How to Deal with Bagworms

Bagworms are some of the best architects in the insect world. These caterpillars take materials from the plants they live in and construct a tough bag to dwell in as they grow. The bag grows in size as they do and protects them from the elements and predators. Bagworm caterpillars have voracious appetites and can drastically damage evergreens like pine, spruce, juniper, arborvitae, and cedar and will occasionally feed on deciduous trees. Luckily we have several tools at our disposal to eliminate these hungry, hungry caterpillars.

Young bagworms just getting started in a tree (Photo courtesy of Jim Kalisch, UNL Entomology)

For the best control you need to understand this pest’s unique life cycle.

•       In the early summer (May-June) bagworm eggs will hatch and the small caterpillar will build their home. You may notice small triangular shaped objects moving in your bush or shrub. Some will stick around the plant they hatched in but other will perform a behavior called “ballooning”. This is where the caterpillar releases a line of silk and the wind carries them, sometimes for miles, to a new plant to infest.
•      The caterpillars will feed for approximately six weeks in order to finish development. They will pupate inside of their bag and then the males emerge as dark, fuzzy moths. The females don’t grow wings or ever leave the bag; they become sort of a super caterpillar and produce a pheromone to attract males to their bag.
•     After mating the female will lay her eggs inside of her bag so they can hide over the winter. She will perish but there will be 200-300 of her eggs safe to hatch the next spring. 

You have a few organic options to control bagworms. You can practice mechanical control, where you would go out in the late fall or early spring and cut bags from trees. This will remove any eggs that may hatch in your tree but won’t protect you from new caterpillars blowing in. You can also keep a close eye on your evergreens and when you start to see the small bags pop up spray a product containing Bt (Bacillus thuringiensis) to control the young caterpillars. Other options at this time would be products with spinosad or azadirectin.

If you miss your chance to do these early stage controls you can control larger bagworms with synthetic products like Sevin (carbaryl), Ortho Tree & Shrub (or other bifenthrin containing products), or Bayer Tree and Shrub (or other products containing cyfluthrin). 

Adult bagworms in a tree (Photo courtesy of Jim Kalisch, UNL Entomology)

4 Facts about Chiggers You should knowHow

It’s beautiful outside and we are all hoping to get out there and enjoy the early summer weather! Sometimes though, we bump into problematic pests that can ruin our day. One such pest is the chigger, which is the bane of many a hiker, gardener, or just general outdoor enthusiast. Here are some quick facts to help understand and avoid this biting bother.

Chigger bites on top of foot by V. Jedlicka

1.  Chiggers are just kids

The chigger that bites you isn’t actually the full grown version; they are the larval stage of a predatory mite. This means that despite being arachnids, if you looked at a chigger under a microscope you would find it only has six legs.

2. Chiggers love the great outdoors

You can encounter chiggers in many different types of places, but their preferred habitat is a nice, damp, low lying area. You may encounter them areas with only turf but are more likely to meet them in areas of tall grass with weeds as well. If you are visiting wooded areas or stumble into a bramble patch, don’t be surprised if you find some chiggers too.

 3. No need for that nail polish

Contrary to popular belief, chiggers do not take up residence under your skin or feed on blood. When you brush up against a plant they are hanging out on they will latch onto you. After this they insert a long straw (called a stylostoma) into your body. They will then inject enzymes into you that will melt bits of your skin and they slurp up the juices like a milkshake. These enzymes are responsible for the intense itching we have after the bite.

How a chigger bite works

4. Gross! I don’t want that

To prevent bites you should wear full length pants and shirts when you can. If you don’t want to be warm, you can also wear protective products such as DEET to repel chiggers from your body. Finally, when picnicking or watching fireworks, lay a blanket down to sit upon and try to avoid sitting directly on turfgrass. If you find that you have recurring chigger issues on your property, treating your yard or just the infested area with an insecticide containing bifenthrin will help to eliminate their populations.

If you ever want to know any more about chiggers here are some helpful links:

Chigger information from the University of Nebraska

Chigger information from Texas A&M

Teenage Bugs are Having Sex in your Trees

If you live in Nebraska or a nearby state, millions of insects will be emerging this May and June, maybe even in your backyard! They are called periodical cicadas and they’re one of nature’s most interesting insects. As nymphs they live in the soil for 17 years feeding on sap from the roots of trees. This makes them the longest living insect in North America. After that 17 year period is up, they emerge from the soil, molt into their final adult form, and take to the trees above them to mate. They emerge in what we call “broods” and and we live in Brood 4's territory. 

Periodical cicada completing its molt into an adult,  photo by Bob Rabaglia.

In order to find one another and mate, cicadas will sing songs. The male produces the loudest portion of the the tune by flexing his tymbals. Tymbals are small membranes between the thorax and abdomen that can be vibrated by a powerful muscle behind them. This flexing produces clicks which are amplified by the cicada's hollow abdomen. The males often gather into groups and create a chorus which can make quite a racket, reaching decibel levels comparable to a jet airplane engine. The females are not silent in this song and create clicking sounds using their wings. This completes the duet and signals acceptance of a mating partner.

Male cicada and his tymbal

ID facts

•  All periodical cicadas are black, with red eyes, and orange trim on their wings.

• There are 3 species of periodical cicada and to tell them apart you need to look at their belly. Magicicada cassini will have an all-black abdomen, M. septendecim will have big thick orange stripes, while M. septendecula will have thin orange stripes.

• You can use their mating calls to ID them as well. Head to www.magicicada.org to learn more about cicada calls. You can help researchers who want to know more about periodical cicadas by filling out the citizen science forms also found at www.magicicada.org/report/report.php.

Control help

Periodical cicadas are not normally pests but occasionally harm fruit trees or newly transplanted trees with their egg laying activity. The female has a sword-like ovipositior that she uses to slice small slits into young tree branches and then to insert her eggs. This can result in weakened branches that snap and create a characteristic "flagging" damage (see image below). Older, more established trees can handle this, but young ones may be stressed by this flagging damage. If you are worried about one of your trees, your best course of action will be to take some fine, mesh netting and wrap it around the trees branches to keep the females from landing on them. 

Top photo: Cicada flagging damage on young tree (Photo by Dan Potter)
Bottom photo: Using netting to protect tree from cicada egg laying 

This is a unique natural phenomenon to be a part of so check your trees or head out to a local state park to meet some of these amazing insects!