Fight the bite — Mild winter means big, bad mosquitoes season

By Jenny Neyman

Photo by Jenny Neyman, Redoubt Reporter. An adult female mosquito is drawn to exposed flesh by warmth and carbon dioxide, seeking a blood meal with which to lay eggs and complete its life cycle.

Redoubt Reporter

Summer arrived with a vengeance last weekend, with the central Kenai Peninsula’s first memorable occurrence of sustained warmth and shade-worthy brightness so far this season. The sun’s siren call enticed people outdoors in droves to work, recreate or just laze about and enjoy the weather.

But Alaska rarely gives a carrot without some sort of caveat: Abundant run of sockeye salmon? Beware of bears. Midnight sun? You’ll have to create your own dark to sleep. Pleasantly warm weather? Watch out for bugs.

Not that anyone needs to put any particular effort into noticing bugs so far this summer, as mosquitoes are out in droves far thicker than the crowds at even the busiest campgrounds and fishing holes.

“Yeah, they’re thick. I’ve got bites all over me,” said Janice Chumley, integrated pest management specialist at the University of Alaska Fairbanks Cooperative Extension Office on Kalifornsky Beach Road.

“They’re buzzing around me right now,” agreed Dr. David Wartinbee, a biology professor at Kenai Peninsula College. “I would say that they’re pretty aggressive, and there’s lots of them.”

Large, aggressive mosquitoes have hatched in abundance on the Kenai Peninsula, thanks to favorable conditions during the winter.

“It’s because we had a lovely, mild winter,” Chumley said. “All that large amount of snow was the perfect insulating layer. It caused the ground not to freeze very deep, so all the bugs said, ‘Thank you,’ for the large quantities of snow that insulated the ground so well. If you have a deep-enough freeze — if the frost goes deep enough into the ground before it snows enough — it kills the insect larvae and knocks back (the bug population) for a couple of years. But when we have a large snow layer before it gets frozen, then you have a lot of insects.”

Don’t spring to conclusions — Springtails not to blame for skin rashes

By Dr. David Wartinbee, for the Redoubt Reporter

Photos courtesy of Dr. David Wartinbee. Collembola specimens are shown next to millimeter markings. Below, a “springtail” is enlarged at over 50 times magnification. They usually are around 4 millimeters long, or the size of the letter “i.”

During the past few months I have been sorting through samples I collected last year from a number of streams and lakes. While I am mostly interested in dipteran insects, I frequently come across other aquatic creatures that pique my interest.

The midges I am looking for are very small, but recently I came across a number of the smallest known aquatic insects, called collembola or springtails.

Springtails are wingless creatures that rarely get larger than a few millimeters in length. They are often only as long as the letter “i” in this paper. The one in the picture is only 4 millimeters long and is magnified more than 40 times.
Within the taxonomic arena, collembola have recently become somewhat of a football.

Dozens of my invertebrate books clearly place them within the class Insecta, since they look like insects and have six legs. Up until recently, that is all I have ever known them to be.

Now, DNA analysis indicates that they are not closely related to other insects and should be classified differently.

Currently they are being described as hexapods (six-legged arthropods) that belong within the class Entognatha. This new class consists of arthropods with an internal jaw, which differs from insects since they have external jaws. No matter what their proper names, they are quite interesting creatures.

Don’t let the bedbugs bite — What to do with pesky bugs making peninsula inroads

By Naomi Klouda

Photo courtesy of Cooperative Extension. The pesky bedbug has been found on the Kenai Peninsula.

Homer Tribune

Bedbugs disappeared from America for the most part about 1940, but since 1990 they have made a comeback as itchy irritants hitchhiking their way from larger cities to smaller towns.

Including, apparently, Homer.

Nowadays, there are new weapons in the form of dogs trained for detection.

“Just like you have dogs that can sniff out drugs, or to sniff out bombs or cadavers, these are dogs that trained specifically to sniff out bedbugs and their eggs,” explained Randy Beuter, owner of Eagle Pest Control and Trees.

For professional verification on bedbugs, Beuter teams up with a beagle named Rudolph provided from the National Anthropology Scent Detection Canine Association, which certifies the dogs in a testing program. These are expensive teammates, not unlike a police dog.

All the better to help root out what appears to be a growing problem.

The Kenai Peninsula Cooperative Extension Service branch of the University of Alaska Fairbanks has received calls and dispenses advice on what to do when people find themselves sharing beds with the bugs. Janice Chumley, integrated pest management technician, identifies the bugs for people.

“That’s my job. People bring me bugs, including bedbugs. Before DDT was done away with, bedbugs were just a part of life. Since heavy chemicals like that are no longer in use, there has been a resurgence of them worldwide,” Chumley said. “People shouldn’t be surprised to see them everywhere.” 

Science of the Seasons: Phantom bugs can barely be seen

By Dr. David Wartinbee, for the Redoubt Reporter

Photos courtesy of Dr. David Wartinbee. These phantom midges are only three-quarters of an inch long. The dark spots are eyes, just behind the pointed mouth area, with two pairs of dark hydrostatic organs in the thorax and far end of the abdomen. These organs control the larval movements up and down in the water column.

Ever since August when I saw a huge mass of bright red larval mites drifting across part of East Mackey Lake, I have been wondering if the mites had been successful parasitizing any of the aquatic insects in the lake.

The experts I contacted indicated that this massive swarm might have been a way for them to find unfortunate hosts. Last week, I took my dip net and collected a number of insects and other invertebrates from the lake. After a lot of very careful looking under a microscope, I did find some parasitized insects, which I’ll discuss in a future article. There were also several creatures in my first sweep that caught my immediate attention — dozens of phantom midges darting about in my collection pan.

Phantom midges are relatives of the mosquito but do not bite. The particular ones I found were in the genus Chaoborus. Thinking back, these were the very first aquatic insects I saw when I was doing a senior project as an undergraduate biology major. I was sampling bottom sediments of a local reservoir and I remember seeing something moving in the collection pan, but was unable to tell what it was. The insects were crystal clear, about three-quarters of an inch long, and only a couple dark spots stood out in clear water. The name phantom midge was certainly appropriate.

These creatures are the larval form of a small dipteran insect found all over the world. Knowing how widely distributed they are, I should not have been surprised to see them here in Alaska. Maybe my surprise came because I have always found them in waters that were tens or hundreds of meters deep, instead of in a waist-deep section of lake. Depending on the species, they spend between six months and two years as a larval individual in a lake. They have a short pupal stage, then emerge as an aerial adult. The adults mate, lay eggs and die within a couple weeks and the cycle starts all over.

Mite concerning — Red mass on East Mackey Lake leaves biologists scratching heads

By Dr. David Wartinbee, for the Redoubt Reporter

Alaskans have been seeing red quite a lot lately.

Photos courtesy of Dr. David Wartinbee. A mysterious red mass drifts to the shore of East Mackey Lake on Aug. 4. The mass is thought to be a massive hatch of larval mites, though it’s not known for sure why so many ended up on the surface at the same time.

We recently heard about reddish-colored fungal spores that were found en masse in Kivalina. Then there was red-colored water in Kachemak Bay, similar to a red tide, though not harmful. Apparently it’s now the central Kenai Peninsula’s turn.

I was taxiing my plane to the dock at the northern end of East Mackey Lake on Aug. 4 when I spotted a 100-yard streak, between 10 and 30 feet wide, of bright red stuff in the water. As I tied up the plane, the wind shifted and this fire-engine red material drifted toward the plane.

As an aquatic biologist for 40 years, I had never seen anything like this and was way beyond curious. I took photographs as it approached and got out a jar to collect a small sample. Yes, as a geeky biologist, I almost always carry a few jars for collecting bugs or other interesting things.

The red stuff was on the surface of the water and was made up of very small particles.

Worms crawl in, cause damage in refuge — Study tracks possible wriggling invasion

By Joseph Robertia

Photos by Joseph Robertia, Redoubt Reporter. Deanna Saltmarsh holds up a preserved nightcrawler sample, one of several worms she collected this past summer while conducting research on invasive species at the Kenai National Wildlife Refuge as part of a graduate project through Alaska Pacific University in Anchorage.

Redoubt Reporter

Anyone who thinks their desk is a mess should see Deanna Saltmarsh’s workspace. It’s one thing to be piled with stacks of paper and associated office debris. It’s quite another to be buried in more than 300 worms.

“I’ve collected 336 worms, to be exact,” she said. “My friends bet me I’d end up being called ‘the worm lady,’ and within the first two weeks that’s what everyone was calling me. I knew it would happen.”

Saltmarsh earned her moniker this summer while conducting field research and collecting samples of earthworms from the Kenai National Wildlife Refuge as part of a graduate project through Alaska Pacific University, in Anchorage. She said she is actually more interested in the effects the worms are having on the environment, than in the worms themselves.

“I’m really interested in invasive species in general,” she said.

This may sound confusing to anyone with a green thumb, but Saltmarsh said that while worms in a garden are a good thing, they may not be as beneficial for the environment outside raised beds and planting boxes, for much the same reasons.

In gardens, earthworms aerate the soil, mix organic material into the soil profile and process coarse organic debris into a form that can increase nutrient availability. But these soil-altering abilities also mean that when they successfully invade regions naturally devoid of earthworms, something is likely to change.

“They’re good in an agricultural setting, but not so good in a forest ecosystem,” she said. “They can limit plant species diversity and plant species richness, they can change nutrient cycling to produce more grasses and weeds, and they can lend to erosion by their consuming of the organic material from the forest floor, which can leave bare earth and plants with their roots exposed.”

Moth feeding frenzy infiltrates trees

By Naomi Klouda

Photo provided. A caterpillar and the results of its feeding frenzy are seen on a leaf earlier this summer.

Homer Tribune

A certain hungry caterpillar is eating its way from Matanuska-Susitna region shrubbery to lower Cook Inlet salmonberries, proliferating in an abundant population that has gardeners worried.

An army of caterpillars is capable of stripping trees and bushes of foliage. But birds sure aren’t complaining.

“Song birds and migratory birds are stuffing themselves on the caterpillars,” said Janice Chumley, an agricultural-horticultural and integrated pest management research technician with the Kenai district of the University of Alaska Fairbanks Cooperative Extension Service.

“This was the second year when we saw this high of a population, which tend to run in cycles,” she said.

Complaints have poured into the Cooperative Extension Service’s Kenai Peninsula office from property owners concerned about the copious consumption of leaves on alders, willows, ornamental plants and beloved berry bushes. While other moth species can eat their way through shrubs sufficient to cause some damage, the main culprits are the autumnal moth and the Bruce spanworm that seem to cause most of the defoliation currently being seen on such a large scale.

According to an article, “Geometrid Moth Information and Control,”  compiled by Michael Ray, of the Cooperative Extension Service, and John Lindquist of the U.S. Forestry Service, the autumnal moth originated in Europe, and was reportedly first seen in Alaska in 2005. The Bruce spanworm is caught flying even in snowstorms and is native to Alaska.

Spruce up — Bumper cone crop aids reforestation on the peninsula

By Joseph Robertia

Photo by Joseph Robertia, Redoubt Reporter. Spruce trees are weighed down with a bumper crop of cones this winter, which will be used for reforestation projects in areas heavily affected by the spruce bark beetle infestation.

Redoubt Reporter

Local spruce trees may look a little stooped these days, and it’s from more than just snow load. They’re also bowing under the weight of a bumper crop of cones.

“Last year was a good cone crop statewide,” said Wade Wahrenbrock, a forestry/fire analyst with the Kenai Peninsula’s Spruce Bark Beetle Mitigation Office.

The cones visible on spruce trees this winter were produced last summer with the buds set the year before that, Wahrenbrock said. The cones typically shed their seeds from August to September, but continue to hang on the tree for a while longer.

High-quantity cone crops are typically only produced every 10 to 12 years, so this past summer, while many trees still had their seeds intact, the bark beetle program, with assistance from the state Division of Forestry, took advantage of this ecological situation. For the first time since 1998, they harvested seeds to be used for reforestation projects.

“We collected 2.5 million seeds from six different sites around the peninsula,” Wahrenbrock said. “We tried to collect from various climate zones around the peninsula.”

Though peninsula spruce trees are all the same species, typically white spruce or Sitka spruce, or a hybrid of the two, trees in Nikiski aren’t exactly like trees in Homer, due to slightly different temperatures, rainfall and other factors.

“When we start seeding we’ll try to use ones that are the closest match to the selected areas,” Wahrenbrock said. “This offers the seedling the best chance of surviving and thriving.”

Science of the Seasons: Pretty interesting — Sedge darner dragonflies are colorful creatures

By Dr. David Wartinbee, for the Redoubt Reporter

Photos courtesy of Dr. David Wartinbee. A sedge darner dragonfly, in the Aeshnidae family, shows off its colors against the blue tail wing of a plane.

This summer, I spent a lot of time around local lakes because I added float flying to my repertoire of favorite activities. In preparation to each flight, there are a variety of preflight checks around the airplane, like pumping out float chambers and loosening the tie-down ropes. Every time I started doing things around the plane, a local inspector sped over to check out the intruder. I was a questionable visitor in an otherwise-established territory.

The inspector was a large male dragonfly, with the common name sedge darner. Those of us interested in aquatic insects know him better as Aeshna juncea. He was a colorful dragonfly with clear wings and blue-and-yellow stripes along the otherwise dark abdomen and thorax.

This dragonfly is more than 3 inches long with a wingspan of about 3 inches. It is a very agile flier that can speed around at close to 35 mph. That flight speed enables him to catch virtually any other insect and to avoid predation by most hungry birds. His head is dominated by large, multifaceted eyes that enable him to spot prey and avoid predators. Each facet is an individual eye structure called an omatidia. When all the individual omatidia are combined, these dragonflies have extraordinary vision.

Sedge darners feed voraciously on small insects, like mosquitoes, midges and other dipterans. Their diet depends on what happens to be around and available. During August, a sedge darner established a feeding territory around our gardens. While I was happy to have a mosquito-feeder in the area, I was not as pleased to watch it periodically feeding on one of my honeybees.

Interestingly, when they feed on larger prey, like a honeybee or hornet, they will land and slowly chew up the captured insect. When they capture smaller prey, like mosquitoes, they will most often continue to fly around the territory and leisurely feed on the wing.

Science of the Seasons: Strength in numbers

By Dr. David Wartinbee, for the Redoubt Reporter

Photo courtesy of Dr. David Wartinbee. Chironomid pupal skins are seen after a large number of them have emerged from the Kenai River. With so many emerging at one time, predators get satiated or confused with all the individuals.

In my backyard the sun has just popped out from behind a cloud and there are patches of brightly lit grass in the yard. Right above several of these bright spots are swarming aquatic insects. These are the nightclubs where males meet females. The males do their own version of karaoke and attract the females into the swarm with high-pitched notes. Within the swarm is where exchanges of gametes take place, so females can then deposit their fertilized eggs in an appropriate setting.

These insect swarms demonstrate a couple interesting ecological phenomena. First, it shows that many members of the same species have synchronously gone from being an aquatic larva to an aerial adult. Most aquatic insect adults live only a very short period of time. Many live only a week but some are limited to a couple days.

During that short window of opportunity they have to find members of their same species, attract a mate and take care of reproductive imperatives. There is no time for delay since the clock is rapidly ticking away. It is important that the larvae of the species be watching the same play book and that the majority of the population do their emerging at the same time.

Remember that most aquatic insects spend about a year as an aquatic larva or nymph. Many then go through a short pupal period and leave the water to become an aerial adult. With lots to do and very little time to do it, it is critical that the majority of the individuals become adults all at the same time. In order to have everyone emerge at the same time, each species seems to look for a particular environmental cue or series of cues. Light provides a major clue for many species. That light cue may be a change in light, such as the change from light to darkness in the evening, or the other way around, such as when the light breaks the darkness in the morning.

Another frequently used environmental cue is water temperature. Many insects require a number of days at a particular temperature in order to complete their growth before emergence. Then, once growth is completed, they need a temperature cue to time their emergence. Some insects emerge when the water temperatures are starting to rise or perhaps when the water temperatures peak.

These environmental cues or triggers also help the particular species go through emergence, when they will have the greatest margin of safety from potential predators. For example, a larger-sized insect might emerge after a change from light to dark, so the adults emerge in darkness. This provides the new adult with some initial protection from visual-feeding predators like dragonflies.

Most insect species seem to follow a particular emergence pattern. No matter what cues they follow, by synchronously emerging, the members of the population are then likely to find a mate and successfully reproduce. The patterns of emergence throughout the summer months are known as seasonal phenology, while the hourly timing sequences are known as diel emergence patterns.

Another aspect that these swarms demonstrate is there is relative safety in large numbers of individuals. While the swarm is an obvious display to potential predators, predators have difficulty feeding in these situations because of the huge numbers of individuals. The large numbers of individuals and their constant movement is confusing to a would-be predator.

As an example, when you see a swarm of insects or a flock of birds, try to concentrate on following a single individual. Nearby individuals will distract your concentration and then the original individual is gone.

Another reason these swarming activities are fairly successful is the sheer number of insects in the swarm. The potential prey individuals overwhelm the needs of local predators. If a swarm consists of a thousand individuals, the loss of even a dozen is a loss of only 1 percent to 2 percent, and that reduction will probably have little impact on the number in the next generation. Essentially, the predators become satiated and stop their feeding efforts.

As an example, a large brown bear will only consume about eight to 10 salmon before leaving the stream area to sleep off its gluttony. Meanwhile, the rest of the migrating salmon move on unmolested.

In many cases, predators are widely scattered due to territories they vigorously defend. If you have a large dragonfly that buzzes around your yard, it is probably the only one present since the male sets up and maintains a well-defined feeding area. The only other dragonflies allowed into the area are females. Once that territorial dragonfly has fed to its limit, and no other dragonflies are allowed into the area, the remaining swarms are left undisturbed.

The easily spotted insect swarms along rivers and lakes turn out to be fairly safe meeting places for insects as they complete the reproductive phase of their life cycles.

David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the ecology of the Kenai River and Cook Inlet watershed.

Science of the Seasions: Big ecological advantages come from being small

By Dr. David Wartinbee, for the Redoubt Reporter

While walking around parts of Mackey Lake, I couldn’t help but notice huge numbers of very tiny aquatic insects along the water’s edge. I recognized them as midges, which are some of the tiniest aquatic insects. Some of the full-grown adults may only be the height of the lowercase letters in this type font.

There were thousands of minute pupal skins left on the water, but even more adults were forming into miniature, cloudlike swarms. The swarms are initiated by males of the species that hover above an object, like a puddle of water, a light-colored rock or even over a light-colored picnic blanket. The males create a high-pitched sound with their wingbeats that is an irresistible siren song to the females. The attraction here is somewhat backward, since, in Greek mythology, it was the females who lured the males to come hither.

The attracted females enter into the undulating swarm of males, attach to a single male, and mating takes place quickly. The female then flies to a suitable aquatic habitat and deposits her fertilized eggs to start the next generation.

The mating swarms of these small midges are often during bright daylight hours and almost always occur in very easily seen areas. Are they tempting fate with their public displays? One would suspect that hovering above a brightly lit area would attract predators, like birds and dragonflies. But they seem to be completely left alone.

Here is where the insect’s small size starts to pay off. While there may be hundreds of insects in the swarm, each individual is so small, it isn’t worth a bird’s effort to chase one down to eat it. The amount of energy spent to capture an individual is more than the energy contained in the prize.

Imagine how much effort it would be for us to bend over and pick up a single poppy seed. We would expend more energy each time we knelt than would be gained by eating the seed. Maybe we can call this the Tiny Midge Diet — sell millions of books, make the rounds of talk shows … .

Let’s get back to reality. The bottom line is there are very few predators interested in chasing after these tiny insects because the effort is more energetically expensive than the reward. There are a few predators that seek tiny midges, but they are small themselves. If you look closely at the weeds around a lake or stream, you find a fair number of spiderwebs no more than a couple inches across. These webs are good at capturing very small flies. The spider doesn’t have to chase down the prey. Instead, the prey comes to her.

If you look even more closely, you may see the spider that made the web somewhere on the edge of the web. She isn’t much bigger than her intended prey, so even a tiny insect caught in the web turns out to be a big, energetic reward.

Perhaps this explains why we don’t often find bears chasing after small hooligan that spawn in the Kenai River about the time bears are hungrily coming out of their dens in the spring. When the larger salmon return to the river, bears make a concerted effort to capture them because salmon do provide a large, energetic reward.

There are hundreds of species of midges in our area and many of them are considerably larger. These larger insects can be more than a half-inch long and contain enough energy that birds actively work to capture them. These supersized midges are a favorite food source for birds, like swallows, that are seen zooming back and forth over local rivers and lakes. Interestingly, since they are a target food item for numerous birds, these larger midges tend to form their swarms away from the limelight. Many of these midges rest under leaves during the day and swarm during dusk or evening hours when avian predators are less active. While a change in swarming habits helps them avoid bird predators, their swarming times make them a target for little brown bats.

Many animal behaviors revolve around the trade-off of energy expended compared to the energy in the food that is acquired. Small insects contain so little energy for a consumer that most predators don’t waste their time with them. When the energy reward increases, then predators are more willing to seek out that food source.

David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus.

Science of the Seasons: Rotifers well worth the little peek

By Dr. David Wartinbee, for the Redoubt Reporter

Photo courtesy of Dr. David Wartinbee. This picture shows two rotifers. One is somewhat retracted while the other is stretched out and has its corona expanded with cilia somewhat visible at the end. It is actively filtering water and straining particles out of the water column. The oval structure below the corona (headlike structure) is the grinder organ called the trophi.

Back in the 1700s, the early microscopist Anton van Leeuwonhoek noted that if he took dried materials from a rain gutter and added water, within a few days there were tiny animals moving around. He was observing anhydrobiosis of a group of organisms known as rotifers. These tiny aquatic animals were able to survive desiccation and then seemingly come back to life when inundated again.

Like Leeuwonhoek, virtually every biologist who has looked at a drop of pond water has seen these interesting creatures. Rotifers can be as long as a millimeter, but most are only a 10th of that. While some might be visible to the unaided eye, most are transparent so it really does take a microscope to see them.

The most prominent feature of rotifers is the source of their name. They have a ring of cilia on the top of their corona (head) that creates currents of water toward, and into, their mouth. These cilia arrangements and their movement was seen by early biologists and the animals were described as “wheel-bearers.” We now understand that there isn’t a spinning wheel on their head area, but rather a bunch of cilia beating synchronously. These cilia function in feeding and also give them the ability to actively swim from one place to another. The rhythmic beating cilia enable some rotifers to swim up to 1.5 millimeters per second. Thus, they can search for food or run away from predators.

Their primary food sources are algae, minute pieces of organic detritus and small protozoans. Once they have swept the particles into their mouth area, another unusual structure comes into play. Within their muscular pharyngeal area is an oval-shaped, gizzardlike grinding structure called trophi.

The trophi enable rotifers to literally grind up their food particles just like we chew our burger and fries. From there, the even finer particles pass into their short intestinal structure for absorption of needed nutrients. Perhaps one of the points about rotifers that biologists marvel at the most is the complexity of structures and organ systems in such a tiny organism.

Oh, and yes, they have a very tiny brain and sometimes eyespots for detection of light.

At the other end of these creatures we often find a pointed footlike structure with miniscule toes. Their toes enable them to attach to structures like a convenient plant stem or mass of detritus. Once attached, they can stretch out and filter food from the water column or retract themselves when they sense danger.

Rotifers are common in all fresh waters and some even thrive in brackish or marine waters. There are many different species and some like to be on the bottom while others seem more comfortable swimming freely in the middle of the lake. While they are tiny, they can be found in large numbers in certain situations. For example, they can be extremely abundant in sewage treatment ponds since there is so much organic detritus available. In low-nutrient, oligotrophic lakes of Alaska, they will probably be in greatest abundance along the shoreline and on the bottom sediments. There are rotifer species that seem to prefer just about every imaginable aquatic situation, such as low oxygen levels, high temperatures or even highly alkaline waters.