Coping with Green Vegetable Bugs

green vegetabl bugs

The Importance of the Right Name

When learning about a pest, begin your journey by finding out it’s scientific name. The bug I’m ruminating on today is the Green Vegetable Bug Nezara Viridula, also called green vegetable beetle, stink bug or shield bug. These other names bring you to an array of bugs, not necessarily Nezara V. With the proper name you can’t go wrong. Searching with the scientific name brings you to the best information.

Beware Their Many Disguises

Green Vegetable Bugs go through many phases, each one quite different from the last. The girls were picking beans for tea and came rushing in to get the camera to photograph the cute bugs they’d found. Newly hatched Nezara they were (and they are cute.) Here’s some excellent photos to aquaint yourself with all the phases (instars).

There is a native green vegetable bug which looks similar, but doesn’t have the three light spots along it’s ‘shoulders’. Don’t worry about him, he wont damage your crops.

Natural Predators

Being stinky and big they wont be ambushed by an Assassin bug or eaten by a bird. Predators and parasitic wasps get a look in at the egg stage (black eggs indicate a parasitic wasp has been at work), but maybe not as often as we’d like, Mrs Stink can be quite the egg protector.

Digital Control

I love this term, as if you can press a button and the problem is solved! Pre infestation (because getting pests at the first sign is the way forward), GVB’s are easily managed by picking them off – especially in the morning (am sure you can relate to getting going slowly), or on a cold day. Squirt dish washing liquid into a bucket of water and drop them in as you find them. While you’re at it check under the leaves for tidy clusters of pale, barrell shaped eggs and rub them off.

Squash one bug and the smell will alert all, sending them plummeting to the ground en masse. In my heavily mulched and over planted wilderness this guarantees their escape. Should your garden be more manicured, you could use this to your advantage. I’ve heard tell of sheets laid down to catch them when they fall.

gvb's been at my berries

Success with Neem

If the population is left to grow (about 100 eggs per season per Mrs), then the damage is big – plant malnutrition, undeveloped fruits and ruined fruits (leaving dry, corky bits – see my poor raspberry!). They pierce then suck – especially loving the fruits.

Anything eating your plants is theoretically impacted by Neem, so I asked Bonny from Naturally Neem, if Neem would work on Green Vegetable Bugs. Yes, she said, but the trick is to spray intensively – 3 times a week.

Neem is not a contact killer, it only kills after it’s been ingested, which is why it doesn’t impact the beneficial insect population. Though Neem is low level toxic to bees, I always spray early morning or late evening once the bees have toddled off to bed. A very helpful article here.

Raspberries

Saving My Raspberries

GVB’s recently exploded in my raspberries. Because the plants were pretty feral (as only brambles can be), it was easy for them to escape my attention until they, well exploded! I pruned the plants back to make spraying more effective and sprayed Neem three times over the period of a week. A fortnight later it’s taken it’s toll and I’m delighted to find only half a dozen lurking – the Raspberries are saved! I’ll be handpicking the odd new comer till they delve down into the mulch to over winter.

Comments

  1. Gillian Waterworth says

    So now I know! Thanks so much for this info kath.

  2. Jardinier says

    They have ruined our corn crop this year, sigh! In previous years they seem to have left it mostly alone, so I wasn’t as watchful as I could have been.

    Calendula seems to be a good trap crop for us (in Blenheim) particularly early in the season. They get covered in the instar phases and can then be pulled and burned or sprayed or just dumped in a wheelie bin.

    We have had much less psyllid this year (the heat??) but a bumper crop of Nezara viridula 🙂

    • Yes, calendula is an excellent catch crop for GVB’s – that’s very helpful for everyone to know.
      Nature sure keeps us on our toes – in a flexible, go with what she throws at us kind of way – doesn’t she?
      Same here low on psyllid high on Nezara (loving your use of this :)) An entomolgist would be the one to answer our pesty wonderings. We had a hot November followed by a cold December. I presumed that summery setback to be the reason for the psyllids late start – I always think of them as loving the warmth. A life times of learning in the garden!
      Am really on the GVB hunt now as I don’t fancy a plague next spring.
      May your Nezara hunt be a great success!
      best Kath