June 30, 2020

Freshwater habitats, flora and fauna?

It seems to me that freshwater habitats are not really being surveyed here in NYC. Plenty of people look at water birds, a few people photograph fish, and some people photograph water plants, as long as they are large enough and picturesque-looking, but beyond that no one seems to be searching on or below the surface of freshwater habitats, including ponds. And this is a shame, because freshwater contains an amazing biodiversity.

All you really need is a pond net (Amazon has a TetraPond telescoping net for about 35 dollars) and one or two white enamel dishes (or similar) to dump the contents into. Add some pond water to the dishes and you should be all set. You probably don't need rubber boots or waders, as long as your pond net is the telescoping kind.

Don't worry if you have no idea what anything is. The great advantage of iNaturalist is that you don't *have* to know what an organism is, as long as you can get an OK photo of it. Some of the organisms you will see are quite small, so you will need to be able to take decent close-ups.

On the surface of ponds there are duckweeds and water striders; in the water there are water beetles, water snails, copepods, nematodes, and a great variety of pond weeds and green algae. If you are lucky you will find the larvae of dragonflies and damselflies.

And, if you have access to a microscope and put a drop of pond water into a cavity slide, it is a whole other world!

Posted on June 30, 2020 13:09 by susanhewitt susanhewitt | 11 observations | 7 comments | Leave a comment

May 23, 2020

Viruses in NYC.............in plants, not people!

Humans are not the only ones who are at risk from a virus. Plants can also be under attack from virus species that are plant pathogens.

Of course you can't photograph the virus itself, but when a plant is infected, you can see the ways in which the virus changes the appearance of the leaves, or sometimes all parts of the plant. The symptoms can be quite striking, and can make interesting photographs. Mosaic viruses cause mosaic-like patterns on leaves. And sometimes a virus can affect a plant in other ways: for example, Cucumber Mosaic Virus, when it is on Nandina domestica, can cause extreme stunting, and make the leaves come out really weirdly: dark red, narrow, and curving downwards.

Some viruses only attack one genus of plants, but some others, including the Cucumber Mosaic Virus, attack a very wide range of plants in different families.

Because many of the viruses have long names, they are usually referred to by their acronyms, so Pagoda Yellow Mosaic Associated Virus is known as PYMAV, and Cucumber Mosaic Virus is CMV.

Here are some plant viruses that I have observed. Please note that @jameskdouch, a virologist in Melbourne, Australia, has given me much assistance by commenting on and correcting my putative virus identifications. And @juhatuomola, a plant pathologist in Helsinki, Finland, has been very helpful too.

Hackberry Mosaic Virus -- on Common Hackberry, Celtis occidentalis

Pokeweed Mosaic Virus -- on American Pokeweed, Phytolacca americana

Cucumber Mosaic Virus -- on Heavenly Bamboo, Nandina domestica

Ribgrass Mosaic Virus -- on Carolina Bluebells, Mertensia virginica

Rose Rosette Emaravirus -- on Multiflora rose, Rosa multiflora

Pagoda Yellow Mosaic Associated Virus -- on Japanese Pagoda Tree, Styphnolobium japonicum


Rose mosaic virus -- one or more of a group of four unrelated viruses which attack Rosa chinensis

Virus on Erigeron:

Virus on Common Blue Violet, Viola sororia:

Mosaic virus on Kirengeshoma (a garden plant):

On June 4th I found symptoms of an interesting, new-to-me plant virus or viroid quite near where I live, on a seedling on White Mulberry. It might perhaps be hop stunt virus, HSVd:


Badnavirus on Japanese Aucuba, Aucuba japonica -- the effects of this virus are highly prized by horticulturists. The virus is transmitted in the seeds from one generation to the next. I guess we have to consider it to be a cultivated virus.


Cucumber Mosaic Virus on Beach Naupaka, Scaevola taccada, in Sanibel, Florida

Begmovirus on Merremia in Nevis West Indies


Posted on May 23, 2020 01:55 by susanhewitt susanhewitt | 13 observations | 15 comments | Leave a comment

May 01, 2020

Mosses of Manhattan

We don't think of Manhattan, NYC, NY, USA as being a particularly "mossy" place, not like overgrown shady ravines in the upstate New York wilderness areas, but when you start paying attention, you discover that mosses are all around us almost everywhere here in the heart of the city: sidewalks, planters, waste ground, edges of paths , etc.

I know nothing about mosses, but I figure that my part of Manhattan must be home to only a limited number of moss species because of the air pollution and lack of fully wild habitat, despite Central Park's extensive "imitation wilderness". So I am guessing there might perhaps be 60 species in Manhattan. I suppose Inwood Park is the closest thing Manhattan has to real wilderness, as it is huge with varied habitat and there is some original forest there, but I have yet to make my way to Inwood. When things normalize I will head up there.

I am working with my iPhone, and the camera is not good at macro/micro pics because there is not enough resolution. However, I am certain there are a number of local mosses that I can learn to ID using the features that are visible to my naked eye, a hand lens, and my somewhat inadequate camera.

I already think I know a small handful of my local moss species, some only to genus. But I could be wrong on some of them -- a little knowledge is dangerous in that way!

One local moss that I have been confident about for a couple of years is Silvery Bryum. Anyone can learn to recognize that moss, even with one hand tied behind their backs.


Here are a few of my few mosses so far:

Silvery Bryum – Bryum argenteum

Seductive Entodon Moss – Entodon seductrix – I may have wrongly ID'ed some of these.

Woody Thyme Moss – Plagiomnium cuspidatum – this could be another species in that genus?

Bristle Mosses, Orthotrichum, I am pretty sure the genus is OK but I am also guessing I have in particular O. stellatum, the Starry Bristle Moss, which may be incorrect, but whatever it is I always find it growing in the crevices of the bark of mature Callery Pear street trees.

Wall Screw-Moss – Tortula muralis

Redshank – Ceratodon purpureus


And with some ID help from a professional moss person, I may also have found:

Common Bladder Moss – Physcomitrium pyriforme

Bonfire Moss – Funaria hygrometrica


The AI/Computer vision has recently started offering guesses on moss IDs. There are many of them, most of which are probably way off, but here is one suggestion:

Bird's Claw Beard Moss – Barbula unguiculata


Posted on May 01, 2020 13:09 by susanhewitt susanhewitt | 10 observations | 6 comments | Leave a comment

April 26, 2020

What does a "stay-at-home" order mean?

I live in Manhattan, in New York City. Some of my friends appear to think that a "stay-at-home" order means they have to stay in their apartment and not go out at all under any circumstances. Of course when they do that, they are having food delivered a couple times a day at least, and that is not great for the delivery people in terms of the delivery people's having to commute in from the outer boroughs and therefore their considerable exposure to the virus.

So anyway, I found this quote:

"What is a stay-at-home order? California and New York, two hotspots for the coronavirus outbreak, were two of the first states to implement stay-at-home orders, which limit the circumstances under which people can leave their houses. Under a stay-at-home order, all non-essential workers must stay home. People can leave their homes only for essential needs like grocery stores and medicine, or for solo outdoor exercise."

(A stay-at-home order is not the same thing as a "shelter in place" order.)

NOTE: As mentioned in the quote, solo outdoor exercise such as walking, running or biking *is allowed* under a stay-at-home order. My husband Ed has been told by his doctor that he needs to walk an hour a day for his health. I go with him, and for me it is a nature walk too. We are very careful to practice social distancing, wear masks and gloves, carry wipes, and so on. Sometimes our walks are longer than an hour (during CNC much longer than an hour), but nonetheless, this amount of exercise is allowed and is healthy.

Of course people who are ill with a somewhat mild case of the virus, and who therefore are not in a hospital, those people should stay in their apartment all the time, and not go out at all for any reason. This is called "self-isolation", which is not the same as "stay-at-home".

Posted on April 26, 2020 12:17 by susanhewitt susanhewitt | 10 comments | Leave a comment

April 15, 2020

Two more Green Men

Today I walked west on 82nd Street from 1st Ave. I was delighted to find two more buildings that have stone-carved images of the Green Man enshrined on them:



The Green Man may sometimes look stern, but he is a great friend as well as being a sort of boss to all gardeners and naturalists. He is the power of nature, the power of growing green things. He is at his strongest in the spring and fall. He is at home everywhere. Nothing can keep nature down.

All the best,


Posted on April 15, 2020 23:20 by susanhewitt susanhewitt | 8 observations | 0 comments | Leave a comment

April 12, 2020

Do you know the Green Man?

I found a stone carving of the Green Man in my neighborhood yesterday, and it made me very happy.

As naturalists we are all familiar with the Green Man, whether we know him by that name or not.

The Green Man is a personification of the powerful magic of nature, which we see most movingly as the natural world splendidly renews itself in the spring. Even in the tropics there is something like spring, when the dry season ends and the rainy season begins.

We all respond to that rebirth of nature at every level, viscerally, emotionally, spiritually and intellectually.

And the power of nature renewing itself is particularly uplifting and inspiring to humans right now in this time of COVID-19, when, from a human perspective, disease and death are stalking the Earth and we are cowering in our burrows.

Green Man is a piece of powerful mythology, and his depiction is found in numerous cultures all round the world and throughout history.

In much of the northern hemisphere, the spring awakening is in full force now, even here in NYC. The unstoppable power of nature to start anew and afresh means that even a dandelion in full flower can move me to tears.

Posted on April 12, 2020 13:45 by susanhewitt susanhewitt | 24 observations | 3 comments | Leave a comment

March 21, 2020

And who bites them?

Jonathan Swift wrote:

"So, Nat'ralists observe, a Flea
Hath smaller Fleas that on him prey,
And these have smaller yet to bite 'em,
And so proceed ad infinitum"

Which is often rendered in the Augustus De Morgan re-write:

"Great fleas have little fleas upon their backs to bite 'em,
And little fleas have lesser fleas, and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on;
While these again have greater still, and greater still, and so on"

So the Ixora plant by my door here on Nevis has Green Scale and green aphids attacking it, and the Green Scale insects have parasitoids in the wasp family Encyrtid attacking them, and so on...

Posted on March 21, 2020 00:20 by susanhewitt susanhewitt | 3 observations | 2 comments | Leave a comment

February 25, 2020

Those amazing Scale Insects!

Over the last year or two I have become interested in plant pests and pathogens. In particular I have found scale insects (Superfamily Coccoidea) to be very bizarre and fascinating creatures.

When you come across scale insects, the ones you notice (the adult females) often do not look like insects at all; many of them just look like small bumps on plants: brown bumps, white bumps, red bumps.

Scale insects are external parasites that suck juice from the host plant. The adult females are cemented down in place, with a hard or soft cover on top of them. The larvae or "crawlers" move around to find a new place for themselves. The adult males are minute winged creatures -- none which I have seen yet.

Many species of scale insects are species-specific, meaning they only live on one species of plant, although a few can be found on more than one genus or even more than one family of host plants.

Here is a list (with links) to the scale insects (and mealybugs) that I have seen so far. Mealybugs are in the same superfamily as the scale insects, but they have legs and can move around.

Many of my earlier observations need an ID for the plant host, and the insect ID is probably incorrect on some of them. I will be grateful to anyone who can assist me with IDing these.

Also, if you know there is a scale insect species which lives (outdoors, not in a greenhouse) here in Manhattan, a species that I have not yet seen, please do tell me. I am very interested to see more of these odd little creatures. :)

Elongate Hemlock Scale, Fiorinia externa, on Eastern Hemlock, NYC

Genus Aonidiella, on a ?Euonymus, NYC

Pine Needle Scale, Chionapsis pinifoliae, on Pinus rigida, NYC

White Prunicola Scale, Pseudaulacapsis prunicola on Cherry Laurel, NYC

Euonymus Scale, Unapsis euonymi, on Japanese Euonymus, NYC

Indian Wax Scale, Ceroplastes ceriferus, on Flowering Quince, NYC

Scale Insect on a palm tree (palm needs ID) in Sanibel , Florida, NYC

Cottony Camellia Scale, Pulvinaria floccifera, on Taxus, Yew bushes, NYC

Pyriform Scale, Protopulvinaria pyriformis, on an evergreen dicot in San Diego County, California

Pyriform Scale, Protopulvinaria pyriformis, on a dicot in San Diego County, California

Prickly Pear Scale, Diapsis echinocacti on Opuntia in San Diego County, California

Iceplant Scale, Pulvinariella mesembryanthemi, on Sea Fig in San Diego County, California

European Fruit Scale, Parthenolecanium corni, on some species of cherry tree, NYC

Yew Scale, Parthenolecanium pomericanum, on Taxus, a yew bush, NYC

Cottony Maple Leaf Scale, Pulvinaria acerticola, on a Little Leaf Linde, NYC

Florida Wax Scale, Ceroplastes floridensis on English Holly, NYC

Scale insects on dicot in San Diego County, California

Ceroplastes on dicot in San Diego County, California

Scale insects on Pelargonium, San Diego County

Scale insect on dicot, San Diego County

Sycamore Scale, Stomacoccus platani, San Diego County

Florida Wax Scale, Ceroplastes floridensis on Flowering Dogwood, NYC

? Mealybugs on salt grass in San Diego County, California

? Mealybugs on Gale of the Wind plant on Nevis, West Indies

? Mealybugs on legume plant on Nevis, West Indies

? Mealybugs on dicot, Nevis, West Indies

? Mealybugs on Allspice, Pimenta dioica, Nevis, West Indies

? Mealybugs on dicot, Nevis, West Indies

? Mealybugs on dicot, Nevis, West Indies

? Mealybugs on Hyssop Spurge -- Euphorbia hyssopifolia, Nevis, West Indies

? Mealybugs on dicot, Nevis, West Indies

Posted on February 25, 2020 01:33 by susanhewitt susanhewitt | 1 observation | 1 comment | Leave a comment

January 01, 2020

On the global leaderboards for December 2019?

December in the more northerly parts of the Northern Hemisphere is usually not a great month for nature observations. However, starting on the 4th of December I was lucky enough to spend almost three weeks in Southwestern Florida -- Sanibel, which is a barrier island on the Gulf Coast, not far from Fort Myers.

Of course I love to try to find new-to-me, or better yet new-to-Sanibel species of shelled marine mollusk, and I like to look at all the other marine organisms that wash up on the beaches. Sanibel beaches are fortunately not "groomed"! I also love to try to see new-to-me species of plants, and even new plant diseases. I was able to get to a nature preserve on a very hot day, and get some pics of some interesting flying insects.

We had a lot of rain storms towards the end of our visit, which was not good for trying to examine the more tiny shells, or more flying insects. However I found I was already on the global leaderboards for the month of December 2019, both for the total number of observations made, and for number of different species observed.

And when I came back to NYC, late on 23rd December, I knew if we got some reasonable weather (as was predicted) I could probably easily rack up a couple hundred more species here in the Big Apple, winter or not.

So that's what I did, and I finished the month still well positioned on December's leaderboards, with 3,027 observations of 587 species. I also was able to have fun with two iNat mini-meetups, one on Sanibel and one here in NYC, thanks to @jayhorn and @steven-cyclist!

Happy New Year to everyone! And happy iNatting!

Posted on January 01, 2020 22:06 by susanhewitt susanhewitt | 18 observations | 0 comments | Leave a comment

August 08, 2019

How can I tell what is a Brown-lipped Snail and what is a White-lipped Snail?

Two very pretty and very similar-looking species of land snails in the genus Cepaea are native to most of Western Europe. And both of them are introduced in some parts of North America. These two species are: the Brown-lipped Snail, aka the Grove Snail, Cepaea nemoralis (adults almost always have a dark out-turned and thickened lip on the aperture of the shell) and the White-lipped Snail Cepaea hortensis (adults almost always have a white out-turned lip).

Both species live in colonies. They both have a fairly large globose shell, which can be yellow, red, or any pale or mixed shade of those colors. The shell can be plain in color or banded. When the shell is banded, it can have from one to five dark bands. Those bands can be narrow, or they can be so wide that two or more bands merge together.

One important thing to know is that you *cannot* put a species ID on a live one of these snails, or an empty shell, unless it is *adult*. The ID of juveniles needs to be left at the genus level. Even dissection cannot separate the juveniles into species.

How can you tell if the snail is an adult? In snails of this genus (and in many other land-snail genera), once the snail reaches adulthood/sexual maturity, the shell stops growing any larger, and instead it grows thicker. In particular, the lip (the very edge of the opening of the shell) becomes greatly strengthened, strongly reinforced, and also it becomes very slightly flared-out. In adults the lip of the shell is thick and strong, and it is out-turned to some degree.

With a lot of experience, you can tell an adult from a juvenile quite easily just by looking, but until then, before trying to ID a live Cepaea to the species level when you are in the field, check to see if the lip is mature. If you press gently on the side of the lip and it is still soft and flexible, then the individual is a juvenile. If there is no sign of thickening and no out-turned appearance to the lip, the snail is a juvenile, and you will have to leave the ID as "Cepaea".

EVEN MORE IMPORTANT: A live juvenile or subadult Cepaea snail that is active will *always appear* to have a white lip on the shell. But what you are seeing is the *live mantle tissue* which is wrapped over the edge of the shell, actively laying down more shell material. That is how the shell increases in size. And any brand-new shell material will also appear whitish, or even transparent.

If an individual snail is starting to become sexually mature, you may see that the thicker lip of the adult is partially formed. You have to look closely then, because even if the adult will have a dark lip on the shell, the thickening often starts out pale; the dark pigment seems to be laid down a bit later, when the construction of the thickened lip is almost finished.

Almost all of the time with adult snails it is true that an adult White-lipped Snail has a white lip on the shell, and an adult Brown-lipped Snail aka Grove Snail has a dark lip to the shell. Very rarely there are exceptions to this rule but it is best to stick with it 99.9% of the time.

Here on iNaturalist we currently have numerous observations of Cepaea that have been misidentified, and many well-meaning people have subsequently "agreed" with those IDs, causing them to become Research Grade.

Research Grade observations are fed to the AI, our Computer Vision tool. Large numbers of misidentifications cause the AI to learn the species incorrectly, and then it offers incorrect suggestions. And that helps perpetuate the mistakes!

If anyone who reads this post would like to help me sort out some of this confusion, please drop me a line. Although many (not all) of the IDs of the Dark-lipped Snail are correct, there are still dozens of observations of "White-lipped"Cepaea which will need to have the ID adjusted to the genus level, and adding a comment with "Please see" and a link to this post.

Thanks for any help you can give in sorting this out. Not only do we want the humans to learn this correctly but we also want the AI/Compute Vision to learn it correctly too.

Posted on August 08, 2019 13:13 by susanhewitt susanhewitt | 8 observations | 5 comments | Leave a comment