Search results for "hyönteiset"
showing 6 items of 56 documents
Interspecific interactions and selection on secondary sexual characters in damselflies
2005
Lajienvälinen aggressiivisuus voi selittää immenkorentokoiraiden seksuaaliominaisuuden koossa havaittavaa vaihtelua, toteaa Katja Tynkkynen väitöskirjatyössään. Sekundaarisien seksuaaliominaisuuksien, kuten koiraslintujen kirkkaan värityksen, on tulkittu olevan seurausta seksuaalivalinnasta. Koiraat, joilla on suurempi tai upeampi seksuaaliominaisuus saavat yleensä muita suuremman lisääntymismenestyksen, minkä seurauksena seksuaaliominaisuuksiin kohdistuu positiivista suuntaavaa valintaa. Näin voi tapahtua esimerkiksi naaraan valinnan seurauksena tai koska suuren tai upean seksuaaliominaisuuden omaavat koiraat menestyvät paremmin koiraiden välisessä kilpailussa. Lajiensisäisten vuorovaikutu…
Verifying the predicted risk of extinction based on ecological characteristics
2021
Red List status of species should reflect species extinction risk. Because data are limited and species response has a time lag, species may be threatened by extinction even if they are not Red‐Listed. The ability to predict species risk of extinction from ecological characteristics holds promises for proactively targeting conservation measures to species at high risk. In 2005, the risk of extinction from ecological characteristics was predicted for 81 species of Finnish butterflies. Now, after 15 years and two additional national Red List assessments, these predictions are verified. Species with a higher risk of extinction according to the original ecological extinction risk rank (EERR) ha…
Alarmist by bad design: Strongly popularized unsubstantiated claims undermine credibility of conservation science
2019
“Unless we change our ways of producing food, insects as a whole will go down the path of extinction in a few decades.” or “Our work reveals dramatic rates of decline that may lead to the extinction of 40% of the world's insect species over the next few decades.” These are verbatim conclusions of the recent paper by Sánchez-Bayoa and Wyckhuys (2019) in Biological Conservation. Because of fundamental methodological flaws, their conclusions are unsubstantiated. Like noted by The Guardian, the conclusions of the paper were set out in unusually forceful terms for a peer-reviewed scientific paper. The current case…
Multiple modalities in insect warning displays have additive effects against wild avian predators
2019
Allocation to different components of defence has been suggested as an explanation for the existence of multiple aposematic morphs in a single population. We tested whether there are trade-offs between warning colouration and chemical defence or whether these have an additive effect when combined, using blue tits (Cyanistes caeruleus) as predators and the polymorphic wood tiger moth (Arctia plantaginis) as prey. We used artificial edible models (with and without the moths’ defensive fluids) with paper wings whose colour and pattern properties matched those of real moths. When the models were presented sans defensive fluids or when the fluids were presented without colour cues, we detected n…
Developing response-ability in human-wasp encounters
2023
Learning to live with unloved others is crucial in the ecological crisis. Unloved wasps are feared and disliked for their sting. Understanding of their ecological importance is increasing, however. Human-wasp encounters are changing with environmental changes, and strategies for multispecies cohabitation are needed. This multispecies study highlights features of wasp biology affecting human-wasp encounters and analyzes how conflicted human-wasp relations could be mitigated. The geographical focus is Finland, in the Northern boreal region. Biological analysis specified spatiotemporal aspects affecting human-wasp encounters: human and wasp habitats and preferences overlap ubiquitously. From a…
Plasticity in Photoperiodism : Drosophila montana Females Have a Life-Long Ability to Switch From Reproduction to Diapause
2022
Photoperiodic reproductive diapause is an essential part of female life cycle in several insect species living on high latitudes, where overwintering in reproductive stage involves high risks for survival and progeny production. The sensitive period (SP), during which photoperiodic cues can trigger the switch from direct development to diapause, can last from a few hours or days after emergence to the entire life span of females. Moreover, in some species, sexually mature females can enter post-reproductive diapause as a response to decreasing day length and/or temperature. We studied the duration of SP for diapause induction and the females’ ability to enter post-reproductive diapause at s…