I was out taking some photos of the mirabilis before they closed for the day and remembered that I wanted to take a photo of the autumn raspberries too. I am actually a day late because I picked lots yesterday and that would have been the time to take the photo, before I picked the fruits.
But while I was looking for ripe fruits (they are yellow-fruited which has the big advantage that birds leave them alone – YAY) I noticed what I assumed were shield bugs in the background.
A bit of research and I think these are Coreus marginatus or dock bugs. I am no expert on insects but bugs (true bugs, which include fleas and bed bugs) differ from beetles in that they have probing, sucking mouthparts rather than jaws that ‘munch’. These are also known as stink bugs because of the nasty smell they can squirt if bothered.
Dock bugs apparently mate and lay eggs in spring, which makes me wonder if the pairs I found were just being romantic. The adults overwinter on old dock flower stems and they prefer to suck on docks (rumex) and related plants. That makes a lot of sense since the surrounding field has lots of docks and nearby is my clump of rhubarb.
In another part of the garden I found these. I spotted them the other day when they were less mature and they were distinctly pink. They have developed and are more adult now but I do not know what species there are. They are on dead stems of nepeta which seems a poor diet. You can see the one on the right is less mature than on the left. My apologies for all these images which are not great.
But back to my dock bugs which are common in Ireland. Apparently they also feed on raspberries, blackberries and other rosaceae as well as dock. As they feed they inject toxins into the plants which cause damage to the plant tissues but they are usually not a big issue. I believe that in the USA where they are called squash bugs, they can be a big problem.
There are ten species of Coreidae (squash bugs) in the British Isles and the dock bug is one of the most common. True shield bugs are not as flat and the most common is the green shield bug (Palomena prasina), which usually feeds on brambles (rubus) but this one was happy with my raspberries. They are supposed to eat fruits as well as leaves and I did notice that some of the drupes on the raspberries were paler than the others so I assume these had been ‘sucked’. It all makes me want to chuck out the raspberries and eat a steak knowing that I am the second creature to enjoy the raspberries.
I know that these little creatures do not bite but when I see their piercing mouthparts it does make me nervous – especially knowing that the group includes assassin bugs which chase after and suck the life from their prey.