Feeding the Ants

I have a few Oak trees out in the yard, which tend to be prolific with caterpillars. Most of which are fairly bland looking and the one above is no exception. Caterpillars that don't have exotic colors to them or aren't covered in hairs, tendrils, or thorns, have to be cautious as they tend to be the easiest for birds to eat. We have several sparrows and robins nests about the yard so naturally their chances of survival are almost zero. So what these caterpillars have to do to escape being a meal is either hide or jump ship. I see droves of these lowering down from the tree each time a bird lands to inspect the tree. Ideally the caterpillar would lower onto another branch, but there's only so much tree to be had.

Once they're on the forest floor (or in this case my yard) they need to locate another host plant, typically a sapling or risk starvation. Some can survive by eating last years leaves that haven't decomposed but this isn't as nutritious for them.

Directly under the Oak Tree in question is a rather health colony of Camponotus castaneus. They tend to forage at night though, so until then other forest ant colonies have a chance to collect up some food. Located in the same area were colonies of Aphaenogaster rudis, Nylanderia faisonensis, Prenolepis imparis, and Tetramorium species E. (formerly T. caespitum), as well as a few young colonies Formica pallidefulva, and Formica incerta. All underneath one oak tree.

(There's also colonies of Lasius interjectus, and Ponera pennsylvanica too but I don't think they eat caterpillars too often. The Lasius colonies farm root aphids like there's no tomorrow, and the Ponera I expect to be predatory towards small mites and spring tails and such.)

So I fed this little caterpillar to my colony of Pheidole bicarinata, which is a rather tiny ant, commonly found in sandy areas. Pheidole is one of the most species rich genera in the world but here in NJ we're approaching their northern limits. They're far more prolific in tropical areas. They occur wherever there's lots of sandy soil and full sun to partial shade conditions. Colonies can get reasonably big, but for now this one fits nicely in a test tube. You can sort of make out the queen but she's out of focus and in the back towards the brood pile. The caterpillar tried to hide under their test tube but the ants soon found it and swarmed it.

Pheidole is a genus with a polymorphic worker caste. The smaller workers do most of the work while the larger ones are there mostly for food storage, milling seeds, and tearing open food items for the smaller workers to more easily get at. They can also block tunnel entrances with their heads when the colony is attacked.

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. 

Wow That's a Tiny Ant

Holy Cow! I know this picture looks a little fake. The Plaster of Paris inside the container caught most of the flash and looks glowing white. The rim of the container, which the ant is on measures 2mm wide. This is a worker to a very small ant species I have, which I think is Pheidole pilifera. Still not good enough magnification to properly identify the species but still a great example of the Panasonic Lumix can focus on. I'm still mad I can't do anything with video files but I love everything else this camera can do.

In this picture the lighting is a little to harsh so it's not what a professional photographer should be using for excellent pictures. But it's great for the casual buyer. Here one worker leads the other by tandem running. That's where the lead ant move a little and waits for physical contact from the ant behind before moving on. In this way young ants learn to forage, where to look, and can even steak out new nest sites. The setup sits in a foraging dish so I'm not worried about that. 

Pheidole pilifera (journal)

My Pheidole pilifera colony. Not that you can tell what they are though from this photo. These ants are incredibly small and normally nest in sand. This is the whole colony and they could all easily fit on the tip of my thumb. They're not digging into the plaster but are able to nibble at it. They do this mostly as a reaction to water, or in this case condensation that sometimes forms on the side. They probably won't dig tunnels into the plaster until they've expanded into the other chambers. That's a long ways off though.


They're in the middle chamber to the far right. The Test Tube is no longer in there of course, this is an old pic from the summer. I keep the surface area clean as best as I can. Black patches of mold grow if food is left there. It scrapes off easily though. I don't think I'm damaging the plaster at all. I'm really surprised that that's the only place where mold is growing. The whole setup is basically a sponge and only the parts with open access to air are really growing. Plaster setups really only last 2 years anyhow and it will be easy enough to move the colony.