Thursday, October 16, 2014

Dotted Wolf Spider

This beautiful pin-striped spider is a Dotted Wolf Spider (Rabidosa punctulata formerly Lycosa punctulata). There are over 2300 species of wolf spiders Worldwide, making them one of the most common spiders in the World. This species is found throughout most of the United States. Autumn is the best time to find spiders as they have reached their adult size and are much more visible. Rest assured they were always present, just not easily seen in their juvenile state. Wolf spiders are some of the most easily recognized spiders in the Missouri. They are almost always large and often furry looking. Which often results in them being mistaken for tarantulas. While we do have tarantulas in Missouri, they only occur in the southern portion of the state. The Missouri River seems to be a barrier for them and they are not found in the northern part of our state.

        (Missouri Tarantula)                                                                        (Wolf Spider)

Wolf spiders however are found all over Missouri; there are five species of wolf spiders within the genus Rabidosa in North America. Dotted wolf spiders are not especially furry-looking like many other wolf spiders tend to be, but they are distinctive in other ways.

(Wolf spider in the genus Tigrosa carrying her babies)

 
                                                      (Wolf Spider that may be Hogna frondicola)

Dotted Wolf Spiders have bold stripes and a light golden color that sets them apart from most wolf spiders in other genus'. This also makes them rather dashing looking. They also have a series of spots or "dots" on the underside of their abdomen, if you can manage to see them.

Spiders differ from insects in some very obvious ways, insects have 3 body parts (Head, thorax and abdomen) whereas spiders have two body parts (cephalothorax (head and thorax combined into one part, and the abdomen). Insects posses 6 legs and spiders 8. All spiders posses venom and only a few insects do, all spiders can spin silk, only a few insects do. Spiders are meat eaters and do not feed on vegetation. Insects run the gambit of food preferences.


Spiders have unique eyes; most possess 8 eyes with a few exceptions like brown recluses which possess 6 eyes. Most spiders have poor eyesight, but spiders like wolf spiders have exceptional eyesight for their size. Wolf spiders are night time hunters and rely more heavily on their eyesight than do other spiders which rely more on their sensitive sense of touch (in their legs).
8-eyed spiders possess two direct sighted eyes, that are usually dark in color and very visible to the human eye, as pictured here (above right). The smaller, or indirect eyes are not as easily seen by us. These eyes usually have a layer of light reflecting crystals. This reflective quality allows them to see better in low light situations, which is a necessity  if you are a night hunter. Because of the reflective quality of their eyes they will glow when you shine a flashlight on them. This is a fun activity to do with your children. Grab a flashlight and head outside and let the kids shine the light in the grass and look for the "glowing eyes." It will amaze you to see just how many spiders are hunting in your yard.



Wolf spiders produce silk but do not use it to spin webs like orb weavers and many other spiders do. Instead the silk is used to spin egg sacs, to protect spiderlings and to capture food to save for later use. When she forms her egg sac she will carry it with her attached to the tip of her abdomen. When the spiderlings are ready to emerge from the egg sac it will change from a shiny bright white to a dark dirty brown.

 (Wolf spider in genus Tigrosa guarding her egg sac from a large predator....ME)

Then they will climb onto their mothers abdomen and ride around with her for awhile. She guards them temporarily until they are ready to be on their own. Usually a few weeks or so , but there are records of some spiderlings staying on their mothers back for up to 6 months. It is not uncommon to see a female traveling with her brood on her backside late in the summer or early fall. This burden may consist of 50 or more babies. Life span for these spiders is two years or so


Their habitat is typically woodlands, cotton fields and other croplands, old buildings, and grasslands. They may also be found near ponds or in old rodent burrows. Look for them near garbage piles, rock piles, log piles, or within holes in the ground. It is reported that wolf spiders can act aggressively towards humans. I really do not like the term aggression when describing an animals reaction to humans. I prefer defensive. Animals, be it a mammal, reptile or insect will defend itself. Often this defense involves a bite, and many fear a bite from one of these spiders, and it is reported to be painful. They do possess venom, as do all spiders, but the venom is not harmful to humans. It is designed to subdue and liquify their prey. The one photographed here did not exhibit any "aggressive" behavior towards me and I was able to coax her onto my hand for a photo. I handled her in a gentle manner and tried to appear as non-threatening as I could.

Wolf spiders are excellent hunters and typically rely on ambush techniques to capture a wide variety of small insects, including crickets, flies, ants, locusts, and other spiders. They may also run down prey. They help control insect populations, which makes them beneficial to humans. While they are excellent predators, they are often the prey. Small mammals, reptiles, amphibians and other spiders all feed on wolf spiders. There are even a group of wasps called spiders hunters that prey on spiders, especially wolf spiders, and uses them to feed their offspring.  In August I photographed a spider hunter capturing a rabid wolf spider. If you want to read about these amazing wasps the link is Spider Hunter.

                  (Spider wasp dragging a rabid wolf spider to her burrow to lay eggs on the paralyzed body)

 For another great article on this species visit my friend Eric Eaton's blog and read what he has to say about this species.....Bug Eric









Thursday, October 9, 2014

Spider Hunter

Spider Wasps in the family Pompilidae are a cosmopolitan group of wasp with somewhere around 5,000 known species and subspecies Worldwide. As their name would suggest they hunt spiders. There is even a subfamily called Ceropalinae that are known to cannibalize their own kind.

While at Squaw Creek awhile back I saw something small, quick and moving erratically across the road in front of me. This begged to be investigated, so I pulled the car over and found this largish wasp dragging a paralyzed spider from one side of the road to other. I couldn't help but feel somewhat sorry for this poor spider. He was stung, paralyzed, drug across the ground, then across the asphalt and was destined to be a meal for a hungry wasp grub. It is highly doubtful that the spider has any cognitive thought, and that is certainly a good thing. To be aware of your paralytic situation and impending doom at the mouth of a hungry wasp baby and not be able to do a darn thing about it would be the stuff of nightmares.

video

My presence was casting shadows over the wasp and causing her some pause and she would temporarily leave her prey and wander away. A few minutes later she would return and drag the spider a few feet more and then in a very nervous manner she would depart again. This went on for quite some time and it took her more than 15 minutes to finally reach the other side of the road with her quarry. The spider was quite a bit larger than she was, so the fact that she could maneuver this spider at all is a feat in and of itself. The species of spider is a type of wolf spider called a Rabid Wold Spider (Rabidosa rabida). This particular spider would be very defensive and I imagine not an easy adversary to subdue. I would have loved to see her initial interaction when she discovered the spider and made the decision to use it as food for her offspring. I'm sure it would have been a sight to see.

In most cases the wasp will have dug a burrow prior to hunting for a spider to provision it with. Occasionally though she will dig the burrow after finding her prey. Once she has maneuvered the spider into the burrow she will lay an egg on the abdomen of the spider and then close up the burrow entrance to protect her offspring from predators. When the egg hatches the wasp grub will feed on the paralyzed spider. They will leave the vital organs of the spider until right before they are ready to pupate, this way the spider does not perish before the wasp larvae is done growing. Once the wasp larvae has reached its full size it will form a silken cocoon and pupate. It will emerge the following spring. The size of the spider can determine the sex of her offspring. Larger prey generally produces larger reproductive females. From the size of this wolf spider I think it was destined to feed a female wasp grub.

Spider hunters are solitary wasps and therefore calmer and gentler by nature. They are only prone to sting if mishandled or mistreated. Colony nesting wasps such as hornets or yellow jackets on the other hand tend to be more defensive and more easily provoked. They are guarding nests, queens, offspring and food stores. With so much to defend they need to be on their guard. Whereas solitary nesters like spider hunters are not guarding anything. Once the eggs are laid the offspring are on their own and survival is all up to luck.



Wednesday, October 8, 2014

Imperial Moth

Imperial Moths (Eacles imperialis) in the family Saturniidae are large silk moths commonly found in forested areas throughout Missouri. They are also often found in suburban areas, especially near lights at night. The biggest one I ever found was at a gas station/convenient mart on the outskirts of St. Joseph.
Their range includes most of the Eastern United States from Nebraska to Maine. There are some reports that they are declining at an alarming rate in the northeastern part of their range. The population decline in these locations could and probably is due to habitat loss. Throughout the rest of their range their numbers are secure to abundant. The adults are large with wingspans up to 5.5 inches and are yellow with variable lavender spots. Males are smaller than females.

These large moths do not feed as adults, instead they get all the nutrition they need as caterpillars. If you've never seen one of these in their larval form, it is truly impressive. When hatched they are barely visible and possess an incredible appetite.

 They feed voraciously and reach lengths up to 3 or 4 inches when ready to pupate. They manage this in the span of several weeks.  It has been said that if a human baby gained weight like a caterpillar, they would weigh as much as a hippo in a single weekend. They feed on a wide variety of tree species like oak, hickory, walnut, pine, maple (including box elder), Norway spruce, sassafras, sweet gum and many others.

Moths are covered in furry scales that protect them from cooler nighttime temperatures. These large moths take it to a whole new level with what appears to be a winter-weight coat, complete with scarf and leg warmers. After midnight the females will begin signalling for males by emitting a pheromone. The males are capable of "smelling" the females from distances of more than a mile. He uses his large, feathery antennae to home in on her scent. Females will lay eggs one at a time, or up to 2 to 5 on the leaves of host plants. Eggs hatch in a couple of weeks. When ready to pupate they will move to the base of the host tree and burrow into the ground to pupate for the winter.

Naturalist Gene Stratton Porter wrote about the Imperial Moth in her novel "A Girl of the Limberlost" It was a prominent character in the plot development of the novel. She had a life long love of silk moths and shared her passion for their beauty in the book Moths of the Limberlost.


Monday, October 6, 2014

Differential Grasshoppers

Differential Grasshoppers (Melanoplus differentialis) are probably one of the most common of all the grasshoppers in Missouri. They have a distinguishing herringbone pattern on their hind legs, and are various shades of olive green with yellowish hind legs. They will range in size from 1 1/2 - 2 1/2 inches.

They are found in a wide variety of habitats, including meadows, tall grassy areas, backyards, gardens, open fields and along stream sides. The nymphs and adults both feed on various grasses and crops, including corn, soybeans, alfalfa, cotton, vegetables, fruit trees, and other small grains.


These grasshoppers have many predators, which include birds, toads, frogs, raccoons, opossums, turtles, bats, praying mantids, red fox, dragonflies, yellow jackets, fish, shrews, lizards, chipmunks, squirrels, spiders, centipedes, crickets, beetles, and the neighborhood cat. The larvae of the Blister Beetles use the eggs of grasshoppers as their primary food source.

Mating occurs in late summer and early fall. The females will press long eggs masses into the ground, near weeds. She may lay up to 8 egg masses each containing about 25 eggs. The eggs will overwinter and hatch the following spring. The newly born nymphs look very much like the adults. They will shed their exoskeleton (outer skeletal skin) several times over a course of two months before reaching adult size (picture 3). It is common to see these shed skins hanging from branches or grasses. Looking very much like they were scared right out of their skin and left it behind


Sometime in the fall when the temperatures begin to drop, and the first freeze hits, the adults will perish. Often time frozen right to the spot that they had been clinging to. It is almost eerie to come across one of these dead grasshoppers, it is almost like some mass weapon of destruction came through and freeze-dried them. (Below)


Sunday, October 5, 2014

Obscure Birdwing Grasshopper

Obscure Bird-Wing Grasshoppers (Schistocerca obscura) are extremely large grasshoppers that can be found from the Northeastern United States westward to Arizona. They are very common in the Midwestern states. Females are larger than males and according to bugguide.net they may reach 65 mm or a little over 2 1/2 inches. I swear that this specimen was much larger than 2 1/2 inches, it was easily 3 inches or more in length. Absolutely the largest grasshopper I've ever seen. There were several other birdwings in the area, and all we more typically sized for the species. This one was like the Arnold Schwarzenegger of grasshoppers. He had probably gorged himself on the multitude of tomatoes and other garden veggies that were left over from our summer garden. I tried numerous times to catch him, but he proved to fast and hoppy for me to succeed. I wanted to get a measurement on him so badly. 



Fields and open woodlands are their usual habitats, but I find them frequently by the garden or in flower beds. I would assume like any grasshopper they go where the food is. They can on occasion become a pest to garden plants or prized flowers, but generally speaking they pose no significant threat and eat on wild grasses, forbes and other plants. 

Grasshoppers seem to be prolific this year and are everywhere in large numbers. They are beneficial to wildlife who will gorge on them in autumn. It is not uncommon to find the craw of a turkey full of grasshoppers, especially young turkeys who seem to favor the tasty little buggers. Other animals such as bobcats, foxes, mice, frogs and all sorts of birds find the bounty to their liking as well. What a great way to find protein without a lot of effort.


These grasshoppers can be difficult to identify as there are other similar birdwing species. This one is a vibrant green color with a gorgeous yellow stripe down the back. The wings are dark brown and the antennae are also yellow. In my area it tends to be the most common birdwing, therefore it would be hard to mistake for anything else, as there is very little to compare it to. However, if you live in areas where other birdwings are common, it may prove difficult to ID.

Mating takes place in the fall and females use their ovipositor to deposit eggs under the soil. The eggs overwinter and hatch in the spring. The nymphs are born looking very much like the adults, minus wings and adult coloring. They will molt up to 9 times before reaching adult size in mid to late summer. Adults die over winter so all grasshoppers spotted are that current years hatch.  




Wednesday, January 8, 2014

Eastern Pondhawk

Eastern Pondhawk Dragonflies (Erythemis simplicicollis)
are one of the most common dragonflies throughout eastern North America. There are also small populations in New Mexico and Arizona. They are a medium sized dragonfly with a wingspan of 2 1/2 to 3 inches. The overall color is green and black which allows them to blend in with vegetation near ponds, lakes, streams and other watery areas where they will be found. They often hunt for food far away from water so it is not uncommon to find them in fields, meadows, prairies and grasslands where no water is present. Like all dragonflies they feed exclusively on insects which they capture on the fly. They will use their legs to scoop bugs out of the air and bring the unfortunate victim to their mouth and begin feeding. They are the original inventors of "fast food." They will sometimes land on a nearby perch to finish their meal.


Mating takes place near water, and the female will lay her eggs in the vegetation in the water. The eggs hatch and the young nymphs will remain in the water feeding off aquatic insects. In about a year they will be ready to leave the water for the first time and shed their skin to become the gorgeous adult that you see here. They will climb onto a stick, rock or other solid surface. While they cling to this vantage point their skin will split down the back and the dragonfly hidden within will crawl out leaving its shed skin behind. The dragonfly is completely helpless at this point. It cannot swim away, crawl away or fly away. The dragonfly will  begin pumping its wings to allow fluid to reach them. This fluid will engorge the wings and ready them for flight. Once the dragonfly has sufficiently dried itself and its wings are strong enough, it will take flight for the first time. Soon after its maiden voyage it will begin seeking mates. This will begin the cycle all over again.

Immature males will be powdery blue (pictured at right) and as they age they will be mostly green. Females are also green with black spots on their abdomen.
These dragonflies also go by the name "Green Jacket" and "Common Pondhawk". They are typically easier to approach than most other species of dragonflies. With over 30,000 lenses per eye they have excellent eyesight and are next to impossible to sneak up on. With dragonflies it is more about temperament, which can vary by species, as well as individuals within each species. 


Tuesday, January 7, 2014

Scooped Scarab

This small black beetle is the Scooped Scarab Beetle (Onthophagus hecate), they are a dung beetle in the family
Scarabaeidae and subfamily Scarabaeinae . They are a small beetle reaching lengths up to 9mm or approximately 1/2 inch. They are uniformly matte black with an excessively pock-marked pronotum. Major males have large horns projecting from their heads. The horns on minor males are much smaller and females lack a horn altogether. It can be presumed that males use the horns for fighting other males to win the affections of nearby females. Many beetles that possess such decoration typically use them to flip their competition over on their backs. Which ever beetle ends up belly-up is the loser and the other wins the right to mate with the nearby female(s). 

They are found on dung, rotting fruit, decaying carcasses and other unsavory substances. Once mated, the female will form dung into a small ball and roll it with her hind legs, which extend far back on the abdomen to allow for such movement. She is trying to locate just the right spot in the dirt that will allow her legs to dig. If the dirt is too compacted her legs are not strong enough to dig into it. Once the right spot is located, she will then dig a small burrow or tunnel around the ball of dung until it is buried under ground. Dung buried in this fashion limit fly resources while providing nutrients for plant growth. She will then deposit eggs on or near the dung ball. When the young hatch they will feed on the dung which contains all the nutrients they need. Rarely is the dung consumed in its entirety which leaves valuable nutrients in the soil to aid in fertilization. These beetles are a dairy farmer, beef farmer and ranchers friend because of the aeration to the soil they provide as well as the nutrients they randomly deposit. 
 
Because these beetles feed on dung, limiting or omitting the use of  Parasiticides to control flies on cattle may be necessary to protect your beetles. Many of these chemicals come out in the waste of the cattle and are consumed by flies which is designed to control their numbers, but this can also kill dung beetles. Do you have dung beetles in your pastures? If you have a long history of using any of the following medications for fly control, abamectin, ivermectin, eprinomectin, doramectin, then most likely you won't have any. Want to encourage the dung beetles back to your farm or ranch, then you may want to consider removing these chemicals from your routine. Flies are the bane of farmers everywhere and cause untold problems for livestock, so controlling them is imperative. However there are chemicals available that will provide fly control, but not release themselves into the cow patty. Do your research and determine the best possible chemical to use that will limit harm to the environment as well as to the dung beetles. Dung beetles show up very quickly to piles of fresh dung and to confirm their presence simply look at the surface of the cow patty. Do you see little holes? If so there may be beetles present. You can use a trowel, shovel or your boot to carefully dig into the patty and look for the beetles. 

You'll notice, if you look closely that the dung beetle pictured below has small reddish colored mites hanging out all over it. These mites do not hurt the beetle, in fact they are aiding the beetle as a beetle-wash by lapping up nasty little hanger-ons from the buffet of dung, rotting fruit, or carcass they just left. The beetle in turn provides transit for the mites by acting like a greyhound bus to transport the mites to other locations. 

They are found throughout most of the United States with exception of the extreme western portion of the country. They are common in most of their range and often show up at porch lights.

Thursday, December 26, 2013

Elderberry Borer Beetle

The Elderberry Borer or Cloaked Knotty-Horned Beetle as it is sometimes referred to (Desmocerus palliatus) is found in North America from Oklahoma to the Appalachian Mountains. They are found more often in the northern portion of their range in marshy, swampy areas where their host plant, elderberries, occur. This small to medium sized beetle reaches lengths up to 26 mm without antennae. They are a gorgeous colored beetle with iridescent bluish wings and  a vibrant yellow or yellow-orange band across the upper portion of the wings. The middle segments of the antennae have distinct knobby points which earned them the common name of Knotty-Horned Beetle or Cloaked Knotty-Horned Beetle. They are unmistakable and not to be confused with any other species as no other beetle carries such vibrant, unique colors and pattern.

A couple of years ago I became acquainted with a woman named Annie Ray who did her doctoral work on beetles in this genus. Her project was centered around the pheromones produced by the female of this species and how the male homes in on her scent. As part of the research we had to dig down into the roots of the elderberries and break open the root masses looking for larvae or pupae.

The objective was to find them in this stage, because when they were located as adults they would not work for her research purposes. In essence she needed the virginal females. This all sounds easy in theory, but I assure you in practice it is much more difficult than you would expect. We were working in 90 degree temperatures often in full sun. We had experienced recent rains, which made one of our locations extremely muddy and digging in soppy, water-logged soil was pure torture, especially with the beating sun baking your skin. I became very adept at using shovels, spades, axes and limb loppers.
 Careful was the word of the day. It was all too easy to accidentally cut a larvae or pupae in half. This was enough to bring you to tears, to have worked so hard to find one, only to realize you destroyed it before you could get it out of its pupal chamber. Often we would work for as much as an hour before finding a single specimen.

Each discovery brought excitement. It really is true that the things we work the hardest for bring the greatest joy, because each time we found one of these elusive larvae or pupae you would have thought we struck gold at the amount of excitement we expressed. Annie spent three days here in NW Missouri working at several different locations, including Squaw Creek NWR, where she was given permission through an application process to search for these beetles on the refuge. All told she went home with 7 specimens. Not near the number we were hoping for, but ever the optimist she was grateful to not have been completely skunked. The beetles were safely ensconced in vials and packed for airplane travel to Ohio. From there they were to be shipped to California to her research assistant to begin extracting pheromones from.




Females of this species will begin "calling" for males as soon as they emerge from their underground pupal cell. Males come from great distances drawn by her scent and mating takes place immediately. We were certain that each adult we found had already been mated because of how rapidly this activity takes place once the females leave their pupal chamber. Females lay their eggs at the base of elderberry bushes, and the larvae will burrow into the roots or stem bases to feed. When they are ready to pupate they will travel to the soft, pithy parts of the branches, often near the roots and form a pupal cell. They emerge in early spring. Timing is everything when you are seeking to find these beetles before emergence. Literally it had to be timed so that we were digging and searching a few days prior to when we thought they would be coming out of their underground chambers. Once the adults are plentiful, your window of opportunity is gone.

These beetles are not known to cause any significant damage to the elderberry bushes. They do not occur in large enough numbers to wreck havoc. As adults they feed on the pollen in spring.Finding these beetles is not always easy, but once you've found one they are sure to leave an impression with their beautiful color and substantial size. Look for elderberries in full bloom in the spring and with any luck you will be awarded with the sight of one of these gorgeous beetles.


Tuesday, December 3, 2013

Mayfly

Mayflies are not actually flies at all. They are insects in the order Ephemeroptera and the family Ephemieridae, which translates into "short-lived" and likely eludes to the very short lifespan of these insects.

How do we know if something is a fly or merely called a fly? Here is an easy way to tell the difference, if the name is all one word like Mayfly, Dobsonfly, Caddisfly, Dragonfly, Damselfly, etc.. then it is definitely NOT a fly, but rather belongs to some other order of insect. If the insect has a first and last name like House Fly, Bot Fly, Flesh Fly, Flower Fly, Robber Fly, Bee Fly....etc. Then it definitely IS a fly.

They are one of the most commonly seen insects at porch lights in early summer or sometimes fall.
 The species I see more often than any other is the Burrowing Mayfly. They are also the largest species of mayfly in Missouri, reaching lengths up to 1 1/2 inches. Most mayflies are found in the Eastern United States, with only few species being found out west. It is not uncommon to have dozens of these at porch light in June, or in the case of this youtube video hundreds of thousands swarming a pole. Check out this Mayfly emergence.

The Burrowing Mayfly, also known as the Golden Mayfly, is a beautiful shade of golden-yellow with pale bands across their abdomen (pictured below).As they age their coloring will become darker.


The lifecycle of a mayfly begins underwater as a nymph with seven pairs of gills. They live in the bottom sediment of streams, slow moving rivers, ponds and lakes. The nymphs feed on sediment, diatoms and several species are predatory and feed on other aquatic insects. After numerous molts (skin sheds), they will emerge approximately one year after hatching in the water. The males typically appear first, as subimago adults,meaning they are not completely formed adults yet, they will shed their skin one more time before completing their lifecycle to adulthood. These subimago's are a favorite food of trout and are often used by fisherman as bait. Trout fishermen also use mayflies as a model for the flies that they tie for bait. Mayflies are the only group of insects to have this subimago stage into adulthood. As a subimago they do not fly well, cannot reproduce and lack the coloring of the adult form that would attract a mate. Within 24 hours after emerging they will shed and become full fledged adults capable of breeding. Females emerge shortly after males and also shed their skin for the final time. Mating occurs within hours of emerging.


Time is of the essence, when you only live a day or two, or perhaps only mere minutes (for some species) there is no time to waste on frivolity. Soon after mating, the female will drop her eggs upstream in the water, the current will softly carry the eggs downstream and deposit them on the substrate in the bottom of the stream. If the eggs are laid in lakes or ponds she will drop them wily-nily on top the water, and the eggs sink to the bottom. In some parts of the world the emergence of mayflies is a sight to behold, they all seem to appear at once in a mass exodus. Millions of mayflies rising up out of the water in one large swarm, landing on every available surface may seem like a nuisance to many humans, but these little insects serve a major role in the lifecycle of other species. Mayflies are not only consumed by trout and other fish, but birds, frogs, toads, and other insect eating creatures get in on the all-u-can-eat buffet of mayflies as well.

                                                         (Jumping spider eating mayfly)

I am not sure of the species of this mayfly pictured below on the Sage, but it is a beautiful shade of russet and is much smaller than the Burrowing Mayfly at only 3/4 of an inch in length. 
Although their large numbers can be intimidating, they are completely harmless to humans. They cannot bite, in fact they do not have functioning mouth parts. This lack of mouth parts, also means they do not feed. Their only reason for existence it would appear is to mate, reproduce, and to be sustenance to other creatures. I did find a website that claimed they eat fruits and flowers, but in my opinion this would be fallacy. I know of no mayfly that has the ability to eat, nor do they live long enough to worry about eating even if they could. I would be curious to see what the experts have to say. This is just one example of how much mixed information is out there on the web and it pays to do numerous searches before settling on the truth about something.

Monday, November 25, 2013

Harvestman



When is a spider not a spider? When it is a Harvestman (a.k.a Daddy Longlegs). These spider-like arthropods are in the order Opiliones. These arachnids are common to abundant in North America as well as worldwide with over 6500 species identified.
Most of us grew up playing with daddy longlegs, after all they were everywhere and easily captured and never tried to bite. Their long legs would tickle your bare skin as they climbed up your arm or leg which
was sure to bring on giggles or squeals depending on your reaction. As a naturalist I am blessed to work with children on a regular basis and I am often transported back to my own childhood when the groups of children who visit our trail are confronted with these charming creatures. Some are frightened, some are unsure, others are excited, but all are enthralled. Oh to be 4 years old again!

They get their common name of Harvestman from their frequency during autumn harvest. Truthfully it is during the fall that they are more easily seen as they are now adults and much larger. They also tend to aggregate in large numbers, sometimes dozens upon dozens along the foundations of homes. The common name of daddy longlegs comes from their protective tendency toward the females and eggs at mating time earning them the name of "daddy", not to mention the "long legs' compared to body size that they possess.
Native Americans referred to them as Grandfather Greybeard which meant Feet of Hairs. One could assume that this was derived from the legs resembling thin strands of hair.

Fossils dating back 400 million years ago have been found of this species in Scotland. Very little has changed in appearance with the daddy longlegs in all that time.
(Fossil image of Harvestman from 50 million years ago
http://en.harunyahya.net/harvestman-fossils-fossil-pictures/)

Harvestmen differ from spiders in several ways, but the most obvious will be the body shape and the eyes. Spiders have two body parts that include an abdomen and a cephalothorax (head and thorax combined into one) and daddy longlegs have one compact body part. Spiders have a cluster of eight or six eyes (depending upon species) whereas daddy longlegs have two eyes. They also have no silk glands, therefore cannot spin silken webs like spiders. Daddy longlegs also possess no fangs or venom unlike spiders which have both.

This lack of venom and fangs brings me to a myth that is commonly associated with this species. It has been said that these "spiders" are the most venomous of all spiders if only their fangs were strong enough and long enough to penetrate human tissue. There is no truth to this myth at all. First we must keep in mind these creatures do not have fangs so biting is an impossibility regardless if we had thin skin or not. They also possess no venom which makes them harmless. Handling them is completely safe and a great way to introduce young children to nature. Encourage your child or grandchild to handle them gently, no pulling off legs.

Other myths associated with this creature include the belief that they could help a cattle rancher locate lost cattle. If a cowboy in search of a wandering cow or calf could pick up a daddy longlegs by 7 of its 8 legs the remaining 8th leg left dangling would point in the direction of the lost cow. 
It was also believed that if you killed a daddy longlegs it would bring rain the next day. This particular myth could be unfortunate for the poor harvestman. Thankfully this belief is not wide spread or passed along generation to generation or the common harvestman may find itself not so common any more.


Without fangs and venom how does this species consume food? Like spiders they have mouth parts, but unlike spiders they do not need to dissolve their food in order to digest it. They can consume their food in small chunks. Their diet also differs from spiders in that they are often scavengers feeding on dead insects, plant matter, and fungi. Spiders are carnivorous and feed exclusively on other arthropods, unless you are a large spider (think tarantula) then you might feed on larger prey like mice, shrews, minnows or even birds. I've witnessed harvestmen feeding on a wide variety of insects, from flies to millipedes. They typically stalk their food using their sensitive second pair of legs to help them feel their environment. This is beneficial to a creature with poor eyesight like the harvestman. They are fastidiously hygienic and will clean their legs after each meal by passing their legs thru their mouth effectively "washing" them. Momma longlegs must be proud.

(Feeding on a dead millipede. You will also notice tiny red mites on the legs of the daddy longlegs)

(This daddy longlegs captured this fly and ate it)


After mating, the female will lay eggs and in many species the males will guard the eggs and protect them from potential predators. The male will clean the eggs  and guard the nest until the eggs hatch. It may take from 20 days to 6 months for them to emerge depending upon species and climate. Once they have hatched the young will go through 6 molts, or instars before reaching adult size. Although some species may go through 8 instars to reach maturity.

Harvestmen have several defenses, including the ability to emit a foul smelling odor from special glands in their legs when disturbed. If bothered by a potential predator many species may also play dead, or detach a leg that will continue twitching which can distract the predator giving the harvestman enough time to escape. Some species will bob their bodies which may also confuse a predator. Escaping a predator is not always that easy and many fall prey to various creatures like other arthropods, birds, and lizards.

 (Five-line skink eating a daddy longlegs)

While daddy longlegs may have some success in warding off potential predators by using distracting measures there are some different types of predators they cannot avoid and those are mites.These mites act as a parasite on the daddy longlegs. They seem to have the same affect on the spider as ticks would have on mammals. In large enough numbers the mite-parasite will destroy the host. The one photographed below was well on its way to deaths door due to mite infestation. It was wobbly and ungainly, unable to keep its balance. It was quickly succumbing to the onslaught of mites.


Each person will have a different reaction to these arachnids. Some will cringe in fear as their arachnophobia is triggered by a creature that looks enough like a spider to be one. Others may find them creepy or disgusting as unfortunately many people do when faced with any 6 or 8 legged creature. Still others may find them comic or fascinating. Whichever category you fall into keep in mind these harmless creatures are beneficial to our yards and gardens. They consume dead or dying arthropods, may even consume the dead flesh of carcasses. They feed on dung, plant matter and fungi, turning their diet into organic matter that benefits soil and garden plants. These endearing spider-like creatures are also reminders to us of a simpler time in our life. The time of lightning bug lanterns, ladybugs, and daddy longlegs the gentle spider of our youth.