Constraint - Native budworm
Description
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Larvae grow to 35 to 40 mm long with their colour ranging from green, yellow, buff, red or brown to almost black, with a broad yellow-white stripe down each side of the body and a dark stripe down the centre of the back
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Pupae are cigar-shaped, 12 to 22 mm long, and yellow-orange to shiny dark brown
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Adult moths are medium-sized (wingspan 30 - 40 mm) and stout bodied
Symptoms
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Larvae feed from plant surfaces such as leaves, flowers or pods
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In some unusual situations, such as adversely hot conditions, the small larvae may burrow straight into pods and seeds
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However, they mostly graze on plant surfaces until they grow to 8-12 mm in length
Damage
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The most notable damage by native budworm is on the pods and seeds
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In most situations pod attack commences with medium-sized larvae entering them and eating all or part of the seed between pods
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Yield penalty can occur if populations are high, due to reduced seed
Control
Surprising levels of mortality of eggs and budworm caterpillars exist in most situations (well over 90% of all eggs and young larvae may die before causing any damage). Eggs and larvae will die if they are dislodged from the plant by wind or rain, or if they are attacked by predators, parasites, or diseases. Spraying when numbers are above 1 medium to large caterpillar per m2 will maximise efficiency of insecticides. In years of very high caterpillar numbers and excessive pod burrowing a higher rate or second spray should be considered.
