Asparagus beetles

Look for

Bright red, cream and dark blue coloured beetles, oval shaped and about 1cm long. They will be feeding or laying eggs on asparagus spears and fronds. Larvae are grey coloured hump-backed grubs with black heads and three pairs of short legs. They will usually be found feeding on the fronds. The tiny dark coloured eggs are laid pointing away from the plant tissue.

About asparagus beetle

* Adult asparagus beetles are up to 8mm long.
* Adults appear in mid to late spring as asparagus spears are emerging through the soil.
* They will mate and lay their dark coloured eggs in small rows on the spears.
* When the eggs hatch the larvae will initially feed on the tips of spears, but later will migrate to the fronds.
* They will feed for a few weeks before pupating in cocoons in the soil around the base of the plant or in nearby mulch.
* There may be two or three generations per year depending on temperature and availability of food.
* Adults will overwinter in the soil, leaf litter, or in hollow stems of asparagus plants.
* Feeding by adults and larvae will cause yellow-brown discolouration of the leaves and stems.
* Large infestations can completely defoliate and eventually kill plants.

Treatment
Chemical

Products containing the following chemical ingredients are all effective on asparagus beetle:

Pyrethrum

Note: It is important to read manufacturers instructions for use and the associated safety data information before applying chemical treatments.
Organic

* Regularly inspect plants and hand pick adults and larvae from the spears and fronds.
* Remove old dead stems and dispose of them to prevent adults over-wintering.

Prevention

* Inspect spears as soon as they emerge for adults mating and laying eggs.
* Wipe away any eggs from the spears.
* Remove any old plant debris around the base of plants to prevent larvae pupating.