What are they?
GREEN SHIELD BUGS are small green beetles about the size of a fingernail. Adults have a shield-shaped green back – some with a darker blackish-brown patch at their base – and are often seen basking in the sun on the leaves of a wide variety of plants in summer. When disturbed or crushed, shield bugs emit a foul smelling odour that is meant to deter predators from attacking them. This also sends an alarm signal to other bugs that a threat is in the area.
Green shield bugs appear in the garden from early spring through summer to autumn. They have strong mouthparts with which they pierce leaves, stems and fruit of plants so that they can suck sap and juices. This causes plants to wilt and produce becomes impaired with holes that can cause fruits to rot. Tomatoes, beans, melons, squashes, grapes and capsicums are popular targets as well as a range of other plants. Shield bugs can establish whole communities in a stand of plants and they are tricky to catch.
Adults lay eggs in clusters on the underside of leaves. Eggs look like tiny barrels and are arranged in rows. The eggs hatch into nymphs that are rounded in shape and often black or dark brown with small red and yellow markings on them. Within 4 to 5 weeks the nymphs mature into adult beetles.
At the end of summer, any remaining adult beetles will find shelter beneath bits of wood, in leaf debris and old pots where they’ll wait out the winter before emerging to start new communities of shield bugs as soon as weather warms in the spring.
Lifecycle
GREEN SHIELD BUGS are small green beetles about the size of a fingernail. Adults have a shield-shaped green back – some with a darker blackish-brown patch at their base – and are often seen basking in the sun on the leaves of a wide variety of plants in summer. When disturbed or crushed, shield bugs emit a foul smelling odour that is meant to deter predators from attacking them. This also sends an alarm signal to other bugs that a threat is in the area.
Green shield bugs appear in the garden from early spring through summer to autumn. They have strong mouthparts with which they pierce leaves, stems and fruit of plants so that they can suck sap and juices. This causes plants to wilt and produce becomes impaired with holes that can cause fruits to rot. Tomatoes, beans, melons, squashes, grapes and capsicums are popular targets as well as a range of other plants. Shield bugs can establish whole communities in a stand of plants and they are tricky to catch.
Adults lay eggs in clusters on the underside of leaves. Eggs look like tiny barrels and are arranged in rows. The eggs hatch into nymphs that are rounded in shape and often black or dark brown with small red and yellow markings on them. Within 4 to 5 weeks the nymphs mature into adult beetles.
At the end of summer, any remaining adult beetles will find shelter beneath bits of wood, in leaf debris and old pots where they’ll wait out the winter before emerging to start new communities of shield bugs as soon as weather warms in the spring.
