Defenses and Survival Tactics of Insects

Caterpillar of the black-etched prominent has highly modified anal prolegs that it can flail to defend itself against predators

 

I love insects. They are amazing.

-Andrea Arnold

 

Many insects never make it to adulthood to complete their life cycles because in the grand scheme of things, they are low on the food chain. Between birds and amphibians, mammals and fellow insects, there is no lack of creatures that rely upon insects as a food source. Insects are not necessarily limpid little defenseless victims of a more sophisticated life form, though. They have strategies for survival. Some use camouflage,  are cryptic in form and color, veil themselves with material, have weapons they use when threatened or they may simply hide. 

Rose hooktip moth hidden by day by blending in on a leaf

Pine sphinx caterpillars blend in with the green and white striped needles of white pine

One of the ways insects can hide in plain sight is by coloration, body form and feeding techniques. Spring caterpillars are often light green and feed on new leaves of similar color. Caterpillars that feed on mature foliage often have colorations or body forms that imitate the dead leaf spots and edges that occur later in the year.

Spongillafly pupates inside this structure it made

Warning coloration protects many insects from being eaten, especially bright reds and oranges. Also, insects may have warts that sport hairs that repel some birds and other predators. One such insect having both is the red-humped caterpillar.

Red- humped caterpillars Schizura concinna have warning colors and warts with hairs that detect air movement

Some caterpillars feed along leaf edges and appear to be part of the leaf itself. Careful scrutiny will reveal the ruse. Two of the prominent caterpillars, the Wavy- lined Heterocampa and the Lace-capped caterpillar are just two examples of this behavior.

Wavy-lined Heterocampa caterpillar hides in plain site feeding along the edge of a sweet birch leaf. It blends in also with cryptic coloration.

Walking sticks are a good example of cryptic coloration and mimicry. Both the insect’s shape and color allow it to blend in with leaf veins and twigs  so that unless they move or cast a shadow, they are very difficult to see.

Early instar walking stick blends in with leaf vein color

Camouflage loopers are small caterpillars that are found on the flowers of composites. They take petals from the plant’s flowers and “glue“ them on their body. They blend in so well that the only evidence of their presence will be that the flowers seems to be deformed.

Camouflage looper sitting atop a flower head from which it has cut and pasted the flower petals upon its body

Caterpillars like woolly bears, Ios, slug moths and some tussocks have defense mechanisms that utilize urticating hairs or venomous barbs to ward off potential predators. Handling these caterpillars may prove a painful experience for some people. Especially to be avoided are the saddleback slug moth and the spiny oak slug caterpillars, which are very small but able to inflict severe pain or a burning sensation that may  last for several hours or even a few days. Use caution around any caterpillar having barbs, hairs or spines.

Tiny saddleback caterpillar has both urticating spines and coloration similar to the host plant leaf for defense

Another means by which insects can protect themselves is by mimicry. Many flies have coloration and markings that are very similar to wasps and bees, especially syrphid flies. These flies can also feed on the pollen of many of the plants that bees and wasps also visit. Birds will tend to avoid any insect that may have the potential to sting, so these bee mimics need not worry as they go about their everyday work acquiring pollen.

This syrphid fly resembles a wasp and birds will leave it alone

Many insects use leaf shelters as a means of hiding from predators by day and then feed at night. They may tie leaves together with silk or fold a leaf. The caterpillar of the  spicebush swallowtail and the poplar tent caterpillars do this. Stink bugs routinely use leaf shelters abandoned by other insects.

Spicebush swallowtail caterpillars hide by day in a leaf folded lengthwise

Chrysalis of the red admiral butterfly is made inside a leaf shelter where it was protected as a caterpillar

Some insects feed as immatures inside plants such as gall makers, borers, leafminers and others. Safely inside plant tissue, success rates of surviving to a mature adult are very high.

Pine cone willow gall houses a midge larva, Rhobdophaga strobiloides

Thief weevil female laid an egg inside two a tightly rolled structures they made by cutting the leaf edge lengthwise while still remaining attached to the pedicel. Larva will feed safely inside on the leaf tissue.

A potter female wasp made this small clay pot and inserted food and its egg inside. Larva will be safe inside.

The larvae of tortoise beetles, 3-lined potato beetles and the infamous lily leaf beetle pile their frass on their bodies to escape predators.  Lacewing larva use their molted skins and other detritus to cover their body in a similar way. They can be found especially on white oak leaves in late summer appearing like a small, light tan, fuzzy pile moving across a leaf.

Tortoise beetle larva raises a “hood” made of frass when disturbed

This is only a brief look at some ways insects survive or attempt to survive in the world. There are many other ways and means by which insects employ subterfuge and other strategies that could fill a book, but this is simply a leaf through…

 

Pamm Cooper

 

August in the Outdoor Landscape

Tiger swallowtail on obedient plant flower

“What dreadful hot weather we have! It keeps me in a continual state of inelegance.” – Jane Austen

What a strange summer we have had so far in New England! I almost thought of going to Florida to escape the heat and humidity. It has been hot and humid, no doubt, but it is August after all, and things are coming along nicely in the out- of-doors. This time of year there is enough good stuff going on in the landscape to overcome any weather difficulties we may be experiencing, so let’s plod on out and see what’s happening.

foggy morning on Horsebarn Hill UConn

 

 

As we head on into the mid= summer, most garden buffs are by now reveling in the abundance of hydrangeas that are now in bloom. The dwarf ‘Little Lime’ is one of several panicle Hydrangeas that have nice full-bodied lime green flowers that pack a visual punch in the landscape. ‘Little Lamb’ is another of the smaller panicle hydrangeas, this one also having a compact form with pure white, ethereal blooms that give it its name.

‘Little lamb’ panicle hydrangea

Hibiscus are also blooming now, with their outstanding large, colorful flowers that really provide some visual excitement in the garden. I came across a nice hedgerow type planting that made a nice privacy screen along a sidewalk. I am not really a hibiscus fan, but a pink- flowered one popped up in my garden, and looks so great there that I guess it can stay. I wonder if someone snuck it in there to get me to have kinder thoughts toward these plants…

Hibiscus

On the wild side, the sweet- smelling Clethra alnifolia is in full bloom and is attracting all types of bees, beetles and butterflies. Look for this small clump-forming shrub in any areas where soils are moist. The white flower spikes are very fragrant, so you can tell where Clethra are long before you actually see them. Groundnut vine is also blooming now, with its pea-like pink flower clusters dangling from its twining stems. Often found twining itself around goldenrods and blue vervain, it is always fun to come across this plant.

Red spotted purple butterfly on Clethra

The barn swallows that are partial to building their nests on the eaves of our equipment building have had their second brood of the year, as have bluebirds. Hopefully that will exit the nest soon and mom and dad can have a much needed rest in the near future. There was a female wood duck taking her brood on a tour in a large beaver pond the other day.

barn swallows ready to fledge

Juvenile wood ducks

I came across a wild grape that had one leaf covered with interesting cone- like galls formed by the grape tube gallmaker midge (Schizomyia viticola). This is a harmless gall, and only affected one leaf on the entire grape plant. Looks like a bunch of tall red, skinny gnome caps were set on the leaf.

grape tube galls

Combing through garden centers for great plants is always enjoyable when you find something like the Blackberry or leopard Lily Belamcanda chinensis. Star shaped flowers only 2 inches wide are heavily spotted with red, while foliage is sword- shaped. The flowers appear in late summer and bloom until frost, so this is a good plant to spiff up areas where other perennials are fading into the sunset.

leopard lily Belamcando chinensis

Interesting plants suitable for containers are agave and other succulents. I saw a good size Agave colorata recently which was very striking in appearance. Its leaves are thick and powdery blue- gray with unusual cross- banding designs on them, plus leaf edges have brown teeth tipped with spines. A spectacular plant!

Agave colorata

patterns on Agave colorata leaves

Caterpillars this time of year are larger and, in my opinion, more interesting than the early season caterpillars. One favorite is the brown- hooded owlet, which is a sports a rich array orange, blue, yellow and red. Look for this caterpillar on goldenrods, where it feeds on flowers and flower buds.

brown-hooded owlet

If you want a nice surprise, with a little careful handling you can check inside folded stinging nettle leaf shelters and may find either caterpillars of the comma or red admiral butterflies, or the chrysalis of the red admiral.

red admiral butterfly chrysalis inside a leaf shelter on stinging nettle

 

The skies can provide some viewing that is better than any television show. Thunderhead clouds can provide some drama as they develop on hot and humid afternoons, and may provide further excitement in the form of thunder and lightning, and rainbows may follow. We can have remarkable sunsets any time of year, so don’t forget to have a look at the sky around sunset. August is also a great time for early morning fogs as well, especially when we have had a humid night. Getting up early does have its good points…

Thunderhead developing on a hot and humid afternoon

 

Pamm Cooper

 

Brushfoot Butterflies

Red-spotted purple

Happiness is a butterfly, which when pursued, is always just beyond your grasp, but which, if you will sit down quietly, may alight upon you.

-Nathaniel Hawthorne

Question mark butterfly resembles a brown leaf with wings folded up. Note white ? on wing.

Brushfoot butterflies are ubiquitous in Connecticut, familiar to most people who spend any time outdoors in the summer. Almost one in every three butterflies in the world is a brushfoot. Members of this subfamily of butterflies, the Nymphalinae, differ from other butterflies in that their forelegs are well shorter than the other four legs and are not used for standing or walking, These forelegs have little brushes or hairs rather than feet, thus the common name, which they use for tasting and smelling. The next time you see a monarch, check out its front legs.

Great spangled fritillary and bumblebee on thistle flower

Great spangled fritillaries on milkweed

Many brushfoots are found in particular habits, common ringlet, which prefers open, sunny fields with plenty of flowers like goldenrods, fleabane and asters. Others may be found along open wood lines, like question marks, commas and mourning cloaks, especially where there are sap flows on tree trunks. Many brushfoots can be found just about anywhere there are open areas with flowers and caterpillar host plants.

The wood nymph is easily identified by the yellow patches on the fore wings that have striking eye spots

The common ringlet prefers open grassy areas like fields or roadsides and may be elusive to find.

One species, the mourning cloak, is notable for overwintering as a butterfly here in the New England cold season. On warm winter days, you may see one flying in open, sunny woods. It normally does not visit flowers, but gets its nourishment from dung, rotting fruit and sap flows on trees.

Mourning cloaks may fly on warm winter days

Caterpillars of the brushfoots usually have spines, which, although menacing enough to the eye, are harmless if touched. A notable exception is the familiar monarch caterpillar which is spineless with a set of horns at both ends of the body. Some caterpillars, like those of the comma, American lady, Baltimore and red admiral, spend the daytime inside leaf shelters made by tying leaf edges or masses of leaves together. Knowing host plants is useful when looking for these caterpillars. If the shelter is opened slightly, you will find the caterpillar resting calmly inside.

Caterpillar of the Eastern comma seen after opening its leaf shelter

Some members of the brush foots like the question mark and the comma butterflies have angled wings. Most are brightly colored and quite beautiful, like the common buckeye, which is a vagrant visitor here in Connecticut. Others have brown camouflage patterns on the undersides of the wings, like the question mark and the comma. When they rest on leaves or twigs with the wings folded upright, they appear to be dead leaves.

Eastern comma

Colors and patterns on the wings can vary dramatically on brushfoots. Often the upper wing surfaces are more brilliantly colored than the undersides. Or they can be just as colorful when viewed either on the top or underside, but have different patterns. An example is the great spangled fritillary, which is orange and black on the upper wing surfaces, but the undersides are orange with brilliant white spots.

Red-spotted purple seen from above. First picture top of page shows the undersides of the wings

Several brushfoot butterflies are migratory, going south in the late summer and early fall, and then returning the next spring. Monarchs, painted and American ladies, and red admirals are some of the migratory species. They return north when wild mustards, crabapples, invasive honeysuckles and early native plants are starting to flower.

The red admiral is one of the migratory brushfoot butterflies

One brushfoot of special concern in Connecticut is the colorful Baltimore butterfly. Smaller than many other brushfoots, the Baltimore is striking as an adult, a caterpillar and a chrysalis. Caterpillars overwinter in large groups inside shelters they make by tying leaves together with silk. Look for these butterflies in large open fields that have water nearby.

Baltimore checkerspot

Baltimore checkerspot topsides

The common buckeye is a tropical visitor to the north

As the winter comes to a close and the spring brings us warmer days and flowers, remember to look for the arrival of the migrating brushfoot butterflies. The first to arrive are usually the red admirals and American ladies and monarchs will follow later on in mid-to-late June. You may be able to sit awhile in the sun and have a red admiral land on you- a common, which is a happy occurrence in the life of a butterfly connoisseur.

Red admiral on my pants

Pamm Cooper                              all photos copyrighted by Pamm Cooper