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Black-tipped Darner

black-tipped darner IMG_3123There are two darners that look very much alike, the Black-tipped (Aeshna tuberculifera) and the Shadow Darner (Aeshna umbrosa). The differences are somewhat subtle, so I spent a great deal of time identifying the egg-layers that I photographed for today’s post, vacillating back and forth between the two species. I finally zoomed in on one photo and determined that the lateral stripes on its thorax were outlined in black, making it a Black-tipped Darner (Shadow Darners lack this outline, and lack coloring on the last abdominal segment). That said, while I knew the identity, I neglected to make sure my post reflected this, and once again, a reader was kind enough to point this out. Thank you, Mike Blust!


Grass of Parnassus Flowering

e-grass of Parnassus 008Grass of Parnassus, Parnassia glauca, (also known as Bog- Star) was named after Mount Parnassus in central Greece. It is not a type of grass, but rather, belongs to the family Celastraceae and can be found growing in fens, bogs and swamps. The striking green lines on its petals guide flies, bees and other pollinating insects to the flower’s supply of nectar.

The structure of Grass of Parnassus’s flower is not typical. In between its five functioning stamens and five petals there is a whorl of five sterile stamens, each of which is three-pronged. The spherical tip of each prong mimics a glistening droplet of nectar. These stamens do not actually produce any nectar – they are there purely to attract pollinators. The actual nectar is located near the base of these false, or sterile, stamens. Only one of the five true stamens in the flower is active at any one time, with each producing pollen on average once every 24 hours.

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Great Horned Owl Fledglings Still Being Fed By Parents

great horned owls-first year IMG_1616Great Horned Owls are one of the earliest nesting birds — you can find them on nests in January, February and March, even in northern New England. Eggs are incubated for about a month, typically in March or April with young usually hatching in May or June. The nestlings remain in the nest for six or seven weeks before fledging. Unable to fly until they are ten or twelve weeks old, the fledglings follow their parents around and continue to be fed and cared for by their parents until fall. In late summer, when they have fledged but are still begging their parents for food, you can hear their distinctive calls. To know what to listen for, go to http://langelliott.com/mary-holland/great-horned_owl.mp3 (Sound recording © Lang Elliott – langelliott.com & miracleofnature.org.)

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Slime Molds on the Move

8-21-15  431As usual, Naturally Curious readers submitted unbelievably creative ideas about the identity of yesterday’s Mystery Photo. Kudos to those of you who recognized that it was a slime mold. Slime molds look like a fungus, and reproduce with spores like fungi do, but are no longer classified as fungi. Slime molds are made up of individual organisms that form a mass called plasmodium. They can be bright orange, red, yellow, brown, black, blue, or white. These large masses act like giant amoebas, creeping slowly along and engulfing food particles (decaying vegetation, bacteria, fungi, and even other slime molds) along the way. If a slime mold is cut up into pieces, the pieces will pull themselves back together.

The most common species are in a group called plasmodial slime molds. They share one big cell wall that surrounds thousands of nuclei. Proteins called microfilaments act like tiny muscles that enable the mass to crawl at rates of about 1/25th of an inch per hour. A slime mold mass can actually navigate and avoid obstacles. If a food source is placed nearby, it seems to sense it and head unerringly for it.

As long as conditions are good, (enough food and moisture and favorable pH), the mass thrives. But when food and water are scarce, the mass transforms itself into spore-bearing fruiting structures. These typically form stalks topped by sphere-like fruiting bodies called sporangia that contain spores that are carried by the rain or wind to new locations. After they have been dispersed, each of these spores will germinate and release a tiny amoeba-like organism which, if it successfully finds and fuses with another similar organism, can then begin to feed and develop into a new plasmodium.

The pictured slime mold, Coral Slime (Ceratiomyxa fruticulosa), is one of the more common slime molds. It is unusual in that it produces its spores externally on small stalks, not in sporangia, which gives it a fuzzy appearance.

To watch a time-lapse video of slime mold moving, go to https://www.youtube.com/watch?v=GY_uMH8Xpy0.

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Checkered Rattlesnake Plantain Flowering

8-7 downy rattlesnake plantain 083Checkered Rattlesnake Plantain (Goodyera tesselata) is an evergreen plant (each leaf lives for about four years) belonging to the Orchid family. It has broad, rounded leaves (like plantain) that bear a design somewhat reminiscent of snake skin. For the latter reason, it was used by Native Americans to treat snakebites. Botanists think it must have been used on bites from non-poisonous snakes, for medicinally it does not cure a venomous snake bite.

This species is quite similar to Downy Rattlesnake Plantain (G.pubescens), the most common species of rattlesnake plantain in New England, but its leaves lack the broad white stripe down the middle and its flowers as not as tightly clustered. At this time of year Checkered Rattlesnake Plantain’s tall flower stalk is bedecked with tiny, delicate, white orchids, each the size of a baby finger nail, which are well worth examining through a hand lens.

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Hover Fly Mimics Bald-faced Hornet

8-5-15 bald-faced hornet and hover flyAdult hover flies, often referred to as syrphid (family Syrphidae) or flower flies, feed on pollen and nectar, and are often seen hovering at or crawling on flowers. Many have black and yellow bands on their abdomen, and are frequently mistaken for bees. There are certain species of hover flies that mimic stinging wasps, including yellow jackets and bald-faced hornets (see photo). Predators such as birds, ambush bugs, and spiders might think twice about eating an insect that can sting, and hover flies take advantage of this. The process through which this occurs is called Batesian mimicry, and refers to when a harmless species evolves to imitate a harmful species that has the some of the same predators.

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Dragonflies & Damselflies Spear Prey With Lower Lip

7-27 dragonfly mouthpart 077Dragonflies and damselflies are unique among aquatic insect larvae in that they have a greatly enlarged hinged lower lip, or labium, which they can rapidly extend outwards to capture prey. When retracted, the prehensile labium fits like a mask over the face or is folded flat beneath the insect’s head. When hunting for prey, the dragonfly larva uses its labium like a speargun. It shoots forward as far as half the larva’s body length away, and moveable hooks on the front edge grab the prey. There are no muscles at the hinge/joint, leading entomologists to believe that the labium is extended by increased blood pressure caused by abdominal muscle contraction. It unfolds at a right angle, and extends extremely rapidly, faster than most prey can react. (photo: cast skin of dragonfly larva from which adult dragonfly emerged)

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