Hemileuca peigleri Lemaire, 1981
This moth is a member of the family Saturniidae - or Giant Silk Worm Moths. Members of this family are responsible for the production of silk for use in fabrics, rugs and other items. They are among the largest and most beautiful of all moths.
As members of the Order Lepidoptera (scale winged insects -- all butterflies and moths) -
these insects undergo a complex process of change known as metamorphosis as they transition from egg to caterpillar to pupa to adult.
The stages in this process are illustrated here:
Adults emerge in mid to late December (Start in the upper left) and focus on mating. They
only have enough fat reserves to live for a few days so breeding is uppermost. When a female is ready to mate, she emits a tell tale "perfume" (pheromone) which attracts male moths. After she breeds
she will take wing and seek out a suitable plant on which to lay her eggs. The larva need to feed on an oak species immediately after hatching so finding the correct plant is critical. Once the
female has selected a plant she begins to lay a series of small eggs in a ring circling a twig. This is known as an ova ring (see below).
She will create as many as two to three of these ova rings before she dies. The ova rings overwinter and begin to hatch just as the larval host plant begins to put out new leaves. Oak leaves when mature become hardened or "sclerotized". These mature leaves are not optimal for the 1/8" long newly hatched caterpillars - they require fresh budded leaves or even catkins. Catkins are the oaks' flowering parts.
When they first hatch the Caterpillars are gregarious -- they stay together in a cluster as they feed. As they age they will begin to disperse. This dispersal is a survival adaptation designed to lessen the risk that a predator can find and eat the entire cluster. Caterpillars are dedicated eating machines - they literally do nothing but eat. They eat and wander about looking for fresh leaves storing up fat for the coming changes.
The caterpillars will go through 6 stages, each called an instar. At 5 - 7 day intervals they will pause feeding and anchor themselves to the end of twig with a pad of silk then they will molt. Molting is the process of shedding their old skins and emerging in a new larger skin to allow for continued growth. The caterpillar splits open their skin down the back and wriggles free. The also cast off the hard fingernail like head covering - known as a head capsule.
After molting is complete they may look different -- especially in the later stages (Instar 3 through 6).
3rd Instar Hemileuca peigleri - image copyright 2014 by Robert J. Nuelle, Jr.
These caterpillars when fully mature look like this:
6th Instar Hemileuca peigleri - image copyright 2014 by Dr. Richard S.
Peigler - used with permission.
These caterpillars are covered with very toxic stinging spines - for their protection. Care must be exercised in handling them or the person can receive an irritating sting.
Note the small reddish blisters on my fingers -- each the result of a caterpillar encounter! These last for several days and are similar in intensity to a Fire Ant sting.
Once the caterpillars have completed all 6 instars they will wander off and seek out a soft
patch of dirt under the leaf litter where they will begin the process of pupation. Their skin splits down the back and they vigorously wiggle to push the discarded skin off. When complete they will
have changed from their caterpillar form to a resisting intermediate form known as a pupa.
Newly pupated Hemileuca peigleri still working to shed the former caterpillars skin.
The newly pupated moths enter a long resting phase (typically from April to December) where they are awaiting the trigger to transform into their final form -- the adult winged insect. The trigger will mostly likely be a combination of temperature and moisture factors. The adults emerge in December from the pupae and then crawl up a nearby piece of vegetation to complete the process of expanding their wings and getting ready for mating.
The females emerge and rest until they are ready to mate - and then they begin "calling" - they release their male attracting pheromones from a gland in their abdomen and wait for the males to arrive.
Mating occurs and then the females fly off to find a place to deposit their eggs.
During the two - three week flight window we typically see males flying in the morning hours seeking calling females and then later in the afternoon females fly and begin searching out places to lay their eggs.
and the cycle repeats . . .
The East Texas Natural History Collection is proud to be the first North American Host and partner with the International Journal of Entomology and Zoology Studies. The Journal of Entomology and Zoology Studies is a peer reviewed international Open Access Journal which is abstracted in various reputed databases. The Journal provides a platform with the aim of motivating students and personnel in all fields of Zoology.
Contact Us - Please visit our Contact Page.