An online resource based on the award-winning nature guide

Arachnids

Cold Snaps & Hardy Invertebrates

1-14-14 TICK IMG_0528As you may have heard, there could be a plus side to the sub-zero temperatures we’re experiencing this winter – the cold weather may well decrease the number of invasive pests we have. For example, the Hemlock Woolly Adelgid (the aphid-like introduced insect decimating the Eastern Hemlock population) succumbs at 4 or 5 degrees F. However, other insects aren’t phased by the cold until it dips way below zero. At -20 F., roughly half of the Emerald Ash Borer larvae (an invasive beetle that is highly destructive to ash trees) overwintering in trees will die. Once the temperature reaches -30 F., there’s a 90 percent mortality rate. Bed bugs face instant death at -22 degrees F., but it takes 24 hours to kill them at -11 degrees F. and 72 hours to kill them at 0 degrees F. Unfortunately, once an invasive insect establishes itself, even if its numbers go way down for whatever reason, it usually rebounds in several years’ time. Some invertebrates are not affected by the cold temperatures. The Black-legged (Deer) Ticks that reside on moose, deer, mice, birds and other hosts can withstand sub-zero temperatures as they have the warmth of their hosts’ bodies to keep them warm. In order for ticks to succumb to the cold, the frigid air has to last until May, when the fertilized female ticks fall off their hosts to lay their eggs.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Some Spiderlings Hatch in the Fall

antmiimic spider egg case 013Have you recently noticed a roundish, flat, papery, 1/4-inch diameter, metallic-looking structure adhering to the top of a rock? If it has tiny bumps in the center, chances are good that it’s a spider egg sac, most likely that of an antmimic spider (spiders resembling ants that often prey on ants), specifically one in the genus Castianeira. One would assume that the contents of the sac that were causing the bumps were eggs that were going to overwinter and hatch once warm weather arrives. This is true for a majority of spider egg sacs, but some, including those of Black-and-Yellow Argiopes and antmimic spiders, hold spiderlings that have already hatched and will remain in the sac throughout the winter. As long as the temperature stays cold, the spiderlings will be safe and secure until spring. If we have periods of cold interspersed with periods of warmer temperatures, or an exceptionally warm winter, the spiderlings will become active when the thermometer rises, and, not having any insects to eat, will be forced to devour each other.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Spider Spinnerets

9-30-13 black and yellow sp. spinnerets2 IMG_4897Responses to yesterday’s Mystery Photo ranged from immediate deletion by a reader (due to the unappealing nature of the photo), to guesses including “bee butt,” “caterpillar mouthparts” and “deer tick.” Most responders, however, guessed correctly – the photograph was of the spinnerets of a Black-and-Yellow Garden Spider, Argiope aurantia.

Most spiders have six spinnerets — organs located on their abdomens from which silk is extruded. The individual spinnerets move independently yet in a highly coordinated manner. Each spinneret is dotted with many tiny spigots, through which various types and thicknesses of silk are extruded. The strong muscles that move the spinnerets also force liquid silk through the narrow spigots. This pressure, as well as external pulling by the spider, rearranges the liquid silk molecules into a solid but flexible thread. Although spider web silk is only about one millionth of an inch thick, weight for weight, it is stronger than steel (but not as strong as Kevlar). Unlike in the Mystery Photo, the spinnerets in this photograph are extruded and in use.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Nursery Web Spiders Hatching

8-27-13 nursery web spider 169Nursery Web Spiders look a lot like Wolf Spiders, and the females of both families carry their respective egg sacs around with them until they hatch, but they do so in a different manner. Wolf Spiders grasp their egg sacs with the spinnerets (silk nozzles) located under their abdomen, whereas Nursery Web Spiders carry their egg sacs with their mouthparts. When hatching is imminent, the female Nursery Web Spider lashes leaves together with silk to form a protective shelter, or “nursery web,” for her egg sac and hatching offspring. The mother stands guard over her spiderlings, aggressively defending her young until they have had their first molt, after which both the spiderlings and the adult female disperse.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Harvestmen

8-1-13 daddylonglegs 148Harvestmen (daddy longlegs) and spiders are closely related and share many characteristics, but they also have significant differences. One such difference is that Harvestmen do not possess venom glands, nor the digestive enzymes capable of breaking down the insides of prey into a liquid. (Some species of Harvestmen are omnivores, eating both plant and animal matter, others are scavengers.) Unlike fellow arachnids (spiders, ticks, scorpions and mites) that drink their food, Harvestmen ingest small particles, breaking them down with their chelicerae, or mouthparts, which resemble miniature, toothed lobster claws. In this photograph, the Harvestman is holding a deer fly with its pedipalps, appendages used to grasp food as well as their mates. Its chelicerae are too small to discern, but they do the job — in the space of about ten minutes, this Harvestman consumed an entire deer fly, bit by bit.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Snow Spider

3-14-13 snow spider IMG_6089It’s always surprising to find any form of life crawling on top of the snow, but for some reason spiders seem particularly fragile and susceptible to the elements. There are species, however, that remain active in winter, even in the northeast. Most live in the leaf litter beneath the snow, but they often emerge when temperatures are about 25°F to 35°F. Tentative I.D. has the spider in the photograph belonging to the genus Tetragnatha.


Green Long-jawed Orbweaver

12-10-12 Green Long-jawed Orbweaver IMG_6635In December, in Vermont, you don’t expect to come across an active spider, but yesterday that’s exactly what happened. A Green Long-jawed Orbweaver (Tetragnatha viridis) was crawling on the duff underneath a stand of hemlocks. Upon noticing me, this slender ¼” spider immediately formed itself into a straight line, with four of its legs stretched forward, and four backwards. Assuming this shape enables these spiders to be very well camouflaged on a blade of grass. There are 25 species in this genus in North America, all of which are called “stretch” spiders, referring to their elongated body form. They are very agile and can navigate on the surface of water very well.


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!


Jumping Spiders

Jumping spiders are aptly named as they can spring more than 50 times their own body length to land on unsuspecting prey. They hunt actively rather than catching prey in a web and they have excellent vision, with four big eyes in front and four smaller eyes on the top of their head.  Jumping spiders have three-dimensional vision which allows them to estimate the range, direction and nature of potential prey, essential skills for a predator that catches prey by pouncing on it.


Black-and-Yellow Argiope Egg Sacs

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Black-and-yellow Argiopes  (Argiope arantia), often referred to as “garden spiders” are one of our most conspicuous orb web-spinning spiders — their webs are often two feet in diameter, and female spiders measure an inch and a half (males are about ¾”).  At this time of year, they (and many other spiders) are busy mating and laying eggs, which the females wrap in a multi-layered “sac” of tan silk that resembles a large marble in size and shape.  Inside a Black-and-Yellow Argiope’s egg sac are between 300 and 1,400 eggs.  In northern New England, the eggs hatch in the fall and the spiderlings overwinter inside the sac, where they remain dormant unless the weather warms appreciably (in which case they become active resort to cannibalism, there being no insects in the sac).  I have often wondered exactly when the eggs hatch, but have chosen not to tear open an egg sac in order to find out.  A bird, the predominant predator of spider egg sacs, did the deed for me recently, and tore into one, exposing the contents, which I photographed.


Silk Rainbow


Spider Spinnerets

All spiders are capable of spinning silk, regardless of whether they use it to spin webs and trap prey or not.  Egg sacs, drag lines (so they can find their way home), drop lines (to catch them if they fall) egg cases and transportation (young spiders disperse by “ballooning” as the wind catches their silk and carries them off) are some of the other functions silk plays in the life of a spider. Silk is extruded through nozzles called spinnerets located near the tip of the abdomen. Typically a spider has two or three pairs of spinnerets.  Each one is the exterior tip of an interior silk gland and has a valve which can control the thickness and the speed with which the silk is extruded.  The different glands produce different kinds of silk used for different purposes. The spinnerets work independently for some functions, and together for others.  In the photograph, the black and yellow argiope is turning her grasshopper prey around and around as she produces a sheet of silk in which she wraps it.  Most, if not all, of the spinnerets are in use.


Milkweed Visitors

Milkweed is in full bloom right now, presenting the perfect opportunity for young and old alike to discover the multitude of butterflies, beetles, bees and other insects that are attracted to these magnificent flowers. If you visit a milkweed patch, don’t leave before getting a good whiff of the flowers’ scent – one of the sweetest on earth. How many of the insects you find are carrying milkweed’s yellow pollen “saddlebags” on their feet? You might want to check out my children’s book, MILKWEED VISITORS, which I wrote after spending the better part of one summer photographing the various insects I found visiting a milkweed patch. ( http://basrelief.org/Pages/MV.html )


Wolf Spider Mother and Spiderlings

Two common spiders that we often see carrying their egg sacs are the wolf spider and the nursery web spider. Wolf spiders attach their egg sacs to their spinnerets, whereas nursery web spiders carry them with their mouthparts. When nursery web spiders are about to hatch, the mother puts her egg sac into a silk tent she has spun, and they live there for a week or so. When a wolf spider’s spiderlings emerge from their egg sac, they climb up onto their mother’s abdomen and cling to it while their mother continues to hunt for food. After about a week, when partially grown, the spiderlings disperse, either by ballooning through the air on silk strands or simply by scurrying off along the ground.


Mud Dauber Wasp Nest

There are many species of mud dauber wasps in New England that use mud to make cells for their eggs, developing larvae and pupae.  One of them is Pison koreense, a small, black wasp with a wingspread of less than half an inch.  This particular wasp is native to Korea, China and Japan, and was accidentally introduced in the United States after World War II.  Like other mud daubers, this wasp constructs one cell at a time with her mandibles; there can be anywhere from 1 to 12 mud cells (each roughly ¼” long) in a nest, which is often located in a crevice or behind bark.  She then hunts for spiders, stinging and paralyzing them before carrying them back to the cell, into which she stuffs them.  After collecting 20 – 30 spiders, she lays a tiny white egg on the last (and often largest) spider to be placed in the cell.  She then flies off and collects mud with which she seals the cell.   The egg hatches, the wasp larva consumes the live spiders and then pupates, spending the winter inside a cocoon inside the mud cell.  In the spring the adult wasp emerges from the cocoon and chews her way out of the cell, leaving a circular exit hole.


Invertebrate Signs

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A quick look recently at the underside of a wooden bench sitting in the middle of a nearby field revealed a multitude of signs of insects and spiders that sought shelter in this protected spot.  They included the empty chrysalis of a monarch butterfly, the flat, red egg  sac of a Phrurotimpus  antmimic  spider (look closely and you’ll see bumps in the middle  made by the eggs underneath the silk), the silk and twig case of a bagworm moth larva , and a cocoon which is housing the pupa of a moth. 


Naturally Curious wins National Outdoor Book Award

I am delighted to be able to tell you that this morning I learned that NATURALLY CURIOUS won the Nature Guidebook category of the 2011 National Outdoor Book Awards.  I’m honored and humbled by this recognition.   http://www.noba-web.org/books11.htm


Spider Silk & Spinnerets

All spiders spin silk — some use it to build webs, eggs sacs, draglines, wrap prey and/or disperse in the air. Inside their bodies are glands which produce different types of silk material for different purposes.  Liquified silk proteins are pushed out spinnerets, or silk-spinning organs, located at the tip of a spider’s abdomen (most spiders have six). Once the silk solution comes in contact with the air, it solidifies.  Each spinneret has a spigot, or nozzle, which controls the consistency of the silk by forming smaller or larger strands. By winding different silk varieties together in varying proportions, spiders can form a wide range of fiber material.   Spider silk is extremely strong and flexible. Some varieties are five times as strong as an equal mass of steel and twice as strong as an equal mass of Kevlar.


Wolf Spiders

Wolf spiders capture prey by hunting them, not by catching them in a web. Two of their eight eyes are enlarged, giving them excellent eyesight with which to locate prey. Typically wolf spiders are solitary, and hunt alone. The females carry their white egg sac with their spinnerets, which are located at the tip of their abdomen (and are also the structures through which silk leaves their body). You can tell them from similar looking nursery web spiders by how they transport their egg sacs. Nursery web spiders carry their egg sacs in their chelicerae, or mouthparts and pedipalps (front appendages which resemble legs).


Spider Egg Sac – Welcome to a photographic journey through the woods, fields and marshes of New England

Find more of my photographs and information similar to that which I post in this blog in my book Naturally Curious, which is being published this fall.

SPIDER EGG SAC

This is the time of year when spiders are mating and laying eggs. The female black and yellow argiope (large orb web spinner) deposits her eggs on a square piece of silk she spins. She then pulls the four corners together, forming it into a ball, which she then attaches to vegetation or a more solid structure. The female then dies; the eggs will hatch this fall. The spiderlings overwinter inside the egg sac, remaining more or less dormant during the cold weather, but becoming more active during warmer days. Because this activity demands energy, and there is no food available inside the egg sac, the young spiders resort to cannabalism. The surviving spiderlings will emerge from the egg sac come spring.


NATURALLY CURIOUS–THE BOOK–WILL BE HERE SOON!

I am delighted to be able to share the good news that you can now pre-order my book, Naturally Curious!  I’ve just seen an advance copy, and the printer did a wonderful job with the photographs, and Trafalgar Square did an equally eye-catching job on the layout – I can truly say I am delighted with the end product of a lifetime of photographing, observing, collecting and researching natural history.  How lucky can one get to have the opportunity to put what one treasures most between the covers of a book?   Naturally Curious will be out October 18th.  If you’re in need of a Christmas present for someone, it might be just the ticket!

I’m offering my blog readers the opportunity to pre-order signed copies of Naturally Curious at a special discount price of $35.00 from my publisher’s web site. This offer is only good until October 15, 2010, at which time the regular retail price of $39.95 will apply. CLICK HERE to take advantage of this special offer!


Spider with Prey – Welcome to a photographic journey through the fields, woods and marshes of New England

Find more of my photographs and information similar to that which I post in this blog in my book Naturally Curious, which is being published this fall.

SPIDER WITH PREY

Fields, especially uncut fields, are filled with all shapes and sizes of insects this time of year, making them a very productive habitat for hungry spiders. This orb web spider, still wearing the morning dew, had met with great success by the time the sun’s rays reached its web.


Spider Silk – Welcome to a photographic journey through the fields, woods and marshes of New England

Many of the images and much of the information in this blog can be found in my book, Naturally Curious, which is being published this fall.

SPIDER SILK

All spiders spin silk – they use it as a safety line when climbing, to wrap their eggs as well as prey in, to disperse when young (it catches the wind and they “balloon” off into the air) – but only certain species of spiders use it to make a trap, or web, in which to catch their prey. Wolf spiders are hunters, as are the crab spiders and jumping spiders that hide in flowers and other locations that are attractive to insects, waiting to surprise and pounce upon their prey. Some spiders, however, spin sticky, silken webs into which unsuspecting insects fly (such as the pictured fly), thereby usually sealing the insect’s fate.


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