8 Yield Killers to Watch out for
With only a few weeks until Christmas, I’m sure you’re looking forward to enjoying lots of good food with the family!?
Well, there’s a few critters that can’t wait that long – they have already started.
We get it… they are small… BUT, they can steal so much of your hard earned $$ if they find a liking to your crop.
So you might be asking:
- What insects might I come across?
- What signs do I look for?
- How much damage will it make to the crop?
- When should I consider controlling them?
Here’s a basic insight, based on what we’ve seen/expect this season:
- Cause damage to germinating and newly emerged seedlings (Looks like the leaf has been hit by a shotgun)
- Very small brown insects about the size of a pin head
- Jump when disturbed
- Detected most easily by placing a white card or cloth on ground and gently disturbing soil.
- Cause damage to young seedlings and mature plants
- Larvae are small maggots that live in the leaf tissue, in mines they create as feed.
- Pictured is early Leaf Miner damage in Turnips
- Damage is done at early emergence stage, in Maize and Brassica
- Losses of well over 10,000 plants/ha can occur at populations of 3 caterpillars/100 plants before the two leaf stage or 6 caterpillars/100 plants at the two to four leaf stage.
- The larger caterpillars are the most damaging, cutting the plant off at the stem.
- Dig near a dying plant to find the caterpillar as pictured.
- Damage is caused to newly planted seedlings, they often wilt and die as a result.
- You will find holes eaten at the base of the plant, below soil level.
- The caterpillar is white as below, and grows into a Click Beetle.
- Common in warm dry areas, prefer open ground
- can be very damaging to germinating crops, particularly those direct drilled
- Adults are often seen on sunny days when their silvery wings reflect.
- These bugs are between 2 – 4mm long, as pictured.
- Also pictured is Nysius damage to a swede crop.
- Moths are around 10mm long, have diamond shape on their wings
- Larvae burrow into leaf and feed on the tissue.
- Caterpillars feed on underside of leaves, and are a yellow grey/green colour
- Butterflies are white with one or two black spots on their wings
- Caterpillars are green with a narrow orange strip down their backs
- Caterpillars may reach 25 mm long, and feed on the leaves only, leaving the veins.
- Its rare to get severe damage from White Butterfly, but it can happen.
ARGENTINE STEM WEEVIL
- Adults are 2 – 3mm long and are difficult to see
- On hatching the white legless larvae tunnel into the stem where they usually remain until ready to pupate
- Most damage is done when the larvae mine the stem, causing the plant to yellow and often die.
Early control is key – so early detection is critical.
Take a photo and send it to your Smart Agronomist, or just call, and you’ll have a recommendation sorted real quick.
Until next time, all the best and keep smiling!
The Smart Team