Amphibians in the Vända artificial wetland

Bakalaureusetöö Keskkonnakaitse õppekavalEestis on seni vaid üks spetsiaalselt põllumajandusreostuse likvideerimiseks loodud tehismärgala – aastail 2014-2015 rajatud Vända kraavi tehismärgala Tartumaal. Kui hästi saab nimetatud märgala hakkama oma peaeesmärgiga, on uuritud juba üksjagu, aga puudusid uuringud selle mõjust kohalikule elustikule. Käesolev töö uurib kahepaiksete levikut ja sigimist Vända kraavi tehismärgalal. Aastatel 2016-2020 viidi kevadel ja suve alguses läbi kahepaiksete seire, mille käigus registreeriti kahepaikseliikide erinevate arengujärkude esinemine ja arvukus nii kahes tehismärgala tiigis kui ka ülesvoolu asuvas juba varem olemas olnud settetiigis ja lähedases metsatukas asuvas varjulises talutiigis. Kõige rohkem said tehismärgala tiikidest kasu rohu- ja rabakonn. Päriskonnalistest leidus tehistiikides ka harilikku kärnkonna ja tiigikonna, sabakonnalistest tähnikvesilikku. Rajatud tiigid sobivad kahepaiksetele elu- ja sigimispaigaks, kuid sobivate tingimuste säilitamiseks tuleb sealt aeg-ajalt eemaldada setteid ja liigselt vohama hakkavat taimestikku. Erinevalt sette- ja talutiigist on tehismärgala tiigid ka kalavabad, mis meeldib just raba- ja rohukonnale.So far, there is only one artificial wetland created in Estonia specifically for the elimination of agricultural pollution – the artificial wetland of Vända ditch in Tartu County built in 2014-2015. The extent to which this wetland can cope with its main objective has already been studied, but there have been no studies on its effects on local biota. The present study focuses on the distribution and reproduction of amphibians in the artificial wetland of Vända ditch. In 2016-2020, monitoring of amphibians was carried out in spring and early summer, during which the occurrence and abundance of different stages of development of different amphibian species were recorded in two artificial wetland ponds as well as in upstream sediment pond and in the shady farm pond in a nearby woodland. Common and moor frogs benefited the most from the artificial wetland ponds. Of the anurans, there were also common toads and pool frogs in the artificial ponds, and of the caudata, there was a smooth newt. The established ponds are suitable habitats for amphibians to live and reproduce, but in order to maintain suitable conditions, sediments and overgrown vegetation must be removed from time to time. Unlike sediment and farm ponds, artificial wetland ponds are fish-free, which is especially popular with common and moor frogs

Dispersioonikomponentide ja päritavuskoefitsiendi hindamine loomapopulatsioonides

http://tartu.ester.ee/record=b1019137~S1*es

Abundance and food plant preferences of different pollen beetle generations

Magistritöö Maastikukaitse ja -hoolduse õppekavalNaeri-hiilamardikas (Brassicogethes aeneus sün. Meligethes aeneus F.; Coleoptera: Nitidulidae) on kõige arvukam kahjur nii Euroopa, kui ka Eesti rapsi põldudel. Euroopas on viimasel ajal süvenenud probleem naeri-hiilamardika kahjustuste suurenemisega, sest mardikatel on pikaaegse taimekaitsevahendite kasutamise või üle doseerimise tõttu kujunenud välja resistentsus teatud taimekaitsevahendite (püretroidide) suhtes. Seetõttu tuleb leida uusi lahendusi jätkusuutliku ja keskkonnasõbraliku taimekaitse väljatöötamiseks, selleks aga tuleb tundma õppida kahjurputuka bioloogiat ja käitumist. Käesoleva magistritöö eesmärgiks oli kevadiste ja hilissuviste välitööde käigus selgitada välja naeri-hiilamardikate talvitunud ja talvituma suunduvate põlvkondade arvukused erinevatel põllumajandusmaastiku elementidel. Uurimiseesmärgiks oli ka selgitada, kui palju naeri-hiilamardika populatsioon suve jooksul suureneb. Kolmandaks uurimiseesmärgiks oli selgitada välja toidutaimede eelistused talvituma suunduvatel ja talvitunud mardikatel, ning selgitada välja ka toidutaimede värvuste eelistused. Viimaseks uurimiseesmärgiks oli selgitada välja, kas 2017. aasta naeri-hiilamardikate arvukused ja toidutaimede eelistused erinevad 2016. aastal saadud tulemustega. 2016. aasta tulemusi võrreldi Gerda Arrase lõputööga. Antud magistritöös selgus, et kuigi kevadel oli talvitumiskohtadest väljuv naerihiilamardikate arvukus madal, suutsid nad oma populatsiooni suve jooksul 44 korda suurendada. Leiti, et maastikuelement mõjutas oluliselt talvitunud ja talvituma suunduvate naeri-hiilamardikate arvukust. Talvitunud naeri-hiilamardikaid leiti kõige rohkem puiskoridorist ja metsaservast. Kõige rohkem suundus talvituma naeri-hiilamardikaid rohumaalt ja rohtselt põlluservalt. Magistritööst selgus, et naeri-hiilamardikatel oli toidutaimede värvuse suhtes eelistused. Talvitunud naeri-hiilamardikad toitusid kollast ja valget värvi õitel, ning talvituma suunduvad naeri-hiilamardikad toitusid paljudel erinevatel õitsevatel taimedel.The pollen beetle (Brassicogethes aeneus syn. Meligethes aeneus F.; Coleoptera: Nitidulidae) is one of the most numerous pests in European and Estonian oilseed rape fields. In Europe, the pollen beetle problem has intensified recently, as beetles have become resistant to certain pesticides (pyrethroids) due to long-term use and overuse of plant protection products. In order to develop more sustainable methods to control pollen beetle abundance, knowledge is needed of the biology and behaviour of this pest. The first aim of this master’s thesis was to study the abundance of overwintered and new generation pollen beetles in various agricultural landscape elements in the spring and late summer. The second aim was to study how much does the population of pollen beetles increase during the summer. The third aim was to study the food plant (species and flower colour) preferences of overwintered and new generation pollen beetles. The last aim was to find out whether the abundance and food plant preference of pollen beetles in 2017 differ from the results obtained in 2016 (master’s thesis of Gerda Arras). Although, the abundance of overwintered pollen beetles was low in 2017, they were able to increase their abundance by 44 times during the summer. Landscape element influenced the abundance of overwintered and new generation pollen beetles. Overwintered beetles were mostly found next to lines of trees and in forest edges, while new generation beetles were the most abundant in grasslands and narrow crop edges. According to the results of this study pollen beetles had a preference regarding the flower colour of their food plants. The overwintered generation of pollen beetles fed on yellow and white coloured flowers and new generation pollen beetles fed on many different flowering plants

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

Additional concentrates do not affect feeding times of cows, but social positions of cows do

ArticleIn robotic milking dairy systems lack of control over intakes can be problematic for balancing the forage and concentrate portions of diets. This can lead to proble ms associated with high concentrate intakes and concomitant low forage intakes. To check this as a problem, the feeding behaviour of cows was observed: the number of daily visits to the feed barrier, the duration of these visits and actual feeding, of high and low yielding cows. The cows were robot - milked and fed a ration comprising, separately, concentrate feed from a robot and a feeder, and a grass/clover silage mix forage at the feed barrier. Individual variation in visiting times and times spent at the feed barrier were greater than the effect of level of production. There was no evidence that cows with higher milk yields are differentially motivated to feed from forage. But more dominant cows spent more time feeding than submissive cows

Low cholesterol levels in children predict impulsivity in young adulthood

Objective: Severe behavioural issues such as impulsive action and suicide have since long been associated with low levels of cholesterol. While it is known that cholesterol plays a role in neural development and hence low levels of serum lipids could have long-term effects on behaviour, there are no longitudinal studies showing association of serum lipids levels with impulsivity. We aimed to examine the prognostic properties of serum lipid levels during childhood and adolescence on measures of impulsivity during early adulthood in a representative birth cohort sample. Methods: We have investigated whether serum lipid levels measured at 9, 15, 18 and 25 years of age have an association with impulsivity in 25 years old young adults. This analysis was based on data of the birth cohort representative samples of the Estonian Children Personality Behaviour and Health Study (original n=1238). Impulsivity was self-reported with the Adaptive and Maladaptive Impulsivity Scale. Results: Total and LDL cholesterol measured in 9, 15 and 18 years old boys predicted Disinhibition and Thoughtlessness in 25 years old young adults. High scores of Disinhibition were associated with low total and LDL cholesterol levels in males but, while less consistently, with high total and LDL cholesterol levels in females. Cross-sectional analysis did not result in systematic outcomes. Conclusions: Serum lipid levels could have an impact on development of maladaptive impulsivity starting from an early age. This effect of cholesterol continues throughout adolescence into young adulthood

Resistance developments in Estonia’s population of pollen beetles (Brassicogethes aeneus)

A total of 111 local pollen beetle populations were collected from both winter and spring oilseed rape fields, in the main oilseed growing regions of Estonia between 2015−2019. The objective was to analyse the insecticide-susceptibility of the pollen beetle population (in the form of Brassicogethes aeneus). The pollen beetle samples were tested for sensitivity to lambda-cyhalothrin, thiacloprid, and chlorpyrifos. The efficacy of the tested insecticides varied considerably by region. We observed a clear decrease in susceptibility to lambda-cyhalothrin and thiacloprid, but sensitivity to chlorpyrifos remained stable throughout the period between 2015 and 2019. Amongst the tested samples in that period, a total of 3% were classified as susceptible to lambda-cyhalothrin, 18% as moderately resistant, 70% as resistant, and 7% as highly resistant. In the case of thiacloprid, 21% of the samples were highly susceptible to the insecticide, 39% were susceptible, and 41% had reduced levels of susceptibility to the insecticide. The information which was presented tended to confirm the ongoing evolution of insecticide resistance in the B. aeneus population in Estonia, while also highlighting the importance of data-based decisions when optimising insecticide resistance management in the field

Changes in dairy cows' behaviour, health, and production after transition from tied to loose housing

BackgroundTransition of dairy cows from a tied to a loose housing system may affect their behaviour, health and production. Such housing system changes have become more frequent in Estonia but knowledge is lacking on how cows adapt to a new system. The aim of this study was to evaluate how cows' behaviour, milk production and composition, and different aspects of their health changed after transition from tied to loose housing.ResultsA herd of 400 dairy cows was moved to a new system on the same farm, so that effects of transport were not confounding factors. Behavioural observations were made for approximately 4 months following transition. Milk production data were recorded from 12 months before to 12 months after transition. Examination for skin alterations and cleanliness, as well as body condition scoring were carried out before transition, and thereafter monthly throughout the study. Significant effects on behaviour were observed just after the transition, with increases in the behaviour indicative of poor welfare, such as vocalisation and aggression, and decreases in those indicative of a good state of welfare, such as ruminating, resting and grooming. These effects were of short duration, with most returning to a steady state after the first week. Milk production declined already before the transition but fell significantly after transition, and this fall lasted longer in older cows. Likewise, somatic cell counts were higher in all cows following transition, but older cows were affected significantly more than cows in the first lactation. The frequency of lameness and skin alterations increased on average after transition. Body condition scores fell after transition but recovered by the second month. Therefore, there were adverse effects on the behaviour, health and production of the dairy cows transferred, although, apart from older cows, of short duration.ConclusionThe transition from tied to loose housing first had negative impacts on the welfare of the cows, although by the tenth day the behavioural indicators had returned to normal values. Impacts were more severe in higher parity cows, indicating that the change was more of a challenge for older cows.The findings of this study suggest that animals' behaviour and health should be more carefully observed within about 2 weeks after transition. It is quite likely that more and more farmers in Estonia and elsewhere will recognize the benefits of keeping their dairy cattle in loose housing, aimed at improving animal welfare and the value of the production chain

Antimicrobial Selection for the Treatment of Clinical Mastitis and the Efficacy of Penicillin Treatment Protocols in Large Estonian Dairy Herds

Clinical mastitis (CM) is the most common microbial disease treated in dairy cows. We analyzed the antimicrobial usage in cows with CM (n = 11,420) in large dairy herds (n = 43) in Estonia. CM treatment data were collected during a 12-month study period. The antimicrobial usage was observed during the 21 days from the initiation of treatment, and the incidence of antimicrobial-treated CM was calculated for each study herd. The effect of intramammary (IMM), systemic, and combined (systemic and IMM) penicillin treatment of CM on the post-treatment somatic cell count (SCC) was analyzed using the treatment records of 2222 cows from 24 herds with a mixed multivariable linear regression model. The median incidence of antimicrobial-treated CM was 35.8 per 100 cow-years. Procaine benzylpenicillin and marbofloxacin were used in 6103 (35.5%, 95% CI 34.8–36.2) and 2839 (16.5%, 95% CI 16.0–17.1) CM treatments, respectively. Post-treatment SCC was higher after IMM penicillin therapy compared to systemic or combination therapy. Treatment of CM usually included first-choice antimicrobials, but different antimicrobial combinations were also widely used. The effect of procaine benzylpenicillin to post-treatment SCC was dependent on the administration route, cow parity, and days in milk. Further studies should evaluate the factors affecting veterinarians’ choice of antimicrobial used in the treatment of CM