For many New Zealanders, the sound of the cicadas evokes cherished memories of summer holidays. But for kiwifruit growers, these noisy insects spell trouble.
Chorus cicadas (Amphipsalta zelandica), the largest and loudest of their species, pose a serious threat to kiwifruit orchards. When they lay eggs in kiwifruit canes, their ovipositors create wounds that weaken the canes, increasing the risk of breakage during winter tie-down. Damaged canes must be pruned, reducing the productive canopy for the following season.
Pieter Van Der Westhuizen, Regional Sales Manager Upper North Island for UPL NZ Ltd, says the wounds on canes can also provide entry points for Psa.
“Cicadas have become a major pest in kiwifruit orchards in some of our largest growing areas including Kerikeri and the western Bay of Plenty,” says Pieter.
“Early intervention is crucial because in-season control options are extremely limited. Prevention is better than cure with cicadas, so winter is the time to get into the orchard and get onto them.”
Pieter recommends the combination of Assail® insecticide together with Engulf® super penetrant applied after leaf-fall but before pruning. “Although, if needed, you can apply this combo immediately after pruning.”
Assail is a synthetic pyrethroid insecticide / miticide (100 g / L bifenthrin in the form of an emulsifiable concentrate) with broad-spectrum activity against chewing and sucking insects, including cicadas. It works through both contact and ingestion, but because Assail is not systemic, it is critical to cover vines thoroughly.
Adding Engulf as an adjuvant enhances penetration, ensuring the insecticide reaches deep into the difficult-to-access nooks of kiwifruit vines, including cicada egg-laying sites.
“To target cicadas effectively, you need to cover every vine thoroughly. If uncontrolled, cicadas can be very persistent. Eggs can survive inside canes, even if the canes have been cut up and left in a pile to decompose, leaving the eggs to hatch and the whole cycle to continue causing damage to valuable vines.”
The cicadas’ lifecycle, which includes larvae surviving underground for up to four years, means populations can build-up rapidly. Cicada eggs usually hatch in early to mid-summer, three to ten months after being deposited. Post-hatching, the larvae burrow into the ground and feed on kiwifruit vine sap through the roots until they emerge as adults.
Pieter says the Assail and Engulf combination also combats passionvine hopper (Scolypopa australis). This pest excretes honeydew, creating ideal conditions for sooty mould to develop on vines and fruit, which can lead to fruit downgrades.
“With Assail and Engulf, you’re tackling two destructive pests in one go. Assail gives you control of the insects and Engulf makes sure delivery is efficient. You get the most out of your spray programme, which is so important when everyone is conscious of the cost of fuel and labour.”
ACVM registration number: Assail #P009642. Read registered label before use.
