Showing posts with label Amblyopone. Show all posts
Showing posts with label Amblyopone. Show all posts

Friday, December 7, 2012

Best of Ants 2012

Alright I do this every year. I go through the albums I made over the year on Ants, Bees, Butterflies, and Nature.

We start with an awful image of the forest floor I took back in March. Up in the trees the Winter Ants, Prenolepis imparis, were swarming. Normally they fly on the first warm day of the year above 70F, but this year they held off for some reason. Hidden among the leaf litter is a P. imparis queen and a few males. This sums up what a pain it is to find ants among leaves (and tall grass).

They're so much easier to photograph when they land on your arm.

The males swarm around trees and wait for new queens to arrive. I like this because she actually made it up the tree to a considerable height. The swarms go all the way up the tree and usually queens get tackled by so many males they don't make it past 6' up.

 
As plants leaf out, aphids, leaf hoppers, and scales become active and provide food for ants. In this case a Lasius alienus worker. This is on a redbud tree and I notice aphids seem to only take hold right at the node where the leaf attaches to the stem.

Stealing nectar from flowers is the other option. In this case it's the Odorous House Ant, Tapinoma sessile, which I've found to be notorious for stealing nectar. I find them in more flowers than any other species, even in those with noted defenses that evolved to prevent ants from stealing from their flowers.  

Aphids make ants so much easier to photograph. Any food really that has the ants holding still. Here a Camponotus sp. tends some on our grape vine.

This year also marked the first time I Hosted/Attended the First Annual New Jersey Ant Together. We came across a Camponotus americanus colony which I don't encounter as much as the brighter colored Camponotus castaneus. So that was nice.

The Formica exsectoides mounds we encountered were awesome! The largest were two mounds next to each other that had to be 3' worth of mounded soil. Their mounds lined a pathway of considerable length all they way down at the Turkey Swamp Park here in NJ.

There were so many F. exsectoides workers pouring in and out of these mounds that you could actually hear the leaves rustling from them all rushing about.

Pheidole have always been a small mystery to me. Small ants in general always are. We have three species in New Jersey and they are all really tiny. This is a Pheidole bicarinata major worker. They're about three times as large as the workers which make them easier to identify of the three.

Pyramica is another rare ant almost never encountered. Seriously if you're not covered in chiggers, ticks, and poison ivy by the end then you're not looking hard enough typically. We found this colony under a rotten log that was near a creek and in a shady area. Apparently a problem with this species is they over heat easily in sunny spots so even dappled shade could be an issue for them. They're also predators of springtails so rotting plant matter is a must. I didn't expect to find an ant this cool after just 3 hours but there they were. I have occasionally found these in my yard.

Polyergus is another fun find. They're not "uncommon" but you don't find them everywhere. They're slave making ants of Formica species, which happen to make them very common all over the US and Canada. This was a first time encounter for me.

Amblyopone pallipes was another cool find, and a first for me. They're called Dracula Ants because they puncture their own developing brood in nonlethal ways to feed. Not a great photo at all compared to what's on the internet, but we held this thing for like 30 seconds before it crawled off and got lost in the pine brush.

This is a distorted angle but these are some of the specimens we collected while on the trip. 

The droughts of summer always limit ant activity but one thing I've always looked forward to is harvesting my Trillium seeds and presenting them to the ants. This year I got a lot more Camponotus castaneus workers at them than ever before. Nylanderia flavipes workers also showed up as they always do. You can really see the drastic difference in size between the two species.


I started work making my own key but never got around to finishing it. The project was going to be an interactive video on youtube where I'd have arrows and Annotation Boxes you could click on to take you elsewhere in the video. It's quite an undertaking and I'm not up to finishing it this year. Hopefully in the future something will come of it.


A Camponotus americanus worker on a Narrow Leaf Sunflower. Two of my most favorite things.

They were actually working tiny aphids but these weren't all that common on the plant. Despite the narrow leaves the aphids did a good job of hiding.

And the last ant photo I took this year that I'm really happy with is this Brachymyrmex queen and male, namely because of how tiny these ants are and how well this came out. 

Friday, July 1, 2011

Identification and Distribution of Amblyoponinae Subfamily


These three genera represent the subfamily Amblyoponinae in North America. All of the members have a poorly defined postpetiole that connects to the gaster with a large surface area. They tend to be specialized predators and, as that implies, are equipped with with a stinger and well defined mandibles.

Prionopelta antillana (2) SE (Florida)

Stigmatomma degeneratum Mexico, Costa Rico
Stigmatomma oregonensis SW, NW
Stigmatomma orizabanum SW, Mexico
Stigmatomma pallipes (2) SW, SC, SE, NC, NE
Stigmatomma trigonignathum SE
Stigmatomma zwaluwenburgi HA


Key
These are rarely encountered by the general public. Encountering these ants can perhaps be a mark of achievement for ant enthusiasts. Stigmatomma pallipes is by far the most common and widely distributed member of this family. Reproductives have not been found for most species but it's likely queens are similar looking to the workers in appearance. Males are perhaps more often encountered but to which species they belong to can be puzzling.

Stigmatomma pallipes (2) SW, SC, SE, NC, NE
The most common and wide spread species in Temperate and subtropical parts of North America. Nests have been found in rotting wood and stumps. Morphologically a good sign of this species is the mandibles widen in the middle with a curve on the inside along the teeth.


Stigmatomma oregonensis SW, NW
Eyes... though incredibly hard to make out on all Amblopone species, are distinctly larger, especially on queens. Mandibles are even in thickness with 9 or 10 teeth.

Stigmatomma zwaluwenburgi HA
The only member of this genus found in Hawaii. How it got there and where it's really from are still unknown as far as I can tell. This ant is small at around 2mm long and paler than most other species.


Stigmatomma trigonignathum SE
Thinner than A. pallipes. Mandibles are wide in the middle too, but more exaggerated and fleshed out. The curves follow the lower head margins more before curving back to the tips of the mandibles.


Stigmatomma orizabanum SW, Mexico
Nest have been found undertones in fields or forests, typically at elevations around 2700 and 2800 feet. Local flora comprises mostly of temperate tree species, especially Carpinus (Hornbeam) and Pines. (It's likely Hornbeam distribution continues down into Mexico where this ant is found.) Morphologically this ant is said to be smaller and paler than most other Amblyopone. However A. degenerata is even paler. Both species are around 2mm long or less.

Stigmatomma degeneratum Mexico, Costa Rico
A ghostly white color and relatively few teeth identify this species.


Prionopelta antillana (2) SE (Florida)
This species is only found in Florida. Unlike Amblyopone this genus is only represented by one species in the US. They differ from that genus by having smaller mandibles with only 3 teeth while the former has lots of teeth. The scape and antenna proportions differ as well; they're clubbed. There's probably differ in other ways too but most of the scientific work about them is written in Spanish. They are normally from South America and it is strange they haven't been reported on various islands such as Costa Rico or Jamaica. These are specialized predators that nest in both soil and in dead wood. Colonies are small, fewer than 1000 ants. 


Sources

Brown, W. L. 1949. A new American Amblyopone, with notes on the genus (Hymenoptera: Formicidae). Psyche 56: 81-88.

Brown, W. L. 1960. Contributions towards a reclassification of the Formicidae. III. Tribe Amblyoponini (Hymenoptera). Bulletin of the Museum of Comparative Zoology of Harvard College 122: 145-230.

Haldeman, S. S. 1844. Descriptions of insects, presumed to be undescribed. Proceedings of the Academy of Natural Sciences of Philadelphia 2: 53-55.

Williams, F. X. 1946. Stigmatomma (Fulakora) zwaluwenburgi, a new species of ponerine ant from Hawaii. Proceedings of the Hawaiian Entomological Society 12: 639-640.