Tags Posts tagged with "Insects"


Moths are drawn to bright lights because they confuse its navigational systems. Pixabay photo

By John L. Turner

“For an increasing proportion of the Earth’s surface, the darkest conditions of night no longer occur” 

— The Ecological Consequences of Artificial Night Lighting

In 1884 William Dutcher, a well-known New York based ornithologist, published notes on a phenomenon which was receiving a lot of attention by avian conservationists of that time — night-time migrating birds, mostly songbirds of many species, crashing into lighthouses including the Fire Island lighthouse, especially on foggy and cloudy nights. Dutcher recognized, as did many others, the birds were attracted to the bright light of the lighthouse with often fatal consequences. It was one of the first accounts to document what we now know to be a much larger, multi-faceted issue —the negative affects of light pollution.

Today the directed light of lighthouses has been supplemented by the direct and diffused light of countless shopping centers and other commercial complexes, high-rise buildings, homes, airport ceilometers, sports stadiums, communication towers, street lighting, even the annual 9-11 paired tribute that send two powerful beacons of light into the night-time sky of southern Manhattan each September 11th. 

Well-lit urban areas have then become traps for many birds as they become entrained within the cities’ collective mesmerizing glow. Like the birds that were victims of collisions with lighthouses, the effects can be just as devastating for these birds today.

Artificial lighting near the shore can cause sea turtle hatchlings to become disoriented and wander inland, where they often die of dehydration or predation. Pixabay photo

Night lighting, in all its myriad forms, not only negatively affects birds but many other animals. A notable example involves sea turtle hatchlings which are attracted to light (a phenomenon called positive phototaxis). To prevent them from moving inland, drawn by the light of street lights and motels, several southeastern states have enacted regulations requiring lights to be as low to the ground as possible and to be shielded.

Other animal groups are affected too. This includes other reptiles, some amphibians, a variety of mammals (including us humans!), fish, some marine invertebrates, and numerous insects, most notably moths and beetles. Even plants can be negatively affected by night lighting!

Many plants and animals, including humans have circadian rhythms which help them to regulate activity and sleep cycles through the production of certain hormones. These hormones are vital to certain life functions such as reproduction, resting/sleep, and migration. In humans a key hormone affected by light is melatonin which plays a significant role in restful sleep and may help to build muscle and body strength by helping the body to generate Human Growth Hormone (HGH); it also may have tumor fighting properties. Unfortunately, too much night light suppresses manufacture of melatonin which, in turn, can cause adverse health impacts including, possibly, several types of human cancer.

Perhaps no other animal is more associated with lighting — being attracted to it and affected by it — than moths (think of those fluttering around your porch and patio lights). I vividly remember a bird tour I led to western Texas many years ago. We met an entomologist while birding in a campground who mentioned he was going “blacklighting” that night and invited the tour participants along. 

By the time we arrived later, surrounded by pitch blackness, he had set up the light trap. It consisted simply of a white bed sheet hung from a thin wooden frame with various types of battery operated lights including black lights (those that emit UV wavelengths) radiating and illuminating the sheet. It was nothing short of remarkable.

Scores upon scores of different moth species sat on the brightly illuminated sheet — some small and drab, other small ones colorful, a bunch of medium sized moths of every color and hue and then the stars — the large, several inch long, colorful moths. The diversity of body shapes matched the diversity of colors. We had a few silk moths, many “underwing” moths belonging to the genus Catocala (a genus of moths found on Long Island — quite attractive!), and hawk moths. And there was no shortage of other non-moth insects, bugs and beetles of all sorts, and many emerald green lacewings.

Moths play a critical role in local food webs — as pollinators and food for birds, bats and other animals. Unfortunately, moths that get entrained in lights can result in them losing valuable time to feed which can affect health and reproductive success or cause them to perish directly, resulting in their being removed from the local food web.

As mentioned with the feeding and reproduction of moths, sublethal health effects of too much illumination at night is an underappreciated concern and is likely more pervasive than we realize. For example, artificially high light levels at night are known to discourage some amphibians from eating or mating and can adversely affect the reproductive success of fireflies. These species aren’t being killed directly, as with the bird and sea turtle examples, but their longterm fitness and abundance may suffer.

Another victim of excessive night lights was the topic of the December column of Nature Matters ­— the night sky and the “Milky Way.” Tens of millions of Americans, those who live in urban areas, can no longer see the Milky Way. According to one estimate, one out every three inhabitants of planet Earth cannot see the Milky Way, including 80% of Americans and nearly 60% of Europeans. We are being bathed in an ever expanding “sky glow” at the expense of seeing star’s planets and the Milky Way.

Fortunately, governments have moved to address the issue. A number of local municipalities on Long Island, including the Town of Brookhaven, have enacted exterior lighting standards designed to minimize light spillage into the sky and surrounding areas. New York City may soon move to enact legislation and there is ongoing discussion about state legislation that would mandate “lights out” in urban areas.

Let’s close the discussion on two excerpted quotes:

Taken from the book referenced in the quote at the beginning of the article: “So let us be reminded, as we light the world to suit our needs and whims, that doing so may come at the expense of other living beings, some of whom detect subtle gradations of light to which we are blind, and for whom the night is home.”

And if the effects of light pollution on animals isn’t your thing but art is — keep in mind this excerpt from the website of the International Dark-Sky Association “Van Gogh painted his famous ‘Starry Night’ in Saint Rémy, France, in 1889. Now, the Milky Way can no longer be seen from there. If he were alive today, would he still be inspired to paint ‘Starry Night’?”

If either or both of these excerpts resonate with you and you wonder what you can do to contribute to a more fully dark night here’s some ideas: use outdoor lighting judiciously (don’t leave it on all night), install timers or motion detectors, use bulbs with “warmer” wavelengths, install only fully shielded outdoor lighting fixtures, and shut window blinds and curtains to reduce light “bleeding” outside (this also helps to keep heat in during the winter!). 

Essentially light only what, when, and how much you need, nothing more. If you take these steps you’ll help countless animals, perhaps your health, and you’ll see the beloved Milky Way just a little bit brighter.

A resident of Setauket, John Turner is conservation chair of the Four Harbors Audubon Society, author of “Exploring the Other Island: A Seasonal Nature Guide to Long Island” and president of Alula Birding & Natural History Tours.

Stock photo

By Ellen Barcel

Recently on the television I heard a newscaster announce that the 17-year cicadas are due to emerge. Sounds ominous, doesn’t it? What effect will this have? Will they damage your plants? Well, not really.

Stock photo
Stock photo

First of all, there are 15 different broods of the 17-year periodic cicadas. They live in the ground for 17 years, each brood emerging during a different year. Brood V is due out this year, Brood VI in 2017, Brood VII in 2018, etc. That means that there is a brood emerging almost every year, but not in the same place. This year’s brood, Brood V, is emerging mainly in Ohio and West Virginia with a small pocket of them on eastern Long Island, around the Wildwood State Park area.

Interestingly, the only place that these 17-year locusts (as they are sometimes known) are found is in the eastern United Sates, nowhere else in the world.

Cicadas live most of their lives, 17 years generally, underground feeding on the roots of plants. Then come spring, usually May, they dig their way to the surface, shed their skin and look for a mate. The males have a high-pitched whine that attracts the females. About a week to 10 days later the females lay lots of eggs. About six to seven weeks later the eggs hatch, the nymphs fall to the ground where they burrow into the soil and feed on plant roots, waiting for 17 years before emerging briefly to mate.

In general, the emerged cicadas don’t do a lot of damage to plants, so there really isn’t a problem, just a lot of noise and a bunch of dead insects when they die off. Mature cicadas are about an inch and a half long, so between the noise and the size you really notice them, that and the strange life cycle. Most of Long Island is home to Brood 10 which is due to emerge in 2021.

A really cool website, Cicada Mania (www.cicadamania.com) has detailed information about not only the 17-year locusts but the 13-year ones as well. Penn State Extension (https://extension.psu.edu) also has detailed scientific information, noting that the 17-year cicadas can do damage to fruit trees, causing slits in the bark when the female lays eggs and taking nutrients away from the fruit trees when the nymphs feed on the roots. If you have weak trees, they could suffer some damage. But, cicadas do not chew on leaves the way other insects do.

Personally, I would be more concerned about aphids on roses and slugs attacking my hostas. Tent caterpillars are sometimes in the area, but, while unsightly, unless the same tree is attacked year after year, the tree usually survives quite nicely. Remember, keep your plants healthy and that keeping the balance in nature is very effective in controlling most pests. Birds in the garden, for example, eat a lot of insects. Praying mantises, while large and scary looking, eat lots of insects as well.

The rule of thumb is that unless more than 10 percent of a plant is affected, you can probably leave the pest alone. Don’t freak out if your hosta leaves have a few small holes in them, but do keep checking to make sure the situation doesn’t get out of control. If it does, use the least offensive way of controlling it. Only if the milder controls don’t work, then use the heavy-duty ones, chemicals. This is known as integrated pest management. For slugs, I find that just hand picking them off the plants at night works quite nicely.

Ellen Barcel is a freelance writer and master gardener. Send your gardening questions to [email protected]. To reach Cornell Cooperative Extension and its Master Gardener program, call 631-727-7850.

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Gypsy moth caterpillars rest on the trunk of this oak tree in Farmingville during the day. Photo by Elyse Sutton

By Ellen Barcel

Recently I received a photo of a Long Island oak tree covered in gypsy moth caterpillars from a reader who noted that chopped leaves were all over her yard and the caterpillar’s droppings covered her driveway. Moths seemed to be everywhere. What was going on?

Well, periodically, when the conditions are right, infestations of certain pests seem to explode. In this case, her offenders were gypsy moth caterpillars. The adult female gypsy moth is whitish in color with a few small brown spots. The male is slightly smaller and is tan with darker brown coloring.

It’s not the moths themselves but the larvae which do a number on the leaves of so many hardwood trees. The moth is indigenous to Europe, but was introduced to the United States when someone thought they could be used to cross with silkworms to develop a silk industry here. That never worked out, but the larvae have attacked trees, particularly in the Northeast, where they have continued to spread south and west.

The gypsy moth was soon recognized as a pest, defoliating trees. Accounts from the late 1800s talk about caterpillars covering roofs and sidewalks.

The female moth lays its eggs which overwinter. In spring, the eggs hatch, and the larvae emerge and feed voraciously on leaves. Usually in early summer the larvae turn into pupa, a stage which lasts two or more weeks. Then the skin splits open and the moth emerges to start the cycle over again. This time line varies as I already saw a female gypsy moth.

Like butterflies, the moths can’t eat, but can consume moisture. So it’s not the moth that’s the problem — it’s the caterpillar. Moths tend to be active at night, while butterflies are active during the day. The moths don’t have a long lifespan, just about a week, just long enough to mate and lay eggs.

The U.S. Department of Agriculture notes that the caterpillars emerge from the eggs at about the same time that trees begin to grow in early spring. While the larvae feed on many different species of trees, on Long Island they can be found on oak,  pine, catalpa, dogwood, American holly, mountain laurel and arborvitae.

Encouraging birds to nest in your garden will help somewhat, as they will eat the caterpillars. But in a major infestation, they just can’t keep up.

The Dept. of Agriculture notes that most healthy trees can recover from infestations and grow a new set of leaves, but that trees already weakened by disease are more likely to die as a result of severe infestation. Repeated infestations also weaken trees, making them more prone to disease. Weather can affect outbreaks. Severely cold winters can kill the eggs, for example.

By now, the worst is over. But, as a gardener, what can you do if you are concerned about a future infestation? Because the life cycle of gypsy moths is year-round, control must be also. Don’t assume that now that the caterpillars are gone, the problem is over. They’ll be back again next year. The Dept. of Agriculture recommends the following:

* Diversify the type of trees you have in your garden
* Destroy egg masses if you see them — they look like a tan colored mass on wood (even firewood and wood furniture), and under leaves.
* Feed, water and fertilize trees as needed to keep them healthy. That way they can recover more easily in a major infestation.

Next spring:
*Use a band of burlap around the base of your trees, particularly oaks, in spring. Lift it up periodically to see how bad the infestation is. Then remove and destroy caterpillars manually if you can.
* Use double sided tape around trees to prevent the caterpillars from climbing up the trunk to the leaves.
* If you’ve had a particularly bad infestation this year, consider having a professional apply a pesticide next spring. This is a last resort, only to be used if your trees were badly damaged this year.

Ellen Barcel is a freelance writer and master gardener. To reach Cornell Cooperative Extension and its Master Gardener program, call 631-727-7850.