Decline in insect populations

[kassy]

Alarming long-term effects of insecticides weaken ant colonies

...

But so far, no data existed to show how exposure to low concentrations, which do not induce direct mortality, affect ants in the long run. The data, collected at the University of Bern in cooperation with Agroscope and the University of Neuchâtel, clearly demonstrate previously overlooked long-term effects, which are not detectable during the first year of colony development. The results are published in "Communications Biology", an Open-Access Journal of Nature. According to the authors, this study highlights the importance to develop sustainable agricultural practices that incorporate reduced use of agro-chemicals to prevent irreparable damages to natural ecosystems.

Worrying long-term impacts

Thiamethoxam has a clear negative impact on the health of ants. Thiamethoxam is a neonicotinoid insecticide used to combat pest insects that threaten our harvest. Unfortunately, there is more and more evidence showing that thiamethoxam and similar agro-chemicals have negative consequences for other beneficial insects, including ants and honey bees.

...

In the present work, colonies of black garden ants were chronically exposed to field realistic concentrations of thiamethoxam over 64 weeks. Colonies were raised in the laboratory from queens that were captured in the field. Before the first overwintering of the colonies no effect of neonicotinoid exposure on colony strength was visible. However, until the second overwintering it became apparent that colonies exposed to thiamethoxam were significantly smaller than control colonies. Because the number of workers is a very important factor for the success of an ant colony, the observed effects are most likely to compromise colony survivorship. Considering the important role of ants in natural ecosystems, our results indicate that neonicotinoids impose a threat to ecosystem functioning.

...

https://www.eurekalert.org/pub_releases/2020-07/uob-ale070120.php

Long-term effects of neonicotinoid insecticides on ants
https://www.nature.com/articles/s42003-020-1066-2

[kassy]

About 94 per cent of wild bee and native plant species networks lost


Climate change and an increase in disturbed bee habitats from expanding agriculture and development in northeastern North America over the last 30 years are likely responsible for a 94 per cent loss of plant-pollinator networks, York University researchers found.

The researchers, corresponding author Professor Sandra Rehan of the Faculty of Science and grad student Minna Mathiasson of the University of New Hampshire, looked at plant-pollinator networks from 125 years ago through present day. The networks are comprised of wild bees and the native plants they historically rely on, although most of those have now been disrupted.

About 30 per cent of plant-pollinator networks were completely lost, which translates to a disappearance of either the bees, the plants or both. In another 64 per cent of the network loss, the wild bees, such as sweat or miner bees, or native plants, such as sumac and willow, are still present in the eco-system, but the bees no longer visit those plants. The association is gone.

The remaining six per cent of the plant-pollinator networks are stable or even thriving with pollinators such as small carpenter bees, which like broken stems for nest making.

"There are several reasons for the losses in the networks. Climate change is likely the biggest driver. We know that over the last 100 years or so annual temperatures have changed by two and a half degrees. This is enough to alter the time when certain native plants bloom," says Rehan.

"For a bee that's out for months on end or is a generalist pollinator, this isn't such a critical mismatch, but for a bee that's only out for two weeks of the year and only has a few floral hosts, this could be devastating." An increase in non-native species of bees and invasive species of plants, which have displaced some of the native species, is another reason for the decline in networks.

...

https://www.sciencedaily.com/releases/2020/07/200716144740.htm

[Alexander555]

Some more stuff about te bees. I'm going to see if i can get some more bees over here. https://watchers.news/2020/07/30/bee-population-decline-threatens-major-crop-yields-in-u-s-and-global-food-security/

[Alexander555]

I placed a home like this for the humblebees. What could i do extra for them, besides extra flowers ? https://www.tuinadvies.be/tuinwinkel/product/2256/hommel-kweekbak-professioneel

[vox_mundi]

Bumblebee Habitats and Diets Change Over Their Lifecycle
https://phys.org/news/2020-07-bumblebee-habitats-diets-lifecycle.html

Bumblebees change their home ranges and dietary preferences after establishing nests, suggesting that diversified landscapes help support bee populations as their needs change during different phases of their lifecycle.

Cavigliasso P, Phifer CC, Adams EM, Flaspohler D, Gennari GP, Licata JA, et al. (2020) Spatio-temporal dynamics of landscape use by the bumblebee Bombus pauloensis (Hymenoptera: Apidae) and its relationship with pollen provisioning. PLoS ONE 15(7): e0216190
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0216190

-------------------------------

Observe what the bee's preference are.

Provide blooms during each season

Here in Connecticut these are the flowers most visited by bumblebees at our community garden

Blueberries - spring
Grape hyacinth - spring
Catmint - Spring
Thyme - spring
Borage - summer
Salvia - late spring
Echinacea - summer
Tomatoes - summer
Squash, cucumbers - summer
St John's wort - summer
Agastache - summer, fall
Joe Pye weed - summer
Milkweed - summer
Sunflowers - summer
Butterfly bush - summer fall
Oregano summer fall
Mint - summer fall
Zinnias - summer fall
Goldenrod - fall
Asters - fall

Don't expect the bumblebee queen to stay in the box if your winters are freezing.

I was a beekeeper in the 90's and 00's

[Alexander555]

We do have freezing in winter. But for what i can find on the internet the bumblebees are  the bees that can handle the cold the best. Do you maybe know when they use a tunnel below the surface as a nest. Do they have like several tunnels for ventilation, or would it just be one tunnel. Or is the nest a little more sophisticated ? The box is developed by bumblebees specialists, and they made a few little holes in the back for ventilation. I was thinking about doing a little experiment. I buy a 2th box, and i dig him in as much as possible. I put sand on top of it, and only keep the entree open. That should protect it a little better against the cold. But should i do something with the ventilation holes ? Maybe straws to the surface.

[vox_mundi]

Bumblebees are tough, but not invincible.

A bumblebee queen does not overwinter in the nest. They overwinter in burrows beneath leaf litter or in brush piles. They will be several cm deep, near or below the frost line in dry soil. They may use abandoned mice/vole nests. Their metabolism is so slow during winter that ventalation is usually not a problem.

In spring, a mated queen emerges from her overwintering site, searches for a spot to nest, and works alone to raise a first cohort of worker daughters. The colony grows over several months, producing successive cohorts of workers before switching to produce males and new queens. In mid‐ to late summer, newly mated queens seek sheltered sites where they overwinter.

Rinse; repeat.

Habitat determines both location.

Nectar and pollen near the colony nest
Dry, unfrozen, leaf litter for overwinter site.

Bumblebees start their year early. I've seen them at flowers early march, anytime it's above 8-10°C.

Honeybees will be out earlier because they can return to the colony and warm up. I've seen honeybees on my Snowdrops on clear sunny days in January

[vox_mundi]

Insect Armageddon: Low Doses of the Insecticide, Imidacloprid, Cause Blindness In Insects
https://phys.org/news/2020-09-insect-armageddon-doses-insecticide-imidacloprid.html

New research has identified a mechanism by which low levels of insecticides such as, the neonicotinoid Imidacloprid, could harm the nervous, metabolic and immune system of insects, including those that are not pests, such as our leading pollinators, bees.

A study published today in the Proceedings of the National Academy of Sciences, led by researchers at the University of Melbourne and Baylor College of Medicine, shows that low doses of Imidacloprid trigger neurodegeneration and disrupt vital body-wide functions, including energy production, vision, movement and the immune system, in the vinegar fly, Drosophila melanogaster.

With insect populations declining around the world and intense use of insecticides suspected to play a role, the findings provide important evidence that even small doses of insecticides reduce the capacity of insects to survive, even those that are not pests.

"Our research was conducted on one insecticide, but there is evidence that other insecticides cause oxidative stress, so they may have similar [or synergistic] impacts"

The researchers arrived at the findings by studying the effects of Imidacloprid in vinegar fly larvae. In the field, the insecticide is generally used at concentrations of up to 2,800 parts per million (ppm). In the lab, researchers tested lower doses, identifying that the very small dose 2.5 ppm was enough to reduce the movement of fly larvae by 50 percent after just two hours of exposure.



"That's an indication of the impact of the insecticide on the function of the brain," ... "From there, the accumulation of massive amounts of reactive oxygen species (ROS) or free radicals inside the brain triggers a cascade of damaging events that spread to many other tissues."

Researchers also tested the insecticide on adult flies, finding that flies exposed to very low doses (4 ppm) over 25 days became blind and developed movement problems that affected their ability to climb, symptomatic of neurodegeneration in other parts of the brain.



Felipe Martelli el al., "Low doses of the neonicotinoid insecticide imidacloprid induce ROS triggering neurological and metabolic impairments in Drosophila," PNAS (2020)
https://www.pnas.org/content/early/2020/09/25/2011828117

[Alexander555]

At least the mosquitos seem to do well. A new virus is spreading, transmitted by mosquito's. And it seems to be a pretty big area. So it's not looking very well for the rest of the insects. If the risk from a mosquito bite just gets bigger. More chemical stuff will be sprayed on every tourist. And that sounds like a virus paradise. The collaps of biodiversity will only continue. https://sputniknews.com/india/202009291080605436-new-threat-in-sight-indian-medics-warn-of-another-virus-outbreak-in-china/

[Alexander555]

A few weeks ago they discovered salmonella in the place where i work. Would things like this also be related to the loss of insects, biodiversity ? Now we have the salmonella hotzone, and the covid-19 restrictions at the same time. And we had many salmonella  infections the last months, in other places.

[kassy]

I don´t think so. Bacteria and insects are quite different.

[vox_mundi]

Two Pesticides Approved for Use in US Harmful to Bees
https://phys.org/news/2020-09-pesticides-bees.html

A previously banned insecticide, which was approved for agricultural use last year in the United States, is harmful for bees and other beneficial insects that are crucial for agriculture, and a second pesticide in widespread use also harms these insects. That is according to a new analysis from researchers at The University of Texas at Austin.

As the agricultural industry turns to new types of pesticides to protect crops, the biologists behind the recent large-scale meta-analysis warn that two of these—flupyradifurone (sold under the brand name Sivanto) and the recently approved pesticide sulfoxaflor (sold under the name Transform WG)—have harmful effects similar to a class of pesticides known as neonicotinoids, several of which were recently banned in the European Union and Canada. Neonicotinoid pesticides have been shown to be detrimental to honeybees and other beneficial insects.

It is clear that these insecticides are harmful to bees," Muth said. She noted that regulators made decisions before scientists had completed all of the research included in the meta-analysis.

In addition to harming honeybees, the insecticides also showed signs of harming other beneficial insects, such as wild bumblebees and lacewings, according to the research.

In addition to increasing mortality in bees, the insecticides had some less than lethal effects, such as reducing reproductive ability and making pollinators less efficient foragers.

"So much of the regulatory process is focused on looking at toxicity, meaning how much of the insecticide you need to kill an insect," Siviter said. "And what research has found over the last decade is that these insecticides can have a lot of sub-lethal effects on pollinators, influencing things like foraging ability or a bee's ability to reproduce. These effects need to be considered in the regulatory process as well, because that can affect survival."

Harry Siviter et al, Do novel insecticides pose a threat to beneficial insects?, Proceedings of the Royal Society B: Biological Sciences (2020)
https://royalsocietypublishing.org/doi/10.1098/rspb.2020.1265

[vox_mundi]

when the pollinators are gone this is what is left ...

Hand Pollination, Not Agrochemicals, Increases Cocoa Yield and Farmer Income
https://phys.org/news/2020-10-pollination-agrochemicals-cocoa-yield-farmer.html

A research team from the University of Göttingen has investigated the relative importance of the use of pesticides, fertilizers and manual pollination in a well replicated field trial in Indonesian agroforestry systems. The result: an increase in both cocoa yield and farming income was achieved—not by agrochemicals, but by manual pollination. The study was published in the journal Agriculture, Ecosystems and Environment.

Cocoa requires cross-pollination by insects to produce fruit. It is unclear how to encourage natural pollination by tiny midges, flies or wasps. In fact, the true identity of the main pollinators has yet to be discovered. Under natural conditions, more than 90% of flowers are not visited by insects and do not develop fruit. These results clearly show that traditional agricultural intensification with agrochemicals is not always the best way forward.

Working together with colleagues and students of the Indonesian University of Tadulako of Palu, the scientists found that hand pollination increased the yield of cocoa trees by 161%. After deducting the costs of manual pollination, this meant a 69% increase in income for small-holder farmers. Using more pesticide and fertilizer did not increase yields.

Manuel Toledo-Hernández et al, Hand pollination, not pesticides or fertilizers, increases cocoa yields and farmer income, Agriculture, Ecosystems & Environment (2020)
https://www.sciencedirect.com/science/article/abs/pii/S0167880920303467

[kassy]

Damn that is sad. 

[Alexander555]

when the pollinators are gone this is what is left ...

Hand Pollination, Not Agrochemicals, Increases Cocoa Yield and Farmer Income
https://phys.org/news/2020-10-pollination-agrochemicals-cocoa-yield-farmer.html

A research team from the University of Göttingen has investigated the relative importance of the use of pesticides, fertilizers and manual pollination in a well replicated field trial in Indonesian agroforestry systems. The result: an increase in both cocoa yield and farming income was achieved—not by agrochemicals, but by manual pollination. The study was published in the journal Agriculture, Ecosystems and Environment.

Cocoa requires cross-pollination by insects to produce fruit. It is unclear how to encourage natural pollination by tiny midges, flies or wasps. In fact, the true identity of the main pollinators has yet to be discovered. Under natural conditions, more than 90% of flowers are not visited by insects and do not develop fruit. These results clearly show that traditional agricultural intensification with agrochemicals is not always the best way forward.

Working together with colleagues and students of the Indonesian University of Tadulako of Palu, the scientists found that hand pollination increased the yield of cocoa trees by 161%. After deducting the costs of manual pollination, this meant a 69% increase in income for small-holder farmers. Using more pesticide and fertilizer did not increase yields.

Manuel Toledo-Hernández et al, Hand pollination, not pesticides or fertilizers, increases cocoa yields and farmer income, Agriculture, Ecosystems & Environment (2020)
https://www.sciencedirect.com/science/article/abs/pii/S0167880920303467

May the cacao is not in his natural place, if 90 % is not visited by insects. Or maybe they don't have the right insects anymore. When i watch the bees over here, they just jump from flower to flower. They don't scip one of them.

[vox_mundi]

Current Chernobyl-Level Radiation Harmful to Bees: Study
https://phys.org/news/2020-10-current-chernobyl-level-bees.html

Bumblebees exposed to levels of radiation found within the Chernobyl exclusion zone suffered a "significant" drop in reproduction, in new research published Wednesday that scientists say should prompt a rethink of international calculations of nuclear environmental risk.

Researchers in Scotland and Germany exposed bee colonies in a laboratory setting to a range of radiation levels found in areas of the exclusion zone around the ruined Chernobyl site, where a reactor exploded in 1986 in the world's worst nuclear disaster.

They found that colony reproduction reduced by 30 to 45 percent at doses previously considered too low to impact insects.

Katherine E. Raines et al. Chernobyl-level radiation exposure damages bumblebee reproduction: a laboratory experiment, Proceedings of the Royal Society B: Biological Sciences (2020)
https://royalsocietypublishing.org/doi/10.1098/rspb.2020.1638

... cockroaches, on the other hand, are doing fine.

[vox_mundi]

First Murder Hornet Nest Had 200 Queens Capable of Spawning New Nests
https://www.theguardian.com/environment/2020/nov/10/murder-hornet-nest-queens-washington

When scientists in Washington state destroyed the first nest of so-called murder hornets found in the US, they discovered about 500 live specimens in various stages of development, officials said Tuesday.

Inside, researchers found:

• 190 total larvae that developed from eggs.
• 108 pupae, the next stage after larvae. They were nearly all queens.
• 112 workers, which included 85 workers previously vacuumed out of the nest.
• 76 queens, nearly all of them virgin queens. New queens emerge from the nest, mate and then leave to find a place to spend winter and later start a new colony.

Most of the specimens were still alive when the nest was opened, among them nearly 200 queens that had the potential to start their own nests, said Sven-Erik Spichiger, an entomologist leading the fight to kill the hornets.

Still, scientists think other nests already exist and say it’s impossible to know if any queens escaped before the first nest was destroyed. Each nest can destroy several honeybee colonies.

[Alexander555]

I'm doing some gardening now. And what i learned so far is probably a good explanation why insects are declining so fast. I was looking for what i need to let something grow, the nutrients. And the  conclusion is that you can do it the biological way, compost with fungi and bacteria to release the nutrients from your compost. Or mechanical work with fertiliser, and that kills your soil. So we kill all live in 600 000 square kilometers of soil every year, extra. On top of what was above that soil. And that will probably continue for dozens of years , with 80 million people extra every year. How are they going to solve that ? Everything is large scale production.

[harpy]

I'm doing some gardening now. And what i learned so far is probably a good explanation why insects are declining so fast. I was looking for what i need to let something grow, the nutrients. And the  conclusion is that you can do it the biological way, compost with fungi and bacteria to release the nutrients from your compost. Or mechanical work with fertiliser, and that kills your soil. So we kill all live in 600 000 square kilometers of soil every year, extra. On top of what was above that soil. And that will probably continue for dozens of years , with 80 million people extra every year. How are they going to solve that ? Everything is large scale production.

The solution does not exist.

[Tom_Mazanec]

How Non-Native Plants Are Contributing to a Global Insect Decline
https://e360.yale.edu/features/how-non-native-plants-are-contributing-to-a-global-insect-decline

The impact of introduced plants on native biodiversity has emerged as a hot-button issue in ecology. But recent research provides new evidence that the displacement of native plant communities is a key cause of a collapse in insect populations and is affecting birds as well.

One year on: Insects still in peril as world struggles with global pandemic
https://news.mongabay.com/2020/11/one-year-on-insects-still-in-peril-as-world-struggles-with-global-pandemic/

In June 2019, in response to media outcry and alarm over a supposed ongoing global “Insect Apocalypse,” Mongabay published a thorough four-part survey on the state of the world’s insect species and their populations.
In four, in-depth stories, science writer Jeremy Hance interviewed 24 leading entomologists and other scientists on six continents and working in 12 nations to get their expert views on the rate of insect decline in Europe, the U.S., and especially the tropics, including Latin America, Africa, and Australia.
Now, 16 months later, Hance reaches out to seven of those scientists to see what’s new. He finds much bad news: butterflies in Ohio declining by 2% per year, 94% of wild bee interactions with native plants lost in New England, and grasshopper abundance falling by 30% in a protected Kansas grassland over 20 years.
Scientists say such losses aren’t surprising; what’s alarming is our inaction. One researcher concludes: “Real insect conservation would mean conserving large whole ecosystems both from the point source attacks, AND the overall blanket of climate change and six billion more people on the planet than there should be.”

[be cause]

normally by this time of year I have encountered  hundreds of queen wasps looking for or in places to hibernate . This year , not one ! Every month this spring and summer had at least one major storm . These have devastated breeding in local birds from rooks to gold finches . I guess one of them did for the wasps too . b.c.

[vox_mundi]

Insect Populations Suffering Death by 1,000 Cuts, Say Scientists
https://www.theguardian.com/environment/2021/jan/11/insect-populations-suffering-death-1000-cuts-scientists

... The 12 new studies are published in the journal Proceedings of the National Academy of Sciences. “Nature is under siege [and] most biologists agree that the world has entered its sixth mass extinction event,” concludes the lead analysis in the package. “Insects are suffering from ‘death by a thousand cuts’ [and] severe insect declines can potentially have global ecological and economic consequences.”

Prof David Wagner of the University of Connecticut in the US, the lead author of the analysis, said the abundance of many insect populations was falling by 1-2% a year, a rate that should not be seen as small: “You’re losing 10-20% of your animals over a single decade and that is just absolutely frightening. You’re tearing apart the tapestry of life.”

Wagner said most of the causes of insect declines were well known. “But there’s one really big unknown and that’s climate change – that’s the one that really scares me the most.” He said increased climate variability could be “driving [insect] extinctions at a rate that we haven’t seen before”.

“Insects are really susceptible to drought because they’re all surface area and no volume,” Wagner said. “Things like dragonflies and damselflies can desiccate to death in an hour with really low humidity.”

One of the studies identifies an increasingly erratic climate as the overarching reason for region-wide losses of moths and other insects in the forests of north-western Costa Rica since 1978. This could be a “harbinger of the broader fate of Earth’s tropical forests”, said Wagner.

Insect Decline In the Anthropocene: Death By a Thousand Cuts
https://www.pnas.org/content/118/2/e2023989118