by Julie McConnell | May 27, 2014
Lady bird beetle and aphids. Photo: Julie McConnell, UF/IFAS
The most numerous animals on the planet are insects and although less than 1% cause damage to our landscapes, most are viewed as pests. Many insects perform clean up tasks that keep our environment from being littered with carcasses and trash while others actually attack and feed upon insects that are direct pests to plants.
It is important to recognize that all insects are not pests and take the time to get to know a few that might actually be performing a beneficial job in your landscape. Probably the most easily recognized beneficial bug family in Florida landscapes are the ladybird beetles (Coccinellidae). There are several species of ladybird beetles with different food preferences including mildews, mites, whiteflies, scale insects, and aphids.
Another group of insects that include some predatory species is the stink bugs. Some stink bugs do eat plants, but there are also many that are beneficial such as Florida predatory stink bug (Euthyrhynchus floridanus). The Florida predatory stink bug preys on velvetbean caterpillar, okra caterpillar, alfalfa weevil, and flatid planthopper. One of the distinguishable characteristics between plant feeding and insect feeding stinkbugs are the shape of their shoulders. Plant feeders have rounded shoulders and predatory have points on their shoulders.
The next time you are disturbed by a bug in your garden, take a moment to watch what it is eating and try to identify it before assuming it is a pest. After all, there are many beneficial bugs that help to balance out the “bad bugs.”
by Beth Bolles | May 27, 2014
Frass (toothpick-like projections) extends from entry holes on a Jeruselum thorn damaged by cold temperatures. Photo by Beth Bolles, UF IFAS Escambia Extension
Winter injury and stress to many trees has attracted granulate ambrosia beetles to landscapes. These beetles mostly prefer weakened trees and cut stumps/logs but have been found to attack some healthy trees as well.
Adult beetles are very small, only about 1/16 inch long and bore into branches and trunks of many woody plants. They will push out small ‘strings’ of boring dust which look like toothpicks. These strings successfully protect the beetles as they establish galleries for laying eggs and rearing young within the tree. The adult females will introduce a fungus (ambrosia) into these galleries on which both the young beetles and adults feed.
Ambrosia Beetle Entry Point. Photo by Matthew Orwat
Many beetles will bore into a plant, mostly along the trunks. Plants may be ultimately killed, not by the beetles but by the fungi that interfere with the movement of fluids within the tree.
If you notice a tree infested with ambrosia beetles, it is best to remove the plant quickly. Remove all infested plant parts from your landscape. If you have a special plant that you want to save, you may be able to cut it back close to the ground, and allow it to resprout. It would be necessary to monitor the remaining portion carefully for reinfestation and treat with an approved insecticide to prevent beetle entry.
Interior of damaged stem.
by Carrie Stevenson | Apr 21, 2014
As spring commences and young wildlife of all species are born, everyone’s favorite flying, furry mammal also begins roosting season. Ideally, bats will find shelter in trees, caves, abandoned buildings, and bat houses, but sometimes they end up in a home. I receive calls often about how to best remove or exclude a group of bats living in an attic or garage. While there are countless benefits (most notably, efficient insect control) to having bats in one’s landscape or neighborhood, most people prefer they not share their own home with them. However, due to their slow reproductive cycle and declining populations in the United States, it is illegal in Florida to prevent bats from returning to any roosting location from April 16 to August 14. Female bats typically give birth during maternity season to one pup (or rarely, two), which will cling to the mother’s fur to nurse for their first few weeks and months of life. Being nocturnal, this means mothers and babies will be inside a dwelling during the day. Typically, if a homeowner is trying to exclude bats from a home, they will put up netting or seal up a hole in an attic entry in the evening after bats have flown off to feed on insects at night. However, if this is done during roosting season, young bats left back in the roost while mothers are hunting can get trapped inside a building and will not survive.
A rare set of twin Seminole bat pups with their mother. Photo credit: Carrie Stevenson
This obviously has the potential to cause conflict between homeowners and the bat population. The Florida Fish & Wildlife Conservation Commission has regulatory oversight for bat-related issues, and they will work with citizens to arrange a positive outcome for both the property owner and the animals involved.
Bat populations are declining in North America due to a devastating disease called white-nose syndrome and loss of habitat. However, you can help these fascinating animals by installing a bat house in your yard. Keep in mind that bats attracted to bat houses prefer to be in open areas away from trees (where their predators hide), and the house should be installed at least 12 feet in the air. Bat houses can be purchased or built rather simply—keep an eye out for Extension workshops near you, or visit this UF Wildlife Ecology publication or Bat Conservation International’s website for simple instructions.
To learn more about bats and how to help them, visit this website or contact me or your local County Extension office!
by Sheila Dunning | Apr 15, 2014
Bagworms on a stop sign
Northwest Florida is the most southern range of the common bagworm, Thyridoptgeryx ephemeraeformis, but the majority of the plants they feed on can be found here. Common host trees include Red Cedar, Live Oak, Maple, Elm and Pine. Other susceptible shrubs include Indian Hawthorn, Juniper, Arborvitae, Ligustrum and Viburnum.
Bagworms overwinter as a clutch of 500-1000 eggs wrapped in the leaves of the infested plant. In late spring the larvae hatch as tiny caterpillars that disperse to surrounding plants by spinning a silken thread and “ballooning” on the wind.
Once established on a host plant the young bagworms begin feeding and constructing a bag which is formed using pieces of twigs, leaves and silk.
From then on, only the head and thorax of the female bagworms emerge from the foliage bag. She continually feeds on the plant, leaving it severely defoliated. As few as four bagworm larvae can cause a four-foot Arborvitae to be so damaged that it can’t ever grow enough foliage to return to a normal appearance. For four to sixteen weeks the caterpillars feed steadily. Once the larva has consumed enough food during the last instar, it attaches its bag securely with a thick silken strand to its host plant or nearby structure. The bagworm seals the posterior end of the bag, molts, and begins pupation. The bagworm’s 7-10 day long metamorphosis results in a moth. However, the adult female’s wings and appendages are reduced to mouthparts, legs and small eyes. She remains in a caterpillar-like state for a couple of weeks. She releases a pheromone that attracts the male. The male bagworm emerges as a free-flying, lacey, black moth that only lives one or two days; just enough time to mate with the female in her bag. Once mated the female then dies, mummifying around her eggs.
Bagworm populations can reappear in the same areas year after year. To control bagworms, mechanical methods and biological insecticides are the most effective practices. Hand-picking them from late fall to early spring and placing them in a bucket of soapy water or a sealed bag prevents new larvae from dispersing. Applying Bt, Bacillus thuringiensis, to the foliage is also an effective means of control when applied to new spring growth. This bacteria stops the feeding of all caterpillars, so be cautious about where it is used. Many desirable butterfly larvae can be harmed if the product lands on other larval plants.
by Beth Bolles | Apr 15, 2014
How can an animal that does such much to help rid your lawn of pests be so hated by most homeowners? Such is the life of the mole.
The beneficial mammal is a soil dweller that tunnels through the soil, increasing aeration as it searches out a meal of beetle grubs, mole crickets, and slugs. Moles prefer loose soil and can tunnel more than 15 feet an hour. Moist soil brings the food source closer to the surface which in turn bring moles up to expose raised tunnels to homeowners. These tunnels are mostly cosmetic and show up easily in mulched areas and lawns with heavier weed populations. Most homeowners with a healthy, thicker lawn will rarely notice mole activity unless they encounter loose areas as they walk over the turf. These can easily be pressed back down with your foot.
Mole tunnel in weedy area. Photo: Beth Bolles, UF IFAS Extension Escambia County
There are management techniques for moles which include traps and ridding the lawn of the food source. The best practices are to manage the turf through proper mowing, watering, and fertilizing to create a uniform, healthy cover. For the most part, mole management is not even required. Consider the benefits of the moles as predators and allow them to be a natural part of the landscape environment. For more information on moles read the University of Florida IFAS Extension publication.
by Gary Knox | Mar 18, 2014
Given crapemyrtle’s reputation for plant vigor and pest resistance, I was shocked to see Chinese crapemyrtles noticeably affected by a previously obscure pest.
Last November I had the privilege of traveling to China with Dave Creech (Stephen F. Austin University), Mengmeng Gu (Texas A&M) and Yan Chen (LSU-Hammond). Crapemyrtles, Lagerstroemia spp., are native to Asia, and China is regarded as the first to cultivate crapemyrtle as a flowering tree. As a crapemyrtle enthusiast, I eagerly looked forward to seeing Lagerstroemia collections in Chinese botanical gardens. What we saw in Beijing surprised us.
![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 in Beijing, China]](https://nwdistrict.ifas.ufl.edu/hort/files/2014/03/crapemyrtle-scale-768x1024.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 in Beijing, China]
Symptoms, Appearance and Distribution in China
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. 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.
![Figure 2. This white to grey colored scale oozes pink when crushed. [Photo by Gary Knox in Beijing, China]](https://nwdistrict.ifas.ufl.edu/hort/files/2014/03/crapemyrtlescale2-505x1024.jpg)
Figure 2. This white to grey colored scale oozes pink when crushed. [Photo by Gary Knox in Beijing, China]
We found this scale on crapemyrtle in all four cities we visited, across hardiness zones roughly equivalent to USDA Cold Hardiness Zones 6b to 9 (Beijing, Zone 6b/7a; Nanjing, Zone 8a/8b; Shanghai, Zone 8b/9a; and Kunming, Zone 9). However, this scale was not found on all crapemyrtle. My personal observation is that stressed plants appeared more susceptible to this scale, as exemplified by infestations on freeze-damaged crapemyrtle in Beijing (Fig. 3) or in a poorly maintained planting in the Nanjing Airport parking lot. Our hosts indicated the problem appeared to be more severe on hybrid cultivars introduced from the U.S., and our observations mostly confirmed that.
In the U.S.?
Unfortunately, crapemyrtle bark scale or a similar scale may already be in the U.S. A new scale insect believed to be a species of Eriococcus was first discovered in the Dallas, Texas, area in 2010 where it is problematic on landscape crapemyrtles. It has not been definitively identified by entomologists yet and management recommendations are still being developed. However, this scale has since been observed in Shreveport, LA, Memphis, TN, and Little Rock, AR, undoubtedly being moved with plants. 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.
![Figure 3. Dr. Gu is dismayed at seeing this crapemyrtle planting infested by scale (note the black sooty mold on stems). [Photo by Gary Knox in Beijing, China]](https://nwdistrict.ifas.ufl.edu/hort/files/2014/03/crapemyrtlescale3-767x1024.jpg)
Figure 3. Dr. Gu is dismayed at seeing this crapemyrtle planting infested by scale (note the black sooty mold on stems). [Photo by Gary Knox in Beijing, China]
![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 in Beijing, China]](https://nwdistrict.ifas.ufl.edu/hort/files/2014/03/crapemyrtle-scale.jpg)
![Figure 2. This white to grey colored scale oozes pink when crushed. [Photo by Gary Knox in Beijing, China]](https://nwdistrict.ifas.ufl.edu/hort/files/2014/03/crapemyrtlescale2.jpg)
![Figure 3. Dr. Gu is dismayed at seeing this crapemyrtle planting infested by scale (note the black sooty mold on stems). [Photo by Gary Knox in Beijing, China]](https://nwdistrict.ifas.ufl.edu/hort/files/2014/03/crapemyrtlescale3.jpg)