Saturday, June 6, 2015

New Jersey Tea: Honeybees, and Holly Blues

Years ago I planted a New Jersey Tea sapling, Ceanothus americanus. It's such a shame most of the mail order nurseries sell this shrub as a 4inch plug. It would really be nice to get it as a quart or gallon size pot instead of treating this like something you'd install in a meadow garden, to be mowed or burned at a later date. NJ Tea is a nice little shrub with a 2' to 3' round habit. It's touted as a hummingbird plant, not because of the flowers, but because of the droves of tiny insects that come to pollinate it. When flowering, these plants are absolutely swarming with little bees and solitary hunting wasps that are overall beneficial to have in the garden. Sadly, despite distribution charts showing how common this species is all across the eastern US, it's in something of a dramatic decline and becoming very hard to find in the wild. 

Part of the problem was that farmers used to believe this plant was a sign of good soil and bulldozed whatever habitats it grew in for farm land. Where it still grows today, it's easily shaded out by tall perennials and encroaching forest land.

What makes it worth blogging about today for me is the fact that my honeybees started working it. This is odd because I almost never see honeybees bothering with plants who's flower shape and nectar is gear more towards wasps and smaller bees (as seen above).

Most of the flowers aren't open yet so it's not bustling with swarms of other pollinators just yet, (and I've never seen a hummingbird go near the thing,) so I'll see if this wasn't just a curious couple of foragers or if the honeybees really do want to work this plant.

Honeybees working a native plant isn't always a good thing for nature. Many conservationist view this as stealing food from the native bees. I'm not sure of any specialists pollinators of this plant though.

Western Ceanothus species and their bright blue flowers tend to get a lot more honeybee attention so I guess this isn't entirely unexpected. Sadly I don't know of any western Ceanothus that's hardy in New Jersey or I'd have tried growing it by now.

Also while photographing the honeybees I noticed what I believe to be a Holly Blue butterfly, and she was laying eggs!

Blue's and Azures are neat butterflies because the caterpillars have special relationships with ants. A failing of most butterfly species is they fall prey to ants all too often. They'll strip the eggs right off the host plant before they hatch, young instars which haven't developed a defense strategy or adaptation yet are an easy meal. I've seen whole clutches of hatching giant silk moth caterpillars get chewed up into a gooey pulp by a single carpenter ant which then carried the mess of caterpillar goo back to the nest. 

This genus (family?) has a different strategy though. For starters they lay their eggs among the unopened blooms on the plant, which is good enough camouflage. Early instars need to eat a little but quickly start to secrete a sugary substance to feed the ants. The caterpillar also "sings" to the ants, making sounds and vibrations like a queen ant might produce. The ants will hang around the caterpillar as it feeds and helps protect it against other predators. Some species will actually overwinter inside ant's nest, either mimicking the larva or a queen ant, which then pupates over the winter and emerges from the colony next spring. 

It's a complex life style for sure. I theorize that not all species of ants are ideal to overwinter inside of. Some of the species that are more finicky about their host plants are uncommon or endangered, such as the Karner Blue Butterfly, which only lays eggs on Lupinus perennis.

So if I get a chance to I'll try and photograph the caterpillars, ideally with ants tending them but I can't promise anything. The eggs she laid were almost microscopic and the caterpillars are absurdly small. Also later instars might prefer consuming ant eggs once they're inside a nest so I may have to setup a fragment colony.

Keeping an eye out for chewed up foliage can help home in on where the caterpillars are. Though finding a Katydid nymph on the plant suggests that might not be the best strategy. I'm tempted to go out and snip off a few flower heads where I know eggs were laid and put them in the outdoor butterfly cage to raise myself. I've never kept a species so small though.  

Sunday, May 24, 2015

Some Early Myrmecochory Action

I so rarely get to see my specimens of Twinleaf, Jeffersonia diphylla, all flowering at once, let alone be pollinated by one another to see the seedpods. Normally the pods don't grow bigger than a nickle and shrivel up with nonviable seed inside. Today though I came across a fairly large seedpod. I reached down to see if it was soft enough to harvest and the darn thing broke right off the stem on me. Worst of all, the seeds weren't ready yet.... Waste not, want not.

Twinleaf disperses its seeds with aid of ants. Normally the seeds are rock hard and brown very much like unpopped popcorn. These had their little bit of elaiosome formed but the seeds were soft and green, like peas or green beans. The ants didn't seem to mind this and carried them off all the same. 

The elaiosome is what's treasured by the ants but with the seeds still soft it's likely they'll be eaten too. This is just as well though. I doubt they would have grown in this early state anyway. 

The ants here are Aphaenogaster rudis, which is actually a complex of several species. DNA analysis to count the number of chromosomes is required for a true species ID but overall they're the same. The species names are more or less scientific codes instead of Latin names, so the blanket term A. rudis works fine. They're all commonly found in woodlands across North America, they all nesting in soil and sometimes rotten wood in contact to the soil. They all form colonies with populations ranging from 2,000 - 12,000 ants. Nests are small and move around on occasion, making them ideal seed dispersers, along with their size.

Ideally the seeds would be rock hard and either discarded in the nest, or hauled out to the waste or midden pile where it would be buried in dead insects and other discarded seed husks anyway. Often plant seeds like this require two winters to germinate, where it's more likely the colony of ants has moved on, and or the garbage heap has decomposed into plant fertilizer. Some plants such as Trilliums emit a terrible odor when they germinate which likely helps encourage the ant colony to move along. 

The ants find nourishment everywhere they can, even among the seedpod itself. If the ants didn't come along to clean out the seeds, rodents, birds, and wasps would have. Rodents and birds love eating the seeds. Wasps go for the elaiosome just like the ants, but are unlikely candidates for seed dispersal. They may drop them on the surface for birds and rodents to find, or bury them too deep within the earth, or the seed could end up within the dead branch of a tree.

One plant that was right on time was the Woodland Poppy, Stylophorum diphyllum. The same idea of seed dispersal applies, however I can't get it out of my head how much the elaiosome to this plant resembles ant brood. It just looks like clusters of eggs and larva, which ants are more than happy to eat, especially if it doesn't belong to them.

The seeds, being ripe, are rock hard and firmly attached to the elaiosome packet. I have trouble removing it and I'm a human! It's unlikely the ants will be able to chew them into dust or "ant bread" so they'll be discarded within the nest and in a few years I'll likely have a patch of woodland poppy growing here.

Where this strategy of seed dispersal can go wrong though is when the wrong sort of ant finds the seed. This is an Acorn Ant known as Temnothorax curvispinosus. They're adorably tiny, with small colonies of ~200 workers that all fit right inside a hollow acorn, hollow plant stems, or dead plant matter. Not only do they nest in the wrong sort medium for starting seeds, but also the workers are too small to carry the seeds off. They're more likely to just recruit more workers from the colony and deal with the elaiosome where they found it, and the seed is simply left where it was beneath the parent plant. 

As a disclaimer I will admit all of these photos were staged to a point. You'll notice I just opened the seedpods and spilled them on a stepping stone where an Aphaenogaster rudis colony happens to nest. I just don't have the time to wait for this to happen naturally in my yard, but trust me it does. There are plenty of Woodland Poppy plants with open seedpods on them right now that have spilled their seeds in the garden. I typically find Tapinoma sessile and Crematogaster cerasi stealing the elaiosome from the seeds where they fell and don't disperse them. The occasional Aphaenogaster forager does find a few though and bring them back to the colony. Since they've been self seeding in my yard for the past three years now I've been finding Woodland Poppies coming up in places where ant colonies tend to nest, and or have been dragged away from the parent plant a short ways at least. Sometimes the ant carrying the seed home gives up or gets disturbed by a spider or something. 

Turkey Corn, Dicentra eximia, will likely be the next plant who's seeds do this to ripen in my garden... sadly I missed my chance with Hepatica this year, but they seem okay about germinating where they fall anyhow. So though a plant uses this strategy to disperse its seeds, it's not always required for success, simply a way to give them a leg up.

Waterleaf Plants

Phacelia has been a genus I've become more and more interested in with each passing year. The issue is most members of the genus I'd like to grow are not commercially available as I'd like to buy them. Most are annuals or biannuals making seeds ideal, so why is it that all the biannuals are sold already germinated and flowering as though they were annuals. The stress of getting planted out of a pot makes them suddenly invest in making roots when they should be pumping out seeds to no end. As a filler though I've been coming to like Waterleaf more and more. 

They're generally easy to grow from seed in places lacking competition. They like moist soil and tolerate average soil with a little watering. It's harder to get them to self seed in dry places but it can be done. Shade to Part Shade is ideal, too much sun you'll have to water them almost daily. Rabbits, and one imagines deer too, like to eat them but in a diverse landscape their tastes venture from plant to plant. 

Virginia Waterleaf, Hydrophyllum virginianum, was the first species I've grown. Each plant is only a couple of stems making them somewhat thin and scraggly. They've been described as aggressive spreading which I agree with but only from their constant habit of self seeding all in one place. Droves of new plants come up in one huge clump from where the flower head laid. They're supposed to spread underground too by an expanding rhizome but I've found seed spreading to be far more aggressive. 

The rabbits did eat a few of my plants, but they only nibbled the leaves off, leaving the flowers in tact. New leaves grew back in a few weeks. This didn't interrupt flowering at all but they did look funny as just some stems with flowers on them. Bumblebees mostly go to them but there's also an Andrenid bee that's a specialized pollinator of Waterleaf plants, Andrena geranii. Though to be fair you'll also find that bee working Roses, Anemone, Raspberries, Geranium, Campanula and the occasional Violet.

By comparison Great Waterleaf, Hydrophyllum appendiculatum, is a robust flowering specimen that's full of foliage. The stems branch out making a single plant fuller looking almost like a small shrub.

This plant also goes by the name Broad-leaf Waterleaf becuase the leaves superficially resemble those of an oak or maple tree. However they're actually much much smaller than the leaves of any tree. An exception to this might be the early rosette of leaves that forms in late winter, which is absolutely spotted with little water stains members of this genus get their name from. New leaves formed in the spring and summer are lacking this trait and completely cover up the initial rosette.

I hadn't realized I'd already planted this species from a previous year, and some Phacelia spp. also have the waterleaf stains on early leaves. It's so easy to forget what's growing when you just throw out hand fulls of seeds mixed with dirt. So I already had a plant of this growing when I ordered more seeds to plant this spring.  

This is what the two year specimen looks like having expanded from the rosette to flower. Most of the seedlings I tossed around didn't produce much more than just a leaf, however one of these first year plants has gotten a little bold and is flowering at only 6" tall. 

My one regret with this species is not having planted it someplace where it would have more room. There's a few Indian Pinks, Stone crop, a patch of yellow Trilliums, Hepatica, and a Bleeding Heart growing there somewhere. And it's just shy of being as tall as the Rhododendron growing behind it. This is the perfect little perennial to put right up against a tree.

Great Waterleaf, along with having nicer flowers, also blooms longer than Virginia Waterleaf. Neither are a huge hit with pollinators but watch a plant long enough and bumblebees always seem to eventually show up. I'm not growing it in as grand a number to get honeybee attention but that should change in a few years.

Dissecting Ants (Video)

Some Black Cherry Diversity

A year or two ago I planted a Black Cherry tree, Prunus serotina. It has yet to flower and is only 5' tall but already it's attracting quite a bit of life.

I've actually read that these trees tend to be more popular with "pests" at this sage because trees of this size tend to be newer, representing the forest edge as it advances into meadow land. The lack of flowers means a lack of berries which are relished by birds. Adult trees of a flowering age get more bird attention because of the berries which perhaps makes young trees more tempting to certain bug species.

Another thought though is this might all be subjective observation. Younger trees still have their lower branches in tact and older trees form most of the new growth at the top, well out of view from the average person. Since caterpillars tend to target young growth more it could just be that we're not seeing it because it's up so high.

Sadly I'm not sure what species this is. There are so many green caterpillars to choose from but tentatively I'm calling this a Distinct Quaker, Achatia distincta. But it might also be a young instar to a Copper Underwing.

Some sort of leaf miner has infested a leaf or two. Without the sun back lighting this leaf it really just looks like the leaf dried out.

Here's another caterpillar that's not quite far enough along for me to ID. Looks kind of worm-ish so and I'm sure that stripe under the body is telling especially with the color but I just don't have the time to figure out what later instars will be.

There's a few scale insects on the stems too. These are attracting in ants which are probably why I'm not finding more caterpillars on it.