by Sheila Dunning | Apr 28, 2015
Bees have been disappearing at an alarming rate and continue to vanish without a trace. Why should anyone care? Well, they matter a lot more than most people think. Bees are the overwhelmingly dominant pollinator for most food crops. Native bees in the United States are responsible for pollinating over $15 billion worth of agricultural commodities annually. However, native bee populations are in decline due to habitat loss. At the same time, managed colonies of European honey bees have suffered a 50% decline over the past few decades. Numerous other pollinating insects are facing the same fate.
European honey bee. Photo credit: UF/IFAS.
As the spring planting season is upon us, it’s exciting to think about all the wonderful produce we will have this summer. But, without pollinators many of these crops would not be available. The majority of fruit and vegetable food sources we eat are dependent on insect pollinators. One of every three bites of food Americans consume comes from a plant visited by bees or other pollinators.
As declining numbers of farmers work to meets the need of increasing populations, they are forced to make choices on alternative to chemicals for pest control. “Good bug blends” of flowers can help attract pollinators as well as beneficial insects that suppress harmful pests. Establishment of these meadows can be done on a small or large scale and in any habitat. One approach to “bring back the pollinators” is to intercrop with blooming plants that attract insects. Selecting a diversity of plants with different flower sizes, shapes and colors, as well as various plant heights and growth habits, will encourage the greatest numbers of pollinators. It is important to provide a continuous source of pollen and nectar throughout the growing season. At minimum, strive for three species to be blooming at any one time; the greater the diversity the better.
To enhance the garden, choose flowering plants that also provide shelter for beneficial insects. Many companion plants are suitable habitat for predators and parasitoids. Research in Florida has demonstrated that predatory minute pirate bugs can build to high numbers in sunflowers. The favorite food of minute pirate bugs is Western flower thrips. So, planting sunflowers on the perimeter of vegetable crops, such as peppers, can greatly reduce the damage caused by the thrips. Similar results were found with the planting of sorghum to attract beneficial mites and intercropping with buckwheat to house syrphid flies and parasitoid wasps. The garden vegetables experienced fewer spider mite, whitefly and aphid problems. Crimson clover, Hairy vetch and cosmos are other annual seed crops that can aid in attracting pollinators and harboring beneficial insects.
Blue Mistflower. Photo Credit Mary Derrick, UF / IFAS Extension.
Insectary meadows can be created in the landscape and along roadways, not just in the garden. For more permanently planted areas, native wildflowers, grasses and woody plants serve as larval host plants for butterflies, and also provide nesting and overwintering sites for bumble bees, predacious beetles and other beneficial insects. Native perennial wildflowers such as blanketflower, tickseed, black-eyed Susan, partridge pea, narrowleaf sunflower, milkweed, beebalm, goldenrod and silkgrass can be installed in the spring as potted plants or seeded in the fall. Seeds require exposure to cold temperatures and damp conditions before germination can occur. In Florida, the best time is November to February.
Though grasses do not offer nectar or high-quality pollen, it is often useful to include at least one native bunch grass or sedge. Short, clump-forming grasses are preferable to large, spreading grasses. Hedgerow planting of woody species is a way to provide winter-blooming plants vital for supporting pollinators. Woody plants and grasses provide more than forage for pollinators, as many native bee species nest in the stems of plants or in the undisturbed ground underneath plantings. Suitable grasses include: beaked panicgrass, purple lovegrass, Muhly grass, broomsedge,little bluestem, wiregrass and toothache grass. Favored woody species that make good “beetle banks” include: fetterbush, American beautyberry, saw palmetto, Chickasaw plum, red maple, sparkleberry, Dahoon holly, redbud, blackgum, magnolia, buttonwood and sourwood.
Regardless of whether the objective is to establish herbaceous or woody vegetation, the time and effort spent on eradicating undesirable plants prior to planting will result in higher success rates in establishing the targeted plant community. Choose level, open sites that receive full sunlight and have limited weed populations. If perennial weeds are a problem, the use of herbicides that have no soil residual (e.g. glyphosate) may be necessary.
For more information on establishing planting for pollinators visit: www.xerces.org/pollinator.
by Larry Williams | Apr 20, 2015
Mole cricket tunnels. Credit: N. Leppla, UF/IFAS
Many people treat their lawn with an insecticide when they see mole crickets in the spring or at the first sign of a brown area in their lawn. What they don’t understand is the biology of this pest.
Mole crickets spend the winter as adults in the soil. As temperatures warm in late February and March, adult mole crickets emerge and begin to mate. Male mole crickets construct a chamber in the soil and chirp to attract female crickets. Attracted females fly to the males. After mating, males die and females fly to a suitable area for egg laying. Mated females begin tunneling and laying eggs in the tunnels. They lay about four clutches of eggs in different areas, averaging 35 eggs per clutch. Female crickets die shortly after laying their eggs.
Use of insecticides during early spring is not recommended because:
- adult mole crickets are not easily killed
- they cause minimal lawn damage during the mating and egg laying process, and,
- reinfestation from subsequent flights is likely.
The best time to treat for mole crickets is during mid-June through July. This will be when eggs have hatched but before the nymphs (immature mole crickets) are large enough to do much damage. Proper timing of the insecticide application is very important to achieve control.
Mole cricket nymphs. Credit: J. Castner, UF/IFAS
If you are not sure if mole crickets are present, you can find out with a soap solution. Mix 1½ fluid ounces of a lemon scented liquid dishwashing soap in two gallons of water in a sprinkling can or bucket. Pour the soapy water over an area approximately four square feet and count the number of mole crickets that emerge. If they are present, it only takes several minutes for mole crickets to crawl to the surface after the soap treatment. Repeat the process around the yard where you suspect mole cricket problems. If you flush an average of two to four crickets per site, treat the lawn with an insecticide. Follow up with spot treatments if any crickets escape the first insecticide treatment. But don’t treat at all if there is no evidence of mole cricket activity.
There are a number of products for mole cricket control in home lawns. Look for insecticides that contain the following active ingredients: bifenthrin, carbaryl, cyfluthrin, deltamethrin, imidacloprid , lambda-cyhalothrin or permethrin.
Before using any product for mole cricket control first identify the problem as mole cricket damage by using the soap flush technique. Then choose an insecticide that lists mole crickets on its label. And finally, read the container carefully for use directions, application techniques, irrigation requirements and precautions.
by Beth Bolles | Apr 7, 2015
One of the most commonly used shrubs in landscapes is the Indian hawthorn, Rhapheolepsis indica. Although not native to Florida, it can be a very attractive shrub when used properly in landscapes. Plants offer spring flowers in pinks and whites followed by berries that are a food source for birds.
Indian hawthorn as a single planting can be attractive.
Indian hawthorn plants in landscapes are susceptible to a couple of pests that create unattractive and unhealthy plants. A leaf spot fungus called Entomosporium leaf spot easily spreads from infected plants through irrigation and rainfall leading to leaf discoloration, leaf drop, and dieback of limbs. Scale insects can also be common on leaves causing yellowing and dieback. The fungal problem is difficult to manage on heavily infected plants but the scale can be managed with a low toxicity pesticide choice such as a horticulture oil.
A heavy infection of leaf spot fungi is often too difficult to manage when plants are routinely irrigated.
Most often the problems on Indian hawthorn, especially fungal, are the result of poor management. This shrub likes sun, well-drained soil, and no overhead irrigation. Once established, plants should need little supplemental irrigation and water should only be applied to the base of plants. Since plants normally form a rounded mound, there is also little need for pruning if planted in a correct spot and spaced appropriately when planting. Most landscape installations of Indian hawthorn space plants based on the gallon pot size and not the mature size of the plant which is about 3-5 feet in height and spread.
Indian hawthorn can still be a good selection for homeowners. Buy healthy plants without any signs of spots on leaves and don’t plant a monoculture of these plants in the landscape. If one plant does have serious pest issue it is easier to either treat or remove one plant versus a mass planting.
by Gary Knox | Mar 31, 2015
![Figure 1 Note the black sooty mold coating the layers of white and grey scale, believed to be crapemyrtle bark scale, Eriococcus lagerstroemiae. [Photo by Gary Knox]](https://nwdistrict.ifas.ufl.edu/hort/files/2015/03/crapemyrtlescalebark1.jpg)
Figure 1 Note the black sooty mold coating the layers of white and grey scale, believed to be crapemyrtle bark scale, Eriococcus lagerstroemiae. [Photo by Gary Knox]
Symptoms and Appearance
An early symptom of crapemyrtle bark scale is black sooty mold covering extensive areas of leaves and stems as a result of honeydew exuded by the scale (Fig. 1). Individual scale insects are white to gray in color and ooze pink when crushed (Fig. 2). Large populations build up in branch crotches and extend up branches, appearing crusty white to gray. This scale usually is not present on new growth, leaves or slender stems unless infestations are heavy.
For more information and additional photos
Resources, up-to-date information and additional photos about crapemyrtle bark scale may be found at http://www.eddmaps.org/cmbs/. This website will be the major portal for information about this pest.
Figure 2. This white to grey colored scale oozes pink when crushed. [Photo by Gary Knox]
Research
Research on crapemyrtle bark scale is ongoing. Scientists from the University of Florida, LSU, University of Arkansas and Texas A&M are collaborating to develop Best Management Practices to manage crapemyrtle bark scale in the nursery and landscape. Initial research is examining the biology of the host-insect interaction to better understand its life cycle and stages when it may be most susceptible for control. Additional research will evaluate pesticides and other IPM strategies for managing this pest.
The expanding distribution of this scale and my personal observations of crapemyrtle bark scale throughout China suggest this scale could have a widespread and severe impact on crapemyrtles in landscapes. Please be on the lookout for crapemyrtle bark scale, and report sightings to your local county extension agent and Florida Department of Agriculture and Consumer Services Division of Plant Industry.
by Sheila Dunning | Mar 31, 2015
As the ant and termite swarm season begins, here is one species to be aware of.
The red dots on the map indicate the known distribution of the Formosan subterranean termite, Coptotermes formosanus Shiraki, in Florida, as of 2013. Figure by Rudolf Scheffrahn, University of Florida.
Formosan subterranean termite (FST) acquired its name because it was first described in Taiwan in the early 1900s.
Formosan subterranean termite, Coptotermes formosanus, is the most widely distributed and most economically important wood destroying insect. In the city of New Orleans where this termite species was introduced in the 1950’s, the control and repair costs due to FST are estimated at $300 million annually. A single colony of FST may contain several million termites (versus several hundred thousand termites for native subterranean termite species) that forage up to 300 ft in soil. Because of its population size and foraging range, the presence of FST colonies poses serious threats to nearby structures. The FST generally invades structures from the ground. They commonly enter through expansion joints, cracks and utility conduits in slabs. Any wood-to-ground contact is an inviting entrance for FST infestations.
Studies also found that FST attack many species of living plants. The FST attacks structural lumbers and living plants because they are sources of cellulose. However, this termite is also known to attack non-cellulose materials such as plaster, plastic, asphalt, and thin sheets of soft metal (lead or copper) in search of food and moisture. The combination of water and wood or other cellulose materials provide attractive conditions for the FST. Leaky plumbing, air conditioning condensate, and any portion of the building that may collect excessive amounts of moisture should be corrected to maintain an environment less attractive to FST.
Conventional method for control of subterranean termites, including the FST is to place a chemical barrier between termites and the structure to be protected. Because of the large size of a FST colony, application of soil termiticide beneath a structure may not impact the overall population. Bait stations containing a monitoring device can be first installed in soil surrounding a home. When termites are found in the station, the monitoring device is replaced with a tube containing pesticide bait. Termites feeding in the stations then carry baits to other members of a colony, leading to the demise of entire colony population.
All baits are to be applied by trained pest control professionals. Efficacy and claims of these commercial bait products may differ from one another. It is prudent to read the fine print and ask questions. Many new Florida residents are unfamiliar with homeowner insurance related to Formosan termite damage. If you want to learn more, plan on attending one of the local workshops listed in the link below.
by Shep Eubanks | Mar 31, 2015
Photo 1 Large Carpenter Bee – Photo by Shep Eubanks
Photo 2 Carpenter Bee Gallery – photo courtesy of bugwood.org
Every year beginning in mid-March to early-April, Extension Agents begin to receive inquiries about managing carpenter bees which are attacking barns, eaves, rafters, and other wooden structures. The bee most commonly responsible for economic damages is typically the large Carpenter bee (see Photo 1)
This is when nesting takes place in structural timbers, fence posts, wooden water tanks, or the like (see Photo 2). Chandler (1958) lists four types of damage done by carpenter bees: weakening of structural timbers,
gallery excavation in wooden water tanks (especially in arid western areas), defecation streaking on houses (see Photo 3) or painted structures, and human annoyance. The last point is included since carpenter bee females may sting (rarely), and male bees may hover or dart at humans who venture into the nesting area.
In general, carpenter bees are a minor problem. Carpenter bees rarely attack painted or varnished wood, while natural wood is more attractive. If there is a problem with carpenter bees, apply a finish to the wood.
These bees often cause problems on structures by boring into the wood surface which is the back face of the trim under the eaves since this surface is usually not painted. A buzzing or drilling sound is heard when the bee is boring into the wood.
If the hole is not visible, often the case when the bee is boring into the backside of trim, look for sawdust on the ground under the hole.
Unpainted, exposed wood is especially attractive to carpenter bees. The most effective deterrent to carpenter bee activities is a painted (oil base or polyurethane) surface.
Insecticide additive paints are available which may repel bees attempting to nest. Wood stains provide little repelling action. Nail holes or exposed saw cuts should be filled in with wood putty or dowels and painted.
If practical, remove severely damaged wood and replace with chemical pressure-treated wood to deter nest construction. To further discourage carpenter bees looking for potential nesting sites, a homeowner should secure all doors, windows, and other building openings during the spring. Non-wood surfaces such as vinyl siding are not damaged by carpenter bees.
A very effective, low cost trap can be constructed from scrap plywood, several of 16 ounce plastic water bottles, a few wood screws, a piece of wire, and a little bit of electrical tape as seen in Photos 4,5, and 6 below. A hole approximately 1/2 inch in diameter works very well. Three or four of these traps positioned at the corners of a building or strategically within a structure can greatly reduce bee numbers with minimal insecticide, structural painting, or other practices. In Photo 4, the trap has only been in place for 5 days. Use of insecticides remains an option.
For more information, contact your local Extension Agent or check out this publication :
Large Carpenter Bees, Xylocopa spp. (Insecta: Hymenoptera: Apidae: Xylocopinae)
Photo 4 Trap Full of Bees – photo by Shep Eubanks
Photo 3 Typical Boring and Defecation Damage – photo by Shep Eubanks
Photo 5 Close up of Trap Construction – photo by Shep Eubanks
Photo 6 Hole Size of 1/2 inch – photo by Shep Eubanks
