Harlequin ladybirds have overtaken the native British ladybirds mostly in the South of England, but they are still great predators to encourage in the garden. They go through a nymph stage, turning into a pupa, before becoming the recognisable beetle shape.
I was actually going to post about berry pirates, better known as the Southern green shield bug but as I was writing I found myself researching an awful lot about ladybirds. You’ll understand when you see next weeks blog. I was also hunting the garden for specimens of both the shield bug and ladybird to take photos of and I found the ladybird in its various stages and thought it might be an interesting read. So pictured here are both ladybirds that are one of the most helpful critters in the garden. Yes, I do realise that pictures are a little blurry, but these are small creatures that are being photographed with an iphone, through a microscope.
Unfortunately, the British native red ladybird (coccinella septempunctata –7 spot or adalia bipunctata – 2 spot) is in decline because the harlequin ladybird (harmonia axyridis) has muscled in. They are all part of the same Coccinellidae family, but the harlequin reportedly came from Asia in 2004 via Europe when it was introduced as a pest predator, according to the natural history museum website. I’m sad to say that I haven’t seen a native ladybird for about 15 years. This is also down to a move from a more rural setting up north to a big southern city, where the harlequin is reportedly more prevalent.
The same website also mentions the STD that the ladybirds are reported to carry. It is a fungus called laboulbenia, and no, it does not affect humans. Phew! I was bitten during my research this week. It hurt but at least there are no lasting effects.
Between the STD and the natural predators like parasitic wasps there will be an equilibrium reached where both native and invasive species should co-exist (so says the website). In the meantime, I’m rather fond of the harlequin ladybirds (even the bugger that bit me) because they are voracious eaters of the aphids that are my most unwelcome garden inhabitants. The photos are all harlequin ladybirds as those are the only ones I seem to have in my garden.
Below are ladybird eggs, I think. I have put them in the bug jar and so will confirm this when they hatch. They were laid on the most aphid infested leaf that was in the garden which is a good indication. Mothers will lay eggs where there is a plentiful supply of food. The leaf would not have made for good eating with that much damage.
Below is a ladybird nymph. They hatch as tiny versions of these. I’m afraid I couldn’t get a photo because bugs that small are hard to find. I did manage to get a photo of a discarded skin though. As the nymph grows it sheds its exoskeleton several times.
They then enter a pupa stage, where its insides change. It then emerges in the beetle shape. This is the adult form with a hard wing case that hides the wings when not in use. They hibernate over winter, ready to lay eggs in the summer.
Despite their very different colouring these are below are all harlequin ladybugs. Their colouring acts as a warning to tell predators that they taste unpleasant and they can extrude a horrible yellow liquid when they feel threatened from their leg joints.
The best way to encourage ladybirds into the garden is to have plenty of food, i.e. aphids, and to not spray pesticides. You can help them to overwinter by providing them with somewhere to hibernate. Apparently the bug hotel of choice is one with narrow tubes of various sizes like a pot stuffed with bamboo and other woody, hollow stems.