Sunday, April 28, 2024

Evergreen Bagworm

Spring is a time of awakening when the landscape is green again, flowers are blooming, birds are making their way back home and the bagworms are hatching. One of the banes of homeowners, landscapers, and arborists is the bagworm. Tree branches decorated with spindle-shaped ornaments are not exactly what we had in mind when we planted our trees. So, what is a bagworm exactly? To me, they are both irritating and fascinating.

In our region, the most common one you will encounter is the Evergreen Bagworm, but Worldwide there are over a thousand different species. They go by several common names including Common Basketworm, North American Bagworm, Bag Moths, and my personal favorite Cuddle Sacs. This reminds me of the term Cul-de-sac, which is French for “bottom of the sack.” What an apt nickname for this unique little insect.

Their lifecycle begins in spring when the eggs hatch within the bag and leave the security of their winter home. Many will remain on the host tree, while others spin a thin thread of silk and wait for the wind to carry them to a new host tree or plant nearby. This phenomenon is called ballooning or parachuting and there is another animal that also uses this mode of transportation, spiders. Do you remember the end of Charlotte's Web when all of Charlotte’s babies, except one, ballooned away to new homes leaving Wilbur behind? Is there a quicker way to arrive at a destination than flying?

After arriving at their new host plant, the tiny larvae will spin a silken cocoon around itself and begin decorating it with bits and baubles found on the host. This sack will effectively camouflage the tiny larvae inside protecting it from predation. Now their only job is to eat and grow. The larvae stick their head and thorax out of the bag to munch on leaves and can retreat quickly if danger is nearby.

If you watch a bagworm closely you can see it move as the larvae wiggle around inside. They can move about freely carrying their sack with them, an insect version of a mobile home. Often we do not know we have a bunch of bagworms using our evergreens (or other trees) as their all-you-can-eat buffet until mid to late summer when the bags have grown exponentially and are now visible. They almost seem to appear overnight! The sacks have somewhat pointed ends, one end is for feeding, one end is for pooping. By August or September, they are ready to attach themselves permanently to their host tree and will use surprisingly strong silk to do so. If you have ever tried to remove a bagworm from a tree branch you can attest to just how strong this silk is, as it takes some effort to pull it free.

Everyone loves a love story, in the days of legends and myths there was a beautiful princess by the name of “Psyche”, and she fell in love with the son of Venus who as most of us knows was “Cupid”. Venus did not approve of this love relationship between her son and his beloved Psyche. Venus made life miserable for the poor princess. After some time, Venus felt guilty for her ill treatment of Psyche, and it was within her power to grant a great gift upon her, this gift was“immortality” Many moths are in the family of Psychidae and are called Psyche moths, which is a perfect name for moths believed to be the spirit of the lovely Princess Psyche.

At this point, they will pupate inside their bags and appear a few weeks later as adults. This is where things get really interesting. Males leave the sack and seek females who are still securely sequestered in their bags. Females cannot fly, they lack wings altogether. Therefore, the male must go to them. Some females will leave the bag and mating will occur after which she returns to the safety of the bag.  Although many more remain in the bag where mating takes place in what I can only imagine is a very awkward moment. The male then flies off in what I would describe as love them and leave them sort of way. Mother Nature, however, has a plan for our tiny Don Juan, he is destined to die shortly after mating. The female still stuck in her bag, having never seen the world like her lousy boyfriend, will lay up to a thousand eggs, and then she too will perish. The eggs overwinter in the bag and the cycle starts over again in the spring. Some females do not lay eggs, instead the larvae emerge directly from her body come spring. No one said life was fair. If all of this isn’t strange enough, in some species the females will lay eggs that are fertile without male fertilization in a phenomenon known as parthenogenesis. Saves the female those awkward love them and leave them moments.

Male Evergreen Bagworm---photo by K. Leeker

The most common bagworm in our region is the Evergreen Bagworm, and they are often found on juniper, cedar, and pine, although other hosts will be used as well such as sycamore, box elder, maple, and locust. For the past several years they have been on my St. John’s Wort plant.

For most of us having bagworms on our trees is just unacceptable and unsightly. I can certainly understand that feeling. Fortunately, the vast majority of the time they cause no lasting harm, in those cases your tree just may not be as aesthetically pleasing to look at. There are a few populations, however, that can be a serious problem. In those situations, when a severe outbreak is occurring, control will need to be used. If the problem is within the normal range handpicking the sacks off will be effective, although time-consuming. In the case of a severe infestation, you will need to use chemical sprays that contain Bt. Be sure to implement your control measures at the right time of the year for the most effective result. Whether handpicking or spraying they need to be removed in early to mid-winter. This is when the eggs are secured in the bag, therefore you can kill them before the eggs hatch. If handpicking, do not drop them to the ground, they will still hatch and find another host plant nearby. The bags must be destroyed to effectively control them

Besides ballooning, these tiny moths can spread by other means. Remember me saying that some females do not lay eggs, but rather the eggs remain inside the mother and the larvae emerge later from her body? Birds find them a tasty treat, and they will seek out these egg-laden females for food. The eggs have a very hard shell for an insect and often pass through the digestive system of the bird and remain unharmed, effectively spreading them far and wide, only to hatch and create a new generation. Not only do birds find them tasty and a great source of protein so do some people around the world. In primitive villages, the bagworms are encouraged to grow and then later harvested for a protein-rich snack.

If you decide the little spindle-like ornaments hanging from your trees are just not fitting in with your design vision, I recommend hand-picking as a means of an environmentally safe control option. If, however, your infestation is too severe chemical measures will need to be taken, just remember to follow directions exactly as given. While we are all busy cursing and controlling the dreaded bagworm, maybe we can take a few minutes to appreciate the uniqueness of the cuddle sack and its lifecycle.


Monday, April 15, 2024

Henbit Deadnettle

The fields are rife with a purple flower that humans seem to have a love-hate relationship with. The Henbit! Having originated in Africa, Asia, and Europe it made its way into North America, most likely hitching a ride with immigrants preparing to arrive in the new world looking for a new way of life. Leaving the only home you’ve ever known and going somewhere completely new, and potentially dangerous can be frightening as well as exciting. What better way to bring a piece of home with you than to tuck some seeds away for the journey with the hope they will like their new home, adapt, and grow, For early settlers, they relied heavily on plants for curing all manner of ailments, and the Henbit was often a part of these natural medicine cabinets.

This important herb goes by many common names including Greater Henbit, Common Henbit, Henbit Deadnettle,  and my personal favorite Fairy Horn. The name Henbit comes from ancient observations that chickens favored this plant in the spring as some of the first available greens.

While often mistaken for the plant deadnettle, it is scientifically different, even though both plants share the same family as mints. These cousins of the wildflower world often grow and bloom together, making identifying them difficult for many. The name deadnettle is in reference to the fact this plant does not produce stinging hairs on its leaves like Common Nettles do.

Henbit is a small plant reaching heights of four to eight inches and a spread of up to sixteen inches with soft fine hairy stems. When thousands of these plants bloom in unison it often seems as if the purple color extends for miles.  It goes to show there is strength in numbers. The flowers range from pink to purple and are a beautiful sight after a long, dreary, colorless winter. Henbit is capable of self-pollination, mainly because pollinators are not very active when Henbit first blooms, which is typically late winter and early spring, and continues into June if the weather conditions are right. Henbit prefers moist, shady locations, once things heat up the Henbit dies back and takes a rest until fall. They propagate by seed and each plant can produce up to two thousand seeds. They can also spread by producing a root at the base of the stem that reaches the soil and starts a new plant. The seeds germinate in autumn and sprout soon after as late as November. When winter's freezing temperatures begin, henbit will die back and then in February and March, they begin to grow. Occasionally germination takes place in the spring as well.  If weather conditions are not conducive to germination the seeds can remain viable in the ground for up to ten years, waiting for the proper growing conditions to return.

Once in bloom they often become the bane of farmers, gardeners, and homeowners who find their fields, gardens, and yards overrun with Henbit. Do these individuals experience a mixed bag of emotions or at least a tad bit of remorse for this plant that they are on a mission to kill? Do they see a beautiful wildflower or just an ugly weed? In some states, they are classified as invasive, and in other states, they are pretty much ignored and left alone as their beauty, edibility, and willingness to grow where many plants couldn’t survive, as well as providing erosion control all equal a plant that is more beneficial than troublesome. Their presence is appreciated, and they are permitted to grow when many other weedy wildflowers are not. Henbit has been a part of North America's landscape for so long that it is considered naturalized and is an important component in a meadow ecosystem. In full bloom, early pollinators wake up on warm days and explore their surroundings, and finding henbit is a welcome sight. Honeybees, Bumblebees, and other early spring risers will gather nectar and help pollinate the flowers that have not closed up and decided to take the task of pollination on themselves.

Early settlers valued Henbit and with good reason, there are numerous medicinal qualities attributed to this plant as well as being edible. All visible parts of the plant above ground are edible and safe to consume.  It can treat fevers, boost your immune system, act as a diuretic, and is shown to reduce anxiety in many individuals. It is used in soups, on top of salads, and as a tea. Careful though, consuming too much may find you in the bathroom. Henbit is high in iron, vitamins A, K, and C. This high vitamin C component provides us with a healthier immune system to help ward off those late winter illnesses that seem to plague us all in February and March. Even though Henbit is related to plants in the mint family, they do not have a distinct mint flavor. Instead, their flavor is described as somewhat peppery, yet a tad sweet with a taste of celery or kale. I personally have never tried it, but I plan to the next time I eat a salad.

On the fun side, Henbit is nature's Kazoo. Pick a flower and gently blow in the end of it like blowing on a bugle. It will send out a loud, kazoo-like sound. It is rumored if the stars align just right, the sound of the Henbit kazoo will summon the Fairy King and he will grant you a wish. We could all use a wish granted right? If nothing else, the sound can be used to announce your location if you find yourself lost in the timber seeking those allusive morels.

Just like for most things in nature, humans will look for and find a negative, and with this newfound knowledge will do everything in their power to destroy it. Henbit definitely falls into this category. Many years ago, before no-till became so popular among farmers, most farmers managed to coexist with Henbit. When fields were turned over, it often destroyed much of the Henbit before it had a chance to germinate in the fall or early spring. No-till planting, while helping in erosion control as well as other things has also changed the way we control plants many consider to be weeds, and that control comes in the form of chemicals. Because of the fuzziness of the leaves, it is often difficult for one chemical, like glyphosate to kill Henbit, therefore broad spectrum glypohsate needs to be used along with additional chemicals like Dicamba. The more chemicals we apply to the ground, the more contaminated our food and water supply become. In many cases, because of its early growing season and early death when things heat up, the shallow root system rarely interferes with the growth of agricultural crops as they are just beginning to peek their tips above ground after the Henbit has departed. Yes, it can be an alternative host for corn earworm and other pests of crops, but these situations are not as common as one would be led to believe. Yes, information is out there about the growth of Henbit interfering with winter wheat, rye, and other cold-weather crops. There is no exact science to back this up. Most studies that have been conducted are not in a controlled setting. A study done by the University of Missouri claimed Henbit caused a 13% reduction in wheat yield. The study was flawed though, only areas with heavy densities of Henbit growth were planted with wheat, and no other plant was counted in the survey, just Henbit. We know Henbit prefers areas with high moisture or low spots in a field, which would have a natural effect on wheat yield. This was also not considered. Also not considered were the other plants present that would have an impact on yield like deadnettle, cheatgrass, and wild oats. To do a study like this correctly you must deliberately plant Henbit in one plot, keeping it excluded from another area of similar soil conditions, and sow wheat in both plots, then compare the yield in both plots. This was not done, instead, areas with high densities of Henbit were blamed for low wheat yield. While it is easy to jump to conclusions, that is not scientific evidence to support cause and effect.

In some things, we should consider accepting the bad with the good and not be so quick to judge a plant by its cover. Henbit is a natural herb with culinary and medicinal qualities. It provides fodder for livestock and wildlife grazers, as well as seeds for many types of birds. It is great for holding moisture in the ground for many crops that require it and provides erosion control. Not to mention you can summon the Fairy King to grant you a wish!