Carpenter Bees Nest in Dead Wood – Including Houses

Carpenter Bees Nest in Dead Wood – Including Houses

The hectic pace to contemporary life can justifiably be compared to the seemingly erratic behavior of insect pollinators. Darting from flower to flower with no apparently logical progression for choice of blooms, all the while emitting a mind numbing buzz.

Adult large carpenter bee, Xylocopa sp. Photograph by Paul M. Choate, University of Florida.

Adult large carpenter bee, Xylocopa sp. Photograph by Paul M. Choate, University of Florida.

This incessant and unending grind of bouncing from task to task has created an atmosphere of tedium and monotony which has become the anthem of many adults. As quick as one chore is complete, another replaces it. Russian composer Nokoli Rimsky-Korsakov wrote what might be considered today’s theme song at the dawn of the 20th century. “Flight of the Bumblebee” catches the frantic haste at which this insect functions, as well as its commonly encountered cousin the carpenter bee.

Bumblebees and carpenter bees are very similar in behavior, coloration and size. The easiest way to differentiate these insects is by their abdomen, the body segment furthest from the head. Bumblebees have an abdomen thickly covered in fine hairs. Carpenter bees lack the fine hairs and have a shiny abdomen.

Xyloxop micans Lepeletier, as the large carpenter bee is known scientifically, is one of more than 500 species worldwide. Almost all members of this genus build their nest by burrowing into dead wood. In the wilds of the panhandle this usually means deadfall timber of almost any sort. Unfortunately, in the areas which include human structures, the nesting sites include wooden timbers and siding.

Unlike European honeybees, the carpenter bees are labeled as solitary bees. There may, however, be several nests in close proximity to these active insects.

Nests are composed of a single parent that lays eggs in a segmented tubular nest. The nest openings are a nearly perfect 5/8 inch (16 mm) hole. Each nest has only a single opening, but multiple tunnels will branch off the main passage. These bees do not eat the wood removed to create the nest channels. Sometimes the holes are not visible to the observer, but the wood emits a buzzing or humming sound when these bees are nesting in hidden locations. In many cases small quantities of saw dust can be found on the ground under the hidden nest.

Heavy or repeated infestations can weaken structural timbers and severely damage siding. Decay and breakage will ultimately follow an untreated incursion.

While the damage caused by carpenter bees can be quite expensive, they may attract an even more destructive predator.  Woodpeckers, especially the native pileated woodpecker, dine on carpenter bee larvae at every opportunity. These feathery insect assassins are attracted to the vibrations and hums of the bees hidden in wood. In some cases, the wood acts as a resonator and amplified the insect noise which assures an aerial assault. When discovery of the larvae is confirmed, the woodpeckers attack with a ferocity seldom seen in nature.  The rapid-fire staccato of their hammering is loud and devastating.

Structural supports are compromised far beyond the damage done by the carpenter bees, and at a quicker rate. Siding is often shredded and left completely useless.

Commonly available insecticides can help control the carpenter bee population and reduce the prospects of woodpecker damage.  Unfortunately, this only adds one more item to the long list of chores and task of contemporary adults.

For more information:

Featured Creatures: Large Carpenter Bees

 

Caterpillars in the Vegetable Garden

Caterpillars in the Vegetable Garden

In the last few weeks, more garden pests have arrived! It is a fact of life in northwest Florida that we will have a few things in our garden including heat, moisture (humidity and rainfall), and BUGS! With a cooler spring the arrival of some of the troublesome pests in the garden seemed to be delayed a few weeks. It was nice while it lasted but the insect pests are here to stay until frost in the fall or winter (at least we hope for a frost this year).

There are thousands of insects that you can see in your garden. It’s wise to identify them before making a decision to spray an insecticide or remove them by another method. Insect samples can be taken to your local county extension office for identification.

In this article we will just discuss one of the top insect pests in the vegetable garden, caterpillars, and what you can do about them.

Mature larva of the cabbage looper. Photograph by John L. Capinera, University of Florida.

Mature larva of the cabbage looper. Photograph by John L. Capinera, University of Florida.

Beet armyworms, fall armyworms, hornworms, cabbage loopers, southern armyworms, tomato fruitworms, and other caterpillars love to feed on tomato foliage and fruit. They will show up eventually on tomato plants in the garden, if not this year then in the future. These larvae are immature moths and cause a lot of damage if left unchecked. The homeowner can control them effectively with Organic Materials Review Institute (OMRI) approved pesticides. A bacterial biological insecticide called Bacillus thuringiensis, also referred to as B.t., can be very effective in controlling these caterpillar pests. B.t. is a stomach toxin to these pests and will cause them to quit eating and starve to death. The key to using B.t. effectively is to routinely apply it before the caterpillars hatch from their eggs as the smaller caterpillars are easiest to control. Larger caterpillars are more difficult to control.

For more information related to using OMRI pesticides:

Organic Vegetable Gardening in Florida

Insecticides for Organic Commercial & Backyard Vegetable Production

 

Lawn Burweed: Back Again for a Second Act

Lawn Burweed: Back Again for a Second Act

Burweed, Soliva Sessilis. – Image Credit: Joseph M. DiTomaso, University of California – Davis, Bugwood.org. Creative Commons License

Burweed, Soliva Sessilis. – Image Credit: Joseph M. DiTomaso, University of California – Davis, Bugwood.org. Creative Commons License

This spring, lawn burweed has been an especially noticeable problem in lawns. Extension offices throughout Northwest Florida have been fielding many questions and finding solutions to lawn burweed infestations!
On the top of my list of lawn related annoyances is stepping into a patch of burweed, Soliva sessilis, which is in the sunflower family and is also known as spurweed. The leaves are opposite along the stem and sometimes resemble parsley. The main ways in which burweed can irk the casual gardener are sticking to socks, sneaking in with the dog, or littering flower beds with its nuisance. It can also hide in the house and reappear when shoes are removed. This causes pain in both the foot and the ear.

Aside from herbicides, maintaining a healthy vigorous lawn will prevent weeds from taking over. If your lawn is reasonably healthy and only a few instances of this weed exist, try to mechanically remove them and encourage the lawn to outgrow them.

If cultural methods aren’t sufficient, science has given us several options to control this irksome pest. Herbicides containing the active ingredients dicamba, 2,4-D or atrazine are good at controlling burweed as a post emergence control when applied from December through March. Be careful to use reduced rates on centipede and St. Augustine lawns, and never use more than the labeled rate since injury can occur when using these products on these species. Later applications have less effect on burweed because as it matures it is harder to control. Additionally the burs, once present on the lawn, are hard to remove. As the daytime temperatures rise to 90ºF, some of these herbicides may cause lawn damage. Try to keep the spray residue outside of the root zone of desirable plants to avoid injury and always follow label directions.

Be aware that burweed reproduces by seed, so mowing it down will only increase the problem by burying the seed for fall germination. Although we are now in the month of May, control of actively growing burweed might still be warranted if it is still flowering and setting seed. As temperatures warm up burweed will die, as it is a winter annual. In cases where it is already dying, control is not warranted since the natural cycle of winter annuals is concluding.

If an infestation of burweed has occurred this year, take note. The best time to apply pre-emergent herbicides to control burweed is in October. A widely used preemergence product for burweed control is isoxaben, which is sold under the brand name of Gallery as well as others. It prevents the weed from emerging from the ground when it germinates and can be used on St. Augustine, centipede, bahia and zoysia lawns, as well as in ornamental shrub beds. In northwest Florida, this herbicide needs to be applied in October for best results. A second application later in the season might be warranted. For more information about control, please consult this excellent article on lawn burweed management.

The active ingredients mentioned above are present in a variety of ‘trade name’ products* available from your local garden center, farm supply or co-op. Be sure to read label instructions carefully and contact your local extension office for any assistance. I hope all the northwest Florida lawn managers prevent burweed during the upcoming fall so that lawns will be burweed free next spring.

Happy Gardening!

 

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Coral Ardisia, A Pretty Problem

Coral Ardisia, A Pretty Problem

Coral ardisia is also known as coral berry, spice berry, and scratchthroat. It was introduced into Florida in the early 1900’s for ornamental purposes.

Coral ardisia. Photo credit: Les Harrison.

Coral ardisia. Photo credit: Les Harrison.

In the ensuing years it has since escaped cultivation and become established in hardwood hammocks and other moist woods of natural areas and grazing lands. Specimens have been collected from 19 western and south-central Florida counties as of 2004.

This evergreen sub-shrub reaches a height of 1.5 to six feet and tends to grow in multi-stemmed clumps. Leaves are alternate, 8 inches long, dark green above, waxy, without hairs, and have scalloped margins and calluses in the margin notches.

Flowers are typically pink to white in stalked axillary clusters, usually drooping below the foliage. The fruit is a bright red, globose, single-seeded berry, measuring approximately 0.25 inches in diameter. White-berried populations are also known to exist.

Coral ardisia is considered invasive. Control of coral ardisia may be accomplished by two methods. A low-volume foliar application of Garlon 4 or Remedy provides suppression of this plant. Complete foliar coverage is essential to success and retreatment will be necessary for complete control.

Basal bark applications with Garlon 4 or Remedy in an oil carrier can also be utilized for suppressing this invasive weed. Do not apply more than 8 quarts of Remedy or Garlon 4 per acre and treat no more than ten percent of the total grazed area if applying greater than two quarts per acre.

For more information:

Identification and Control of Coral Ardisia (Ardisia crenata): A Potentially Poisonous Plant

 

Cool, Wet Spring Favors Azalea and Camellia Leaf Gall

Do you have azaleas or camellias with leaves that are thickened, curled and waxy in appearance? This is fairly common this year and is caused by a fungus.

Camellia leaf gall on Sasanqua Camellia. Note swollen, malformed leaves. Photo credit: Larry Williams

Camellia leaf gall on Sasanqua Camellia. Note swollen, malformed leaves. Photo credit: Larry Williams

Exobasidium vaccinii is a fungus that causes leaves, and in some cases flower petals, to enlarge abnormally and is commonly referred to as azalea leaf and flower gall.

Infected azalea and camellia leaves become large and distorted. Eventually a white powder covers the galls. The white growth consists of spores, which is how the fungus reproduces. Galls ultimately turn brown and harden. Not every leaf will be infected.

The disease relies on airborne spores produced in the whitish mold on the surface of galls in late spring to early summer to reproduce. Some plant pathologists believe that once the spores are released, they are blown and washed to leaf and flower buds where they cause new infections. Galls then form the following spring. Other plant pathologists think that the spores are produced the following year from the old dried, brown galls that fell to the ground around infected plants the previous year. In spring, the spores blow and splash onto new leaves and petals as they emerge causing infection. One or both lines of thought may be true. But in either case, it’s important to remove and dispose of infected leaves before they turn white with spores.

Once you see evidence of infected leaves, it’s too late for chemical control. Besides, there currently is no effective or practical fungicide to control this disease in home landscapes. But you can reduce the amount of infection the following year by pruning infected leaves and throwing them away before spores develop. After removing infected leaves with galls, never leave them on the ground around the plants.

It’s best to bury, burn or place infected leaves in a plastic bag and throw them away. This disease is more severe during a cool, wet spring, which we experienced this year. It’s advisable to not add to the problem by artificially providing the “wet weather” the spores need by frequently using an overhead sprinkler and keeping the foliage wet in the spring during disease development. This is exactly what this and many other plant diseases need – wet conditions. It’s best to water established landscape plants on an as needed basis.

In the home landscape, the fungus does not cause any long-term problems for the plant. It just makes the plant’s leaves look ugly. Infected leaves will usually fall prematurely.