Wednesday, February 10, 2021

Periodical Cicadas

 


     They're coming! And in a BIG way! Billions of periodical cicadas will be emerging from mid April to the beginning of June after spending 17 years underground! These are different from the many species of annual cicadas which grace us with their songs each summer. Though each individual annual cicada lives 2-5 years underground before emerging, they're life cycles are staggered so we get some each year. Most annuals emerge after the last of the periodicals have finished reproducing. 
     Periodical cicadas emerge on prime numbered years, either 13 or 17. The 13 year ones are restricted to the South. There are a couple of theories why this is. One has to do with the ice ages during the Pleistocene Epoch 1.8 million years ago. Summers then were believed to be cyclical, with warmer summers each 13 or 17 years. While underground the temperatures were regulated, the adults emerged on these warmer years. This was a good adaptation as no predators could evolve to take advantage of them emerging so far apart. By all of them emerging in synchronization over a short time period, when ground temperatures reach 64 degrees Fahrenheit in a sustained pattern, usually after a rain, they overwhelm the predators that remain. Through what is called predator satiation, where animals who would eat them are flooded with so many cicadas that they can consume only a small amount, reducing the probability of an individual being eaten, many survive to lay eggs. 
     The cicadas that emerge together in the same year are collectively called a "Brood" which are labeled with Roman numerals. There were at one time 17 broods in North America, but now some are now extinct. Take for example Brood XI which was last seen in Connecticut in 1954. The ones emerging in the DMV and other parts are parts of Brood X, the Great Eastern Brood. This is one of the larger and most widespread of them. For the first time since 2004, periodical cicadas will emerge in parts of Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, North Carolina, New Jersey, New York (though almost extinct (extirpated) here), Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Washington, DC. 
     While there are 3,000 species of cicadas (Latin for "tree cricket"), periodical cicadas are a rarity, with only North America having them. This is a natural phenomenon where cicadas form huge choruses by species. For while they may seem the same, there are actually three species that emerge together to then attract their specific females. Each male chorus (for only the males call) has its own species specific songs to attract their mates and they group together for best effect. They last for 5-6 weeks as adults. You will start to notice the burrows as they emerge, or occasionally chimneys that they form when digging out and then the empty molts of old skins from the emerging nymphs. Most periodical cicadas have red eyes, but some also have white or grey eyes. 

Periodical burrows and a molt

     Brood X includes these three species, which are not always easy to tell apart. The Pharaoh cicadas, Magicicada septendecim, are the largest and the ones that can be found the furthest north of all the periodical cicadas. They are characterized by their broad orange stripes on their abdomen, the patch of orange between their eyes and wing, and of course their species specific song that they all have. The Dwarf cicada, Magicicada cassini, or Cassini's periodical cicada, is smaller, has no orange between the eye and wing, and usually an all black abdomen. The Decula cicada, Magicicada septendecula, is similar in size to the dwarf Cassini, also lacks an orange patch between the eye and wing, and has some orange on its abdomen. The last two are easily confused. They of course have species specific calls. While the 13 year periodical cicadas are often treated as different species, many now think they're variations of these three species that come out in their own broods of 13 years. 

A periodical cicada sheds its skin for the last time.

     Periodical cicadas, no matter which species, are often called locusts. Actual locust are grasshoppers, so why did they call cicadas locust? This goes back to the first time that a brood was seen by European settlers. In 1633, in the Plymouth colony in Massachusetts, a large emergence of periodical cicadas was reported. This was shortly followed by what they called a "pestilent fever" that raged through the colony and the Indian neighbors. This was close enough to the biblical plagues that included locusts in huge numbers to ensure that name for them. It was a new experience for the colonists and the only thing they could compare it was the locust plagues of the bible. 
     And though the biblical proportions of the cicadas is still hard to believe, and though they pale in comparison to what they used to be, the billions that will arrive will be of epic proportions. Cicadas are known to be among the loudest of insects. Choruses of males singing can reach from 100-120 decibels. This is enough to affect many people with sensitive hearing. This as loud as a rock concert, but will last for many, many days. Interestingly enough, the sound of leaf blowers, power tools, and lawn mowers may attract them. Such chores are best left to early morning or late after noon to avoid any such confusion. 
      The females twitch their wings in response to the males songs when they accept a male to mate with. Once they've mated, the females search for places to lay their eggs. While adult cicadas don't really feed, except for some harmless sucking of some plant sap, the egg laying is what people worry about. For the 3-4 week adult life span, mated female cicadas use their ovipositors to slice into pencil-sized twigs to lay their eggs. They lay 24-48 eggs into the slits they carve out until they reach the 600 more so eggs they're allotted. 

Flagging damage by cicadas inserting eggs in to stems.

     The egg laying inside these slender twigs causes many to die off. They often wilt and hang down, while others may break off. The wilted and hanging branches are referred to as flagging. Cicadas are picky as to which tree (they don't disturb plants or ferns) they choose to insert their eggs in. They are usually 6 feet or more tall, mostly at the edge of mature woods, where's there some sun, and usually have pencil-sized stems to oviposit in. They tend to avoid lawn areas with small shrubs unless they're near mature woods. For those people who were around the last time cicadas emerged, they normally use the same places to try and lay eggs again. They don't like to use any evergreens, sumacs, pawpaws, many viburnums, euonymus, or Osage orange. Studies have shown that healthy trees don't show long term ill affects. Think of it as natural pruning that has been going on for millennia. If you do want to be cautious, leave your tree planting until the fall. Or protect your trees with 1.0cm netting. One thing that did not help was the use of pesticides. Studies have shown that this did not make a difference in egg laying. The young nymphs hatch out after 6-10 weeks and burrow underground to feed on tree roots for 17 years.

Evidence of egg slits left by cicada ovipositor.

     Now many animals feast on the cicadas, including things you don't normally think of eating them such as squirrels, chipmunks, turkeys, and even copperheads. Many animals, especially birds, will benefit and rear more young due to the extra food supply. Dogs and cats will also feed on them, and this where you may want to be cautious. Cicadas are edible (more on that in a second), but eating too many of the hard shells may cause digestive issues in pets. They do make good bait as some people have learned. I caught a huge carp on one that had decided to surface feed.

A house sparrow feeds on a periodical cicada

     So I did mention they were edible, which includes by people? The native American tribes would consume them when they were available. They've been called the "shrimp of the land" and that is true. They are both arthropods and can make good meals. Just be aware if your allergic to shellfish. People every year start to practice entomophagy (eating of insects) when they appear. Don't be surprised to see some of the local restaurants including them on their menus. 

A freshly emerged, or teneral, cicada, still white and soft.

      Cicadas are gluten free, low in fat, low carb, rich in protein (the same pound for pound as beef). They've been grilled, skewered, steamed, barbecued, blanched, boiled, blanched, and used in cocktails. My old boss would fill the empty skins with Cheez Whiz and serve them as appetizers. But there are a few things you want to know if trying them (I know I will again!). First of all, they are best when their teneral, meaning freshly molted adults. Get them while their white and soft, before the chitin on their shells have hardened, you don't need all that crunch. Collect them from places that have not been exposed to pesticides and herbicides. As they come up from the ground at night and in the early morning to climb anything they can molt on, that's the best time to get them. Pull off the legs and wings as well. With a bit of Old Bay, they really do taste like seafood. You can see eat one here: (15) Capital Naturalist: Eating Cicadas - YouTube

The author tastes one yet again...

     Periodical cicadas emerge and mate well before cicada killers emerge to paralyze the annual green ones to feed their young. More on cicada killers in this blog I put together: Capital Naturalist by Alonso Abugattas: Cicada Killers or Cicada Hawks.  One thing that periodical cicadas can't elude is the Massospora fungi that infects them. This fungus fills their abdomens and destroys their ability to reproduce. Sometimes the entire abdomen falls off. 
     So some of you may remember seeing some earlier than the 17 years. This pre-emergence happens quite a bit. These stragglers, as they're called, usually come especially come out 4 years earlier. This has led to the theory that these actually may be the 13 year ones that some classify as different species. For more on this, check out this blog I did on them: Capital Naturalist by Alonso Abugattas: Periodical Cicadas Early Emergence
     So enjoy this natural phenomenon while you can. These "locust" don't spread disease or eat our crops. They can provide benefits such as aerating the soil or providing food for countless creatures. The next time we can hear and see this unique event won't be until 2038.



Thursday, November 12, 2020

Eastern Coyote


     Our Eastern Coyote (Canis latrans) is a recent arrival with an interesting story. It was first noticed around 1930 or so spreading East near the Great Lakes, as Western Coyotes wandered over and took over the areas vacated by most gray wolves. They mixed with Algonquian Wolves and continued to travel, mixing along the way with dogs as well. What resulted was a mix of about 60% Western Coyote, 30% Algonquian Wolf, and the remainder dog, though these averages can vary. They are now found in every county in the mid-Atlantic. 
     The Eastern Coyote is bigger than those in the West, about the size of a border collie or even German Shepherd, often between 45 to 55lbs, though occasionally bigger. The males are usually larger than the females. They are not only larger, but often tend to be more quiet than their western cousins, not howling as much, and often in much smaller groups. They're color can be variable as well, though they're often some shade of tan, with erect ears, bushy downward-pointing tail with a dark tip. Most have white chins as well.
     Coyotes are opportunistic feeders, including vegetables and fruits in their diet along with meat. They are great scavengers, often eating roadkill deer. They rarely take down adult deer, unless the deer is injured or otherwise ill. They will however see any small pets as food, particularly outdoor cats, when they find them wandering off in the woods. This is just one more good reason among so many to not let cats out. 
     Coyotes are remarkably shy and avoid people any way they can. Most are rarely seen, and certainly are no danger to people, unless they are very sick. If you do think that the animal is sick, you should call Animal Control. Coyotes will usually run away at the first site of any people. Now if you do encounter a coyote, that is obviously not sick, clapping of hands, yelling, throwing things, shaking a can with pennies, are all ways to get the animal to run away. You should never feed coyotes, or leave food out for other animals such as cats. That can lead to them becoming accustomed to people, which can be bad for the coyote and people. Here is an example of a coyote that has become accustomed to people: 


.
     People have been living near coyotes for a long time, though most have no idea that coyotes are around them due to the coyotes' shy nature. If you do see a coyote, consider yourself very lucky. Most have no idea that they are around at all, especially since they are mostly active at night. See below an example of one investigating a fox den and the lights from a game camera, all in one of our urban parks: 

Thursday, May 7, 2020

Asian Giant Hornets

Asian Giant Hornet (Vespa mandarina)
Photo by: [q13fox.com/2019/12/22/invasive-asian-giant-hornet-found-in-washington-state/amp/]
 
     There's been a lot of hype lately concerning the Asian Giant Hornet (Vespa mandarina) after a New York Times article revealed that some had been found in Washington state a year ago. They even gave them an equally sensational name of "murder hornets" despite no entomologist ever having called them this. So I think it's time to set the record straight on these large wasps and the couple of things locally you really are much more likely to get them confused with.
     So let's be clear that this discovery was last year, first in September in Nanaimo in Vancouver in British Columbia, Canada, They quickly destroyed the nest and set up traps to see if any other ones were around. It was in December of last year that they found dead Asian Giant Hornet about 50 miles away in Washington state. Despite it's proximity, some tests determined that it was not from the same underground colony as the others. Since then, there have not been any more of these hornets seen live or dead in the USA, just the ones from 2800 miles away the previous year.
     Now if these Asian Giant Hornets, the largest of all hornets, are found to have been established colonies, that would be bad for our European honeybees that did not evolve with them and have no defenses such as the Japanese honeybees do. But this unlikely to happen with controls in place and it would be near impossible for that to happen here in the DC area.
     So all the hype is just that, just hype. I've already been getting people sending me pictures to see if they have found one. They have of course all been negative, just local species that people have people have made the villains. Let's recall a few natural history facts relating to Asian Giant Hornets. Much like other hornets, they only produce queens that can start a new colony at the end of the year when their original nests fall apart. Each individual worker hornet cannot produce any new nests. Only those at the end of the year that have been fertilized by male nonstinging hornets can produce eggs. Please recall that no male bees, hornets, or yellowjackets can sting, as the stinger is a modified ovipositor (egg layer). So males, as they don't lay eggs, can't sting. The odds of a fertilized queen finding their way over here in the DC area, knowing that a very small population at best was found 2800 miles away, is extremely small. They also prefer deep woods to establish their underground nests, which again is not as likely to happen in our DC urbanized area.
     Let's also look at this sensationalized name of "murder hornets". Now despite the claims, they are actually have less toxic venom than some of our local yellowjacket species. Now they are bigger so likely may inject more, but they are not looking to sting people. Much like our other social wasps, they will defend their nests, when they're threatened, but overall do not look for people or attack them in more numbers than any of our local wasps. If someone does have an allergy to them, then that could be a problem, and no tests have shown they are any more likely to have people allergic to them than our own honeybees. In fact, more people die of allergic reactions to honeybees in the US than they do from Asian Giant Hornets worldwide each year. And this is still less than those that die from getting hit by lightning each year as well.
     Now complete disclosure, I am (or perhaps was) allergic to yellowjacket stings. This did not mean I was allergic to other stinging insects such as paper wasps or honeybees.When you have an allergic reaction, it is often pretty specific. The venom of each is different, so just because someone is allergic to bees, does not mean that they are also allergic to hornets or yellowjackets, or vice versa. For me, as I'm outdoors all the time, I had been stung too many times, including when I was with kids who batted at yellowjackets for which I got stung getting them out of the way. I got stung once too many times and ended up in the hospital. I've since gone through therapy getting injections from yellowjackets so that I'm supposedly resistant again to them. Funny that since I was aware of this, I've not gotten stung in many years. I'm gotten almost a 6th sense about yellowjackets, even though my job often requires me to investigate these stinging reports.
     Now again, despite all the hype, you are very unlikely to find any anywhere near the DC area, we will show what they look like compared to the two other locally found large species in our area. Now of course many people will look at size as the first thing they will notice. And it would be important. Maxing out at 2.2 inches, Asian Giant Hornet queens are the largest of the hornets. The workers which you would most likely see if any were any in this area are much smaller at 1.5inches. Believe it or not, people actually eat their larvae in some places.
 
A comparison of the 3 largest stinging insects in our area. These are all workers, except for the Cicada Killer which is a female. Notice the eye placement of the Asian Giant Hornet well in front of the head.
Photo from Franklin Master Gardeners

     While size maybe the first thing you notice, we have two others of similar or greater sizes (recall a Cicada Killer is not a hornet and the females who prey on cicadas are larger than other workers). For Asian Giant Hornets, their eyes are set far forward on their yellowish/orange heads. They tend to have distinctive fairly similar stripes across their abdomen. And once again, a reminder that No Asian Giant Hornets have been found in the DC area, or outside of last year's discovery of a dead one in Washington state.
     The creature most likely to be confused with the Asian Giant Hornet around here is the European Hornet, a rather large relative with a dark head and irregular stripes across its abdomen. These were originally introduced into the USA over a 150 years ago, and have in that time extended their range to the eastern third of the United States. This does go to show, that with similar life cycle to Asian Giant Hornets, it would indeed take a long time for them to really expand their range. Right now the extremely large queen European Hornets have overwintered and are looking for places to build their nests. These are the most easily confused to the Asian Giant Hornets. They usually choose an opening in a tree, but some have occupied sides of buildings.
    
A European Hornet worker (Vespa crabro) showing its size difference with a Yellowjacket flying over top. They take all sorts of other insects as food for their young, particularly preferring cicadas leading many to confuse them with Cicada Killers.

     These nonnatives have never endeared themselves to people. Workers are large at about 1.4inches long. They spend most of the summer hunting other insects to feed their young. This includes taking of large butterflies like swallowtails and Monarchs, along with large bees and wasps. I've seen them wait for the pollinator to use a flower and then trap their prey against the bloom. I've also seen them take down full grown mantids.
     They also cause damage to trees. They will tear off small pieces of bark to use in making their nests. They seem to really prefer lilacs, but also take advantage of sapsucker wells to start striping the bark in squares. They will often eventually lead to stripping so much bark they girdle the tree so it dies.

A tree girdled by hornets.

    These are also one of the few wasps and hornets that are attracted to light. This does confuse and puts them in a bad mood, should they come to your porch lights.


An injured European Hornet that has been attracted to light and then caused damage to itself against the light fixture.

    In the Fall, after much of their raising of their young has concluded, they are often attracted to fruit. This does make these nonnatives a pest of orchards.

An apple tree feeding European Hornets.

     The other large creature (they can get to just over 2inches) often confused for Asian Giant Hornets are Cicada Killers (Sphecius speciosus) or Cicada Hawks. These are large solitary wasps that build individual holes in the ground they then fill with cicadas for their young to feed on. Though on average larger than the other species talked about here, they are actually quite docile and difficult to get angered enough to sting. People often mow grass right along side them with no fear of retaliation. They're stings are also said to be very mild as well, contrary to the reputation of the previous wasps discussed. As these are solitary, they prefer to fly away than to defend their nests, for if they die, no one will raise their young. So despite their large and ominous appearance (the males who can't sting are often flying low over burrows and can be intimidating), females only go after cicadas and are harmless to other creatures. These tend to come out in mid summer and look for sandy areas to build their holes. You can read more about them here in this blog: https://capitalnaturalist.blogspot.com/2016/07/cicada-killers-or-cicada-hawks.html

A female Cicada Killer makes off with a cicada to provision her burrow for her young.

     There are few others that are large enough to be mistaken for Asian Giant Hornets. One is another hornet, the Bald-faced Hornets that are large and have their nests in trees. More on the in this blog: https://capitalnaturalist.blogspot.com/2016/09/bald-faced-hornets.html

A Bald-faced Hornet (Dolichovespula maculate )
     A short video of several wasps taking advantage of an injured tree with sap is here: https://www.youtube.com/watch?v=FaUB2v9H4Go&t=2s
     Most people recognize fuzzy bumblebees so as to not confuse them with others. A few though get worried due to the size of carpenter bees, as I've been sent some pictures to ID them. While they may also seem to be intimidating, they are pretty much harmless. More here on them and bumblebees here: https://capitalnaturalist.blogspot.com/2014/10/carpenter-bees.html .
     The bottom line is that though it's always good to be aware of invasives, the scare tactics out there so far is just hype. Calling them "murder hornets" and scaring people on what really is an extremely low chance of anything happening around here is poor reporting at the very least. The damage they've done as people just start destroying other beneficial pollinators has already taken place. While destroying a few nonnatives European Hornets is not a bad thing, the others such as cicada killers and other pollinators that will also suffer is sad to see. Folks, please don't get scared by these poor reports that are going on out there. The chances of seeing any Asian Giant Hornets, "murder hornets", when they've only been seen a year ago 2800 miles away is extremely low. So its good to be aware, but irrational to let this scare you that every big bug you see is a danger to you.

Sunday, May 3, 2020

Citizen Science and the City Nature Challenge 2020

Citizen Science and the City Nature Challenge 2020
 

     Citizen Science is a growing trend. It is scientific research gathering and data collection done by the general public rather than by professionals. This can truly add to scientific knowledge. The largest of all these efforts is the City Nature Challenge. This worldwide 4-day competition involves over 244 cities throughout the globe, each using the free iNaturalist application to report observations of all things natural using both cell phone and camera pictures. These observations are data mined by scientists and add to natural history knowledge. This year, due to the corvid19 issues, there was no worldwide competition, but rather an effort to get people to get to know and practice with the app, discover what was growing in their backyards.
     Every year, I look forward to see what new discoveries are made during the challenge. Often its personal observations, such as the one I made of a Common Loon at one of my neighborhood lakes. A first for me and only the second recorded this year for the DC region. But there's always some great new more dramatic discoveries as well.
     This year was no different. A longtime student volunteer named Luca Catanzaro was just starting his City Nature Challenge observations near Long Branch Nature Center. Luca is no stranger to the iNaturalist app and this competition. He's currently 4th in observations with 669 and 6th in species count with 248. He's been part of bioblitzes and part of the Virginia Herpetological Society and their surveys as well. He did not need the suggestions offered by the iNaturalist app to know he had found something new. When he made the observations of a White-spotted Slimy Salamander (Plethodon cylindriceus), he new it was something special. His experience with the Virginia Herpetological Society told him he should report what he had not just to iNaturalist as part of the City Nature Challenge, but to the state ID team, of which I'm a member. The discovery was quickly verified.
 
A White-spotted Slimy Salamander (Plethodon cylindriceus) called this due to their habit of releasing sticky slime when handled.
 
     A White-spotted Slimy Salamander had not been seen in Arlington County since 1977! Now this discovery was special on many counts. Long Branch Nature Center had been part of numerous biotic surveys for years. I myself had conducted surveys there for many years, as had numerous others. In all those years, no one had found one. A search for this species had been done in other parks in Arlington where it had not been seen for many years, without success. Despite all these searches, a young amateur herpetologist and citizen scientist during the City Nature Challenge had been the one who had finally found it.
 
 
 
 
     This is the essence of Citizen Science, not professionals making these discoveries, but regular citizens using all their additional eyes and using a free app to record their observations. That this was part of an organized global survey of citizen scientists just goes to prove how everyday people with an interest in research can supply these observations that can benefit all. There are more discoveries to be made in our own backyards, and it doesn't take a professional to make them. It also shows that some of what we're doing battling invasives, allowing native plants to grow back, and protecting the environment does indeed work. If you ever wanted to now what you can do to help out, it can be as easy becoming a citizen scientist.
 
The iNaturalist observation as part of the City Nature Challenge for DC that Luca made.
 


Monday, June 17, 2019

Pollinator Garden Basics


A Green-Headed Coneflower provides nectar for multiple Sweat Bees, a Bumblebee, and Orange Mint Moth.

     There are over 200,000 species of pollinators worldwide. These include such diverse animals as bees, wasps, butterflies, moths, flies, beetles, and hummingbirds. We owe them much, as it is often said that one out of every three bites of food we enjoy is due to the direct actions of an animal pollinator. In fact, three-quarters of all plants, regardless of whether we eat them or not, depend on animal pollinators in order to reproduce. There are many basic things we can do to make our gardens and landscape more pollinator friendly:

      Avoid using pesticides and/or herbicides.

      Plant for continuous blooms throughout the seasons (so you have continuous food).

      Use mass plantings (they’re easier to see by pollinators flying by)

      Include host plants for caterpillar and oligolectic plants for bees (the native plants 1/5
        of our native bees evolved with and need in order to reproduce).

      Provide basking sites (they all need to warm up).

      Consider wet mud spots to serve as puddling areas for butterflies, mud plots for
         mason bees/wasps.

      Try to locate your garden in the sunniest location you have for the most blooms.

      Consider flower color & shape (white, yellow or blue composite flowers are often
        best).

      Avoid double-flowered or other cultivars (cultivars are chosen for traits people want; 
   evolution chose what the pollinators want).

     Leave old stalks, if not diseased, to overwinter. If you can cut stalks to a foot or so
        high and leave them for the new growth to grow over, you can provide nesting spots
        for insects such as bees, of which 30% nest in places like old stalks. It will still look
        neat, but provide nesting platforms throughout the year. If you resist the urge to
        clean up and remove fallen leaves, you also provide good habitat.

      Go Native!

A Goldenrod is covered in small pollinators.
 
Why Choose Natives?
 
-    They provide more food/shelter for the animals with whom they evolved. 96%
       of terrestrial birds feed their young caterpillars (and sawflies) as their major food source,
       particularly while nesting. All 17 of our bat species feed on insects preferring moths
       (which of course are adult caterpillars).
 
-    They are preferred by native wildlife (with whom they evolved). Indeed many are
       necessary as host plants for caterpillars and 1/5 of our bees.
 
-    Given that most insects lay large number of eggs, supplying the plants they need can
       make a big difference locally. Of all the insects that feed on plants, 90% are specialists
       needing the native plants they evolved with, and many of these are pollinators such as
       butterflies and bees.     
 
-    They are adapted to our environmental and soil conditions in which they evolved.  
 
-    There are so many to choose from adapted to just about every growing condition (over
       1700 species in NoVA alone).
 
-    The same plants can have multiple uses (aesthetics, edible landscaping, herbal, wildlife
       gardening, etc.).
 
-    They are attractive!
     
     So do your part for pollinators and other wildlife by following these guidelines, most especially by going Native!

A Bumblebee and Monarch Caterpillar share a Swamp Milkweed.