January 14, 2018
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SEAGRAPE SAWFLY
It all started several months ago, during the mid rainy season. On the sapling Grape Tree, Coccoloba spicata, right in front of the hut, one morning at breakfast I noticed that one of the tree's large, leathery leaves was getting worm-eaten, and that here and there on a certain leaf something strange was showing up at the borders of the worm-eaten parts. Up close I saw what's shown at https://www.backyardnature.net/n/18/180114sg.jpg
Tiny green caterpillars with oversized, roundish, orange heads were munching the leaves. Maybe 30 packed themselves close together along leaf margins and the margins of holes they'd eaten into the leaves, and most of them stuck the rear 4/5ths or so of their bodies into the air, causing the margins to look like they had some kind of frilly fringe. Of course each day thereafter I checked on the caterpillars' development. You can see a later-stage, larger instar of one of the caterpillars holding its rear end high at https://www.backyardnature.net/n/18/180114sh.jpg
I sent my pictures to volunteer identifier Bea in Ontario, who instantly saw that they were very similar to sawfly caterpillars she'd identified in Ontario. However, the world of sawflies is enormous, so I hoped to narrow down the ID beyond that. Maybe I could even watch the caterpillars pupate, and eventually emerge as adults, at which stage Bea could give me a less general name. But then one day all the caterpillars disappeared -- probably eaten by a bird. During later weeks similar populations turned up, and all shared the same destiny, disappearing all at once before pupating.
About three weeks ago on the undersurface of one of the Grape Tree's leaves I noticed a grouping of tiny, reddish eggs, shown at https://www.backyardnature.net/n/18/180114si.jpg
Those I checked on daily, and this week they hatched. In fact I got a fine picture showing some larvae exiting their egg shells, shown at https://www.backyardnature.net/n/18/180114sj.jpg
Notice how the one at the far right in the picture appears to be standing on its head! As soon as the larvae left their egg shells, they migrated to the leaf's margin and began forming the earlier-seen fringe of caterpillars with their rear ends poking into the air, as shown at https://www.backyardnature.net/n/18/180114sk.jpg
A closeup of these freshly hatched larvae at the leaf's edge is shown at https://www.backyardnature.net/n/18/180114sl.jpg
About a month ago I'd noticed a certain boldly marked, black and orange insect flitting around the Grape Tree as if it were scouting for places to lay eggs, and I managed to get a single shot of it. This had been the only insect that for all the months I'd watched showing interest in the Grape Tree, so I wondered whether this might be the adult I'd hoped for. It didn't look like other sawflies I'd seen, but I sent the picture to Bea for her opinion. You can see it at https://www.backyardnature.net/n/18/180114sm.jpg
Bea quickly found that a few sawfly species do look similar to our black-and-orange adult, so in all likelihood our picture shows the adult stage of the species to which the Grape Tree caterpillars belong. Bea found a species at the BugGuide.Net website very similar to ours, though it wasn't the same species. However, it belonged to the sawfly family the Tenthredinidae, and when I searched on "Yucatan Tenthredinidae" I found at the Invasive.Org website pictures showing caterpillars that were similar or identical to ours feeding on leaves of Seagrapes, which are seaside shrubs belonging not only to the same family, the Buckwheat or Knotweed Family, the Polygonaceae, but also the same genus, Coccolobo, as our Grape tree. And the adults on that page were similar or identical to the adult I'd seen visiting our Grape Tree.
So, thanks to Bea's help, now we can figure that we're dealing with a sawfly of the genus Sericoceros. Very possibly it's SERICOCEROS MEXICANUS, the species featured at the Invasive.Org site, though the colors are a little different. Searching on that name, I found a nicely illustrated and informative 2002 work in The Forestry Chronicle by William M. Ciesla entitled "Observations on the life history and habits of a tropical sawfly, Seriococeros mexicanus (Kirby), (Hymenoptera: argidae) on Roatán Island, Honduras." That work can be feely dowloaded in PDF format at http://pubs.cif-ifc.org/doi/pdf/10.5558/tfc78515-4
That paper says that about 20 Seriococeros species are recognized, but little is known about any of them. Seriococeros mexicanus has been recorded from southern Mexico south to Panama. As of the 2002 publication date, the species doesn't appear to have been documented in the Yucatan, or of feeding on the Grape Tree, Coccoloba spicata. Therefore, here either we are adding new information about Seriococeros mexicanus, or else we're dealing with a species different from that, but which can't be determined with information available.
Ciesla writes that Seriococeros mexicanus larvae build cocoons of partially chewed leaves in which they pupate. The cocoons are attached to branches, leaf petioles and leaf undersides individually or in small clusters.
That's what I'm watching for now.
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BIG YELLOW VELVETLEAF
Here in mid January there's a feeling in the air a little like early fall in the eastern US. It's our coolest time of the year, certain trees already are losing a few leaves as the dry season progresses, and it all feels pretty good. At the weedy garden edge -- I'm letting weeds grow as "green mulch," keeping wind and sunlight from parching the soil -- a 7-ft-tall (2m) herb struck me as particularly early autumnish with its bug-eaten leaves and diffuse flowering head silhouetted against a slightly unsettled-looking, coldfront-announcing sky, as shown at https://www.backyardnature.net/n/18/180114wi.jpg
A close look at the inflorescence shows both small flowers and fruits at the tips of exceptionally long stems, or pedicels, at https://www.backyardnature.net/n/18/180114wj.jpg
Close up, the flowers display a familiar color and pattern, as seen at https://www.backyardnature.net/n/18/180114wl.jpg
Several genera in the big Hibiscus Family, the Malvaceae, produce flowers of this same orangish-yellow hue, with numerous stamens with their filament basis attached at their bases, so already we know the family. However, the Hibiscus Family embraces so many genera and species that learning the family only advises us of the need to "do the botany " -- to gather all the field marks we can so that later we can figure out the plant's name. Turning the blossom over, a neat little calyx with five reddish-brown tipped sepals was seen, shown at https://www.backyardnature.net/n/18/180114wm.jpg
In that picture an important field mark that easily is overlooked if someone doesn't bring it to your attention is that toward the calyx cup's base there's a slight constriction encircling the calyx. This constriction becomes more obvious in the fruiting stage and helps considerably with the ID.
Sometimes in this family leaf venation and form help with IDs more than the flowers. A leaf base with two noteworthy, broad, rounded, backward-projecting, bug-eaten lobes is shown at https://www.backyardnature.net/n/18/180114wp.jpg
In the Hibiscus Family, fruits often show more variation than either flowers or leaves. This species' fruits show important characteristics, especially the 3-5 pointy-topped capsules called schizocarps, which as they mature develop distinctive purplish-black tops, as shown at https://www.backyardnature.net/n/18/180114wn.jpg
Each matured schizocarp splits down the middle to release a single hairy seed, as shown at https://www.backyardnature.net/n/18/180114wo.jpg
The above details suffice to reveal that here we're dealing with what in English has been named the Big Yellow Velvetleaf, even though the name velvetleaf normally is reserved for species in the Hibiscus Family genus Abutilon. This is WISSADULA AMPLISSIMA, a species so widely and commonly distributed throughout the Earth's tropics and subtropics that it's considered "pantropical." In the Americas it's found from Texas south to deep into South America. Darwin collected the plant during his voyage on the Beagle among the Cape Verde Islands.
Belonging to the Hibiscus Family, one expected feature found here is that the plant's stems contain very strong fibers. If you need a string, just pull sideways on a stem branch and your string will tear from the main stem.
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TICK TREFOIL
At the garden's weedy edge a relatively dainty looking little member of the Bean Family turned up with trifoliate leaves (leaves with three leaflets) and pale rose colored flowers structured more or less like blossoms of common garden beans, as shown at https://www.backyardnature.net/n/18/180114dm.jpg
The leaflets were broad and soft-textured, with very short stems, or petiolules, as shown at https://www.backyardnature.net/n/18/180114dn.jpg
The flowers were small but pretty, of the classic "papilionaceous" design, meaning that each corolla consisted of an expanded top petal -- the standard, or banner -- two side petals known as wings, and two lower petals fused together along their common margins into a scoop-shaped structure known as the keel. The flowers are shown at https://www.backyardnature.net/n/18/180114do.jpg
A flower with its wings and keel bent down to reveal the stamens' filaments fused into a tube around the ovary and style is shown at https://www.backyardnature.net/n/18/180114dp.jpg
The Bean Family is enormous, but when after a few days the plant's flowers dropped their corollas and fruits appeared, I knew we had a member of the genus Desmodium, species of which are known as tick trefoils. You can see the distinctive, loment-type fruit at https://www.backyardnature.net/n/18/180114dq.jpg
A close-up of a loment joint is at https://www.backyardnature.net/n/18/180114dr.jpg
Notice that the joint's hairs tend to hook at their ends. When the loment is mature, its segments easily break from one another. If a hairy animal brushes the plant, the hooked hairs latch onto the fur and the joint with its seed inside is disseminated to a new location.
Our little tick trefoil is DESMODIUM AFFINE, which has no commonly used English name, and occurs from Mexico south through Central America to Argentina in South America. Despite its extensive distribution, there's not much information on it. It's not a very aggressive weed, or a big or colorful one, and it isn't known to contain interesting chemical compounds. It's just one of those little plants that turn up from time to time surprising you with its charm if you only take the time to pay attention to it.
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KATRINA'S NOSE
Katrina, the second-ranked dog of the rancho pack, and who sleeps at the hut, either has an exceptionally good sense of odor, or else is immoderately sensitive to what she smells. She's always displayed the curious habit of throughout the day raising her nose skyward and for minutes at a time sniffing in all directions. You can see what that looks like at https://www.backyardnature.net/n/18/180114kt.jpg
About a month ago, one afternoon during one of her sniffings, suddenly her eyes got big, her nostrils became animated in a way I'd not see, she hunched her back, hooked her tail between her rear legs, and hurried into the hut's darkest corner, where she stood for a long time trembling. Since then this behavior has been repeated several times, and it's happening more frequently. The other dogs either smell nothing, or are unconcerned about it.
Maybe one day one of several poachers who work the surrounding woods shot at her, thinking she was a wild animal, so now when he's out stalking wildlife his odor scares here. Whatever the scent's source, it makes her more and more nervous. The other day a weather front was moving through with gusts that sent entire trees heaving and groaning. None of this bothered Katrina until one certain gust caught her nose, and she went to pieces, shaking uncontrollably, her eyes riveted on the trees' upper limbs as if the wind itself were after her.
At first all this got me to thinking along the usual channels, about how dogs live in a different world than we humans, because their sense of smell gives them a different view of reality than ours. However as the above story repeated again and again, my thoughts focused more and more on the fact that we are what we sense.
And, our human senses detect only a tiny fraction of what's really going on. Just think how vulnerable we all are to brain-formulated perceptions of what our human senses detect, keeping in mind that both our brains and our senses are a fickle set, whose functionality depends entirely on our bodies' often-wildly fluctuating hormonal and otherwise biochemical states. We are all as likely to be enlightened or unhinged as thoroughly by a few mobile little molecules as Katrina.
Almost as comic relief from this train of thought I let Katrina's nose point me to one of my pet notions, which is that maybe a Universal Mentality exists, with us individual sentient, thinking beings serving as its "nerve endings." The Universe is populated with innumerable star systems in which on a regular basis new planets similar to Earth are found. Since Life on Earth appeared and began evolving as readily as it did, why not assume that the Universe is populated with unimaginable numbers and kinds of sentient, thinking beings and, if that's so, then what can be the purpose of it all other than that we're all feeding our sensations into the Universal Mentality? Maybe our combined Earthly experiences contribute to a certain flavor on the tongue of the Universal Mentality, or causes a certain tickling like a flea wandering among the Mentality's leg hairs.
In the end, here's what Katrina's nose has done for me this week:
First, it's reminded me to be on guard against getting too serious about any belief at all, like's Katrina's belief that a certain smell means her doom.
The other insight has more meat to it. It's that, if we are all hooked into, or are part, of a Universal Mentality -- and I suspect we are -- then all our human, Earthly experiences are of value to the Universal Mentality, whether they're "good"or "bad". The job of us nerve endings is to experience.
In that light, the big "sins" of our time are those social structures, belief systems, and one's own laziness or timidness, that keep us from getting involved with things here on Earth, developing thoughts and feelings about them, of immersing ourselves in non-destructive sensory stimuli, and to gleefully submit ourselves to as many thoughts, feelings and interpretations we can stand.
And that's what Katrina's nose got me thinking about this week.
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Best wishes to all Newsletter readers,
Jim
