|Ladybird Beetle Larvae |
Feeding on an Aphid
The abundance and diversity of beneficial insects in a particular landscape depends on:
- the diversity of the landscape
- the quality and abundance of forage plants
- the availability of prey
- the number and quality of nesting sites
- the overall health of the plant community
Predators feed on insects as adults and/or as larvae. Solitary wasps are excellent predators of large prey; prey, once caught, are cached in the nest live for the hatched larvae to feed on and fuel development. They help control caterpillars, sawfly larvae, katydids, crickets, and grasshoppers - all insects that feed on foliage.
Predator Profile - Great Golden Digger Wasp, Sphex ichneumoneus
|Nest Excavation - The female excavates clumps of soil and|
holding the clumps between her mandibles
and forelegs, backs out of the nest and deposits
the soil away from the nest entrance.
Nests are excavated in sand or gravelly soil. Females can be observed excavating nests in mid-summer, pictured on the left excavating a nest in mid-July this year.
Providing native plants for nectar foraging helps support these solitary wasps and fuel their hunting activities. A diverse native plant community also provides cover for their prey.
Syrphid flies are active from spring through late fall and visit a large variety of native plants where they can access floral resources, typically in less complex flower forms.
Adult syrphid flies visit flowers to feed on both pollen and nectar. Females foraging for pollen often hold the flower's anthers with their forelegs while they sponge up the protein-rich pollen with their mouthparts.
Many syrphid flies are excellent mimics and are often mistaken for bees or wasps as their coloration and behavior mimics bees and wasps (left). This mimicry helps protect them from predation by birds and other predators.
Pesticides have a serious impact on beneficial insect (and pollinator) populations. If insecticides are applied to control a problem pest, the beneficial insect population is eliminated at the same time. It often takes less time for the pest population to recover from an application than it does for the beneficial insect populations to recover. Continous pesticide use can result in the ongoing imbalance of pest and beneficial insect populations.