Rhododendron Ant Trap

The odorous house ant, Tapinoma sessile, is a noted nectar thief of assorted flowers. Often they'll steal the nectar to plants that have noted defenses against ants robbing he nectar. But this times it seems the odorous house ant has met its match.

Our native Flame Azalea, Rhododendron calendulaceum, has some very pretty yellow-orange and sometimes red flowers that are fragrant. Hummingbirds, butterflies and bumblebees are all occasional visitors to this plant. The dead ants and gnats attached to the flower stem entice Hummingbirds in for a different reason.

 Free Hummingbird Food

Early Ant Activity

2013 Best of Ants

Well it has been a bustling year this one. I've just realized I took a tone of photos this year, perhaps even more than on previous years. Part of the reason was that I went to three major events where I took lots of photos, and partly because I bought a new camera with a cool new snap on lens.

My anting year started with an unusually early war between two Tetramorium colonies. We had a warm spring and wet year so the ant activity was good this year.

Here is a colony of Camponotus castaneus which seems to have moved on to a new location. I'm not sure where or why but one day they were there and the next they vanished. They didn't reappear at all later in the year either so that's a shame. I really like this species.

The flowers in my meadow garden were the best they've been yet, and many of the species I've chosen secrete extra floral nectar. Here a Camponotus subbarbatus worker is nectar scraping. Basically they just run their mandibles along the surface of the bud to squeeze out what has to be only a surface thick layer of carbohydrates.

You have to wonder if the nectar is worth the effort but apparently after a few hours of doing this they've collected enough to fill their social stomach. Eventually one of the major workers of the colony would check in on them and trophallaxis ensued. Major workers can hold more food so they're used mostly as storage ants.

One of my rare plants, Purple Milkweed, Asclepias purpurascens, finally flowered this year... only to have it's nectar robbed by Odorous House Ants, Tapinoma sessile. This ant is hands down the most notorious nectar thief because this particular milkweed is covered in hairs along the stem which are supposed to secrete a sticky goo to stop ants dead in their tracks. No one told this species that because they robbed out all the flowers.

Testing out my new camera I got an image of what I think is Lasius claviger. The hairs on the gaster are randomly spaced out and not in rows the way they are with Lasius interjectus. 

 On the NJ Ant Together this year we found a few colonies of Northern Fungus Growing Ants, Trachymyrmex septentrionalis.

They weren't very active so next year I'll try and hit the location sooner. There were a few out digging though.

This was a test for me to realize just how varied one species can be. This is Formica pallidefulva which I have in my yard, but didn't recognize it here. I'm so used to them being a coppery brass color that it never occurred to me that there could be populations with such an abrupt color difference. I'm told they get even darker the farther north you go.

Their cousins live in considerably larger nests. Formic exsectoides for small super colonies in relatively well preserved woodland areas. I think the only thing preventing them from distributing farther is their appetite. In the short while we were there we watched them haul in caterpillars, cicadas, and wasps. 

Anywhere that you stepped on the ground, because our shoes disturbed the colony scent on the ground, the ants quickly swarmed the location. It didn't help that there were so many running along the ground that we couldn't help but step on them, thus releasing alarm pheromone.

Outside of their range there were a few foragers of Camponotus chromaiodes. Note the pubescence on the gaster as well as the dark shoulders (which is only consistent on the larger members of the colony). Formica forage during the day and the Camponotus take over at night.

Crematogaster cerasi tending some sort of aphid which had a liking to this Rudbeckia flower. This was the first year I'd ever noticed aphids on Rudbeckia that weren't bright red and on the stems. These were actually green and some seemed to latch onto the seeds or various nodes where they were being developed. The caterpillar here is some sort of inchworm or possibly a looper. These normally feed on the flowers to these plants but was cautious about approaching this flower.

The last thing of anting for the year was observing another one of my rare plants Gentiana catesbaei. Other members of this genus keep the flower tightly closed and it's only through bumblebees forcing their way inside that they get pollinated. This species oddly keeps the flower open and invites everything on in. This also includes the ants. In this case it's the tiny Nylanderia faisonensis though they didn't seem all that interested in it really.

More Ant Plant Relations

Ants marching around on plants is something of a common sight in my yard. 

Here a Camponotus nearcticus worker explores the leaves to a cup plant. Likely she's interested in small amounts of pollen or sweetness on the leaves or simply foraging for some insect or some other resource for the colony. Occasionally aphids will drip honeydew down onto lower leaves and it's this that ants go for, but that's not the case here. I've actually never found aphids on cup plants before. Cup Plants are related to Perennial Sunflowers which produce extra floral nectar so I suspect that might be what's going on.

I'd never found aphids on parsley before either but that's happened this year. Sometimes aphids don't afflict the same host plants each year or at least don't do so as badly as on previous years. The ants here are Tapinoma sessile which has become one of the most common ants in my yard. I believe my use of a green house to grow seedlings is the cause. Because their colonies move into the flats I effectively divide the colony every time I plant something in the yard.

Some insects only require the protection from ants during the early stages. Here is a bad photo of some Leaf Hoppers. The younger nymphs are tended by ants but older ones, who've gained their hood, "wings", and brighter color, tend away from this relation. They become fidgety and are quick to flee when predators approach, something aphids don't do.

In the absence of aphids ants and free sources of nectar, ants will out right steal it from flowers. Here a tiny Nylanderia faisonensis worker explores the fanged flowers of an Asclepias tuberosa plant. They're a rather small ant that's able to get into the deep crevices. 

Oddly enough the flowers of Swamp Milkweed, Asclepias incarnatta, are even smaller and I found them being robbed out by a much larger species of ant, Camponotus pennsylvanicus. I suspect the large mandibles of this carpenter ant aid in their ability to get at the nectar somehow but I haven't had the time to inspect the flowers for damage.

Purple Milkweed Flowers

Purple Milkweed, Asclepias purpurascens, has finally started flowering! I've been growing this plant for three years and finally it blooms! I initially bought three of them, of which only one survived. As it turns out this species is a little finicky to grow. This one is growing in partial sun/mostly shade in ....uhh average, leaning more toward damp, soil. I have tried to start this plant from seed, which germinated, and I then planted them all over, only to have them all die over the winter time. I don't know what it is about this one plant or this one spot but I'm happy it's thriving. That said, this milkweed species isn't self compatable, so it will never pollinate itself and won't produce seeds until I manage to get another one established and flowering. 

No sooner does it start blooming, that Odorous House Ants, Tapinoma sessile, start raiding the flowers for nectar. I've noted how this ant species seems to specialize in robbing nectar from flowers in the past, and I'm quite annoyed they've chosen this plant to steal from. The flowers to Purple Milkweed are actually larger than those of Asclepias tuberosa. I've never seen these ants going nuts like this over milkweed flowers. Usually it's just a few workers, but this plant at times had almost five ants per flower! It suggests to me that this species produces a higher quality of nectar more deserving of insects that may actually pollinate it.

Ants Swarming in My Green House

After all this rain we've been getting, I went out to the green house to find a nuptial flight of Odorous House Ants, Tapinoma sessile, trying to take off.

Queens are only a hair bigger than the workers. This ant is a minor annoyance in homes, despite being a native species. Colonies often have multiple queens, and divide as needed. It's been noted that colonies are enormous in urban settings, sometimes taking up several city blocks, while suburban and rural settings yield much smaller colonies, often only a few thousand ants.

Despite their name, Odorous House Ant, they are only odorous if squished, and can be discouraged out of homes simply by sealing up holes they happen to be coming in through. This is sometimes easier said than done. They're opportunistic nesting and find the hollow space behind a loose kitchen back splash very appealing. Resorting to baits might be called for if they're out staying their welcome. 

Out in the green house they nest right the flats to my plants as well as the loose space inside of pots along the outer edge of the soil. I'm certain I've divided this colony a few times simply by planting seedlings out in the garden.

I've also been noticing termite alates flying out and about in the yard. The Robins in particular are enjoying them.

1 Queen, 2 Queen, 3 Queen, 4

Colonies of Tapinoma sessile, Odorous House Ant, normally stay outside. They thrive in places where there's lots of grass, and debris laying around. I've also found then nesting in hollow cavities in logs, and mason bee tubes. They're opportunistic and will nest anywhere they can. The common name comes from their habit of nesting in homes. The odor only occurs from crushing them so it might be better to discourage them than to fight back. They don't do a whole lot of nest building so sealing up where they're coming in from is an easy option if applicable. The smell is nothing unbearable I'm told. 

Shortly after their mating season, April to June, (occasionally July), queen number for each colony jumps drastically. Presumably they are either inbreeding within the nest, or colonies generally accept queens they come across into the nest.  

This leads to a lot more queens suddenly appearing into the nest and fuels budding behavior. At some point in the year colonies will divide as needed to setup new nesting sites elsewhere. Once divided colonies typically don't want anything to do with one another. The more urban the location though, it seems the more connected these colonies remain and they end up getting much larger than they would out in a suburban or rural area. There's something about city life that encourages colonies to stay connected in a series of sub-colonies as opposed to setting up new ones. What's neat though is that individual queens are fully capable of starting a colony on their own.

This kind of variation within a single species I've learned is more common in ants than previously thought. I've seen this in Monomorium minimum, both queen inbreeding, and loan queen colony founding. The Red Imported Fire Ant, Solenopsis invicta, do this too. With fire ants it's more genetically divided. Monogynic (one queen) colonies produce monogynic colony founding queens while polygynic (more than one queen) reproduce by queen adoption and budding. What's really neat about fire ants is their reaction to water. When floods come, all the members of the colony form a living raft and float away, but while adrift there's nothing stopping two colonies from bumping into one another. Floating for survival is no time for war, so the two colonies may merge into one floating raft, and upon reaching land they remain as one colony regardless of mono or polygynic status before the flood. Perhaps this is how polygynic colonies got their start with this species.  

I've seen colonies of Temnothorax sometimes combine to better survive the winter. The following spring they disperse and go their separate ways, though it's unclear if the workers are pared with their genetic mother or just going with the flow. Camponotus pennsylvanicus colonies are strictly monogynic but they still produce sub-colonies as extensions of their nest and territory. Each autumn these satellite locations are abandoned to better overwinter in one location. 

Perhaps the most notorious ant to talk about queen number is the Argentine Ant, Linepithema humile. In North America at least, this species spreads exclusively by budding. Queens mate inside the nest causing their numbers to skyrocket at one time of the year. Workers in L. humile have very high standards when it comes to queens though and each year they kill off ~90% of their own queens. This massacre occurs at the same time of year each year. It would seem they don't like their queens to be more than a year old, perhaps to maintain queens at the peak of their egg laying capacity. 

Though the queens to polygynic colonies ultimately produce larger colonies, their monogynic counterparts typically live longer.

Some Aphid Guardians

Formica subsericea (I think) either knowing the answer to a question I asked it, or clearly marking it's territory. By which I mean glaring at the camera and chasing me farther away from the precious aphid herds.

Aphids and other dew producing insects are finally becoming abundant enough to catch the attention of ants far and wide. Though some species prefer to collect the nectar second hand as tiny droplets drip down onto lower leaves. 

This ant attention benefits the plant because the ants drive away insect herbivores. Some plants do this naturally by producing extra floral nectar, which also discourages the ants from stealing it from the flowers.

The downside for the plant is they can't control the number of aphids. This can be a real problem for the plant but typically it only inhibits the production of new growth and doesn't cause as much damage as a veracious horde of caterpillars. Some caterpillars can completely defoliate a host tree twice over in a year. So having some ants crawling all over to discourage or even remove the problem of caterpillars greatly benefits the plant.

A Lasius alienus tending some aphids on an Eastern Redbud.

Crematogaster cerasi blanketing over aphids on the stem to a Viburnum.

Crematogaster cerasi blanketing over aphids on the stem to a Viburnum.

Tapinoma sessile tending aphids on the stem to a Golden Alexander.

Tapinoma sessile tending aphids on the stem to a Golden Alexander.

Trillium Colors and Design

Trillium grandiflorum

In an earlier post I questioned when the peak bloom phase is for Trillium grandiflorum. I said it's a choice between all the flowers being white, or when they fade to purple. What I didn't consider is the line in between.

Trillium grandiflorum

Trillium grandiflorum

There's something to be said for when both are seen next to one another. I think the vibrancy of the younger whites is exemplified by the contrasting older pink, magentas, and purples.

 

Trillium luteum

Trillium luteum

Trillium luteum is another species I have in abundance blooming now. The flower doesn't make any dramatic color change other than to grow even more yellow and less green.

A Tapinoma sessile and Nylanderia flavipes foraging on a Trillium simile flower.

Later in the year the Trilliums will be going to seed and I'll be relishing the ant elaiosome action their seeds attract. For now though the Trilliums offer another dimension to the forest floor for ants to scout  and occasionally steal a taste of nectar. 

Temnothorax species walking on Trillium luteum leaf.

Temnothorax species exiting Trillium grandiflorum flower.

Ant Chat Episode 27: Ants and Wildflowers

A pairing of spring wildflowers and the ants I find around them. Even before planting all these wildflowers I already had a lot of ant diversity. So with this video I'm basically documenting the wildflowers I've planted around certain ant colonies and in the future I'll be noting any interest if at all.

I also open up one of my honey bee hives that didn't survive the winter and see what's lurking about. I am certain they died of starvation and not CCD.

Some Ant Flight Activity

Earlier this week a colony of Odorous House Ants, Tapinoma sessile, attempted conducting a nuptial flight inside my house. They failed miserably and I was greeted by the occasional alate (winged ant) every few minutes. They climbed up from wherever the colony is and made their way across the computer table to the window and eventually found freedom. Clearly anting season is here, which begs the question, what else is flying?

First incredibly hot night of the year that lacked any wind or in coming cold fronts treated me to a full pallet of what's flying now. The main ant for my area is Camponotus castaneus, pictured above and previously here on the blog. Males are hard to identify but I'm reasonably sure C. castaneus is the only one (for my area) that has orange males. This is uncommon for ants across the board. Usually male ants are black regardless of the species color. There were other Camponotus males there that were black but without knowing what the queen or workers look like an ID can't really be made. At least not by me. There is also a Lasius species that seems to over winter it's alates, instead of flying in the fall like most of the other species.

This is an awful picture of male Tetramorium males. They're suspended in a spider web which is a good way to see what was flying the night before.

That night I found a Tetramorium queen, Pavement Ant. These didn't fly until midnight.

So there's a full succession of flights based on the hour of the day. Early on Nylanderia, Tapinoma, and I've found a few Myrmica (with wings) this early in the year before. As the afternoon comes and night falls Camponotus, and Lasius seem to fly next. And very late at night and probably well into the morning Tetramorium fly.

You could argue there's to much to do in the day for someone interested in ants. Thankfully I've found there is roughly a 24 hour period after a flight that queens seem to be abundant and about. Making a habit of checking under the same rocks, logs, flower pots, etc... can yield results.

Passion Flowers

Passionflowers are the more complex looking Clematis vine of choice. Unlike Clematis, these can go on to produce Passion Fruit. The trouble is where am Passionflowers are annuals. I tried getting our native Passiflora incarnata, Maypop, established last year but it died. Some plants are self incomparable and have to pollinate with another passionflower, though it can be any variety even a clone of the same plant. Other plants are self compatable. I don't know which needs which, that's why I bought two.

Looks like it's 6 ants past the hour. Passionflowers in all their complexity try to be ant proof by coating the back of their flowers with sticky goo. Clearly it doesn't work for all ants, and twining vines tend to accidentally tough their own flowers essentially building a bridge for the ants to get across.

They go for the nectar and small amounts of extra floral sap laying around.

The culprit here is Tapinoma sessile, the odorous house ant. I have to say I see this ant on more flowers that are supposidly protected against ants more than any other. They're clearly skilled at getting around little hazards in the name of food.