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Damselflies

Antlions Trapping Insects

8-14-14  antlions - 230The larvae of a predaceous group of winged insects (family Myrmeleontidae) that closely resemble dragonflies and damselflies are referred to as “antlions” – they have the ferociousness of a lion and prey mainly on ants. The manner in which an antlion traps its prey is ingenious. It excavates a conical pit in sandy soil (an antlion is also called a “doodlebug” because of the squiggly trails it leaves in the sand looking for just the right spot for a pit). Using its head as a shovel, it tosses out sand as it turns in a circle, digging deeper and deeper, until it forms a pit roughly two inches deep and three inches wide. The antlion lies at the bottom of the pit, covered by a thin layer of sand except for it pincer-like mandibles, which are ready to snatch prey at a second’s notice.

The slope of the sides of the pit is at the angle of repose – as steep as it can be without giving way – so when an ant accidentally steps over the edge of the pit and falls in, the sand beneath it collapses, carrying the ant to the bottom of the pit and into the pincers of the waiting antlion. If the ant tries to scramble up and out of the pit, the antlion tosses a load of sand at the ant, knocking it back down. The antlion then injects venom and digestive fluids into the prey via grooves in its mandibles, and drinks the innards of the ant through these same grooves.

The antlion’s anatomy is as unusual as its method of capturing prey. It has a mouth cavity, but no mouth opening, and no external opening for solid waste. Because digestion takes place outside of its body, the antlion doesn’t accumulate a lot of waste, but what it does accumulate stays inside of it until the antlion matures into an adult. This can be anywhere from one to three years, depending on the species. When fully developed, the antlion constructs a small, round pupal case out of silk and sand, in which it overwinters. It emerges from this case the following spring as a winged adult. (Thanks to Joan Waltermire and John Douglas for photo op.)

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Spreadwing Damselflies Mating & Laying Eggs

10-18-13 spreadwing damselflies 019Believe it or not, there are still damselflies (and dragonflies) that are flying, mating and laying eggs in the middle of October in northern New England. Certain damselflies known as “spreadwings,” unlike most other damselflies, perch with their wings partially open. (Another tell-tale spreadwing sign is that they often perch at roughly a 45 degree angle.) Spreadwings are weak flyers, and you usually see them flying low and for short distances. When sexually mature, the males tend to spend their days perched on vegetation along a pond’s shoreline. The females, like most dragonflies and damselflies, return to the water only when ready to breed. The pictured spreadwings (Spotted Spreadwings, Lestes congener, I believe) are one of the latest species of damselflies active in the fall; these two were resting before resuming egg-laying. The male (at top of photo) grasps the female’s “neck” (to prevent other males from replacing his sperm in her) while the female uses the sharp ovipositor at the end of her abdomen to slice into emergent vegetation and lay her eggs, which eventually end up in the water when the plants die.


Damselfly Reflections

Taken 10 minutes ago — sometimes no words are necessary. Have a glorious late summer weekend! 8-16-13  damselfly reflections 085


Sundews Capture Their Meals

8-12-13 sundew & damselfly 060Sundews (Drosera spp.) are carnivorous plants often found in acidic bogs, fens and cedar swamps. They have numerous small leaves arranged in a circular, or rosette, pattern and they are covered with reddish, glandular hairs, or tentacles, that exude a sticky secretion at their tips. Insects, attracted to the glistening sticky droplets which resemble dew, land on a leaf and become stuck. The movement of the struggling insect triggers cell growth in the glandular hairs and they begin folding over the insect within 60 seconds. An anesthetic is released by the plant’s hairs, causing the insect to become motionless. Digestive enzymes are then secreted which liquefy the insect’s internal organs so that they can then be absorbed by the plant’s hairs. Although insect prey is not vital to sundews, the nitrogen the plants receive from the insects enables them to thrive in environments where nitrogen is in short supply. The damselfly pictured has been captured by a Round-leaved Sundew’s glandular hairs which have rendered it motionless and have started to grow and fold over the tip of the damselfly’s abdomen and its wings.

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Damselflies Laying Eggs

damselfly laying eggs2 354The two damselflies in this photograph have mated, but the male is still clasping the back of the female’s head so as to guard her and prevent her from receiving the sperm of another male before she is through laying eggs. Damselflies lay their eggs both in the water as well as in plants. The pictured female (bottom damselfly) is in the act of using her ovipositor (thin black structure at tip of abdomen) to puncture a cattail leaf and insert her 1 mm- long egg into the plant tissue. If you look closely, you will see holes in the leaf blade above the hole she’s currently making, where she has previously laid eggs. Thousands of these holes may be drilled and eggs inserted into them during her brief life.


Damselflies Hunting

6-12-13 damselfly eating prey2 147Damselflies, nature’s more delicate version of a dragonfly, spend most of their life underwater, first as an egg and then as a nymph. Eventually, after a year or so, they crawl out of the water onto nearby vegetation, shed their nymphal skin for the final time and emerge as winged adults. A damselfly’s beauty belies its behavior — most damselflies are voracious predators, both as aquatic nymphs as well as adults. In flight, they hold their bristly hind legs in a basket shape to scoop up their prey. The prey is then transferred to their front legs, which hold it while the damselfly devours it.


A Great Christmas Present!

If you’re looking for a present for someone that will be used year round, year after year, Naturally Curious may just fit the bill.  A relative, a friend, your child’s school teacher – it’s the gift that keeps on giving to both young and old!

One reader wrote, “This is a unique book as far as I know. I have several naturalists’ books covering Vermont and the Northeast, and have seen nothing of this breadth, covered to this depth. So much interesting information about birds, amphibians, mammals, insects, plants. This would be useful to those in the mid-Atlantic, New York, and even wider geographic regions. The author gives a month-by-month look at what’s going on in the natural world, and so much of the information would simply be moved forward or back a month in other regions, but would still be relevant because of the wide overlap of species. Very readable. Couldn’t put it down. I consider myself pretty knowledgeable about the natural world, but there was much that was new to me in this book. I would have loved to have this to use as a text when I was teaching. Suitable for a wide range of ages.”

In a recent email to me a parent wrote, “Naturally Curious is our five year old’s unqualified f-a-v-o-r-I-t-e  book. He spends hours regularly returning to it to study it’s vivid pictures and have us read to him about all the different creatures. It is a ‘must have’ for any family with children living in New England…or for anyone that simply shares a love of the outdoors.”

I am a firm believer in fostering a love of nature in young children – the younger the better — but I admit that when I wrote Naturally Curious, I was writing it with adults in mind. It delights me no end to know that children don’t even need a grown-up middleman to enjoy it!


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