Monday, November 30, 2015

Metallic Sweatbee

This beautiful bee is one of the metallic sweatbees within the genus Agapostemon, known as A. spendens. There are 45 species within this genus and all occur within the western hemisphere, of those 45 species, 14 are found within Canada and the United States. Metallic sweatbees are commonly encountered during the hot summer months. They can be found on a wide variety of flowers, but seem to favor sunflowers or sunflower-like flowers. Like most bees they have specialized hairs on their legs that allow them to "pick up" pollen as they forage on blooming flowers. Bees within this genus specialize on pollen, in fact Agapostemon translates to "Stamen Loving". The stamen refers to the portion of the plant that produces pollen.

Many species of sweat bees are attracted to humans and will seek us out to lap up the sweat on our bodies. They glean salt and moisture from the by-product we produce when overexerted. Often these bees will sting with no provocation, and for such a tiny bee they can give a wallop of a sting too. Metallic sweatbees however have  little to no preference for lapping at our sweat covered bodies. Although I have been on the receiving end of a few stings by this species when one lands on me for a salty drink and I am unaware that it is there and I inadvertently bend my knee or elbow and POW I am stung for accidentally squishing the poor bee in the crevice of those joints. Why do they always seem to favor those sensitive areas? Usually though they seem to prefer to hang out in our gardens busily visiting flowers. This habit of flying from flower-to-flower provides valuable pollination of many plants. Many people associate pollination with honey bees, and while honey bees are the poster bee for pollination, there are still numerous native bees that provide this service as well, and often times they are as proficient or at least nearly so, as the famous honey bee.

Metallic sweatbees are almost always solitary ground nesters and will dig a tunnel that may have a mound of loose soil or sand at the entrance. Burrows will be created off the main tunnel in which the female provisions with a combination of nectar and pollen in a little pollen-ball. They will lay an egg on this ball of sweetness and then seal up the entrance to the burrow. When the egg hatches it will have enough food to complete it's lifecycle. Some species of metallic sweatbees will nest in a communal nest of sorts......they share the same entrance, but each female (up to 20) will create their own separate burrows to lay their eggs. A. spendens is known to be completely solitary and places single burrows scattered across vast areas, which makes them hard to find.

This species is approximately 3/8-1/2 inch in length making them a medium sized bee and quite large for a sweatbee, which are typically tiny at approximately 1/4 inch or smaller. Males will usually have a striped abdomen and females generally have a solid metallic abdomen like the rest of their body. Some species may be metallic blue, gold or even black, but green seems to be the most common color seen.

Wednesday, November 25, 2015

Straight-Lanced Meadow Katydid

Female
The Straight-Lanced Meadow Katydid (Conocephalus strictus) is a commonly encountered katydid of grasslands, fence rows and other dry grassy areas. They are found east of the Rocky Mountains with exception of Florida, North Dakota and the northeastern states. There are two basic types of meadow katydids the Conocephalus which are the smaller meadow katydids and the Orchelimum which are the larger meadow katydids (like the black-legged meadow katydid). Of the smaller meadow katydids the straight-lanced species is more heavily bodied in appearance. The female has a long, straight ovipositor that easily exceeds the length of her body. It is this oversized appendage that earned them their common name. Even the males seems excessively endowed and feature larger than average cerci.
This species comes in two forms, a short-winged form with wings that extend 1/3 to 2/3 the length of the body. They will measure about 3/4 of inch in length. The long-winged form have wings that extend past the abdomen, and their overall length will be a little more than a inch.

Male

Males attract females with song and call out incessantly once they reach adult size. When a suitable female has been serenaded and is receptive to his attention mating will take place. Females will use their long ovipositor to scissor into plant stems in which to deposit their eggs. A single female is capable of laying 1,000's of eggs that will overwinter and hatch the following spring. Nymphs are born looking very much like their adult counterparts. They lack wings and reproductive organs. After several molts they will reach adult size sometime in mid-summer. Mating will take place shortly after that and the cycle will begin again.

The sounds I associate with summer are the call of the katydids and cicadas. Each song is as unique as the species creating it. It is possible to identify individual species by sound alone. Challenge yourself to learn the songs and see how many species you can identify, of course it might be
challenge enough to just locate the noise maker among the vegetation. Many katydids are camouflage experts and nearly impossible to see among the plants. This particular species is not prone to hopping away when disturbed, instead they tend to flatten themselves out, stretching their legs behind them, holding their body as close to the substrate or plant surface as they can, in the hopes that you will not see them. It seems to be a pretty good strategy as it took me awhile to spot the individuals photographed here.

Like most insects these katydids are not without predators. Birds, frogs, mammals, and other invertebrates all savor these tasty morsels. The great-golden digger wasp is a solitary wasp that seems to favor katydids as a food source for their offspring.
Great Golden Digger Wasp
A female wasp will locate a katydid, sting it to paralyze it, then she will drag it to a ready-made burrow. She will pull the paralyzed katydid into the burrow and deposit one or more eggs on the unlucky victim. The egg(s) hatch and the wasp grub will begin feeding on this fresh supply of food. The feeding activities of the grub will not kill the katydid quickly. The grub seems to know not to eat any vital organs until right before it is ready to pupate. It seems a gruesome fate for the katydid, but the wasp has to eat too, right?

Generally this species is green , but darker specimens are also found, like pictured here. The eyes are typically pale, almost white, but may also have pale peach or reddish eyes. So variability is common is this species.

Tuesday, November 17, 2015

Six-Spotted Fishing Spider

The Six-Spotted Fishing Spiders (Dolomedes triton) are pretty common in Missouri as well as throughout much of their range. They are easy to identify by their greenish-brown bodies and white stripes on their cephalothorax, and along the edge of their abdomen as well as the twelve white spots running in two rows along the top of their abdomen. It is the six black spots on their underside that gives them their common name.
They can get pretty large with a body measurement up to one inch and a legspan twice that large.

They will be found along the shoreline of shallow calm waters, like ponds, lakes, marshes and slow-moving streams. They will walk on the aquatic plants hunting for insects to eat. These spiders are unique in being one of the few creatures able to walk on water. They can also dive underneath the water, row across the surface, and glide. They can walk down aquatic plants beneath the surface of the water and can remain under water for up to 30 minutes by trapping an air bubble between their legs that they will use to breath oxygen. They glide by remaining perfectly still on the surface of the water and letting the wind blow them to new locations and hunting grounds. They walk on water with specially adapted hairs on their legs. Rowing is done by using some of their legs as oars to motivate them across the surface of the water.

Fishing spiders can escape predators in a number of ways, by jumping straight in the air, running rapidly across the water or diving below the surface. Even on land they are quite quick and able to run away from danger. They will always be found near plants whether in the water or on the shore. This allows them to hide from predators.

These spiders are excellent hunters and have a lot of choices available to them.
They will feed on aquatic insects as well as terrestrial insects, but more often than not they will scavenge on insects, like the one pictured here that captured a damselfly, which happened to fall into the water and could not escape again.  Larger fishing spiders will even attack young newts, small frogs, tadpoles and minnows.

Female fishing spiders are larger than the males, and females will not hesitate to kill and eat a male fishing spider if the opportunity arises. When a male approaches a female that has already mated she will most likely eat him. The male seriously lives life on the edge. Females lay their eggs inside a silken sac that she will carry to the shore and hide among the plants. She will remain near the egg sac and guard it until the eggs hatch. She will even remain with the spiderlings until they are ready to disperse. The spiderlings will over winter two times before they are old enough to mate.

Even though these spiders are apex hunters they still have to be ever vigilant of predators such as frogs, fish and birds. Excellent eyesight gives them an added advantage when avoiding predation.
These spiders are active during the day and are easily seen as they rest on the aquatic plants floating on top the waters surfaces. I've seen a dozen or more of these spiders already this year.

Recently while leading a group of school children to the pond at work where we planned to dip for aquatic insects, tadpoles and anything else we could capture in our nets to learn about, the kids caught one of these spiders. I placed it in the shallow tub of water we had sitting on the shoreline. Along with her there was also numerous aquatic lifeforms the kids had captured inside this same tub. When I checked on her a few minutes later she had taken full advantaged of the insects that were unable to escape and had caught a water bug. She was busy chowing down on this opportunistic meal that was provided for her when several of the kids came over to watch her eat. She grew tired very quickly of all the eyes peering down at her and she made a dash for the side of the small tub she was in and jumped ship right over the edge and ran like crazy for the pond, with the water bug still held firmly in her mouth. We let her go about her business and the kids thought it was pretty awesome to see her capture her prey, kill it and eat it....then run away with it as if we planned to steal it from her.

I wish I would have had a camera with me at that time to capture this moment with the kids and the awe and wonder they expressed at the smallest of creatures.