my new sworn enemy: the brown marmorated stink bug

So I was down in North Carolina earlier this week to do some preliminary work on my thesis, mostly at the JC Raulston Arboretum at NC State University, but also at the North Carolina Botanical Gardens in Chapel Hill. Great trip overall, I'm tempted to move down there. I have roughly 200 or so photos I still need to go through before figuring out what I want to blog about next. Though there is still plenty to do on Magnolias, I have a few great Redbud photos I'd like to show you (also might mention Sinojackia, which is closer to the kinds of plants I actually went down there to look at). For now though, I'm going to take a brief break from plants to talk about a creature which has plagued my existence since I moved here: The Brown Marmorated Stinkbug.

Brown Marmorated Stink Bug (Halyomorpha halys)

I've never taken an Entomology course and all I have for an insect reference is a butterfly field guide which is not particularly relevant, so based on my Wikipedia research, I understand that the Stinkbugs comprise family Pentatomidae, all sharing a common "shield-shaped" body structure and tendency to emit a foul odor when disturbed. The Brown Marmorated Stink Bug is an Asian species that hitchhiked into our country sometime in the mid-nineties, and seems to particularly enjoy the Mid-Atlantic regions where it is predominately observed.

Growing up in New England I was vaguely aware of what a stinkbug was... I thought of them as being green in color (probably thinking of a different species) and was under the impression killing them would result in the release of a foul odor. I'm not sure if I ever actually saw one though. I would however, become intimately acquainted with them as soon as I entered Delaware. When I first visited the state last year, there were a few of them wandering around the house I was staying in, so I essentially was in Delaware for a mere four hours before encountering the ubiquitous pest. I actually found one in my truck during my drive back to Boston. Thankfully it was dead, so I won't be credited with introducing the species to New England.

When I first moved here, I remember seeing a few of them, as well as a few spiders, crawling along my bedroom walls. I figured the spiders were keeping them in check so I didn't do much about it. A few stinkbugs were no big deal. As long as they kept their numbers small, their noise levels down, and stayed off of me and out of my bed, I could handle it.

This all worked out fine until one fall day. I was studying for my first Biochemistry exam, and while in a state of panic trying to wrap my mind around kinetics and first order rate constants, noticed that the Stinkbug population in my bedroom had increased by a factor of ten. They were swarming all over both of my windows, making their way in through the cracks and rapidly establishing themselves on my walls, bed, and orchids.

Apparently this swarming effect is a result of an aggregation chemical they release. There was about to be a stinkbug party in my room, and they were apparently texting all their friends.

This still wasn't enough to make me stop studying, as I was pretty stressed out for the test, though I had noted that I would probably need to do something about this shortly. The threshold was not crossed until a bunch of them got a bit belligerent and decided where they really wanted to be was in the lamp at the other side of the room. Now if you haven't heard these things when they fly, they make a racket: particularly when they are all flying around in the same place. That was the breaking point. I threw my book down, and carried and probably close to forty of them into the bathroom where they were deposited into and flushed down the toilet. I got a B+ on the test, and had no more significant problems with Stinkbugs for the next six months.

Now with the spring temperatures, they've become a bit more active again. I should have probably taken the fact that one of them made some kind of bizarre kamikaze attack at me last month (charging into my face from the other side of the room) as a sign that the war was back on. I thought the truce was still good. But they crossed the line again this week. After getting back from North Carolina, I was just falling asleep and rolled over a bit, thinking I felt something on my cheek but thinking nothing of it. I soon heard this weird buzz, characteristic of a stinkbug trying to fly, and then was next greeted by a the foul cilantro-like odor. Stinkbug blasted me in the face at point-blank range. The essence was still with me for a good few hours the next morning. This was obviously not appreciated by me, and I have now issued a personal "exterminate on sight" order.

Apparently the stinkbug is considered more of an agricultural pest than a residential pest in the state, though I certainly find them an annoyance, and hope to make the species realize that the foul odor they release when being disturbed is nothing near as severe as what happens when they disturb me.


Though I guess it could have been worse. Could have been Delaware's new invasive pest. the Nutria.

Actually I really wish I hadn't thought of that. Now I'm haunted by the idea of rolling over during the night to find my face up against a wet 2' long rat. Luckily they're still only in Southern Delaware... i think...

Magnolia kobus, stellata, and x loebneri (with a little bit about hybrid naming)

In my last post about the Saucer Magnolia, I mentioned there was another popular magnolia also blooming now: the Star Magnolia or Magnolia stellata. It's very closely related to the Kobus Magnolia (Magnolia kobus), to the point where some taxonomists consider it the Star Magnolia to be a variety of it (Magnolia kobus var. stellata). There is also a hybrid of the Kobus and Star Magnolia, the Loebner Magnolia, Magnolia x loebneri.

Magnolia x loebneri 'Merril'

As I mentioned last time, the Saucer Magnolia (Magnolia x soulangeana) is a hybrid of two asian Magnolias: The combination of the Yulan Magnolia (Magnolia denudata) as the seed parent, and the Lily Magnolia (Magnolia liliiflora) as the pollen parent. So where does the "x soulangeana" part of the name come from? Some hybrids, particularly those which are either naturally occurring or common in the trade with many named cultivars, will be formally named and described by botanists. This allows the Saucer Magnolia to have a slightly less complicated botanic name, as were it not described, the plant would be referred to by using a hybrid formula (Magnolia denudata x liliiflora), which gets to be a bit unwieldy.

Rarely, you might actually see described intergeneric hybrids (pollen and seed plants of two different genera), such as x Sorbaronia alpina, a hybrid between Sorbus aria (Whitebeam) and Aronia arbutifolia (Red Chokecherry).  In this case, since the hybrid is between two species of two different genera as opposed to between two species of the same genus, the "X" proceeds the name of the genus, which in this case is an amalgam of its two parent genera.

A graft where the stem (above) is noticeable outgrowing the
rootstock (below). From Wikipedia's article on Grafting. 

Even more rarely, you might see a name resembling the above, but proceed by a "+", as in +Crataegomespilus. This indicates a graft chimera between Crataegus (Hawthorn) and Mespilus (Medlar). Graft chimeras are weird, there's no way around it, and two my knowledge there are only a scant few known to exist.
For those who may be unaware, grafting is basically when you take the stem of one plant, and attach it to the rootstock of another plant. This is commonly done with fruit trees: you don't necessarily want to let your apple trees get up to 40 feet tall since that makes it a lot harder to harvest the fruit. By taking the stem of the apple tree you like the fruit of and grafting it to the rootstock of a smaller growing apple tree, you can control the adult height of the plant. I unfortunately don't have any of my own photos of the process to share, but there are many available at Wikipedia's article on Grafting.
The graft in the photo above is quite clean, but in many cases the rootstock may send up stems of its own as well.

A graft chimera is when the resulting grafted plant has three distinct types of shoots or stems: shoots of the grafted stem, shoots of the rootstock, and shoots which oddly enough have characteristics of both of the plants. These are quite rare, and you're unlikely to come across them, but I think its an interesting example of some of the odd things that plants can do.

Moving back to Magnolias, we'll start out with a straight species...

Kobus Magnolia (Magnolia kobus)

An old, now deceased Kobus Magnolia at the Arnold Arboretum

I've seen the Kobus Magnolia quite frequently in Botanic Gardens, but less frequently in the residential landscape. I suspect it's displaced in the trade by the Star and Loebner Magnolias, as those tend to flower a bit more heavily as well as at a younger age. I find the flowers of the Kobus Magnolia to be a bit larger in general however.

The species is native to Japan mostly, though is also found in South Korea. The name "Kobus" is apparently dervied from the Japanese common name for the species, Kobushi. I have no idea what kobushi means.

Embarrassingly enough, I don't currently have a picture of the Magnolia stellata (Star Magnolia), though I did heavily photograph the one at the Rose Kennedy Greenway during my two years there. Here's a link to a 4/25/11 article I wrote on the species while working there, which includes a good photograph of the plant framed by One International Place in the background.

The Star Magnolia is actually fairly rare in the wild, currently found only in Honshu, Japan. It has long been in cultivation however, with many popular cultivars such as 'Centennial', ' Royal Star', and 'Waterlily'. The name stellata refers to the shape of the flowers, which resemble stars.

Magnolia x loebneri 'Leonard Messel'

The Loebner Magnolia (Magnolia x loebneri or Magnolia kobus var. loebneri) is a hybrid of the Star and Kobus Magnolias. Like the Saucer Magnolia, its not a natural hybrid, as the native ranges of these two species (or varieties) don't overlap, so they were never really introduced to each other without human help. The hybrid is named for a german breeder, M. Loebner, who made the first hybrids and introduced the species into cultivation.

Magnolia x loebneri 'Ballerina' 

Still cultivated today, It seems to be about as popular as the Star Magnolia, though it has its own niche in the landscape as it tends to grow about 10' higher, owing to its heritage from the Kobus Magnolia. Fortunately, it still flowers at quite a young age/

There are quite a few popular cultivars of the Loebner Magnolia, 'Leonard Messel' (Pictured above) is arguably the most so, owning to its distinct flowers which have petals (well, we should probably use the term "tepals", but more on that later) that are pink on the outside and white on the inside.

'Merril', also pictured above, tends to flower at a younger age than other Loebner Magnolias and is also quite a popular cultivar.

Though I photographed entirely white cultivars save for 'Leonard Messel', pink is not an uncommon color for this species, and many cultivars will have at least some pink, and sometimes flowers which are pink when first emerging from the bud but mature to white. I'm not sure I've ever seen a cultivar with a pure pink flower though.

Magnolia x loebneri 'Ballerina' 

I haven't seen 'Ballerina' quite as much as the other two, but it's a bit smaller than 'Merril', and as is evident by comparing the two photos, it has far more petals (...or tepals) per flower. I'm honestly not quite sure which of the two I prefer... is more petals preferable or does it just make the flower look more crowded? Maybe I'm just waiting for a Star Magnolia that really wows me and I haven't come across one yet. These are probably my least favorite of the spring-flowering magnolias... I prefer the rarer Magnolia salicifolia to it as they seem to flower for a bit longer, albiet never explode into bloom quite as much as the Star and Loebner Magnolias. However, I still enjoy watching the Star Magnolias come into bloom this time of year, and they are probably the first spring-flowering tree I get excited about.

Still have a few more magnolias to talk about, and at some point I'll go into the characteristics of the Magnolia Family (as well as this mysterious "tepal" term I kept trying to drop).

Saucer Magnolias in march

Saucer Magnolia (Magnolia x soulangeana) outside of
Worrilow Hall at the University of Delaware

In the month when we would generally be expecting to see snowdrops and the earliest few daffodils flowering, we're instead greeted by cherries and magnolias in full bloom. The whole situation has me feeling a bit uneasy... maybe it's just that I grew up in New England, but I'm still fearing a late frost or snowstorm will decimate this premature spring landscape. A quick look at the extended forecast however shows no such thing, so maybe we're safe.
Were I still a full-time horticulturist, I'm sure I'd be feeling a further sense of panic as my busy season would be starting up far before I had planned, but now as a full-time student, maybe I can afford to take a relatively worry-free approach to the early arrival of the spring flora, and in particular my personal favorite, the magnolias.

My interest in the genus began the first time I saw Magnolia macrophylla, a native summer-flowering species I'll discuss on this blog a bit later. I didn't pay as much attention to the spring flowering species until doing a year-round internship at the Polly Hill Arboretum, where one of my projects involved recording the flowering status of the magnolia collection on a weekly basis.




I was surprised to see the Magnolias burst into full flower so quickly this year, as I usually notice a solid gap between the time when the Star Magnolias (Magnolia stellata) start, and when the Saucer Magnolias join them. Though Magnolia biondii entered bloom about when expected, I recall seeing a few Star Magnolias breaking bud, then when I checked again a few days later a good half of the UD Magnolia collection was approaching full bloom.
Though I certainly enjoy the Star Magnolias, I find their flowers a bit flimsy in comparison to those species flowering later in the season, with the Saucer Magnolia one of the first to begin the trend. Maybe it's the size of the flowers (sometimes reaching 10" in diameter), or the way the thickness of the petals give the flower a more "solid" appearance than much of what else is in bloom this time of year.

The Saucer Magnolia is actually a hybrid between two asian species, the Yulan Magnolia (Magnolia denudata) and the Lily Magnolia (Magnolia liliiflora). The Yulan Magnolia was long cultivated in asia for its pure white flowers, and the Lily Magnolia is a shrubbier species with pink flowers. The offspring has found a home in our landscape, as is probably one of the two more commonly planted and easily recognizable of the spring-flowering Magnolias (the other being the Star Magnolia).

Magnolia x soulangeana 'Sundew'

All the above images are of the standard hybrid, but I also witnessed the cultivar 'Sundew', which based on what I just read at the Magnolia Society's Cultivar Checklist, is an older cultivar which may possibly have some relationship to Magnolia cambellii. It also appears to be somewhat uncommon, or at least I would assume so based on it's notable absence from Dirr's Manual of Woody Landscape Plants and Callaway's The World of Magnolias.

Though Saucer Magnolias often struggle in less mild springs, with an early warm snap followed by a late frost almost certain to kill off the emerging flowers, when it does flower successfully, I find its firm, upright flowers a sign that spring has arrived, albeit surprisingly early in this case.

Took many pictures of magnolias on Saturday (with many more to come next week) so probably plenty more magnolia posts to come over the next few days. Next time I'll probably talk about Magnolia kobus and Magnolia x loebneri. Until then there's always plenty about Magnolias on the Magnolia Society's facebook page.

A few native pines

Though spring is rapidly approaching, with snowdrops and some of the earliest daffodils and crocuses already appearing (as well as flowering cherries and magnolias in some places), the canopy still looks noticeable sparse as our deciduous trees have yet to show signs of leafing out, the only green up high provided by either broadleaf evergreens such as the American Holly (Ilex opaca), or the needles of conifers such as the pines.

The evergreen nature, as well as their distinct needles make members of the Pine Family (Pinaceae) one of the easiest groups of trees for the less botanically inclined to identify: Pines have needles, other trees have leaves. The strength of this distinction holds well in plant taxonomy, as it is actually made at the phylum (or division) level, which as you remember is the second category after kingdom: this is indicative of the fact that Conifers and deciduous trees took a different evolutionary path quite a long time ago, with deciduous trees and other flowering plants or angiosperms branching off from the conifers sometime in the Cretaceous Period 65,000,000 to 145,000,000 years ago.

Regardless, needles are considered to be the leaves of the pine: they photosynthesize and have similar anatomy, they're simply round instead of flat, and have a tendency to stay on the tree for more than one year (2-5 is probably a good range). They also usually have a thick waxy cuticle that leaves of most deciduous trees lack.

Pines are distinguished from their relatives such as Spruces, Firs, and Hemlocks in that they have needles borne on the stem of a plant in groups of two or more in a structure called a fascicle, as opposed to being borne singly.

Small grove of Eastern White Pines (Pinus strobus) at the University of Delaware

Cone of Pinus strobus

The Eastern White Pine (Pinus strobus) can easily be distinguished from the other pines listed here as they have five needles per fascicle as opposed to two or three. The needles are also a good deal thinner, less prickly to the touch, and give the tree in general a much softer appearance, even when viewed from a distance. The tree usually reaches a height of 50-80 feet in height, and can also grow quite quickly, sometimes upwards of two feet a year. It is unfortunately very intolerant of pollution, making it quite difficult to grow in urban settings.

Pinus palustris (Longelaf Pine)

Longleaf Pine (Pinus palustris) is a more southern species, and quite easily identifiable due to the sheer length of its needles: they can approach upwards of a foot. There are some other pines which get as long or even longer, but in tropical, not temperate areas. The terminal bud on the stem is also a good ID characteristic, being large and white, though probably unnecessary given how distinct the leaves are.

The growth habit of Longleaf Pine is also somewhat interesting: for the first seven years of its life, it looks more or less like a grass, barely reaching a foot in height. It is however in the process of developing a root system, and once established, it rapidly increases in height, usually getting to about 60' but in some cases well over 100'. This growth habit actually makes the Longleaf Pine an undesirable plant for foresters, as the amount of time it spends in the "grass stage" makes it rather economically nonviable in terms of wood production.

Close up of the needles of Pinus palustris. Almost wish I had my hand in the frame for size comparison, but regardless, you'll know this species when you see it.

And in colder weather...

The next three pines are a bit less distinct: Pitch Pine (Pinus rigida), Pond Pine (Pinus serotina), and Loblolly Pine (Pinus taeda) all have either two or three needles per fascicle (usually three).  If you're in New England however, you're unlikely to see the latter two species as they don't really start appearing in the wild until you get to New Jersey and points south.

A young Pitch Pine (Pinus rigida) at my parents' house in West Tisbury, MA

Pinus rigida as a bonsai, seen
at the Philadelphia Flower Show

Pitch Pine (Pinus rigida) was one of the first trees I learned how to identify. When at summer camp one year (I cant remember if it or Sassafras came first), I remember the counselor talking about the three needles per bundle (I doubt the term "fascicle" was used), saying we could remember that since in baseball they throw pitches, and three strikes is an out. The only other pines I remember seeing on the Vineyard were Red Pine (Pinus resinosa) which only has two needles per fascicle, and Eastern White Pine (Pinus strobus), which as we already know has five, though maybe there were a few other two-needle pines as well. I'll have to ask about it next time I'm down there (well, actually "up" there now that I've moved to Delaware).

Pitch Pine is quite ubiquitous on the vineyard, especially around my parents house right now as most of the oaks have died following repeated attacks by the Forest Tent Caterpillar. opw the Pitch Pines have the sun they need and are rapidly taking over the property. I'm all for it personally but haven't been able to convince my dad to let them live: they're one of his most hated trees, and probably justifiably so as I seem to recall him needing to cut a rather mature specimen down right next to the house which had its own established Yellow Jacket population associated with it. Still, though the species is probably not the most ornamental of pines, it does do quite well in poor soils so it at leasts has its place in the wild.

Loblolly Pine (Pinus taeda)

Loblolly Pine (Pinus taeda) resembles Pitch Pine to a certain extent, though it does have a tendency to get a bit taller (upwards of 90' where Pitch Pine usually, but not always, maxes out around 60'), and as noted about Loblolly Pine isn't generally found in the wild up north. Most notably however, the needles of Loblolly Pine are a bit longer: between 6-10" as opposed to Pitch Pine's 3-5".

What Loblolly Pine really resembles, in both range and needle length is Pond Pine (Pinus serotina). There are two easy ways to tell them apart however. First, the cones of Loblolly Pine are quite a bit longer and more extended. Since cones are not always present however, you can also look at the terminal bud on the stem. In Pond Pine, the bud will be white and covered in resin, whereas in Loblolly Pine, it is not and is red in color.

The word "Loblolly", according to dictionary.com anyway, apparently refers to a mud pit with the consistency of porridge. Who knew?

Shorter and rounder cones of Pond Pine (Pinus serotina)

Longer cones of Loblolly Pine (Pinus taeda)

White, resin covered bud of Pond Pine (Pinus serotina)

Redder terminal bud of Loblolly Pine (Pinus taeda), you want to look at the structure on
the end of the stem: try not to be distracted by the developing male cones underneath.

Pond Pine (Pinus serotina)

Not much more to say about Pond Pine (Pinus serotina). It's a close relative of Pitch Pine with a more southern range. It also tends to inhabit a wetter habitat, as it's common name would suggest, generally found in areas with wet, poorly drained soils. Such as in the proximity of pines.

Out of the five pines discussed here, only one of them, Eastern White Pine, is really popular as a landscape plant. Though Pitch, Pond, and Loblolly Pine probably aren't the most ornamental and interesting of trees, I find it surprising that Longleaf Pine isn't more popular due to the needle length. I suspect that the same production issues which bar it from use in timber production may be to blame, with nurserymen perhaps unwilling to dedicate greenhouse space to a plant which won't be of a decent size until almost seven years. Still, I think it's a neat pine I'll be keeping an eye out for in the future.


Not really sure what to talk about next... waiting on some of the Maple and Oak ID posts until I can get some leaf photos. I want to talk a little bit about algae but need to read up on that first, but I do have a few photos of trees with interesting bark it might be fun to discuss as well...

The Jungle: Orchids and their velamen

Wall of Orchids at Longwood Gardens, displaying some of the diversity

The orchid family is one of the most diverse groups of flowering plants, essentially in a tie for first with the asters. They can roughly be split into two groups based on their growth habit: the terrestrial, or those that live in the ground, and the epiphytic: those that live aerially, often planting themselves in the crotches of branches of canopy trees within the jungle.

Paphiopedilum, a terrestrial orchid

The Jungle was the second biome featured in the Living Planet, and one I found particularly interesting as it depicts a compound ecosystem consisting of three distinct "stacked" habitats where an organism might live: the forest floor, the trunks of trees, or the canopy of these trees. The epiphytic orchids reside in this second layer: not planted in the ground as we tend to think of plants as always being, and not tall enough to have unrestricted access to the sun.

Due to their choice of habitat, the Orchids can't rely on ground water, so must instead draw water from the air of the humid environment around them. In order to accomplish this, they have modified roots, some of which are actually aerial, white or silvery-grey in color, and spongy in texture.  This color and texture results from a covering of velamen, actually the modified epidermis of the root which helps to absorb and hold in water.

An Aerial root on a Phalaenopsis I've acquired

These specialized roots are what often serve as a source of difficulty when many try to grow these in their homes. They assume that due to their native habitat the plant needs a lot of water, and overwater the plant resulting in these roots rotting. They do like this humid environment (some orchids actually wiliting as soon as they're removed from 70-80% humidity), but can't stand having their "feet wet", so to speak.

Probably the most common type of orchid grown, and probably the easiest as well, is the Phalaenopsis, or the Moth Orchid. The common name comes from the floweres, but I feel saying they resemble moths is an understatement. When I first had the opportunity to look at one of these flowers close up, I was taken aback by how accurate this mimicry seems to be, with the center of the flower so approximating the head and eyes of the insect.

Eye to eye, or rather eye column to with a Phalaenopsis

Aggregate of several Phalaenopsis at Longwood Gardens

Last time my Phalaenopsis flowered, I was curious enough to lift up the "moth face" (which is considered the "column" of the flower), curious as to what was underneath. Immediately upon lifting it up, two anther sacs popped out from underneath, exposing the reproductive parts of the flower. This stigma is further below in this structure. The pollinator would inadvertently lift up the "face" or cap of the column when inside the flower, then be covered with the pollen from the anthers, which would be deposited into the stigma when they do the same with another Phalaenopsis flower.

I wish I could show some detailed photos of the column, but couldn't this time around as I took all these at Longwood Gardens. Merkle's Orchids however has a great rundown on orchid flower morphology.

A hybrid containing Cattleya, another popular though more difficult orchid

I'm hoping to get a few more orchids for myself at some point. Planning on trying to grow a Paphiopedilum as well as a Bulbophyllum which I think I'll need to grow in a hanging basket. I was actually going to buy them last year but held off when I learned I'd be moving to Delaware, so I'll see if I can find the money this time around.

A little later this week we're going to revisit Tree ID, and learn how to identify a few Pines.