Polk County Conservation

Insect and Spider Questions

  • I haven’t seen any woolly bears anywhere this fall. Is this something to be concerned about?

    Now that you mention it, I haven’t seen any either. Woolly bear caterpillar populations vary from year to year for several reasons, weather being one of them. The extreme drought this year probably had an impact on their numbers. I wouldn’t be too concerned as they will most likely rebound in the coming years. If you do happen to see one, the size of the brown band does not indicate what kind of winter we’ll have. Woolly bears survive the winter by creating natural antifreeze in their bodies and freezing solid. When spring arrives the woolly bear caterpillar spins a cocoon and transforms into the Isabella Tiger Moth.

  • I am an elementary school teacher and found a praying mantis a couple of weeks ago. I put it in a jar, brought it into my classroom and the next day it laid an egg case. What should I do with the egg case? If I keep it inside, will the young hatch? If I put it outside, will they overwinter okay and hatch next spring? Your help is appreciated.

    You have a couple of options. You can take the egg case (ootheca) outside and attach it to the stem of some tall grass somewhere that is isolated out of the wind. The mantid nymphs should emerge next spring after they overwinter.

    You can also try raising preying mantids indoors. It would be an excellent classroom activity with your students. You’ll need to pseudo-overwinter the egg case in the refrigerator for several weeks. Then bring it back out and the new nymphs should start emerging in several days to weeks (if it is a viable egg case). From a single egg case, several dozen to hundreds of nymphs can emerge. Nymphs will feed on each other and are very tiny, so make sure you have a lot of sticks and hiding places available for the newly emerging nymphs. Mantids need a warm, (70 to 90 degrees F) spacious container with the humidity between 40 and 95%. A ten-gallon terrarium works nicely. Fruit flies, pinhead crickets, and other small insects are excellent food for young nymphs.

  • My daughter found a black widow spider in an old tire in their yard. Are black widows indigenous to Iowa and how dangerous are they?

    Yes, black widow spiders are native to Iowa but they are not common. They can be found in logs and woodpiles around homes. Black widows are very shy and avoid light. They range in size from 1/8-3/8 inches long. The female black widow is entirely black with a red hourglass shape on the underside of her abdomen. Male black widows do not bite and are often eaten by the female after mating.

    All spiders are venomous. Their venom helps them kill or subdue their prey. Even though they are venomous, most spiders are harmless and won’t hurt humans. However, Iowans have to be cautious around brown recluse and black widow spiders. The venom from these two spiders can cause serious medical problems but is rarely fatal. Black widow venom can affect the nervous system causing nausea, muscle spasms and breathing difficulty in humans. Some people are slightly affected by the venom, but others may have a severe response. I wouldn’t be too alarmed. Just remember that spiders rarely bite humans and use caution when grabbing logs or reaching into wood piles.

  • I was recently "buzzed" by something that looked like a large hornet or something. It was quite large and vicious looking. Its noise was intimidating. It flew into what looked like an anthill. I’m curious what it is, how dangerous is it, and is it native to Iowa?

    P.S. Someone told me they saw one snatch a cicada in mid-air.

    The wasp you saw was a cicada killer. They are Iowa’s largest wasp measuring up to two inches long. They are black with bright yellow stripes and rusty colored wings. Cicada killers are native to Iowa. They are very active in July and August when their prey, cicadas, are active. Cicada killers will attack, sting, and carry paralyzed cicadas to their underground burrows. The anthill you saw was their burrow. Once the paralyzed cicada is underground, the wasp lays an egg on it. When the egg hatches the wasp larva feeds on the cicada. The larva will develop into a wasp that emerges the following summer.

    I know these wasps look rather scary, but they are not dangerous. The cicada killer has the ability to sting, but won’t unless handled or threatened. Only the females are capable of stinging because the stinger is actually a modified ovipositor or egg-laying tube. Stings inflicted by cicada killers are not severe but reaction varies with each individual. These wasps are normally very docile and are unlikely to sting unless provoked. Wasps are beneficial insects and a nest in an out of the way location should be left alone.

  • There is a huge nest hanging from a tree in my yard. The nest looks like it’s covered in paper and is about the size of a soccer ball. What is it and do I need to be concerned?

    Sounds like a hornet nest. Every spring a queen bald-faced hornet will chew bits of wood into pulp. She spits out the pulp to make layers of six-sided cells for her eggs. Finally she wraps the entire nest in paper with an entrance hole at the bottom. A colony of hornets lasts only one year and the nest will not be reused. At the end of the summer, all the worker wasps die. Only the queen survives the winter hibernation and she starts a new colony in the spring.

    There is no need to remove the nest or kill the wasps. Wasps are very beneficial insects that help regulate destructive insect populations which might otherwise adversely affect our health, homes, livestock or crops. However, this is a nest you’ll want to steer clear of until fall or early winter. Hornets can be very protective of their nest and will repeatedly sting if disturbed.

  • How do insects survive the winter?

    Insects survive the winter in a variety of ways. Some insects like mosquitoes and preying mantids overwinter as eggs, lying dormant until hatching conditions are right in the spring. Other insects overwinter in the larva or pupa stage. In the fall, some moth caterpillars dig down into the ground and form pupae (cocoons). The earth keeps them warm during winter and hides them from hungry birds and mice. Many insects hibernate as adults. To keep from freezing, insects are able to replace the water in their bodies with glycerol, which acts as antifreeze. Tree holes, leaf litter, and under logs and rocks are common shelters for overwintering adult insects. The Mourning Cloak Butterfly is usually the first butterfly that is noticed in the spring because it hibernates in tree holes or other shelters during the winter. Then there are insects like the monarch butterfly that migrate to escape the cold temperatures. Believe it or not, but some insects are active in the winter. The nymphs of dragonflies, mayflies and stoneflies live underwater in ponds and streams. They feed and grow during winter to emerge as adults in early spring.

  • There are boxelder bugs and ladybugs covering the entire south side of my house. Now they are finding their way into my home as well. Will they harm my house in any way?

    Boxelder bugs and Asian lady beetles are harmless and will not damage your house or furnishings. Boxelder bugs and Asian lady beetles often become pests in the fall when they leave plants and trees to search for hiding places for the winter. They often stray into houses through cracks in the foundation and siding, gaps along windows and doors, and other small openings. These insects will not reproduce or feed indoors. To prevent them from entering your home, caulk and seal possible entry points. A soapy water spray (5 tablespoons of liquid detergent per gallon of water) can also be sprayed along the foundation in the fall. Repeated applications are usually necessary. The best way to remove in your house is by vacuuming, sweeping or picking them up and discarding.

  • I have a wasp nest in one of the swings on my swing set. It stung my daughter recently and wondered why it didn’t die afterward. Don’t all bees and wasps die after stinging you?

    No. The reason bees and wasps sting is because you are seen as a threat to the hive or nest. Honey bees live in huge colonies and will give up their life to save the colony. Once you are stung, a barbed stinger is left in the skin. The stinger is actually part of the bee’s abdomen and without it the bee dies. A wasp’s stinger consists of a tube attached to a sac of venom. Wasps can sting more than once by pulling out their stingers and using them again. As much as we may not like wasps, they are an enormous help to people by feeding chewed up insect pests to their larvae. Bees and wasps also help pollinate many crops and plants.

  • I recently found a tick attached to my son and wondered what’s the best way to remove it? I’ve heard that if you hold a lit match to the tick it will drop right off. Is this true?

    Do not, I repeat, do not burn, prick or crush an attached tick as it may release infected fluids. You should never try to smother the tick with petroleum jelly or nail polish because the tick has enough oxygen to complete feeding. If you find a tick attached, use fine pointed tweezers to pull it out. Place the tweezers as close to the skin as possible and around the tick’s mouthparts. Avoid crushing the tick’s body and gently pull the tick out. Wash your hands and disinfect the bite site and tweezers. After being outside, you should always check closely for ticks. Pay attention to anything that looks like a small black freckle or poppy seed. Look closely at parts of the body covered with hair. Put clothing worn outdoors in the dryer and run on high heat for 30 minutes. The heat will kill any ticks that may be in your clothing.

    Save the tick if possible. Entomologists at Iowa State University want to determine where certain ticks live in Iowa and if ticks have Lyme disease. If you find a tick, wrap it in tissue, add a small drop of water, and place in a sealed zip lock bag. Send it to: Department of Entomology, Lyme Disease Project, 440 Science II, Iowa State University, Ames, IA 50011. They will send you a postcard telling you what species of tick you have found.

  • I’ve heard a rumor that daddy longlegs are one of the most poisonous spiders in the world but their fangs are too short to bite humans? What’s the real story?

    I have also heard this rumor and it is not true! Part of the misunderstanding is that two different animals are referred to as Daddy longlegs. Daddy longlegs and daddy longlegs spiders belong to two separate groups of animals. Daddy longlegs, also known as Harvestmen, are arachnids but not spiders. They have only one body section that is segmented, two eyes, no silk, venom, or fangs. Harvestmen eat decomposing plant and animal material, small insects, and earthworms. Daddy longlegs spiders are also known as house spiders or cellar spiders. They build a messy, tangled web in dark corners in buildings, under rocks and loose bark. Daddy longlegs spiders do have small fangs, but so do brown recluse spiders and they are able to puncture human skin. There is no scientific research to prove daddy longlegs spider venom is deadly to humans. To learn more about spiders, check our Calendar page for October’s Spooky Spiders event.

  • What are those tiny black bugs biting me every time I walk outside? Their bite really hurts!

    Those insects are called minute pirate bugs. They are 1/5 of an inch long, oval to triangular in shape, and black with whitish marks on the back. Minute pirate bugs are beneficial predators that feed on insect eggs and small insects. They use their sharp needle like mouthparts to suck juices from their prey. During the summer, pirate bugs are found in fields, woodlands, and gardens. As they begin to migrate from these areas during late summer they start biting humans. They are not feeding on our blood, nor do they inject venom or saliva. To protect yourself from getting bitten, you can wear dark colored clothing, long pants and long sleeves. But who wants to do that on a nice warm day? So, we’ll just have to put up with those pesky pirate bugs for a few more weeks until next year!

  • My son recently came down with a bunch of chigger bites on his legs after playing in the yard. What are chiggers and will mosquito spray keep them off?

    Chiggers are not insects, but are actually young mites. Mites are closely related to ticks and spiders and are members of the arachnid family. Chiggers are very tiny, only 1/150th inch in diameter. A common myth about chiggers is that they burrow into our skin and eventually die within the tissues, thus causing the persistent itch. They do not burrow under skin or drink blood. Chiggers attach by inserting tiny mouth parts into skin depressions, usually at skin pores or hair follicles. Their saliva contains an enzyme that dissolves skin cells. The chigger ingests this liquid tissue for food. The saliva is what causes the persistent itching. Most chigger bites are around the ankles, the back of the knees, around the groin, under the belt line and in the armpits. If undisturbed, chiggers will take three or four days, and sometimes longer, to eat their dinner. Although most humans accidentally brush or scratch off the chiggers before they finish their meal.

    Mosquito sprays will work at keeping chiggers from climbing onto you, but only for a couple of hours. Repeated application may be necessary. In chigger infested areas, wear tightly woven socks and clothes, long pants, long sleeved shirts, and high shoes or boots. Tucking pant legs inside boots and buttoning cuffs and collars as tightly as possible also helps keep the wandering chiggers on the outside of your clothes. Once inside, remove and wash your clothes before wearing them again. If you are bitten, there are some over the counter treatments to help relieve the itching. Try calamine lotion, soaking in a cool tub with Aveeno, or hydrocortisone cream (with at least 1% hydrocortisone).

  • My neighbor was recently bitten by a brown recluse spider at a park. He ended up having surgery to remove some of the dead, infected tissue. Could there be recluse spiders living around my house? Are there any other poisonous spiders besides the brown recluse in Iowa?

    I hope your neighbor is doing well. All spiders are venomous. Their venom helps them kill or subdue their prey. Most spiders are harmless and won’t hurt humans. Iowans only have to be cautious around two spiders, the brown recluse and black widow spider. These two spiders can cause serious medical problems but is rarely fatal.

    Brown recluse spiders are found throughout the state in logs, mulch, outbuildings, and occasionally in dark areas of houses. Recluses are shy spiders that are not aggressive, but will bite if disturbed. These tiny spiders are only 1/4-3/8 inches long. A distinguishing characteristic of the brown recluse is the dark fiddle shaped area on the front half of its body.

    The black widow spider is not common in the state and is found in logs and woodpiles around homes. They are very shy and avoid light. Black widows range in size from 1/8-3/8 inches long. The female black widow is entirely black with a red hourglass shape on the underside of her abdomen. Male black widows do not bite and are often eaten by the female after mating.

  • Ticks give me the creeps. I’ve heard that ticks fall out of trees and that you should wear a hat so they won’t get in your hair. Is this true?

    Ticks do not fall out of trees and wearing a hat will not prevent you from getting a tick. Ticks cling to grasses and brush while extending its front legs to grab a passing animal or person. They crawl up your leg and body until they find a nice place to attach themselves. Ticks are neither insects nor spiders, but are in a group related closely to mites. The best method of prevention is wearing repellent with DEET as the active ingredient and checking for ticks before they become attached. You can also tuck your pant cuffs into your socks and wear light colored clothing. It’s easier to see ticks on light colored clothes than dark clothes.

    If you do have a tick attached to you, grasp the tick close to your skin with tweezers. Pull the tick straight out. Save the tick if possible. Entomologists at Iowa State University want to determine where certain ticks live in Iowa and if ticks have Lyme disease. If you find a tick, wrap it in tissue, add a small drop of water, and place in a sealed zip lock bag. Send it to: Department of Entomology, Lyme Disease Project, 440 Science II, Iowa State University, Ames, IA 50011. They will send you a postcard telling you what species of tick you have found.

  • I received my first mosquito bites of the season and wondered several things. Why do mosquitoes need my blood? What other animals do mosquitoes take blood from? And why is it that my neighbor doesn’t get any bug bites, while I get tons of bites?

    Protein in blood is needed for the development of mosquito eggs. So only female mosquitoes do the "biting." Both male and female mosquitoes get their nutrition from flower nectar.

    Mosquitoes will take blood from about any animal with blood, including mammals, birds, reptiles, etc. In fact, some species of mosquitoes actually prefer blood from birds over humans. Mosquito mouthparts can puncture the leathery skin of a toad or through the overlapping scales of a snake. So don’t be surprised when mosquitoes bite through your clothes!

    Sorry to tell you, but you must be smellier than your neighbor. Mosquitoes live in a chemical world. They can change their flight pattern depending on what they smell. They pick up cues such as carbon dioxide, lactic acid, natural skin oils, and heat from humans or animals. So some people get bitten more often because they smell better to mosquitoes than others. If you can prevent yourself from breathing and sweating, you might be left alone!

  • I am having a problem with ants in my home. I would like to get rid of them, but I am concerned that the pesticide might affect my baby. What can I do?

    Ants have come into your home because they’ve detected a food source. Remove their food source if possible or seal containers so no odor can escape. The next step is locating the nest and the path they take to and from the food source. Some natural repellents to try using in the home include vinegar, cayenne pepper, citric extracts, bone meal, cinnamon, cream of tartar, salt, and perfume. Place the repellents at points of entry and various points along their path. Keep trying different repellents until you find one your ants aren’t willing to tolerate. You can also try eliminating the nest by pouring boiling water over the nest. If that isn't sufficient, you can try adding cayenne pepper to the boiling water, or using citrus extracts. If none of these work, contact an exterminator and let them know you have a small child.

  • There is a huge honeybee hive in the tree next to my front door. What’s the best way to remove the hive?

    If the bees are not bothering you, please leave the hive alone. Bees feed pollen and nectar to their young and are beneficial pollinators of many crops and plants. An estimated 80% of insect pollinated crops are accomplished by honeybees. If a hive is causing problems, contact a beekeeper or a licensed pest control professional for removal. An experienced beekeeper can usually remove bees and honeycombs from easily accessible places like hollow trees, but bees often live in building walls or are tucked away where they are impossible to reach. In these cases, a licensed pest control company may be the best solution.

    If you wish to try killing the bees yourself, it is important to exterminate a colony when all the bees are in the nest, usually dusk or dawn. This reduces the number of bees that are in the field that may return to cause problems. Sprays are popular because they can be used from a distance. Dust formulations may also be pumped onto an enclosed nest. There is some evidence that soapy water is also a good substance to use and is inexpensive and somewhat harmless to the environment.

Contact Us

Administration Office
11407 NW Jester Park Drive
Granger, IA 50109

P: (515) 323-5300
F: (515) 323-5354
pccb_info@polkcountyiowa.gov

Monday – Friday, 8:00 a.m. – 4:30 p.m.

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