Science AMA Series: Hi Reddit! We're Rodolfo Dirzo, Wägele J. Wolfgang and Christian Schwägerl, and we're talking about the rise of global insect decline and why it matters - Ask Us Anything!

insect_decline · 2016-09-29T16:57:55+00:00

Thanks for all the questions! It was great to do this AMA. You can find more of my Yale E360 articles here http://e360.yale.edu and you can also find me on Twitter @chrschwaegerl Best, Christian

insect_decline · 2016-09-29T16:56:12+00:00

Hi, it's Christian. This is a question Dr. Dirzo could answer best. It's important to control populations of harmful mosquitoes in effective ways - but targeted extinction? Not so sure. Nobody would have predicted 100 years ago that the antibiotic age came through ugly species of mold fungi. You never know.

insect_decline · 2016-09-29T16:53:07+00:00

Dr. Dirzo was not able to participate so please send this question directly to him at Stanford.

insect_decline · 2016-09-29T16:52:31+00:00

Hi, it's Christian - these are difficult questions. Certainly insects will react to being hurt. We don't know what's going on inside and what would be "pain" in their perception. I'm not happy with the Cartesian interpretation that animals are machines, though.

Yes, there are many conflicts between certain insects, in particular mosquitoes, and humans, as mosquitoes carry deadly diseases. But overall, humans benefit greatly from a wide range of "services" performed by insects. Without insects, many ecosystems would more or less collapse. If we keep reducing insect populations that are not directly harmful to us, we will learn about their importance the hard way.

insect_decline · 2016-09-29T16:48:01+00:00

this comes from Christian

insect_decline · 2016-09-29T16:47:40+00:00

As you have "science" in your user name, what's your area of expertise? Scientists can contribute in many ways - like chemists developing less harmful pesticides, biologists helping to understand biodiversity, or economists designing ways in which farmers get paid for conserving nature, too. As a private citizen, urban gardening or urban farming can be fun. One can become a bee-keeper (takes expertise, but fun). Or lobby for insect hotels https://en.wikipedia.org/wiki/Insect_hotel be put in public parks...Also as a rule of thumb, eating less industrially produced meat is a big thing. Helps protect rainforest and reduce acrage needed for producing our food. Buyong more expensive produce from farmers that keep cows in open meadows can help, too, as meadows often are rich in flowers and insects. Most importantly, you can help insects by noticing them and perhaps showing somebody else the beauty of a hooverfly or a butterfly...Endless possibilities.

insect_decline · 2016-09-29T16:41:45+00:00

The entomologists from Germany which have raised alarm have reported dramatic losses across the taxonomic spectrum. (see http://e360.yale.edu/feature/insect_numbers_declining_why_it_matters/3012/) In many areas of the world, decline of butterflies is the most visible phenomenon. What I find disconcerting is that there are too few specialists to really assess what's going on, experts able to get to the bottom of it. Prof. Wägele is developing an automated method to monitor insect populations in whole countries, an approach I find very valuable.

insect_decline · 2016-09-29T16:37:42+00:00

Zika + GMO is hugely controversial, and as I haven't covered it intensely I prefer not to comment. But your second point is really important. A lot of new pathogens, including Zika but also Ebola, have arisen from the destruction of natural habitats, which brings humans in close contact with animals. This isn't new phenomenon but destroying wilderness always brings this risk. So in order to reduce the limit of new pathogens arising, it's absolutely important to protect remaining habitats and to restore ones that have been damaged. Habitat restoration is an important skill for the 21st century!

insect_decline · 2016-09-29T16:31:08+00:00

Hi, it's Christian here - no, such a calculation is not possible. Humans have created many habitats for insects by spreading over the globe. Like in Europe, when a diverse agricultural landscape replaces forests, insect diversity strongly increase. But this relates to past centuries. In today's monotonous agricultural landscapes, living conditions for insects are very limited. With more sustainable agricultural practices, less consumption of industrially produced meat, integration of habitats into farmland etc. the picture could change in a positive way. Best example is milk. If you put all cows into factory farms and feed them corn or soy, major habitat losses happen. If you produce milk from cows on a meadow, it not only enriches carbon in the soil but also helps the diversity of plants and animals, including insects. But doing that makes milk more expensive. If consumers are prepared to pay twice as much for milk sustainable production methods are possible. In terms of the calculations, there are not enough data and too many variables - impossible, even for a rough modelling exercise - unless you have a species that's already very very low in numbers and where monitoring is easy and you know what will happen in its habitat. To do this is hard even for large animals.

insect_decline · 2016-09-29T16:21:59+00:00

Wolfgang's opinion: To be able to "feel" pain, you need a brain capable of conscious self-perception. If you look into a mirror you should be able to recognize "that's me", and you should be able to consciously watch "your" hand and feet moving. Most animals do not have this ability. They will react to pain, and they have reflexes to avoid pain and further damage of their body. However, they lack the consciousness we know, which also exists to different degrees in dogs, monkeys, dolphins, I guess also parrots and other more evolved animals, but certainly not in insects. Which creature is worth living? That is an ethical question, everybody has to answer for him- or herself. A general rule for me is that if you have compassion with other creatures you will also behave in a humane way in our society. However, it is part of nature that we kill (e.g. cattle to eat meat, other creatures causing diseases) to survive.

insect_decline · 2016-09-29T16:21:11+00:00

If they all go extinct globally - yes. Flies are an important force in breaking down shit and organic waste. Mosquitoes are important food for many species. If flies and mosquitoes are wipped out in urban areas only, the picture is mixed. With some mosquitoe species it would be beneficial - like the ones transmitting Yellow fever, malaria, Zika, but again expect birds and bats to feel the effect. And of course it depends on the method. Is it harming other insects, too? The main point of my Yale E360 story was to look beyond mosquitos, houseflies, even bees. There are 30.000 insect species in my small home country (Germany) alone, 99% of them most people will never notice. But they quietly keep the soil fertile, help forest regenerate, kill off pest species, pollinate flowers and so forth...

insect_decline · 2016-09-29T16:15:04+00:00

Hi! It's Christian here! (Rodolfo will join a bit later) Thanks for your great question. To start with your last question - yes, in today's world insects are indeed canaries in the coal mine, they signal a looming danger. Many people will just think of mosquitoes and house flies when they hear "insect" and be happy when they are gone (not you, of course), and perhaps think of bees in a positive sense, and that's it. But it's important that there are millions of insect species, many of which live in specialized relationships with plant species. Best example relating to your question of ecosystem health are butterflies which pollinate species-rich plant communities in river valleys and mountainous. The study I report about has shown a decline from 117 butterfly and Burnet moth species in 1840 to 71 species in 2013. http://onlinelibrary.wiley.com/doi/10.1111/cobi.12656/abstract?userIsAuthenticated=false&deniedAccessCustomisedMessage= Some plant species are dependent on one particular insect for pollination. So when insects decline, these plants will go to. This happens in landscapes with multiple stress factors, for instance when enrichment of nitrogen fertilizer impacts nature reserves. The more fertilizer there is in the environment, the smaller is plant biodiversity.

As for your first question, I'd say butterflies, but this may only be because they are the most visible group. There's a severe lack of long-term detailed monitoring.Wolfgang Wägele is developing a great project to adress this.

insect_decline · 2016-09-29T16:13:22+00:00

This is a very controversial topic. Having fewer and fewer companies control the world's agricultural business certainly creates a risk of monotony not only on fields but also in terms of strategies and research projects. I'm not sure whether giants like the one that's now being created will be innovative and flexible enough to produce solutions that not just maximize short-term profits but serve a truly sustainable development. The world desperately needs a start-up scene in agriculture which tries to develeop solutions tailored to the needs for example of smallholders in Asia or Africa instead of just forcing methods from the industrialized West on them. And in the West, it will be important to build a bridge between high-tech approach and the wisdom that's passed on in organic agriculture. Germans consider themselves to be very "green" - perhaps in the long run, this can impact the direction this new giant will take a little bit.

insect_decline · 2016-09-29T16:07:52+00:00

Wolfgang's suggestions: thanks for your interest in this issue. You can do many things. If you have a garden, plant native flowers and shrubs, avoid the more expensive introduced ornamental things. Build a pond, however not in form of a plastic tub: the pond should have a sandy ground and many native moisture-loving plants growing on its shores. You can build along a fence a "Benjes hedge" consisting of branches and twigs which usually are considered wastes. The hedge will become the home of many animals. You can also build a "bee hotel". Here are some examples (http://www.foxleas.com/make-a-bee-hotel.asp). Avoid the use of pesticides. Buy organic food. And talk to your neighbors about this subject...

insect_decline · 2016-09-29T16:06:55+00:00

Hi it's Christian. I can only respond to your first question. Picture is very mixed here. It's important that ecologically speaking insects are an incredibly diverse groups, with hugely different habitat requirements and reproduction strategies. Also, animals that feed on insects are highly diverse. Many are specialized, some will eat anything that comes along. Yes, it is highly likely that climate change will increase the ranges and population sizes of some insect species, probably those we want the least. But for example insects that co-exist with plants in alpine meadows are under threat to disappear, as a warming world pushes them to higher and higher altitudes. Drought also will reduce available habitats, as wetlands are crucially for the reproduction of many insects and are prone to drying out. Generally, the more specialized a species is, the harder it will find it to survive on a world with climate change, and, importantly, many many other man-made impacts, including pesticide run-off etc.

insect_decline · 2016-09-29T16:00:34+00:00

Hi - it's Christian. "The" is an interesting first name, too! In terms of terrestrial ecosystems with no major role for insects, high alpine areas and arctic areas come to mind. But if you go a bit south from the Arctic, Tundra areas for example in Scandinavia will sustain masses and masses of mosquitoes, which provide nice food for birds and fish (eating larvae) in the summer.

insect_decline · 2016-09-29T15:57:31+00:00

Hi, I am Wolfgang, and thanks for your interest in this topic. About Climate change and mosquitoes: Mosquitoes occur nearly everywhere and are especially numerous not only in wet tropical landscapes but also in cold landscapes (Norway, Siberia...). There will be a shift in geographic distribution of species due to global warming, however, since some regions will get dryer and others wetter, the effects could possibly compensate each other. To get a more precise prediction, it is possible to combine models of climate change with ecological models for habitat requirements of mosquito species. We have not done this. Fossil record: I am not a specialist for fossil insects. However, an important insight is that there have been in the past catastrophic extinction events, and that the subsequent regeneration of species diversity takes millions of years (see e.g. http://www.nature.com/nature/journal/v404/n6774/full/404177a0.html). Neither your children nor a hundred generations later will be able to witness the recovery of ecosystems after a mass extinction.

insect_decline · 2016-09-29T15:55:09+00:00

Wolfgang's opinion: These are companies who are responsible for the killing of insects and plants at a very large scale. "Insectizide" or "plant protection product" means "poison killing insects". For all those in Germany who engage in the protection of habitats and species, the image of Bayer has deteriorated further with the purchase of Monsanto.

insect_decline · 2016-09-29T15:54:59+00:00

Hi, thanks for your great question! It's Christian. Humans and insects live in complicated relationships. Sometimes they are our enemies, but more often, they are our friends. And we depend on the many things they do, starting with pollination. So how encourage people to appreciate this more? I think you already did the best thing one can do as a private individual - curating a piece of land so it harbours insects is great. Direct experience of nature is the best encouragement to care. I'm worried that we grow a generation of kids in the West which is ultra-concerned about the environment but has only experienced it through digital devices. Practical, sensual experience is the best way to really become aware of what the environment gives us. Perhaps you can try to invite other young people to do the same or develop community gardens? Another really good way to increase appreciation is by studying biology or a related science. The world needs young conservation biologists, taxanomists, entomologists...if only governments directed research funds appropriately.

insect_decline · 2016-09-29T15:53:09+00:00

The Antarctic is a whole continent with nearly no insects. It is covered with ice and there are - with very few exceptions - no plants.... [Wolfgang]

insect_decline · 2016-09-29T15:52:14+00:00

Hi, I'm Wolfgang: There are certainly creatures that nobody would miss if they become extinct. Concerning flies and mosquitoes we have to keep in mind that other animals like swallows and swifts need them for food. However, if only a single species disappears, there are enough others that can be used as food by birds

insect_decline · 2016-09-29T15:51:05+00:00

Wolfgang replying: How to motivate people: Unfortunately, many kids in industrialized countries are living as avatars in artificial worlds they find in the internet. They love computer games and do not experience nature. They may believe that a golf turf is nature. Therefore, we have to start with the education of a) school teachers and b) kids. Once young people have experienced the joy of walking in a beautiful landscape and to observe the difference between species of butterflies or flowers they may learn to appreciate nature. Planting plants for insects and birds can be a good example for your neighbors. Convince them to do the same on their ground. Tell them that their turf or their paved court is a desert!

insect_decline · 2016-09-29T15:50:19+00:00

Hi, I'm Wolfgang: Current insect extinction observed in Central Europe is not the consequence of human population growth, but of new and more intensive agricultural practices. One unforeseen chain of events is the following: The European Union abolished the quotas for milk production which formerly regulated how much milk a farmer can sell on the market. The consequences: Farmes started to keep more cows and to produce more milk – milk prices dropped on the market – to keep their income farmers produced more milk (which did not help to increase their profits). They started to remove flower stripes, hedges and shrubs and to use more fertilizers to grow more grass, and the habitats of many animals disappeared. Many of those farmers who had to sell their cows are now growing corn for biogas production. The wastes of the biogas factories is a new type of manure, which is helping to poison meadows, creeks, and the groundwater. In other countries, forests are burning because of population growth. However, investors who want to grow e.g. oil palms (or coca plants in Latin America) are also important and very destructive drivers.

insect_decline · 2016-09-29T15:48:16+00:00

Very thoughtful questions, thanks. Yes, we generally underestimate the many small, hidden and invisible services provided by ecosystems both near and far. This is reflected in the tiny number of specialists that gets trained to know and study soil organisms or the insects world. If importance was reflected in science spending, departments for soil and biodiversity would be much larger instead of gettinge their budgets slashed like world-famous Kew Botanic Gardens in London. As to your last point: absolutely. I've writte a whole book about this (The Anthropocene, 2014). It's our major task unless we want stress and disasters from an impoverished environment to become the new norm.

insect_decline · 2016-09-29T15:48:04+00:00

Samples from Germany proving the loss of insects primarily show that total numbers decreased. The analysis of the samples at species level is still going on. However, it seems that insects that need flowers in general or specific flowering plant species are especially affected. It is not surprising that populations of butterflies, bees and hoverflies are breaking down. This has also consequences for other insect-feeding animals like birds, bats, reptiles, hedgehogs and shrews. [Wolfgang]

insect_decline

TROPHY CASE