Monday, October 31, 2011

Ants: Facts and Fiction, by Eleanor Spicer Rice, NCSU Entomology Dept.

Think you’re an ant expert? Quiz yourself with these quirky questions about some of our favorite insect friends. The answers may surprise you!
  1. (True/False) Most ants are pests.
  2. (True/False) All ants have nests.
  3. (True/False) There is an Argentine ant colony right now with billions of workers that spans nearly 4,000 miles.
  4. (True/False) Ant workers are both male and female.
  5. (True/False) Smaller ants never grow up to be bigger ants in the colony.
  6. Which of the following is an effective home remedy for killing fire ants? (A) dumping grits on the nest; or (B) dumping a pot of boiling water on the nest 
Time to check your super ant knowledge!

Question 1: Most ants are pests. 
This is false! In fact, most ants are NOT pests! Of the more than 30,000 ant species in existence worldwide, fewer than 100 of them are pest species. And in North Carolina alone, fewer than a dozen of the over 250 known species are pest species.

What do all of the other ant species do? Ants are a valuable part of our ecosystem. Because they fill so many jobs, from predators and scavengers to plant protectors, they play a central role in maintaining the ecological balance and biodiversity present in our natural world.

Aphaenogaster carolinensis (Photo: Alex Wild, alexanderwild.com).
Some ants, like a group in North Carolina called Aphaenogaster, are responsible for planting seeds in the forest floor. Many seeds have evolved a tasty outer layer that ants love to snack on. After they remove this delicious shell, the ants plant the seeds in the ground. Without Aphaenogaster and ants like them, we would be missing a lot of our forest herbs.

Ants also protect plants from harmful insects and even aerate the soil as they dig out their nests. It has been estimated that ants turn more soil than earthworms!

Question 2: All ants have nests. 
This is also false! African driver ants and army ants do not have nests. These restless wanderers travel around without stopping, eating everything in sight. When the driver ants come through villages in Africa, residents pack up all their things and move out, allowing the ants to clean up after them. Check out the video below to see army ants in action!



Question 3: There is an Argentine ant colony right now with billions of workers that spans nearly 4,000 miles. 
It’s true! Argentine ants are little brown ants that look a lot like odorous house ants, also known as sugar ants, which are pretty common around here. Unlike odorous house ants, Argentine ants don’t fight each other, which allows them to form tremendous colonies called supercolonies like the one that spans nearly 4,000 miles of the Mediterranean coastline. We have a couple of supercolonies in North Carolina, too! Although they don’t sting, these miniature marauders are ruthless and can wipe out native ant populations when they move in. As we learned from question 1, we need our native ants!

Question 4: Ant workers are both male and female. 
False! All ant workers are females. Ant colonies have a female queen and female workers. Colonies only produce males once or twice a year. However, males don’t do any work. Their only purpose is to eat and mate (sound familiar, anyone?). After mating season is over, the female workers take girl power to a whole new level by either kicking the males out into the cold or eating them.

Fire ants range in size from 2-6mm. Nests typically contain workers in a range of sizes
(Photo: Texas A&M Univ.)
Question 5: Smaller ants never grow up to be bigger ants in the colony. 
It’s true! Although some colonies have workers of many different sizes, the littlest ones are fully grown. That’s because ants have something called complete metamorphosis. That means they’re like butterflies, flies, and beetles in how they develop from egg to adult. Just how a beetle baby is a grub, an ant baby is a grub-like larva. Ants pupate like butterflies and moths do, too. After they pupate, they emerge as fully grown ants.

Question 6: Which of the following is an effective home remedy for killing fire ants? (A) dumping grits on the nest; or (B) dumping a pot of boiling water on the nest.
The answer is B. A lot of people have tried dumping grits on a fire ant nest, but it just doesn’t work. First of all, as many North Carolinians can attest to, grits aren’t poisonous! Second of all, ants have tiny waists and can’t process grits by themselves.

Even so, some people insist they’ve poured grits on fire ant nests and come back to find the fire ants all gone. This could happen, as fire ants move around frequently and don’t like people tampering with their nests. However, it’s important to note that these fire ants just moved; they were not killed by the grits.

Dumping boiling water over the nest can put a swift end to fire ant mounds. This is because the scalding water boils the ants alive. Adding a little detergent to the water can increase effectiveness, too! The water must be boiling, however. Fire ants are used to flooding and can make rafts out of workers. If the water is not hot enough to kill them, they can just float away.

Using boiling water to treat a fire ant nest does have its limitations. First, you've got to get the boiling water outside to the nest without scalding yourself. Second, the boiling water can actually damage and/or kill any vegetation that's around the treated area. So, while it does work, boiling water is not always the most practical way to treat a fire ant nest.

Thursday, October 27, 2011

Insect of the Week - The Antlion

Antlion larva
(Photo: Alex Wild, http://www.alexanderwild.com)
Antlions are quite fierce and scary looking. One look and you know you're dealing with a voracious predator (see photo above)! The antlion digs a pit in sand or other loose soil and hides beneath the sand at the bottom of the pit. When an ant or another small insect comes by, it falls into the pit where it slips to the bottom and is grabbed and made into a meal by the antlion. If the prey attempts to scramble up the walls of the pit, the antlion throws loose sand from below. This causes the sides of the pit to collapse, bringing the prey down into the bottom of the pit.

Check out this awesome video to see an antlion in action:  http://www.youtube.com/watch?v=7lYAWwMOCXE

Adult antlion (Photo: Joseph Berger, Bugwood.org)
An antlion is actually the larval form of what will become a beautiful, dainty lacewing. The adult has two pairs of long, narrow, multi-veined wings, and a long, slender abdomen (see photo at right). Adult antlions look very similar to small dragonflies or damselflies, but are easily distinguished from these insects by their prominent, clubbed antennae (dragonflies and damselflies have very short, bristle-like antennae). Also, adult antlions are typically active in the evening, so they are normally not encountered as often. Lacewings are attracted to light so it is not uncommon, however, to see them around porch lights at night.

Antlions are commonly referred to as doodlebugs because they leave lines in the sand that resemble "scribbling" or "doodling" as they meander through the sand searching for the perfect place to make their pit. Check out the video below to see an antlion "doodling."

http://www.youtube.com/watch?v=exzPhd1abnw&feature=fvwrel

Antlion pits (Photo: Whitney Cranshaw, CSU)
You can easily observe antlion behavior in nature. If you ever run across an antlion pit, you can use a small blade of grass to brush the sides of the pit. This will usually cause the antlion to flick sand up in the pit. You can also capture an antlion by carefully scooping out the entire pit (using your hand or a cup), being careful to dig deep and wide enough so the antlion isn't crushed. Pour the sand through a strainer until you see the exposed antlion. 

Thursday, October 20, 2011

Insect of the Week - The Wheel Bug

Adult wheel bug
(Photo: Johnny N. Dell, Bugwood.org)
The wheel bug is an assassin in the insect world, literally. The wheel bug belongs in the Family Reduviidae, commonly referred to as assassin bugs, and for good reason! These insects are predators and pierce their prey (soft-bodied insects such as caterpillars, moths, aphids, small beetles etc.) with their beak-like mouthpart and inject a potent saliva. The saliva contains enzymes that quickly subdue the prey and then digest the tissues inside. The wheel bug then sucks this digested liquid from the prey as it shrivels up. What a way to go! Wheel bugs are not aggressive and will try to avoid contact, but can inflict a painful bite if aggravated or handled, so it's best to leave it alone if you run across one.
Wheel bug egg mass and hatched nymphs
(Photo: Johnny N. Dell, Bugwood.org)

The wheel bug is one of the largest assassin bugs in NC; adults measure 1 - 1.25 inches in length. They are very distinct looking, sporting a large, gear-shaped half wheel on their thorax and a large, piercing beak tucked under the head.

In the fall, female wheel bugs lay masses of eggs by gluing them to bark or some other object. Tiny wheel bug nymphs hatch in April and May and begin to feed on aphids and other small insects. As nymphs develop they become larger and thus capable of attacking larger prey. When prey is scarce, wheel bugs feed on other wheel bugs, and female wheel bugs commonly feed on male wheel bugs after mating.

Check out the spectacular video below by Daniel R. Jusino, Rutgers University Entomology Department. It showcases the wheel bug and includes some amazing footage of nymphs hatching, molting, and feeding.



Friday, October 14, 2011

Insect of the Week - The Ladybug

Adult ladybird beetle
(Photo: Scott Bauer, USDA)
Since we've all heard the life cycle, habits, and problems with ladybugs ad nauseam, I thought it might be fun to write about fun facts about the beetles instead. For those of you that would like more information on the above aspects of these beetles, please see our fact sheet: http://insects.ncsu.edu/Other/goodpest/note107.html

Ladybugs aren't really bugs. 
In the entomology world, the term bug refers to insects in the Order Hemiptera. Ladybugs are beetles and belong to the Order Coleoptera. Us entomologists refer to ladybugs as ladybird beetles or lady beetles since they are not really bugs. But I won't mind if you still call them ladybugs. If you want to know what makes an insect a true bug, you can read more here: http://www.cals.ncsu.edu/course/ent425/compendium/hetero~1.html

Where did the name "ladybird" come from?
The most common species of lady beetle in Britain is the seven-spot ladybird beetle. This bright red ladybird has seven spots and is thought to have inspired the name ladybird. Lady, referring to the Virgin Mary (Our Lady), is seen wearing a red cloak in early paintings; the seven spots are symbolic of the seven joys and seven sorrows of Mary.

Lady beetle larva attacking aphids
(Photo: David Cappaert, Mich. State Univ.)
Immature lady beetles look like monsters and are voracious predators.Both the larval and adult forms of predatory ladybird beetle species feed on a wide variety of insects, including aphids, scale insects, and other insect larvae (including other lady beetle larvae). Both the adults and larvae actively hunt for prey in field crops, gardens, and ornamental trees and shrubs.

Do lady beetles get bigger as they get older?
No. Once an adult, it stays the same size for the rest of its life. Insects wear their skeleton on the outside; therefore, they must molt in order to grow. Insects with complete metamorphosis, including the lady beetle, do not molt as adults.

Ladybird beetles ooze blood from their leg joints when alarmed.A lady beetle's blood, referred to as hemolymph, is both toxic and smelly. When a ladybird beetle is startled, the blood seeps from its leg joints, leaving a stink and yellow stains behind. These secretions from the leg joints also taste bad and protect the beetles from being eaten from predators such as birds.

The lowdown on lady beetle spots.
Variations of spot patterns and colors of the
Asian mulit-colored lady beetle
(Photo: Bill Ree, Texas A&M Univ.)
The spots on a ladybird beetle do not tell its age. The sex of a lady beetle cannot be determined by the number of spots either. The spot patterns of the beetles vary widely from species to species. The number of spots and the color among ladybird beetles of the same species can vary greatly as well. The bright colors and spots of lady beetles warn predators that they taste yucky.

Can I keep a lady beetle as a temporary pet?
Sure! Keep your ladybird beetle in a bug box or terrarium-type container. Keep the container and foliage moist by gently misting the interior container with water using a spray bottle. You can feed your lady beetle moistened raisins or other sweet, non-acidic fruits. Or you may want to collect some aphids from ornamental shrubs and place them in the container for the beetle to eat. You can even watch the entire life cycle with a ladybird rearing kit (can be purchased online) where you get to watch the larvae grow and turn into adult ladybird beetles.

Wives tales and superstitions about lady beetles:
  • The ladybird beetle is supposedly a luck-bringer. I was always told that it was a sign of good fortune if one landed on a person. The beetle must, however, be allowed to fly away on its own and not be brushed off. Supposedly, you can cause the lady beetle to fly away by singing a children's nursery rhyme, which goes like this:
Ladybird, ladybird, fly away home. 

Your house is on fire and your children are gone. 
All except one, and that's Little Anne.
For she has crept under the warming pan.
  • If a ladybird beetle does lands on you and then flies away, then watch it carefully; the way it flies is the direction of your true love.
  • If a ladybird beetle enters your house, a visitor will come (for folks dealing with large numbers of lady beetles invading their house this fall, this may or may not be good news!). 
  • In northern Germany, it was believed that if the ladybird beetle had less than seven spots, then they would have a large harvest.




     

    Wednesday, October 5, 2011

    Insect of the Week - Carolina Mantid

    Carolina mantid
    (Photo: Patty Alder, NCSU)

    Mantids are one of the most well-recognized groups of insects. One of the most distinctive features about mantids is their large, grasping front legs, which they use for grabbing and holding prey. Mantids have a very elongated prothorax and a triangular-shaped head, which they can turn in nearly all directions. The mantid is commonly called the praying mantis, which comes from the way it holds the front legs in "prayer-like" stance. They are sometimes mistakenly referred to as the "preying mantis" because they are predatory, feeding on a wide variety of other insects.

    There are actually several species of mantids found in NC. The European mantid and the Chinese species were introduced in the northeast about 75 years ago as garden predators in hopes of controlling the native insect pest populations. The Carolina mantid is a native insect.

    Carolina mantid egg case
    (Photo: Jim Kalisch)
    Carolina mantids overwinter as eggs. Females lay eggs in large masses in a frothy material that hardens into a protective shell, called an ootheca. The new mantids hatch in the spring and mature into adults over the summer.

    Mantids are beneficial insects; they feed on other insects, some of which we consider pests. However, their overall effectiveness in pest management is small, especially compared to other insect predators, such lady beetles and green lacewings. This is due to their cannibalistic nature which limits the number of mantids in a particular area.

    Rearing mantids
    A glass jar set-up for rearing mantids
    (Picture: Univ. of AZ)
    If you have kids, or if you just want a cool "pet" yourself, egg masses can be collected in the fall and brought indoors. Mantid egg cases and young mantids can also be purchased online. Because they are in a warm environment, the mantids may actually hatch as early as December once brought indoors. It's a good idea to have several small containers available because when they hatch, large numbers of very tiny mantids will suddenly appear. If they do not have fresh, live food available, they will eat each other until only one or a few mantids are left.

    Small flying insects that are attracted to porch lights are a good source of food for the newly emerged mantids. As they get older and larger, they can be fed larger insects, such as crickets, which can be purchased from pet shops. Mantids do need water, which can be provided by gently misting the inside of the container once a week. Or place a small, wet sponge in the container that the mantid can collect water from.

    For more information on rearing mantids, see this rearing sheet prepared by The Center for Insect Science Education Outreach, University of Arizona:  http://insected.arizona.edu/mantidrear.htm.

    Monday, October 3, 2011

    Cool Weather Brings Not-So-Cool Pest Problems

    By Mike Waldvogel and Patricia Alder


    Fire Ants
    Moist soils and warm weather have made conditions suitable for fire ant mounds to pop up in various places. In most cases, there is still plenty of time to bait the ants. If someone has fire ants in locations that pose an imminent hazard to the public (e.g., playgrounds, school grounds, etc.), then a mound drench may be the best course of action. Any of the common pyrethroids labeled for turf will work. If there is concern about children coming into contact with the chemical, you can flatten the mound after it's been treated and the chemical has soaked down below the soil surface. Untreated soil can then be placed on top of the treated area. If the mounds are in less critical areas, stick with using baits.

    It's also important to remember that your options for treatment are often limited by the target site of application. There are many more products available for lawns and similar areas as compared to field crops, vegetables, and pastures (depending on the type of animals grazed). For that reason, Steve Bambara, recently retired Extension Specialist from NCSU, developed a program that you can use to select fire ant products based on application site and application preference (e.g., liquids vs. baits vs. granular insecticides). The program is accessible online: http://insects.ncsu.edu/fireant-products.

    Check our information about fire ants:
    http://www.ces.ncsu.edu/depts/ent/notes/O&T/lawn/note145/note145.html
    http://insects.ncsu.edu/Urban/ifa.htm

    Kudzu Bugs
    Kudzu bug (Photo: Phillip Roberts, Univ. of GA.)
    This is a relatively new pest that feeds on kudzu (but not enough to wipe it out). Unfortunately, it also favors soybeans and some other legumes where it has actually caused yield losses. Kudzu bugs are 4 - 6 mm long, somewhat oblong in shape, and olive-green colored with brown speckles. So far this year, it's been found in over 55 counties on kudzu and soybeans. On the homeowner side of things, this critter can be a significant nuisance when temperatures drop and days grow shorter. Like another well-known nuisance, the Asian lady beetle, the kudzu bug has the habit of invading homes while it seeks out somewhere to rest its legs (all six of them) and pass the winter. We've already heard of some complaints in Union County where the bugs have invaded homes. This has mostly been rural areas with homes adjacent to soybean fields (and likely some kudzu). There is no real effective chemical control to stop the invasion. So, be prepared for a lot of frustrated callers. For more information about the kudzu bug, check out this fact sheet: http://insects.ncsu.edu/Urban/kudzubug.htm.

    Multi-colored Asian Ladybird Beetles
    Multi-colored Asian ladybird beetle
    (Photo: Bill Ree, Texas A&M Univ.)
    Most of us have probably encountered this insect by now. Adult multi-colored Asian ladybird beetles are convex in shape and about 1/4” long. Specimens from higher elevations are larger than those from the Piedmont and Coastal Plains. There are usually ten black spots on each forewing, but some have fewer spots or faded spots and some have no spots at all.

    As temperatures start to drop in the fall, adult beetles begin to search for suitable overwintering sites. They tend to congregate on the sunnier or warmer sides of buildings, or on exposed, light-colored buildings. Of course, this doesn’t mean that people with dark-colored siding, brick or log homes are immune to the lady beetle assault. On warm winter days, the beetles may become active and move towards light or bright surfaces. They are often found on windows, light fixtures and ceilings.

    Ladybird beetles are primarily a nuisance. They do not eat wood or furniture. However, the beetles may stain fabric and painted surfaces if squashed. In addition, there have been concerns that large numbers of beetles may possibly cause air quality problems indoors that could trigger allergies and/or asthmatic reactions.

    While it is not 100% effective, preventing the beetles from entering structures is one of the best long-term approaches for dealing with ladybird beetles. Recommend that clients install tight-fitting sweeps on exterior doors and weather stripping around door frames. Openings where utility pipes and wires enter the foundation and siding should be sealed. Make sure that window screens are in good condition. Indoor sprays tend to be ineffective against ladybird beetles. Invading beetles should simply be vacuumed up. The vacuum bag should be sealed up and disposed of. Outdoors, a residual spray insecticide applied around windows, doors, eaves, soffits, attic vents, etc. may provide temporary relief.

    For more information on ladybird beetles, click here:
    http://www.ces.ncsu.edu/depts/ent/notes/Other/goodpest/note107.html

    Brown marmorated stink bug
    Brown marmorated stink bug
    (Photo: David R. Lance,  USDA)
    The brown marmorated stink bug was first detected in North Carolina in the Winston-Salem area in 2009. Adult brown marmorated stink bugs are slightly larger than 1/2” and vary in color from brown to gray. Adults have characteristic brown and white bands on the outer edge of the thorax, and white and brown banding on the next to last antennal segment. 

    In the fall, adult brown marmorated stink bugs aggregate on and inside houses, sheds and other structures in search of an overwintering sites. The bugs can give off a characteristic odor if they are crushed or disturbed.

    Just as with ladybird beetles, exclusion goes a long way in preventing brown marmorated stink bug invasions. Make sure exterior doors have tight-fitting sweeps, seal openings where utility pipes and wires enter the foundation, and make sure window screens are in good condition. The use of pesticides indoors for controlling the brown marmorated stink bug is not warranted; invading stink bugs should be removed with a vacuum cleaner. Outdoors, a residual spray applied around windows, doors, soffits, attic vents, and other potential entry points may provide some relief.

    For more information on the brown marmorated stink bug, check out our fact sheet:
    http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/note148/note148.html
     
    Paper Wasps
    Treatment of a paper wasp nest
    (Photo: Patty Alder, NCSU)
    Adult paper wasps are about ¾” to 1” long and reddish brown to dark brown in color with yellow stripes on the abdomen. Paper wasp colonies are annual; workers die off in the fall and only inseminated queens survive. The surviving queens are often seen hovering around chimneys and rooflines as they search for a suitable place to spend the winter. On warm winter days, the queens may become active and may move into living areas of the home through openings such as heating vents, baseboards, and gaps around light fixtures. Wasps that invade homes can be controlled mechanically, by swatting or vacuuming, or with an aerosol insecticide. Openings through which wasps can enter the structure should be caulked or sealed. In homes, attic vents should be properly vented to exclude overwintering queens. If a paper was nest poses a hazard, use a Wasp & Hornet spray that will propel the insecticide about 10-15 feet and direct the spray into the nest opening for 5-10 seconds.

    More information about paper wasps can be found here: http://insects.ncsu.edu/Urban/paperwasp.htm.

    Spiders
    Yellow garden spider
    (Photo: Ronald F. Billings,
    Texas Forest Service)
    At this time of year, many of the orb-weaving spiders are very conspicuous. Among those prominent species is the yellow garden spider, Argiope aurantia, which is the distinctively colored (black and yellow), large spider that is frequently seen in gardens, yards and along walls typically near lights or "flyways" where moths and other flying insects are likely to travel and get snared. The female builds a web that has a conspicuous zig-zag band of white silk in the center of the web. For this reason, these spiders are often called "writing" spiders. People often assume that because of the bright colors that this spider is particularly dangerous, which is true if you're a moth. If callers ask about what they should do about the spider, tell them to thank it for catching stuff that probably is laying eggs in the fall garden or eating other plants in the yard. Suggest that they just leave them alone to do their job. Since fall is often a time of yard work and cleanup before the winter, people are out moving debris, firewood, etc. and encounter spiders. You may see black widow spiders and a host of other spiders out there. Any spider with a marking on its back usually gets declared to be a brown recluse and in North Carolina about 99.99% of the spiders sent to us as brown recluses are in fact, fishing spiders, cellar spiders and wolf spiders. If people want to know about control, the best choice is to leave the spider alone to eat critters that folks equally dislike. When working outside and particularly if you're moving debris and items that haven't been disturbed in several days/weeks, take simple precautions like wearing long pants and gloves (and of course your other clothes so as not to upset your neighbors). Check out our note: http://www.ces.ncsu.edu/depts/ent/notes/Other/note137/note137.html

    Snakes
    Fall is also the time when our no-legged friends start seeking out shelter. From my experience under and around houses, most of the snakes that people encounter are black rat snakes. Juvenile black rat snakes have distinct color patterns that immediately send people into a frenzy because they believe it's a copperhead. And they're not about to stop to look at the shape of the head or eyes before they beat it to death or cut into pieces with a shovel. Although black rats can bite (I can attest to that personally), they are more inclined to move away from a fight. There will be encounters with copperheads, and one wildlife management company recently pulled three juvenile copperheads from under a porch. As leaves start to drop, it's not unusual for the snakes to go unnoticed in leaf piles, under debris and under logs. Startled snakes will strike and bite. Copperhead bites are not typically fatal (of course "not typically" isn't much comfort to people!) but the bite can land you in the ER and potentially an overnight stay in the hospital. Obviously, children, the elderly, and other folks who might have health-related issues are more likely to have the more severe reactions to a bite. The secret to avoiding snake bites? Avoid snake bite opportunities. Follow the same advice about work clothing appropriate for encounters with spiders.

    Chimney Swifts
    Cold weather means people will be stoking the fires in the fireplace soon and so it's a good idea safety-wise to make sure their chimney is in good working condition. This includes making sure they don't have a build-up of soot and creosote or have cracks in their chimney/flue. Another unwanted item is the nests of chimney swifts. These birds often drive people crazy when they hear the chirping coming from their fireplace and they proceed to burn logs to drive the birds out. Chimney swifts are protected by the Migratory Bird Treaty Act, which means that while nesting in your chimney, you are not allowed to kill/disturb them. And of course that is not something most people want to hear particularly now because their is a bed bug relative that on some occasions may drop down the chimney and show up indoors. That's not meant to scare people and cause them to go to extremes like setting off foggers in their fireplace or starting fires to drive out the birds. At this point of the year, the birds have already bailed out of the nests. So tell your local clients that NOW is the time to clean their chimney to remove the nesting material and/or put a screen cap on their chimney to prevent the birds from building nests next year. A good chimney cap will also keep out other unwanted visitors in search of a home - namely raccoons and opossums. If you think the birds are a problem, try serving an "eviction notice" next year to a mother raccoon that decided your chimney was an ideal home.