Gypsy Moths Are Here In High Numbers

Gypsy moth caterpillar. Note the faint blue spots on the back toward the head, followed by several red dots.

Can you hear the munching? Are the leaves of your trees being eaten? If you are finding hairy, black caterpillars with blue and red spots with a little white thrown in for good measure,  gypsy moth (Lymantria dispar) caterpillars are present. High populations are being found around the state, probably due to the warmer winter which allowed many egg masses to make it through the winter.

Gypsy moth egg cases, p.cooper photo

Gypsy moth females laying eggs, psu.edu,Credit- Katriona Shea, Penn State

Around 500 eggs are laid in buff-colored masses of  during July. Egg masses can be laid on trees, homes, fence posts and just about anywhere the female moth is able to reach. Scrape off any you find, and crush or put in a container of soapy water. Alternative control is to spray mass with horticultural oil. Egg masses not eradicated will over-winter, waiting to hatch during late April into early May. Newly hatched caterpillars spin a fine thread of silk to ‘balloon’, carried by the wind hoping to land on a host plant. Oak trees are their preferred food source, but they will feed on many other plants if opportunity presents.

There are five to six larval stages of the caterpillar. The early stages of the young caterpillar stay in the trees to feed at night, hiding under leaves during the day. Later stage or older caterpillars drop to the ground to find hiding places during the day. This is the stage people notice them congregating under eaves, on houses, tree trunks and other shaded places providing protection from heat and sun, and predators.

Gypsy moth caterpillars on foundation.

These caterpillars can be killed by spraying with soapy water or collecting them to put in a bucket of soap and water. Wear gloves as some people are allergic to the hairs along their bodies.The caterpillars climb back up the trees in late afternoon and evening to continue feeding. Banding the trees with burlap coated with a sticky substance such as Tanglefoot or petroleum jelly will catch the caterpillars as they try to climb the trunk to reach the leaves. Daily cleaning of the burlap to remove the stuck caterpillars will keep them off the leafy portion of the tree.

gypsy moth Burlap-band-iwex/edu

By the third week of June until mid July, caterpillars are done feeding. Caterpillars leave the trees to a seek a protected spot to pupate. Pupation lasts about two weeks, then the adult moths emerge. The female moth is whitish with faint brown marks. The male moth is darker brownish. The female cannot fly so the male flies to her to mate. Females then climb up trunks or other objects to lay the egg mass. Adults only live about two weeks and there is only one generation per year.

Gypsy moth male and female, (Photo by Lilly Calderon, Kelly Estes) hyg.ipm.illinois.edu

 

-Carol Quish

 

Woolly Bear Caterpillars

Woolly Bear Caterpillar, photo by c.quish

Do woolly bear caterpillars really predict how intense and cold the coming winter will be? This is the often repeated folk tale heard upon spotting the readily recognizable, black and orange/brown colored, fuzzy caterpillar in the autumn. The theory is  that the wider the black end sections, and shorter the orange/brown section, the longer the winter will be. Well, it is not true folks! There is really no actual research proving it is fact. We do know that some years the center section is longer than other years. This is due to the weather, not future weather but past weather.

Isabella Moth Adults, photo from purdue.edu

The woolly bears are the larval stage of the Isabella Tiger Moth, Pyrrharctia isabella. The caterpillar has four stages of life; egg, larva(caterpillar), pupa(chrysalis), and adult moth. The caterpillars molt several times during the summer and fall. At each molt, a portion of the black setae (hairs) are replaced with orange/brown setae, making the middle sections longer. So the older the caterpillar, the more molts it has gone through, therefore the less black areas and more orange/brown.

The caterpillars you see now will seek hiding places to over-winter. They will produce a chemical protein just like anti-freeze, allowing them to live through the winter in a resting state. When the spring comes they will break their dormancy to become active once again. To continue their life cycle in the spring, they will pupate into a chrysalis where they will turn into the Isabella Moth adult. Adults will fly around, mate and the female will lay eggs. Eggs hatch into the woolly bear caterpillar to complete the cycle. If you have an early spring, the cycle starts sooner than normal, resulting in a longer growing period for the caterpillar. So when we see a larger woolly bear with a less black and more orange/brown, it is just older and will have gone through another molt sooner, possibly, than at the same time the year before.

So the woolly bear is a reporter of past weather, not a predictor of what has yet to come.

-Carol Quish

 

The Spicebush Swallowtail

The Spicebush Swallowtail butterfly (Papilio troilus Linnaeus )  is a large, dark  swallowtail  native to Eastern North America. The wings are black with a single line of ivory spots along the outside edge and the “ tails “ along the edge of the hind wings from which the swallowtails get their common name. Females have a blue wash and males a greenish blue wash on the upper side of the hind wings. Wingspans range from three to four inches, making swallowtails our largest butterfly. These butterflies are found especially near woodlands, where the males patrol looking for females, but they can turn up in any open areas such as fields or roadsides as they search for nectar sources and larval host plants. Flight in New England is from April- October. Look for them when Japanese honeysuckles begin to bloom in the spring.

The Spicebush Swallowtail has to be one of the most spectacular caterpillars of any of the North American Lepidoptera. Tucked in a leaf shelter during the day, these caterpillars often go undiscovered unless you know how to find them. First of all, check out the main larval host plants- principally spicebush, sassafras or sweet bay- and then look for leaves that are folded in half length- wise. Gently open the leaf and see if there might be a caterpillar inside. The caterpillar has eye spots on the thorax and usually the head faces the outward tip of the leaf, where it will resemble a little snake. It gets more spectacular in appearance as it progresses through its instars. The eye spots are a good defense against  many a bird that would otherwise have  them for dinner.

Swallowtail caterpillars also have another defense mechanism- a gland called an osmeterium  that can be flashed from the thorax when the caterpillars is alarmed. It emits a disagreeable odor that is thought to deter predators. Sometimes just jostling the branch where the leaf shelter is located is enough to cause the caterpillar to use this line of defense. You will be alerted to its presence by the foul aroma, and need only look for the source nearby.

When caterpillars are ready to pupate they turn an orange or yellow color t as feeding stops. The host plant may not be the same plant where the caterpillar will pupate, and they will often travel some distance to find a suitable place for pupating. Like all swallowtails, the chrysalis is formed by the caterpillar hanging in a   head up position. Feet are tied down with silk and the thorax is hung away from the supporting stalk or branch by means of a silk “girdle “. The swallowtail chrysalis will have a set of “ ears “ where the head is, bearing a resemblance to Batman.  Chrysalises are green if the butterfly will emerge in the current year, and are brown if they will overwinter until eclosing the next spring.

To attract the butterflies to your property, plant good nectar sources that will provide food from spring to fall. Buddleia davidii  is a favorite long- season nectar source for many butterflies. Bush honeysuckle, Lantana, goldenrods, Joe- Pye weed, purple coneflower and milkweeds are some plants that are attractive to swallowtail butterflies. In spring, phlox is a good source of nectar, and geraniums, impatiens and marigolds are good annuals to use. The Spicebush Swallowtail is singular in that it is able to enter the flowers of certain lilies like day lilies and Tiger Lilies to obtain nectar that is deep in the flowers. They are able to reach the nectar and then back out again with no harm done.

Including larval host plants on your property may encourage females to lay eggs nearby, making it possible to enjoy this creature in all of its life stages.

Pamm Cooper                  All Photos Copyrighted 2014 by Pamm Cooper