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.

Happy National Pollinator Week!

A Bumblebee, Metallic Sweat Bee, and Orange-Spotted Mint Moth share a meal on a Green-headed Coneflower.

   Happy National Pollinator Week! 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.
     When thinking about planting things to benefit our pollinators who benefit us so often, a critical thing to consider is the use of native plants. Studies show that native plants are four or more times more attractive to native pollinators than exotic plants. This, of course, makes perfect sense since these plants and animals evolved together, sometimes to the point that one cannot exist without the other. Many caterpillars for example cannot survive without their specific native host plant to feed on. About one out of every five of our 450 native bees in the Mid-Atlantic area need the specific pollen of certain native plants or they cannot reproduce. Just any flower or plant simply won't due.

A Hibiscus Bee (Ptilothrix bombiformis) digs its nesting hole. While it can visit many flowers, it needs pollen from plants in the hibiscus family or it cannot reproduce.

     So the most important consideration is to plant plants that are locally native. These plants are not only adapted to grow in this type of habitat, but are what the pollinators have been using for thousands of years. It is also always best to use straight wild species, rather than cultivars or nativars which have been selected for certain traits. When we plant a flower that has been bred to appeal to us through a novel color or look, it may not have the same appeal to the pollinator its parent plants originally evolved with. What might be attractive to us may not be attractive to pollinators, some of which see flowers through different spectrums or look for certain traits in them. This is especially true of plants bred to have double flowers or blooms with extra large petals, since they often sacrifice nectar/pollen for the extra showy flowers. To remove any doubt and provide maximum habitat value, go native.


Multiple Great Spangled Fritillaries nectar on Swamp Milkweed, the host plant for Monarch butterflies and 11 other caterpillar species. With 15 species of milkweed alone in Virginia, there's a native one for just about every growing condition, not just swamps.

     Also something to consider are the multiple uses you get with native plants. Many exotic plants may have a pretty flower that may (or may not) provide nectar for a short time each year while blooming, but it otherwise provides little habitat or nutrition for pollinators or other native wildlife. Take the Chinese Aster (Callistephus) for example. It is a pretty flower, comes in many color forms and is widely planted (and has escaped and naturalized into some areas). The blooms on some varieties provide some nectar and pollen to a few pollinators for a short bloom time each year. But only two species of caterpillars have been recorded as feeding on it. It is for the most part and for most of its plant life a barren habitat for wildlife, taking the place of what might have been a much more beneficial native plant.
     Contrast that with one of our many (Virginia alone has 43 different species) colorful and attractive native asters, many adapted to a variety of growing conditions. Now you have flowers that not only provide attractive flowers for the garden and a similar look, but also serve a habitat and food function. In addition to pollinators visiting them, most also supply seeds for birds such as finches and sparrows. But 109 different caterpillar species have also been documented feeding on asters. These in turn feed the vast majority of our nesting native birds (96% of terrestrial birds feed on insects, particularly during the nesting season, most of which are caterpillars) and most of the 18 bat species found in our region (all of which are insectivores and many of which prefer moths over other insects). At least 8 different bee species need their pollen or they cannot reproduce.

A Pearl Crescent nectars on an aster, which also is the only food its caterpillars can feed on.

      So you can see how something as simple as choosing a native plant species can not only serve to provide for pollinators, but then serve many other habitat functions as well. So this National Pollinator Week, enjoy the pollinators in our gardens, farms, and parks. Include locally native plants in your gardens. This way you too can help the pollinators who are always helping us.

A Syrphid Fly, a wonderful bee mimic, pollinating Tickseed Sunflower.

     In Arlington County, we try and make the vast majority of the plants we use natives for all the reasons stated above, it is part of our planting policy. This week serves as the two year anniversary that Arlington County made the Mayor's Monarch Pledge to commit to doing several different things to help monarch butterflies. We of course will continue to do many other things to help monarchs and so many other pollinators. Here's a look at the Bluemont Pollinator Patch one year later during National Pollinator Week in June of 2018: https://www.youtube.com/watch?v=PLu9pEFCpEo.

A pair of Long-Horned Locust Borer Beetles multitasking, feeding, mating and pollinating Goldenrod all at the same time.

     The establishing of Pollinator Patches and Monarch Way Stations is just one way to continue to support pollinator numbers. Please join us in supporting our pollinators by planting native plants when you can and taking pollinator needs in to consideration when you do things at home. 

A Sweat bee and Bumblebee sharing a Wingstem meal.