Another day, another grub – and being a nerdy type I haven’t killed any of them yet as I had no data, I have just been collecting them. After all who would I be to wipe out an entire grub population because I suspected they were weapons of plant mass destruction? So another day, another intense session on Google discovering that I knew less than nothing about larvae, that indeed they do NOT all look the same and that my enthusiastically identified June grubs, are not June grubs, nor even though I found them in May are they May grubs, no indeedy – they are Rose Chafer Beetle larvae. This is spectacularly good news.
Photograph courtesy of : http://de.wikipedia.org/wiki/Goldgl%C3%A4nzender_Rosenk%C3%A4fer
Pretty, shiny lovely little things, they are our FRIENDS – they eat organic matter, make compost, and generally tidy up underneath the soil so that everything will grow better. The larvae make compost, the adults drink nectar from roses and at most eat the odd leaf…They are a protected species in Germany, and were elected beetle of the year in 2000,and there is a book which lists them too (it doesn’t sound like much fun though): Protected species in planning and planning permission discussions (loose translation forgive me) authors Jürgen Trautner,Johannes Mayer,Heiner Lambrecht,Kirsten Kockelkes. More info can be found on http://www.nhm.ac.uk/nature-online/species-of-the-day/collections/our-collections/cetonia-aurata/index.html
So these little sweeties are not to be confused with the evil May or June grub larvae. The ravenous monsters that do indeed survive and go through their life cycle happily in your pots for years until they pupate before they fly out to lay more eggs. Probably in newly acquired pots on your balcony. So yesterday’s drama and mad search for good ways to kill grubs were educational, but no longer relevant to my situation. I will share though that weed growers recommend Milky spoor, which is sold in US and nematodes will kill young June and May beetle larvae (and also the protected rose chafer….) but not the older larvae, and then there are various bacteria that you can buy and dig into your topsoil that cause death to all larvae.
Would have been better if I’d identified the grubs properly yesterday instead of seeking terminal solutions to a misidentified problem. So today I learned: All larvae are not created equal. Although on the face of it they all look the same to me, they actually are very different. They do different things, they move in mysterious way. So while May and June bugs will try to crawl away on their tummies, the rose chafer larvae has a different approach…….
And if you don’t see them move you can look at their anal slits, because, ladies and gents, anal slits are not all the same, no, no, no, they come in many different shapes and can help you identify your grub. Anal slits can be crescent shaped, or smiley mouthed, star shaped, think Mercedes star, row or zipper shaped – if you are into this kind of thing check out the following link http://www.msuent.com/assets/pdf/03GrubID.pdf lots of information. Admittedly you need to have a curious mind for this kind of thing, or lots of time, ideally both.
I also learned that American rose chafers (Macrodactylus subspinosus) and European rose chafers (anyone who is an insect specialist please comment at any time.) (Cetonia aurata) behave very differently. The lovely green Cetonia aurata, protected species in Germany, and benefactor of all compost near you, brightens the day with happy whirrings and coloured green glintiness, while the American rose chafer is a nasty brute, with lots in common regarding general destructive behavior with June and May beetles
But you might wonder why am I so sure about my larvae’s identity? It’s all thanks to Maria Fremlin’s homepage, who saved my larvae. Her blog has a wealth of insect information on it, and her CV shows she takes her bugs seriously – according to her CV she is a kind of Queen of grubs. There are even – PUBLICATIONS, although I didn’t check the impact factor :)…. She has written about stag, rose chafer and other beetles. If you are still wondering what you have got in your pots, l check out her website http://maria.fremlin.de/
So I did Maria’s beetle test, tipped the larvae onto some paper and watched them wriggle away on their backs. Very impressive. I have started to develop a liking for them. You have to like a being that out of it’s element (dark, moist, soil) in an alien environment (nasty, dry, sunny, light air) – doesn’t just lie back and take it but starts to crawl away at lightning speed on its back! They are quite cute and very fast. As I cannot upload my video check out Marias: youtube http://www.youtube.com/watch?v=xBF7e4b-_-0
So, although I am now feeling the love, a little, I am torn. Here is my dilemma – I spent hours digging through 120 litres of soil yesterday and packing it in trash bags, and while it wasn’t hard work, it was work. So putting it all back seems a bit too Sisyphus like and what if I am wrong and I have a special type of back crawling June beetle, that has adapted camouflage tactics? After all, if the larvae only eat dead organic matter, why were they all concentrated on my peony’s roots? And why did my peony look sad? In order to proceed I need additional moral support. So I’ve sent Maria my video and am awaiting her response.
In the meantime the larvae have been put into a big flower pot and covered with soil containing lots of root cuttings………I might just keep them there, put a net over the pot and see what hatches…..