
18 September 2000
Volume 8: no. 6
Insects have really come back to Mississippi since the rains began to refresh things, again. The sphinx moths are active now and I've seen Luna and other of the larger more colorful species around night lights. Butterflies are also visiting the late season flowering plants. The last generation is well into full swing. We have gone almost all year with only a few Gulf Fritillaries on the maypop trellis in our butterfly garden, but they came on last week and in less than 7 days completely stripped the leaves from the plants. Bees and wasps have also been very active on the flowers. Field crickets have been extremely abundant this fall both around lights and in most gardens. We've had reports of damaging numbers of these critters in the cracked ground feeding on sweetpotatoes.
I ran a number of reminders in `Gloworm' 5 and have chosen to run them prominently again as a reminder that we'd really like to stimulate more participation.
Fall is the best time to do insect collections. Insects are the most abundant at this time of year, until frost. If you anticipate having to do a school insect collection for the spring, getting a head start now is very smart. Lights are especially good on the warm nights during the fall.


Each year in the spring
thousands of Monarch butterflies migrate northward from overwintering
grounds in Mexico toward Canada. They visit milkweed plants along the
way laying eggs and raising broods of monarch offspring who move ever
northward until late July and early August. Then the final summer
generation begins its return journey south to Mexico. Hundreds of
them will mass on plants along the Gulf Coast in the fall getting one
last nectar meal before striking out across the water to their
overwintering quarters in Mexico. Females Monarchs secrete a small
amount of glue to attach the eggs directly to a suitable host plant.
The average female butterfly lays from 100 to 300 eggs. Researchers
have studied egg numbers in captive females; Monarch butterflies
average about 700 eggs per female over two to five weeks of egg
laying. Most caterpillars, including Monarchs, begin life by eating
their eggshell, and then move on to the plant on which they were
laid. The Monarch larvae passes through 5 instars and lasts from nine
to fourteen days under normal summer temperatures. Monarch larvae are
somewhat protected from bird predation by the toxins in the milkweed
that they eat, but many are eaten by other insects and spiders. Just
before they pupate, Monarch larvae spin a silk mat from which they
hang upside down. The silk comes from the spinneret on the bottom of
the head. After shedding its skin for the last time, the caterpillar
stabs a stem into the silk pad to hang. This stem extends from its
rear end and is called the
cremaster.
During the pupal stage the transformation from larva to adult is
completed. Monarch pupae are green with small golden spots! The
function of the beautiful gold spots is unknown. The primary job of
the adult stage is to reproduce - to mate and lay the eggs that will
become the next generation. Monarchs do not mate until they are three
to eight days old. When they mate they remain together from one
afternoon until early the next morning - often up to 16 hours!
Females begin laying eggs right after their first mating, and both
sexes will mate several times during their lives. Adults in summer
generations live from two to five weeks. Each year, the final
generation of Monarchs, which emerges in late summer and early fall,
has an
additional
job: to migrate to their overwintering grounds, either in central
Mexico for eastern Monarchs or in California for western Monarchs.
Here they survive the long winter until conditions in the United
States allow them to return to reproduce. These adults can live up to
eight or nine months.
Happy Bugging!
Dr. Michael R. Williams
Entomology & Plant Pathology
Box 9775
Mississippi State, MS 39762-9775
phone - 601-325-2085
home - 601-323-5699
FAX - 601-325-8837
Visit: DAFVM
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