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Pölyttäjähyönteisten katoaminen on osallistanut ihmisiä lajien suojeluun. Vihertalouden myötä on muotoutunut myös mielikuvia pölyttäjähyönteisten optimaalisista elinympäristöistä sekä pölyttäjäkasveista. Suomessa tieteelliset pölyttäjähyönteisten pitkäkestoiset elinympäristötutkimukset ovat rahoituksen puuttuessa tuottaneet vain niukasti tietoa pölyttäjäkeskusteluun. Tämä monivuotinen ja useampaan metodiin pohjautuva tutkimus tarkastelee kimalaisten vuorovaikutussuhdetta erilaisiin ihmisen muokkaamiin ympäristöihin ja niiden kasveihin. Vahvan kestävyysajattelun tavoitteiden mukaisesti tutkimus hyödyntää tutkimusasetelmissaan eri tieteenalojen lähestymiskulmia: taidetta ja taidekasvatusta elämäsidonnaisemman tutkimusaluerakenteen muodostamisessa, maantiedettä mittausmenetelmissä ja alueellisissa tarkasteluissa, kasvi- ja eläinbiologiaa lajistovuorovaikutusseurannoissa ja filosofiaa pohdintojen kokoajana. Tutkimus tarttuu eettisiin kysymyksiin paitsi pölyttäjähyönteisten elinympäristöjen myös tutkimusmenetelmien ja tutkijan itsensä osalta., The disappearance of pollinating insects has increased people’s interest in protecting them. Ideas of green economy have informed images of optimal habitats for plant-pollinator interactions. In Finland, long-term scientific habitat researches of pollinating insects have only produced little information for the pollinator discussion. This long-term, multi-method research observes the interaction of bumblebees with various man-made environments and their plants. The article reports the results of field studies conducted in 2019 and 2020 and also raises ethical issues concerning the methods of insect research from the perspective of strong sustainability thinking.

Pollination is often used as a classic example of mutualism. However, not all plants produce any food reward for their pollinators. Such non-rewarding pollination strategies are called pollinator deception, as plants take advantage of innate and learned sensory traits that interest their pollinators. Pollinator deception has evolved several times in different plant lineages but reduces the seed production in relation to rewarding plant species. Resource allocation to growth and increased cross-pollination have been both presented as plausible hypotheses for the evolutionary ecology of deceptive pollination. However, it is still unclear if there are ecological factors affecting the profitability of pollinator deception. My aim was to study spatial effects of pollinator deception. I started my studies by monitoring the pollination of a deceptive orchid Calypso bulbosa in natural plant populations. My results show that C. bulbosa competes for pollinator attraction, as increasing neighbour distances and small local populations both positively affected male pollination success. After that I wanted to study similar questions experimentally in controlled settings. For that reason, I developed an automated computer controlled robotic flower system. Using bumblebees as test animals, my results show that pollinators move longer flower-to-flower distances when foraging on deceptive artificial plants compared with rewarding settings, probably increasing cross-pollination in real plant populations. My results also show that in patchy and deceptive settings, a greater proportion of flower visitations are patch-connecting, compared with patchy and rewarding settings. By avoiding trapping the pollinators into distinctive rewarding patches, pollinator deception could increase the gene flow and effective population size in fragmented habitats. During my experiments, I became interested in a timely question related to pollination, the inadvertent effects of neonicotinoid pesticides on pollinator behaviour. My results show that bumblebee’s foraging motivation reduces before any effects on physical performance or learning abilities appear. Such reduction in foraging motivation could partly explain bee pollinator decline, as similar concentrations of neonicotinoids as were used in the study are commonly measured from plant nectar and pollen in agriculturally intensive regions. Tiivistelmä Kasvien ja pölyttäjien vuorovaikutuksia pidetään usein klassisena esimerkkinä mutualismista. Kaikki kasvit eivät kuitenkaan palkitse pölyttäjiään ruualla, vaan huijaavat pölyttäjiä niiden sisäsyntyisillä ja opituilla preferensseillä. Huijaavia pölytysstrategioita on kehittynyt useissa kehityslinjoissa, ja ne ovat erityisen yleisiä kämmekkäkasveilla. Pölyttäjiä huijaavilla kasveilla on keskimäärin kaksi kertaa huonompi siementuotto medellisiin verrattuna. Meden tuottamiseen käytettävän energian allokointi kasvuun ja vähäisempi itsepölytys ovat yleisimpiä hypoteeseja selittämään kuinka pölyttäjien huijaus voisi olla evolutiivisesti vakaa pölytysstrategia. Vielä ei ole kuitenkaan selvyyttä, mitkä ympäristötekijät voivat suosia medettömyyttä. Tässä työssä pyrin tutkimaan vaikuttaako kasvipopulaatioiden spatiaalinen rakenne pölyttäjien huijauksen kannattavuuteen, ja erityisesti onko pölyttäjien huijaus kannattavampaa pirstoutuneissa habitaateissa. Tulokseni osoittavat, että medettömän neidonkengän (Calypso bulbosa) luonnonpopulaatioissa paras pölytysmenestys on, kun neidonkenkäyksilöt ovat kaukana toisistaan ja kun paikallispopulaatiot ovat pieniä. Tämän tutkimuksen jälkeen halusin tutkia vastaavia kysymyksiä kontrolloiduissa olosuhteissa, mitä varten kehitin tietokoneohjasteisen robottikukkasysteemin. Tämän systeemin avulla sain selville, että medettömillä keinokukilla vierailevat kimalaiset lentävät pitempiä matkoja kukasta kukkaan medellisiin verrattuna, mikä tukee ristipölytyshypoteesia. Lisäksi pölyttäjien huijaus laikkumaisissa habitaateissa lisäsi kasvilaikkujen välisiä pölytystapahtumia, mikä voi kasvattaa pirstoutuneiden paikallispopulaatioiden välistä geenivirtaa ja efektiivistä populaatiokokoa. Näiden tutkimusten aikana tulin kiinnostuneeksi minkälaisia käyttäytymismuutoksia torjunta-aineena käytetyt neonikotinoidit aiheuttavat kimalaisille. Tulosteni mukaan kimalaisyksilöiden motivaatio ravinnonkeräykseen heikkenee ennen kuin mitään fyysiseen suorituskykyyn tai oppimiseen liittyviä muutoksia on havaittavissa. Kokeessani käytettyä neonikotinoidipitoisuutta on mitattu yleisesti kasvien medestä ja siitepölystä intensiivisen maatalouden alueilta. Tämä neonikotinoidien aiheuttama heikentynyt motivaatio ravinnonkeräykseen voi osaltaan selittää pölyttäjäkatoa.

Imaging the visual systems of bumblebees and other pollinating insects may increase understanding of their dependence on specific habitats and how they will be affected by climate change. Current high-resolution imaging methods are either limited to two dimensions (light- and electron microscopy) or have limited access (synchrotron radiation x-ray tomography). For x-ray imaging, heavy metal stains are often used to increase contrast. Here, we present micron-resolution imaging of compound eyes of buff-tailed bumblebees (Bombus terrestris) using a table-top x-ray nanotomography (nano-CT) system. By propagation-based phase-contrast imaging, the use of stains was avoided and the microanatomy could more accurately be reconstructed than in samples stained with phosphotungstic acid or osmium tetroxide. The findings in the nano-CT images of the compound eye were confirmed by comparisons with light- and transmission electron microscopy of the same sample and finally, comparisons to synchrotron radiation tomography as well as to a commercial micro-CT system were done. peerReviewed

Using social information can be an efficient strategy for learning in a new environment while reducing the risks associated with trial-and-error learning. Whereas social information from conspecifics has long been assumed to be preferentially attended by animals, heterospecifics can also provide relevant information. Because different species may vary in their informative value, using heterospecific social information indiscriminately can be ineffective and even detrimental. Here, we evaluated how selective use of social information might arise at a proximate level in bumblebees (Bombus terrestris) as a result of experience with demonstrators differing in their visual appearance and in their informative value as reward predictors. Bumblebees were first trained to discriminate rewarding from unrewarding flowers based on which type of &ldquo, heterospecific&rdquo, (one of two differently painted model bees) was next to each flower. Subsequently, these bumblebees were exposed to a novel foraging context with two live painted bees. In this novel context, observer bumblebees showed significantly more social information-seeking behavior towards the type of bees that had predicted reward during training. Bumblebees were not attracted by paint-marked small wooden balls (moved via magnets) or paint-marked non-pollinating heterospecifics (woodlice, Porcellio laevis) in the novel context, indicating that bees did not simply respond to conditioned color cues nor to irrelevant social cues, but rather had a &ldquo, search image&rdquo, of what previously constituted a valuable, versus invaluable, information provider. The behavior of our bumblebees suggests that their use of social information is governed by learning, is selective, and extends beyond conspecifics.

Mitigation tools aimed at counteracting the loss of farmland insect diversity and associated ecosystem services are usually conducted on cultivated fields. Possibilities of managing field-forest ecotones for biodiversity have been rarely discussed, despite their importance for flower-visiting insects. The effectiveness of logging in enhancing three aspects of insect diversity (bumblebee abundance, total species richness, and habitat specialist butterfly abundance) and changes in insect community composition were studied in a three-year field experiment. The study included 15 field-forest ecotones, each with a 50 m long and 25 m wide treated area and a corresponding control. At forest edge, a 5 m wide strip was clear-cut and behind this strip, a 20 m wide belt was thinned to a basal area of 8 m2 ha−1. Logging simultaneously promoted all three aspects of insect diversity. Changes were more apparent at clear-cut edge than in the thinned interior. Community composition changed via increased abundance of open habitat species, especially butterflies. Logging promoted warm microclimates and flower availability at clear-cut edges. All three aspects of insect diversity showed a positive response to flower coverage, which in turn was negatively correlated with the amount of logging residue. Creating open field-forest ecotones is beneficial for flower-visiting insects and open habitat species in particular. This approach is expected to be most beneficial at sunny forest edges and sites which become overgrown slowly. In addition, we suggest logging residue to be removed when aiming to promote flower-visitors.

Long-term grassland fallow and short-term meadow fallow represent alternative fallowing strategies for biodiversity conservation on farmland. Conventional grassland mixtures are used to establish long-term grassland fallows, whereas short-term meadow fallows are sown with specific meadow seed mixtures and require regular re-establishment to maintain the abundance of sown species. This study examined the impact of fallow type and landscape structure on the species richness and abundance of four taxa: plants, bumblebees, butterflies and birds. Long-term grassland fallows and short-term meadow fallows were studied in four contrasting landscape types in Finland, differing in the cover of forest and perennial grasslands. The fallow type and landscape structure affected each species group differently, and the value of a particular fallow type was also modified by landscape setting. Bumblebees were most abundant in short-term meadow fallows, whereas butterflies benefited more from long-term grassland fallows. Species richness of plants and butterflies were higher in forested than in open landscapes. Long-term grassland fallows promoted species richness of butterflies as well as the abundance of foraging edge birds in forested landscapes, whereas short-term meadow fallows enhanced the abundance of foraging edge birds in open landscapes. In landscapes with high grassland cover, the breeding density of open farmland birds was higher in meadow fallows than in grassland fallows, while the reverse was true in landscapes with low perennial grassland cover. The fallowing strategy thus can be adapted to the landscape context depending on the specific objectives. For overall biodiversity enhancement, establishing and managing different kinds of fallows is important.