Friday, October 27, 2017

"Seriously, we’re all going to die: Insect populations are at apocalyptic levels"

You may have read in the news of a catastrophic decline in insects based on research conducted by scientists from Radboud University in the Netherlands and the Entomological Society Krefeld in Germany. It has been all across most news platforms for the past few days and makes for worrying reading. 

The number of flying insects has declined by more than three-fourths since 1989, threatening food supplies

This is the conclusion of a study published on Wednesday in the peer-reviewed scientific journal PLOS One:

"Our analysis estimates a seasonal decline of 76 percent, and mid-summer decline of 82 percent in flying insect biomass over the 27 years of study, we show that this decline is apparent regardless of habitat type, while changes in weather, land use, and habitat characteristics cannot explain this overall decline."

The study added, "Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and to jeopardize ecosystem services."

The plight of honeybees has been well documented and it is now widely believed that a type of pesticide known as 'neonicotinoids' are responsible for the precipitous decline in honeybee populations.

Coincidentally, I have been reading Rachel Carson's 'Silent Spring' which deals with an ever-growing threat posed by insecticides and pesticides. She points out in quite graphic form how there is a global threat from the misuse and over-use of these chemicals, together with intensive farming methods. The really sad thing is that her book was published 55 years ago, and we seem to have learned nothing!

Or maybe we have, but just don't care, because nature comes second to the pursuit of the dollar!

Even that back-stabbing numpty Michael Gove had this to say on the subject: The Environment Secretary said "heavy farm machinery and overuse of chemicals was boosting short-term productivity but would render large tracts of soil infertile within a generation."

A reminder from LWEC (Living With Environmental Change) about why pollinating insects are vital to our ecology:

Why are insect pollinators important?

Bees, flies, wasps, beetles, butterflies and moths are part of a nation’s biodiversity and natural capital. They have intrinsic value and provide environmental and economic benefits because:

 — Pollinators improve or stabilize the yield of three-quarters of all crop types globally; these pollinated crops represent around one third of global crop production by volume.

 — Many fruit, vegetable, oil, seed and nut crops that provide vital nutrients for human diets worldwide, including more than 90% of our vitamin C, are pollinated by insects.

— The cultivated area of pollinator-dependent crops has risen, raising worldwide demand for insect pollination services three-fold since the 1960s. Globally the crop production attributable to insect pollination was valued at US $215 billion in 2005.

 — Honeybees, but also bumblebees and solitary bees, are managed and traded commercially for their pollination service. Wild pollinators are at least as important as managed pollinators in providing these benefits.

That opening to this update was a bit heavy eh? In fact it was heavier than regret! And so in true BBC 'One Show' fashion, let's move on to something  a bit more ...

My last update was all about caterpillars, which by the way are doing fine, there are just 2 left eating now, the others have all pupated. It is strange though how they all came from the same batch of eggs and yet the final two are about three weeks behind the others. Anyway, I will continue the theme with some more caterpillars in this update. 

Here's what the excellent UK Moths website has to say about the Convolvulus Hawk-moth:

A large species, with a wingspan of over 10cm, this is a migrant in Britain, appearing sometimes in fairly good numbers.
It most often occurs in late summer and autumn, usually with influxes of other migrant species, when it turns up in light traps and feeding at garden flowers, especially those of the tobacco plant (Nicotiana)

Although larvae are sometimes found in Britain, usually on bindweed (Convolvulus), it does not regularly breed.

I was very lucky to get some early (probably 2nd) instar larvae to rear. They came to me looking a little like Twiggy on a diet (ask yer gran who Twiggy is, and I don't mean Ramirez!) Oh! Hang you are look, this Twiggy...

You get the picture now? Well, if not, here it is...

Quite an aerial though eh?

What to feed them on then? The clue is in the name of 'Convolvulus'. But what exactly is convolvulus? It's this...

The gardeners enemy: good old-fashioned bindweed. Should be easy enough to find plenty of bindweed? Maybe so, although it is getting quite late in our year to find any that is still growing and green. Then there is the little matter of me looking like a right plonker gathering the one weed that everybody else seems to hate. No matter, most folk around here think I am retarded anyway! Being spotted laying in wet grass, or photographing what looked like (and was) a cow pat...that kind of thing, hasn't helped my cause. 

And so it was that I went out and scored my bag of weed to feed to the hungry caterpillars. They appreciated my offering and probably gave my efforts short shrift as they devoured it. It wasn't long before they began to moult and look like this...

It is a good thing that these are hungry little blighters, because, once cut, bindweed soon wilts like a flower without sun, or a woman without love. By the time of the next moult, they were looking different again...


Oh yes! They were now entering their 'new-wave' period: they even acquired 'Adam Ant' face stripes. Some of them moved on further, to what I am going to call the 'Buster Bloodvessel' period. You know the one - the chubby chappy from Bad Manners... 


I don't usually add YouTube videos in the midst of an update for fear you might not return to the remainder of my writing, however, you are reading this right, so you must still be here. Why is there nothing as silly as this in today's music, who dumbed it down?

Where were we? Oh yes, they were starting to get a bit portly themselves...

It was at about this time that the difference between the fastest growing larvae and the slowest became quite apparent. In fact, prior to the smaller ones moulting again, the large green ones had already dug into the soil to pupate. Right before this happened, I measure one: it was 75mm long...

When they did eventually moult, something amazing happened: they changed from green to almost black...

Just completing a moult

Free from the moult

A few hours later and they looked like this (apologies, I have run out of music genre analogies)...

And finally this...

And that just about brings us up to date. There are two of these blackish caterpillars still eating, but I am expecting them to pupate at any time. Will I get any adult moths emerge come spring? Certainly hope to. 


  1. Interesting blog entry JJ

  2. Amazing as ever! Lovely to see the progress through the different instars.
    Made me laugh about the local folk's thoughts about you. I always get odd looks too, and occasionally, people give me a wide berth! Lol!! If only they knew what they were missing...

    As regards the general decline in inverts, it is a very sad and worrying situation. Can't see this current government doing anything about it soon either. We all try to do out bit, but it's just not enough on an individual scale. As you rightly said, money will always speak louder.


    1. Hi Maria,

      Yes, most folk around here know me now and just ignore the odd things I get up to, but newcomers are a different matter and feel compelled to ask. Then they wish they hadn't ;-)

      Yeah, the insect problem is way bigger than most realise (or care about) and you're right, governments are really not interested in forcing farmers to tow the line. As a nation, we are becoming more aware but it's actions we need, and fast!

      Thanks for yet another visit and lovely comment.


Please feel free to comment on my blog. I am always grateful for any feedback, good or bad. Commenting should be fast and easy. Just enter your comment in the box, then click on the drop-down box beside 'Comment as'. You can use your Google ID if you have one, or just choose 'Name/URL and enter your name (URL is not needed). You can also just choose anonymous, if you would rather not be identified.

Regards 'JJ'.

If you do experience any difficulties, you can contact me directly from this blog and I will try to help.