Tuesday, July 21, 2015

Peacock Fly

Peacock flies are a type of fruit fly in the family Tephritidae. There are approximately 500 genera, that include over 5,000 described species Worldwide within this family. The one pictured here is Paracantha cultaris and can be found throughout Western North America. This particular species lays its eggs within sunflower stems where the maggots hatch and feed within the head of the sunflower. Adults are typically found around sunflowers or other related plants.
 Some species within this family nectar at flowers and on some level would be considered pollinators because of their feeding habits. By nectaring at flowers which contain high levels of pollen, like sunflowers, they will in turn spread that pollen from plant to plant essentially pollinating them just like bees. We don't always think of flies being pollinators, but many of them are quite good at it.

These flies run the gamut of being beneficial or harmful depending upon the species and their feeding habits. Some feed on crops and cause significant agricultural losses each year. Some are host specific and feed only on one plant species, like the olive fruit fly, which as its name would suggest feeds on olive trees. They cause vast amounts of damage to these trees in areas where they occur in large numbers.  Other species cause no damage at all and instead are beneficial to humans and are being used as a biological control measure against noxious plants like knapweed.

Because of their agricultural importance, fruit flies, might  be the most vastly studied of all insects found throughout the World. Whether they are being studied to learn control measures to keep them from destroying crops, or to learn more about their feeding habits and exploit them to benefit us in biological control measures; one thing is certain they are important enough ecologically to warrant time and money spent on learning more about them.

Flies within the family Tephritidae are small to medium in size and distinctive in coloration. Many are orange, golden, yellow, greenish and any number of other colors. They have beautiful picture-wings and eyes that look almost psychedelic in appearance. Others use Batesian mimicry to mimic bees and wasps, and others are experts at camouflage. Many of  these flies are strikingly handsome and always a fun insect to find among the flowers.

Some species live short lives and die within a weeks time. Other species live a full season or two. Be on the look-out for these flies among the blooming flowers as they feed, lay eggs and spread pollen from flower to flower.



Thursday, July 16, 2015

World Snake Day

To celebrate World Snake Day I thought I would share with you one of my personal favorites, the black rat snake (Pantherophis obsoletus). This particular species is the most widely distributed of all rat snakes in the United States. They are found throughout the Eastern United States, west to Texas, Lousiana, and Mississippi and north into small portions of Southern Canada. In Missouri this is probably the most commonly encountered snake we have, second only to garter snakes. They are found in a wide variety of habitats from rocky hillsides that they share will timber rattlesnakes, to farmlands, backyards, parks, prairies and woodlands. Of these habitat occurrences woodlands is the preferred home of these snakes. They adept at climbing and are often seen high in trees.

Their diet is highly variable, and includes rats, mice, voles, bunnies, birds, and bird eggs, including chicken eggs, which has earned them another common name of Black Chicken Snake.

I've often heard blue jays and other birds raising a loud ruckus in the trees and when I investigate I almost always see a black snake causing all the commotion. I've witnessed on more than one occasion birds pecking at snakes trying to protect their eggs and nestlings from being eaten by this hungry predator. I also know these snakes will frequently invade bird houses for the eggs and nestlings hidden within. While this can be very upsetting to those who love birds and who invite birds into their yards by feeding them or providing housing. I personally find it hard to be mad at the snake. They are only trying to survive and find food like any other animal, and when that food presents itself in such an easily accessible location as a bird house how can we fault the snake for doing what instinct drives it to do? We also raise chickens and once in awhile we encounter a black snake within the nesting boxes feeding on the eggs. Generally we are drawn to the chicken coop by loud clucking and panicked commotion going on inside the coop. I remember a couple of years ago my husband (who is not a fan of snakes) came and got me and told me he needed my help.

I followed him to the hen house and he pointed to a nest box. There was a gorgeous black rat snake feasting on the chicken eggs. I found the situation a little humorous, much to my husbands irritation who just wanted the snake gone. I picked up the snake and placed her outside, after snapping a photo. As soon as I placed her on the ground she turned around and slithered right past my husband and straight into the hen house again!! She disappeared into a crack in the wall inside and wasn't seen again. My husband just looked at me and rolled his eyes and said "Well, that was helpful!"
I'm sure the snake was hanging out in the hen house after the mice who hang out there feeding on the chicken feed. Once in the hen house it discovered the eggs and decided that meal was much easier to catch than a nervous, fast moving mouse that fights back by biting.

Black snakes, like all snakes hibernate over the winter and will often use hibernation sites occupied by rattlesnakes and copperheads. This communal hibernation habit earned them another common name of Black Pilot Snake, because it was believed by many that the black snake led, or piloted, the copperheads and rattlesnakes to the hibernation den. We of course know this is not true, they simply share the same locations.

Several years ago black snakes began using a crawl space in our basement for a hibernation site. Each spring I remove from 5 to 8 black snakes, yellow-bellied racers and garter snakes from the basement and put them outside. I assume they get turned around when trying to find their way back outside and end up in our laundry room where the opening of the crawl space is located. It is not unusual for me to be doing laundry and find a snake peeking back at me.

It is also rumored that black snakes will eat rattlesnakes, and there are videos on the internet claiming this to be true. Black snakes are not known to favor eating other snakes and the video's in question are showing black kingsnakes or indigo snakes which choose snakes as their primary food source. Another rumor involving rat snakes and rattlesnakes is that they will cross breed and create hybrid offspring of both species, this simply is not biologically possible. They are too far removed on the evolutionary scale to accomplish something like that in natural settings.

Black snakes mate in the early spring and lay their eggs sometime in June or July. They often share the same location as other black rat snakes to lay their eggs, creating a rookery of many different clutches. I have such a location in my back yard. Many years ago we cut down a large maple tree that was in danger of falling on our house. We used the stump for many years as an over-sized planter until eventually it began rotting away to such a degree that we could no longer plant flowers in there. Bugs had worked on the stump and it was in an advanced stage of decay. It was at this point it seemed like a preferred site for black snakes to use for a place to lay their eggs. A few years ago I noticed two black snakes laying their eggs under the loose soil around this stump. Two months later I noticed a shed skin of a baby snake on the stump and wondered if the snakes were beginning to hatch and emerge. I dug around in the dirt and found the eggs and they were indeed hatching. Imagine my excitement to witness something like that!!!




All told there were 57 babies that hatched from those eggs. That sounds like a lot of baby snakes, but only about 10% of those babies will survive. While snakes are excellent predators they are also prey for many animals. Foxes, raccoons, coyotes, other snakes, birds and even your house cat will all eat snakes. Juvenile snakes tend to be much more defensive in their behavior and much more apt to bite when faced with a predator, including a human who may want to capture one. This super defensive behavior is in response to the fact that when you are a baby snake everything wants to eat you.

Juvenile rat snakes look entirely different than they do as adults. As juveniles they have a gray or brownish background color with darker blotches or spots along the length of their body. This acts as camouflage to protect them to some degree from predators. The pattern breaks up their shape making them harder to see. Some even speculate that it is also a form of mimicry, because they superficially resemble rattlesnakes. If you look like something venomous it could be assumed a predator might think twice about trying to eat you.

 A couple of weeks ago I discovered the stump was being used again by the black snakes. This time I counted 7 females using the stump over the course of a week all laying eggs. One night there were three snakes at once laying eggs. I was fascinated by them and sat by the stump for over 3 hours watching them. 
video 
Short video of black snakes in the stump.

If two snakes from a few years ago succeeded in leaving 57 or more eggs, I can only imagine the amount of eggs that 7 snakes will leave behind. If they average 20-25 eggs per clutch that's a lot of babies! 

  Predation by animals is not the only thing snakes have to fear in the struggle to survive. Humans are notoriously prone to kill snakes and I've heard uttered on more than one occasion by intolerant people "the only good snake is a dead snake!" This attitude frustrates me and even angers me to some degree. Snakes are excellent rodent control and we all know rodents carry diseases. Just Google Hantavirus! Not to mention rodents are host to ticks which spread many types of deadly diseases to humans and our pets. Snakes help control those disease by controlling the rodents.  Roads and deadly drivers also take a huge toll one snakes. Rodents are also estimated to be responsible for up to 30% of house fires, caused from their habit of chewing on wiring. 

I know many drivers go out of their way to run over snakes, I've witnessed people purposely crossing the dividing line on a highway to run over a snake. Not only are they risking an accident, they are killing an innocent animal using the road as a basking location or as means to get from one location to another. Did the snake deserve that? 

Humans also use glue traps to catch rodents, bugs, spiders and even snakes in their homes. These traps do not kill their captors quickly, instead the animal dies a slow agonizing death by starvation. They cannot move or escape, and they feel fear, hunger and thirst before perishing. These traps are cruel and in my opinion should not be used.
Several times a year people will bring glue traps into my office with a still alive snake attached to it wanting me to ID the snake. Their fear is often that the snake is venomous. So far there has never been a venomous snake brought in, nearly always it is black rat snakes. Once the person leaves I spend sometimes as much as an hour painstakingly and gently removing the snake from the glue board. This involves a lot of dawn dish soap, Avon Skin-so-soft and patience. Once removed then I release them in the timber behind our building.

Another problem is litter. Humans are very messy creatures and we often leave behind trash that we don't give a second thought about. As evidenced by the following pictures. My daughter found this young black rat snake near our back door three years ago. It had somehow slithered through a piece of PVC pipe when it was a juvenile and became stuck. We know we had hired a plumber a few years prior to this and we assume the plumber left behind some small pieces of PVC that he had cut, then the snake unwittingly found them and carried this bracelet around with it for quite some time. Had we not found it when we did, it most likely would have died. My husband helped me and we sawed the plastic off which took about 30 minutes and resulted in the snake biting me, but we were able to release the snake.
Over the years I've often wondered what became of this snake and if it survived and that question was answered this year when I found those snakes laying eggs by the stump. One of them had the tell-tale scar from the PVC pipe it had once worn. I was so happy to know that snake had not only survived, but thrived and went on get bred and leave behind her offspring. She is a true survivor.

Here is the snake with the PVC pipe scar 3 years after her ordeal. 



When I was a kid every black snake we encountered was glossy black with a white belly. That isn't so much the case anymore. I find snakes with red, yellow, white and some orange coloration between the scales and a strong pattern visible more often than not now. This coloration varies from a lot to a little depending upon the specimen and the location. The ones at my house seem to have a lot of color, whereas other locations only a small amount. But I have not seen a completely black black rat snake for many years.
I'm not certain what this color change indicates, or why it has been happening over the past few decades. Is it an adaptation for future survival? Is it a fluke of breeding that produced this color and now breeding is selecting for this as a dominant feature? I don't have the answers, but I can attest to the fact that they are different now.
Notice the red and white coloring between the scales
Many people fear snakes and this fear usually comes from well meaning adults telling children that snakes are nasty, dangerous or will bite. While it is true that a snake will bite, but that is no reason to fear something. Most any animal will bite if threatened or afraid and it cannot escape. Bites happen when we try to handle the snake, or accidentally step on one or inadvertently put our hand on one, like in the hen house when gathering eggs. These bites are not offensive, they are DEFENSIVE. Snakes will not chase you down with the intention of biting or harming you. Snakes are not nasty, vile creatures. They aren't known to spread disease, instead they help control animals that do. The only snakes that could be considered dangerous are the venomous variety, and once again bites only occur when the snake is protecting itself or if you accidentally touch one or step on one. Bites are rare by these snakes, and death is even more rare. We should strive to be more tolerant of all wild animals, especially snakes. They are our friends and provide free rodent control.


Sunday, July 12, 2015

Brilliant Jumping Spider

Male
Brilliant Jumping Spiders (Phidippus clarus) are sometimes referred to has Red & Black Jumping Spiders and are common throughout the Eastern United States but also occur throughout much of the remaining portion of the United States and Southern Canada. They are one of approximately 5,000 spiders in the family of spiders called Salticidae, within this family there are 60 or so within the genus Phidippus. Nearly 10% of all spiders fall into this family of spiders making them one of the largest groups of spiders in the natural World. Jumping spiders have very large front facing eyes and excellent eyesight that is reported to be be better than a dragonflies, which is saying a lot! Because of their super eyesight they are excellent hunters, that typically sit on the top of blades of grass or other short growing plants waiting for prey to pass by, or they may actively seek out prey. Capable of jumping 50 times their own body length, they are the Olympic jumpers of the arachnid world. If humans were able to jump like these spiders, we'd be able to jump 300 feet; that is nearly the size of an NFL football field (360 feet)!


Female
 Males and females in this species look entirely different from each other. Males are predominately black with bolder coloration. They have rusty orange side stripes with a black median  stripe and white at the front of the abdomen near the carapace. Females are usually grayish with a burnt orange or orange-yellow abdomen with two black bands each containing 4 pairs of white dots.


Male
Female guarding eggs









 Early in the season males out number females, but by late summer many of the males have died off and the ratio of male to female becomes a little more equal. By late July or August mating is on their mind. Males begin to compete with other males for the right to mate with nearby females. Larger males typically win these competitions which include loud vibrations and some unique footwork. Males choose the larger females to mate with as they produce the most eggs. If a bred female comes in contact with a larger male, she may mate again with this larger more vigorous partner. He may prove to be a better mate and provide stronger offspring and offer her more protection while she guards the eggs within the nest.  Females may lay up to 135 eggs per egg sac and may lay more than one sac. They will guard the eggs within curled leaves held together by a silken nest created by the female. It is also reported that the male will remain near the female standing guard.  This species, unlike other species in this genus will only produce one brood and then die as soon as the spiderlings leave the safety of the nest.

Adult male guarding female


The spiderlings will overwinter after leaving the nest late in the summer or early fall. The cycle will begin all over again the following spring.
These spiders are being used as biological control of the four-lined plant bug within greenhouses. They are excellent hunters and feed on a wide variety of insects including cockroaches, beetles, and moths. They are harmless to humans and not really known to bite unless severely threatened.



Male

Female


Wednesday, July 1, 2015

Horse Fly

I found this beautiful horse fly at Squaw Creek NWR last week and had no idea which horse fly it was, I only knew that I'd never seen one like it. I photographed it and submitted the image to http://bugguide.net for identification. After several days I finally had a name for this fly, Tabanus venustus. Then the real challenge began, where to find information on it. I looked in every field guide I own, which includes well over 20 quality books on general insects, and one specific to flies and could not find this particular fly. So then I embarked on an internet search that lead no where. There were a few hits on the species name, but nothing useful beyond the fact that I now know this species of fly is found as far west as Oklahoma.



The eyes are a striking light blue with darker swirls, the thorax is dark brown with lighter brown streaks and furry in appearance. The abdomen was marked with white margins at each segment and the wings are spotted. It measured approximately 1/2 to 3/4 of an inch in length. Unlike most flies, who see a human approaching, it did not fly away. It sat perfectly still and seemed to be sunning itself on the piece of wood it was sitting on. I noticed several in the same general vicinity of the one I photographed all apparently soaking up the warm sunshine.

Females in this genus are known for biting to gain a blood meal. They have scissor like mouthparts that tear into flesh then they lap up the blood. Blood from warm-blooded animals provide essential nutrients for egg production. Eggs are generally laid near water and when the eggs hatch the larvae fall into the water to complete their lifecycle.

Flies in this genus are sometimes called "Gad Flies" and this might be in reference to their habit of roving to seek out potential victims of a future bite. This particular genus of flies contain numerous species that are capable of vectoring diseases such as anthrax.


Bites from a horse fly can be quite painful to a human and may cause severe itching and swelling that may last hours or even months. My husband was bitten by a "black horse fly" many years ago and the bite was so irritating that it was painful and itchy for nearly 6 months. When seeking a blood meal these flies are relentless and will follow you many hundreds of yards determined to get what they want. I've known of them to chase people on ATV's, and there are reports of them coming after cars, I assume thinking they are giant mammals.

Horse flies are rarely anyone's favorite insect and the sight of them can send grown men running fearing a bite, but as larvae they feed on a wide variety of aquatic insects including mosquito wigglers. This food preference should be considered beneficial to humans, especially on a year like this year when we've had record amounts of rain fall and there is standing water everywhere, providing ample breeding spots for mosquitoes. 

Sometimes we find beauty where we least expect, in this case it is was on the wings of a fly.