asters, goldenrods and black-eyed Susans are the
mainstays of fall gardens. An assortment of beneficial
bugs comes with them.
the way itís supposed to work, according to Helen
Hamilton. Sheís author of "Wildflowers and
Grasses of Virginiaís Coastal Plain" and past
president of the John Clayton Chapter, Virginia Native
plants with clusters of tiny flowers feed the beetles
that hibernate as adults and nourish others that form
pupae cases in the soil," she says.
and clouded sulphur butterflies have headed south and
bumblebees, beetles and hoverflies are preparing to
overwinter in leaf litter, under bark or in the stems of
goldenrod and asters."
asters have small heads, 1-2 inches in diameter, with
white or bluish rays and usually a yellow center,
according to Hamilton. The tiny-flowered disk furnishes
nectar to visiting insects.
flowers are often two types ó yellow or white rays
surrounding a central disk with disk flowers.
white asters bloom late summer-November and even into
December. Frost aster (Symphyotrichum pilosum) is one of
the last plants in flower before heavy frost, and is
seen along roadsides and meadows. The stems and leaves
are covered with tiny white hairs, creating a frost-like
appearance. The shrub-like aster is a broadly branched
perennial with needle-like leaves; it grows 1-3 feet
late bloomer is often called calico aster (S.
lateriflorum), since the centers are first yellow, then
purplish-red, according to Hamilton.
aster (S. grandiflorum) is well named with its yellow
disk surrounded by red-purple rays that are 1 Ĺ- inch
long. Also shrubby in looks, each flower is solitary at
the tip of a branchlet. This aster flowers in dry woods
and along roadsides, while New York aster (S.
novi-belgii) prefers fresh and brackish marshes, swamps
and other wet habitats, she adds.
asters are easy to grow and are good additions to the
fall garden," Hamilton says.
insects are collecting the flower nectar and pollen,
they are transferring pollen from male flower to female
flower, ensuring the production of seeds for additional
plants next spring."
flies feed on many garden flowers March through
called flower flies, these syphrid flies have dual
lives," says Hamilton.
adults, syrphids collect pollen and nectar for energy
and to mature sperm and eggs. Females lay oblong eggs,
1mm in length, usually near aphids or within aphid
colonies, which furnish food for the larvae. Not only do
these flies perform important pollinator services in
gardens and agricultural fields, their larvae are
voracious feeders of aphids, scale insects, mealybugs
known as hoverflies, syrphids hover in flight and can
even fly backward. They are true flies with large
compound eyes nearly covering their head, two wings and
small antennae. Like all flies, they have a complete
metamorphosis ó egg, larval, pupal and adult stages.
Eggs hatch in three to four days as soft-bodied
maggot-like larvae. They feed for seven to 10 days, then
fasten to a leaf or twig when ready to pupate, where
adults will emerge 10-15 days later. There are several
overlapping generations each year.
predators, hoverflies are as important as ladybird
beetles and lacewings. The larvae are legless and
wormlike, dull green, less than one-half inch long.
During its development, each larvae consumes 100s of
aphids. Crawling about on plant surfaces, they grasp
their prey, usually an aphid, with their mouth hooks.
Holding it over their head, they suck its body contents
dry while still alive and discard the skin. When aphids
are plentiful, hoverfly larvae can control 70-100
percent of an aphid population, which can seriously
species mimic bees or wasps with bands of yellow and
black around their bodies, to avoid predatory birds and
other insects seeking a meal," says Hamilton.
species of hoverflies feed on fungi, and most are
considered beneficial. The adults do not sting and
pollinate flowers, and the predatory larvae eat insect
a win-win situation for gardeners."