Are any of you signed up for the 2011 Ant Course? It is going to be held at the American Museum of Natural History's Southwestern Research Station near Portal, Arizona this year, or at least it was supposed to be. You see, there is a big fire burning in southeastern Arizona right now. They had to evacuate the station over the weekend.
And ants sure don't have those iridescent chelicerae in front. Or the row of eyes right above the chelicerae.
It's a jumping spider, apparently Myrmarachne formicaria. Look how the spider even holds its palps under the chelicerae to help with the disguise.
This is one of four males found overwintering in an old toy bulldozer left in the woods of upstate New York. We brought the toy inside and a day or so later noticed these. Once they had warmed up, they were quite active and readily accepted small flies.
Myrmarachne formicaria is a ant-mimic jumping spider that was first found in the United States (in Ohio) in 2001. Obviously its range is spreading.
Have you ever been fooled momentarily by a spider that was an ant mimic? Have you ever seen one of these?
Richard A. Bradley, Bruce Cutler, Maggie Hodge. 2006. The first records of Myrmarachne formicaria (Aranae, Salticidae) in the Americas. Journal of Arachnology. 34(2):483-484.
Have you heard about this? The harsh spotlight of agricultural fame has been taken off the social insects by the paper in Nature last month. It turns out that amoebae of the species Dictyostelium discoideum treat their food bacteria like leafcutter ants treat the fungi they eat. In fact, the single-celled wonders might be called "farmers."
Did you know there were social amoebae? When levels of their "prey bacteria" get low, the amoebae gather together to form what is called a migrating slug (see video below). The clustered amoebae move a certain distance, and then form a towering fruiting body, with a thin stalk supporting a round sorus at the top. The cells within the sorus form spores, which disperse.
Be patient for the first 30 seconds of the video. The amoebae have been deprived off food. It takes a bit of time, but then they form the slug. I wonder if the stragglers that try to catch up to the main slug should be called "sluglets?" 🙂 (You'll see what I'm talking about.)
When the "farmer" amoebae are ready to disperse, rather than eating absolutely all the bacteria available to them, they leave some. The bacteria are incorporated into the amoebae, into the slug, and carried via spores to the new area. Once at a suitable location to grow, the farmers "seed" the area with the bacteria, thus ensuring a certain food supply.
Non-farming clones of the same species of amoeba, on the other hand, consume all of the bacteria in the original area. Whether there will be food where their spores land is left to chance.
A fascinating species. And thanks to SN for bringing this to my attention,
This summer I stumbled upon a sweat bee nest while moving some old boards. The nest was between two boards and this is what it looked like when I lifted the top one off. (Sweat bees, family Halictidae, are often metallic, shiny green or blue.)
Sweat bees vary from solitary to social. This nest had multiple adults, which probably indicates they were living socially. Does anyone recognize the species?
All life stages were present. In this cell there is a ball of food and what looks like an egg (it seems to have a knob at one end?). Usually the food is a mixture of pollen and nectar, hence the yellow-orange color. See the water beads in the cell? The sweat bees line the cells with wax.
The older larvae are plump grubs. Prior to pupating, the larvae enter a resting stage called a prepupa.
Sweat bee pupae look like most bee pupae. You can see their eyes, mouthparts and antennae. This species does not appear to spin a cocoon.
Everything is pretty neat and tidy.
I tried to replace the board, but when I checked the next day, it was obvious the disturbance was too much. Many of the cells were empty.
The nest was overrun with snails (I think they ate the larval food),
and of course, ants.
What a difference a day makes in the life of a sweat bee.