema. Aedmaasika kui ühe maailmas enim kasvatatud viljakultuuri suurima kahjustaja, seene Botrytis cinerea Pers. põhjustatava hahkhallituse tõrjumisel kasutatakse praeguseni kõige rohkem sünteetilisi fungitsiidide. Arvestades nende võimalikku kahjulikku mõju, näiteks pestitsiidijääkide kogunemist viljadesse, püütakse järjest enam leida võimalusi, kuidas asendada keemiline tõrje biotõrjega. Üks selliseid võimalusi on rakendada entomovektortehnoloogiat, kus tolmeldajad ehk entomovektorid kannavad biotõrjepreparaadi taimeni, millel hahkhallitust tõrjuda soovitakse. Magistritöö esimeseks eesmärgiks oli teada saada, millised toidutaimed on karukimalastele ja meemesilastele (entomovektoritele) atraktiivsed aedmaasika õitsemise ajal. Teiseks uuriti entomovektortehnoloogia efektiivsust aedmaasika hahkhallituse tõrjes Eesti tingimustes. Eesmärkide saavutamiseks tehti 2012. aasta neljal katsealal välitööd. Holsta ja Polli katsealal kasutati entomovektoritena karukimalasi, Nõo ja Vasula katsealal meemesilasi. Välitöödele järgnesid tolmeldajate kogutud õietolmu analüüsimine ja andmetöötlus. Uuringu tulemused näitasid, et mitmed konkureerivad toidutaimed on karukimalastele ja meemesilastele atraktiivsed ning see mõjutas oluliselt õietolmukorjet aedmaasikal, mida külastati seeläbi vähem. Tulemused kinnitasid töös püstitatud esimest hüpoteesi – konkureerivad toidutaimed mõjutavad karukimalaste ja meemesilaste õietolmukorjet aedmaasikal. Entomovektortehnoloogia kasutamisel vähenes hahkhallitusse haigestumine 2,5– 10,7% võrra. Kinnitust sai ka teine töös püstitatud hüpotees, mille kohaselt karukimalased ja meemesilased külastavad aedmaasikat piisavalt, et tagada haiguse efektiivne tõrje. Entomovektortehnoloogia rakendamine annaks võimaluse vähendada keemiliste taimekaitsevahendite kasutamist, mis säästaks keskkonda ja inimeste tervist ning omaks erilist tähtsust mahepõllumajanduses, kus saaks tõhustada kontrolli hahkhallituse ning teiste taimehaiguste üle kasutades keskkonnasõbralikku meetodit. Lähtudes tulemustest peaks entomovektortehnoloogia kasutamisel pöörama tähelepanu ümbritseva maastiku erisusele, mis mõjutab tolmeldajate õietolmukorjet aedmaasikal. Kui võimalik, tuleks jälgida, et tolmeldajate korjelennukaugusest jääks võimalusel välja rikkalikult õitsevad ning atraktiivsed toidutaimed.Extensive use of synthetic pesticides and their potential negative impact to the environment and human health is one of the most troubling issue nowadays. Strawberry is a fruit crop grown worldwide. The most destructive pathogen of strawberry, grey mould is so far mainly managed by synthetic fungicides. Considering potential negative effects of chemical control, such as pesticide residues in fruits, it is essential to find different solutions how to replace chemical control with biocontrol. One of these strategies is to apply entomovector technology: pollinators (entomovectors) carry biofungicide to the plant, on which grey mould managing is wanted. The first aim of this thesis was to find out which competitive food plants are attractive to entomovectoring bumble bees and honey bees during strawberry flowering time. The second aim was to evaluate the efficiency of entomovector technology against strawberry grey mould in Estonian conditions. To achieve aims of this thesis, fieldwork was carried out in four different experimental areas in year 2012. Bumble bees were used as entomovectors in Holsta and Polli. Honey bees were used as entomovectors in Nõo and Vasula. After fieldwork pollen analysis and data processing were done. Results of the study showed that many competitive food plants are attractive to both bumble bees and honey bees. This significally affected pollen collecting from strawberries, which were thereby less visited. These results confirmed the first hypothesis of this thesis: competitive food plants affect bumble bees and honey bees pollen collecting from strawberries. Entomovector technology reduced the infection rate of grey mould up to 10,7%. So the other hypothesis was also confirmed: bumble bees and honey bees visit strawberry flowers enough to ensure effective control of the disease. In conclusion of this study it can be said that entomovector technology would provide an opportunity to reduce the use of chemical pesticides for protecting environment and human health. Moreover, it would have a special importance in organic agriculture, where using biocontrol methods could improve the control of grey mould and other plant diseases. When using entomovector technology in open fields one should be pay attention to the surrounding landscape which can affect pollinators foraging. If possible, other blooming and attractive food plants should be out of pollinators foraging distance