Insects

By Hazel Shinholt, Abbott’s Mill Nature Center Teacher/Naturalist

Warm weather is upon us and we see all kinds of insects scurrying about at Abbott’s Mill Nature Center.  One of the insects you may have walked right by (maybe even walked on) and never noticed is the antlion.   Antlions are in the family Myrmeleontidae and order Neuroptera.  They undergo complete metamorphosis.  The larvae look nothing like the adult.  The adults have wings and can look similar to a damselfly. The most noticeable differences are that the antlion has longer antennae that are clubbed at the end and the vein pattern in their wings is different from the damselfly.  The adult antlion is nocturnal but the larval stage is very active during the day.

Antlion Larva showing its big grasping mouthparts that is uses to subdue small insects that fall into its funnel-shaped trap.

Antlion Larva showing its big grasping mouthparts that is uses to subdue small insects that fall into its funnel-shaped trap.

It is larval stage of the antlion that I find most fascinating!  Antlion larvae are ominous looking creatures. They are gray/brown in color, with an oval shaped body covered in bristles, have short legs and large mandibles.  We have many near our meadow habitat at Abbott’s Mill Nature Center.

The Antlion larva waits for prey to drop into the bottom of the funnel-shaped trap, submerged in the sand.

The Antlion larva waits for prey to drop into the bottom of the funnel-shaped trap, submerged in the sand.

Antlion larvae dig a cone-shaped “pit” in loose sandy or dry soil (look for soil that looks like a rain drop hit it and left a cone-shaped impression in the soil).  The antlion buries itself in the bottom of the pit and waits for its next meal to arrive. Only part of its head is visible at the bottom of the pit.  When an ant or other small insect crawls near the edge of the trap, the loose soil gives way and the prey falls into the “pit of death.”    When the prey reaches the bottom, the antlion then grabs the prey with its strong mandibles and drags it under the soil.  It pierces the prey and feasts on the body fluid of the prey.  The antlion has no use for the carcass of the prey and flicks it out of the pit and the cycle begins again.

By Sheila Vincent, Group Program Coordinator

Occasionally we write book reviews on The Nature of Delaware blog, so since we recently added this book to our staff collection, we thought you might want to know about it.

Beetles of Eastern North America

Beetles of Eastern North America, by Arthur V. Evans, is not a field guide.

In fact, this tome, published by Princeton University Press, is beefy enough, and beautiful enough, to be the ultimate geek coffee-table book. It is comprehensive, 560-page, gorgeous, fascinating, and relentlessly technical. Take this random sample from one of the extremely thorough species accounts for example: “…Maxillary palp ornate in male, simple in female. Abdomen with six (male) or seven (female) ventrites…”. If your response to this description is “Um…..what?”, take heart. The book includes a good glossary, lots of excellent labeled illustrations and diagrams, and a dichotomous key, among many other aids to understanding. There are sections on beetle anatomy, when and where to find beetles, their behaviors and natural history, trapping, collecting, pinning…even a segment on rearing.

And of course, there are the striking, full-color photographs. Most depict living beetles in natural surroundings -on leaves, flowers, soil, wood, etc – in all their diverse, vivid glory. There is no way to do justice to these photos with mere descriptions, except to say that they actually make it possible to use the words “stunning” and “beautiful” and “beetles” in the same sentence. If you plan to use the book for specimen identification, however, you will need to have your own good photograph of the beetle in question, or ideally, have the specimen in hand.

Bottom line: Beetles of Eastern North America is a wonderful beast of a book. I learn something, and have some nerdy fun, every time I open it, whether it’s to ID a difficult specimen, answer a specific question about beetledom, randomly pick a page and start reading, or just gawk at the splendid photographs.  If you know someone who is seriously into insects, this book will keep them busy and amazed for a really long time.

By Joe Sebastiani, Seasonal Program Team Leader

Until a few weeks ago, the only Giant Swallowtail butterflies I had ever seen were in Florida.  Recently, I have had two of these southern butterflies whiz past me, and finally today, I found one at the Flint Woods Preserve that I was able to get photos of while it was feeding.  What is so special about seeing this large butterfly in Delaware?  They normally are found further south from here, and are considered a rare stray to our area.  This year is different.  People are reporting them from all over the mid-Atlantic and even up into New England.  This is the largest species of swallowtail that can be found in our area, and it is a beauty.  It is dark on the back, with yellow lines that form an “X” near the wingtip.  Underneath, they are largely yellow, with a blue median spot-band.  The tails also have a dab of yellow in the middle.

This Giant Swallowtail was found today at the Flint Woods Preserve.  Normally, they are rare this far north, but right now, they seem to be fairly common.  Photo by Joe Sebastiani

This Giant Swallowtail was found today at the Flint Woods Preserve. Normally, they are rare this far north, but right now, they seem to be fairly common. Photo by Joe Sebastiani

Giant Swallowtail caterpillars usually feed on leaves of citrus plants down south, in fact, in some areas, they are considered a citrus “pest” species.  Around here, there isn’t much citrus to go around, but some observers have seen them laying eggs on potted grapefruit and other potted citrus trees.  Otherwise, the caterpillars have been known to feed on Prickly-ash shrubs.  Too bad there isn’t any of that in Delaware either, at least not in the wild.  It historically occurred here, but is thought to be extirpated.  So what are these Giant Swallowtails doing here???  Who knows, but it could have to do with a super-abundance of them in one area, forcing them to leave to find new food resources, or it could have to do with weather patterns or other factors we haven’t considered.  One thing is for sure, they are here, and you have a good chance of seeing them over the next few weeks.

From this angle, you can see the upperside of the wing, which is black, and has a yellow "X" near the tip.  The tails are black with a yellow dot in the center.  Photo by Joe Sebastiani

From this angle, you can see the upperside of the wing, which is black, and has a yellow “X” near the tip. The tails are black with a yellow dot in the center. Photo by Joe Sebastiani

There are other swallowtail butterflies in the area as well.  Most commonly, you will see Eastern Tiger Swallowtails, which are large and very yellow.  The black form of the Tiger Swallowtail doesn’t have much yellow on it at all.  Black Swallowtails are smaller than Tigers and Giant Swallowtails.  They are black and have yellow lines that do not cross.  Other species include Spicebush and Pipevine Swallowtails, but they also have very little yellow.  So if you see a big, black swallowtail, with yellow lines that cross near the wingtip, and a very yellow underside, it should be a Giant Swallowtail.  Take a look around you flower garden, or go for a walk in a wildflower meadow and report back here if you find any.  You can email photos to me at joe@delawarenaturesociety.org if you want a species confirmation.

By Lori Athey, Habitat Outreach Coordinator

It is high summer now and my early summer flowers are looking a bit tired while the late summer/fall show has yet to begin. Nonetheless, there is a lot of wildlife activity in my garden right now. The pollinators are all over the Echinacea/Purple Coneflower, Coreopsis, Butterflyweed and Beebalm, tired-looking though they may be. However, the big story right now in the habitat garden is happening in the leaves: that giant munching sound you hear is the caterpillars feeding.

Bees nectaring on Echinacea, purple coneflower.

Bees nectaring on Echinacea, purple coneflower.

If you have read University of Delaware Professor Douglas Tallamy’s book “Bringing Nature Home”, you already know that most (about 96%) of our songbird species need insects as part of their diet. Lepidoptera (butterfly and moth) caterpillars are a large diet component of insectivorous birds. Summer is prime Lepidoptera season both for caterpillars and mature adults. Some of the best plants for supporting caterpillars, and thereby birds, also provide nectar and pollen for other pollinators, fruits or nuts for the birds, insects and other critters, shelter, nesting material and good places to raise babies.

This big juicy caterpillar could be food for a hungry bird in your garden.

This big juicy caterpillar could be food for a hungry bird in your garden.

So here are a few plant superstars to try in your wildlife garden:

Do you have room for a tree? Oak (Quercus species) trees are champion providers for native caterpillars at 518 species, but they also provide pollen in the spring for the bees, acorns in the fall and winter for squirrels and other critters, as well as shelter and places to raise babies for all sorts of birds, insects and mammals. Especially lovely specimens for your garden are the Willow Oak (Q. phellos), Scarlet Oak (Q. coccinea) and Swamp White Oak (Q. bicolor).

This northern pin oak will provide great wildlife value to your landscape, as well as fall color.

This northern pin oak will provide great wildlife value to your landscape, as well as fall color.

Do you have a native Cherry Tree? Our native cherries and plums (Prunus species) support 429 native caterpillar species. They also provide pollen and nectar in the spring and fruit in the summer enjoyed by both insects and birds. In addition to the Wild Black Cherry (P. serotina), others to try include the American Plum (P. americana), and for your beach home, the Beach Plum (P. maritima).

This American plum is a fine plant to add to your backyard habitat for native pollinators, fruit-eating birds, as well as insects that will eat the leaves, providing more food for birds.

This American plum is a fine plant to add to your backyard habitat for native pollinators, fruit-eating birds, as well as insects that will eat the leaves, providing more food for birds.

Don’t have room for a large tree? Try one of our native Dogwood (Cornus species) trees or shrubs. Not only do these plants offer pollen/nectar, fruits and foliage for the critters, they also are very attractive as landscape plants with lovely flowers, pretty fruit and attractive fall foliage color. Try our common Flowering Dogwood (C. florida), or one of the large shrubs such as Redosier Dogwood (C. serecia) or Silky Dogwood (C. amomum).  Another superstar shrub is the Blueberry (Vaccinium species), which supports 286 species of caterpillars. Just like the others, it also provides nectar and pollen for the bees, and fruits relished by the birds but in a much smaller size, including dwarf selections. It too has pretty spring flowers, attractive fruit and lovely fall color. Plant several named varieties for the best fruit set.

Here, a Unicorn Caterpillar feeds on a blueberry bush.

Here, a Unicorn Caterpillar feeds on a blueberry bush.

We also have some superstar herbaceous flowering plants. Members of the Aster Family (Asteraceae) are standouts for supporting Lepidoptera caterpillars with their foliage, especially Goldenrods (Solidago), Asters (Eurybia, Symphyotrichum), perennial Sunflowers (Helianthus) and the butterfly favorite, Joe Pye Weed (Eutrochium). Some are just beginning to bloom now while others will bloom in early and late fall, providing an important source of late-season pollen for the pollinators, as well as seeds for the birds.

A Meadow Fritillary feeds on nectar from a blooming goldenrod, which will begin blooming in early August.

A Meadow Fritillary feeds on nectar from a blooming goldenrod, which will begin blooming in early August.

So plant some of these superstars in your garden and then put out the all-you-can-eat buffet sign for your birds and critters!