by Blake Thaxton | Aug 19, 2013
It is that time of year where mysterious webs have invaded pecan trees throughout the Southeast United States. This is definitely the case in the panhandle of Florida. Many have called into the extension office asking for identification of the web mass in their pecan trees. It is the Fall Webworm that has made a home in the pecan tree this fall.
Photograph by James Castner, University of Florida.
Photograph by Andrei Sourakov, University of Florida.
Fall Webworm
The adult fall webworm is a moth that is bright white in color and may have darker spots on its wings. The larvae of the moth are what lives in the tent web masses. Immediately when the larvae webworm hatches out of the eggs it begins to create its webs around foliage in which it will feed on.
Damage
The damage cause by the feeding of the larvae on the pecan trees is isolated to the leaves and they will not eat the nuts. If Defoliation is severe enough it can reduce the current years crop and the following years crop. Several years of defoliation can lead to death of the tree but this is not likely. Obviously the webs are ugly as well and if the tree is not only a producer of pecans but also functioning as an attractive shade tree in a ornamental since this can be a problem.
Control
In most commercial pecan production settings webworms are not very prevalent because of the spray programs implemented. For residential settings the best solution is to manually prune them out because of the lack of proper spray equipment to cover the entire tree. If the problem is bad enough call your local extension agent to get recommendations on products that could be used.
Sources:
Andrei Sourakov and Thomson Paris (2011, April) Fall webworm,Hyphantria cunea (Drury) (Insecta: Lepidoptera: Arctiidae: Arctiinae). Retrieved from http://edis.ifas.ufl.edu/pdffiles/IN/IN87800.pdf
Michael J. Hall. Fall Webworm. Retrieved from http://www.lsuagcenter.com/NR/rdonlyres/68665E57-A2F4-4030-A4E6-55821DCFBDD6/16783/FallWebworm_sheet_.pdf
by Larry Williams | Aug 12, 2013
German cockroach (left), Asian cockroach (right). Credit: Dina L. Richman, University of Florida
When people first see Asian cockroaches they may think they are seeing little flying moths. Or they may believe they are seeing German cockroaches because the two species look similar. Keen observation will indicate that there are differences, particularly in behavior.
In appearance, both German and Asian cockroach adults are about 5/8 inch long and are brown in color with two darker parallel bands running lengthwise behind their head. But unlike German cockroaches, Asian cockroaches are strong fliers with sustained flights of at least 120 feet. As a person is watering a mulched plant bed with a hose, the water disturbs the roaches and they quickly fly out of the mulch, resembling little moths. Or home gardeners may see them flying out of the lawn during mowing.
German cockroaches prefer to live indoors and are a major household pest as a result. Asian cockroaches prefer to live outside in mulched beds, compost piles and lawns. Their numbers can be high with populations of 30,000 to 250,000 per acre.
They become active at sundown and are attracted to lights. They often fly inside through any opening in a house such as lighted doorways or windows. Once inside, they fly to and crawl on illuminated television or computer screens and walk on walls while lights are on during the evening. This is when people believe they are seeing a German cockroach invasion in their house, but German cockroaches do not fly.
Many people become upset when they see Asian roaches inside their home. The good news is, however, that indoor infestations are rare occurrences.
Asian cockroaches are susceptible to insecticides but they are difficult to control because of their abundant population and their ability to fly considerable distances.
Because they can fly 120 feet or more in a single flight, large areas around a home require treatment. And cockroaches in surrounding untreated areas may result in re-infestation.
Residual sprays around the perimeter of structures are usually unsuccessful because of numerous infested areas in adjacent lawns, mulch and wooded areas. Adults enter homes through windows and doorways and immediately fly to walls, avoiding baseboards and other typical areas normally treated for German cockroaches.
Best control has been attained by using insecticide baits (labeled for roach control) in infested areas outdoors.
For additional information on Asian cockroaches and their control, contact your local University of Florida / IFAS Extension Office or Pest Control Operator.
by Matthew Orwat | Jul 15, 2013
Why is my squash wilting? Assuming you have been giving your vegetable garden adequate water, the Squah Vine Borer may be the cause.
Squash Vine Borer larva. Image Credit Matthew Orwat
Adult Moth. Image Credit Theresa Friday
Unfortunately presence of the squash vine borer, the larval form of a clearwing moth, is usually noticed only after damage is permanent. Prevention is possible with early recognition through vigilant scouting.
The adult moth is common in gardens throughout Northwest Florida, and is easily recognizable due to its black and orange coloration.The 1/2 inch moth is active during the day and will lay a single tiny orange egg at the base of healthy squash plants.
It only takes a week for the egg to hatch and for the larva to bore into the stem. Once the larva in inside the stem, it chews its way up the stem, blocking the transport of water from the roots to the shoots. By the time wilting is noticed, total blockage of the water conducting tissue (Xylem) is likely.
If the moth is noticed in the garden, preventitive application of Bt (Bacillus thuringiensis) or pyrethroid (permethrin or bifenthrin) insecticide to the base of the stem may stop their incursion into the vine. Yellow traps full of water can be put out to monitor for them, since they are attracted to anything yellow.
Squash Vine Borer Egg. Image Credit Theresa Friday
If the vine is already affected, insecticide applications will not help. There is a slim chance of saving it by cutting out the larva. While performing this task make sure to preserve the stem and bury the stem of the plant in a few inches of protective soil. The plant may grow new roots and resume production.
For more information about the Squash Vine Borer, proceed to this University of Kentucky article. To learn more about pests of Cucurbits, check out this informative UF / IFAS publication, Insects Management for Cucurbits.
by Larry Williams | Jun 17, 2013
Tree cattle webbing. Photograph by Douglas L. Caldwell, University of Florida
Many people are noticing small insects on trunks and branches of their trees. When disturbed, these insects move in a group and are commonly called tree cattle because of this herding habit. They are ¼ inch brownish-black insects with white markings. Some people assume that these insects will injure their trees but they are harmless. They could be considered beneficial.
Before you spray your tree to control these insects, click on the following link and read the entire article.
Tree cattle are harmless
Tree cattle. Photograph by Jim Castner, University of Florida
by Blake Thaxton | Jun 12, 2013
Credit: Lyle Buss, University of Florida
In recent weeks Spittlebugs have been found everywhere in the western parts of the panhandle. Spittlebugs are the little black and orange insects you find everywhere in early June. The adult spittlebug is about 1/4 inch long and has two orange lines across its back. You may notice them flying on you while you mow the lawn.
The immature spittlebugs called nymphs, are usually found in a foamy white mass that characterizes the name of the insect. The spittle mass is for protection of the nymphs from predators and desiccation.
Credit: E. A. Buss, University of Florida
The spittlebug can cause injury to ornamental turfs and other ornamental plants. The adults feed on turf, centipede is the turf of choice. When feeding, the insect injects a toxin into the leaf blade with its piercing/sucking mouthparts. The pierced leaf blade will take on purple, white, or yellow stripes along the turfgrass blade vertically. Heavy infestations are best identified by a combinations of finding the injury, spittle masses, and large numbers of adults present.
Credit: Larry Williams, UF/IFAS
Recently spittlebugs have been spotted across many counties in the panhandle. Many have brought them to the extension offices for identification and treatment recommendations. Identification is the correct first step when having an IPM or Integrated Pest Management approach to insect control.
Bryan Unruh Ph.D is the UF/IFAS turf specialist stationed in Jay at the West Florida Research and Education Center. Dr. Unruh posted on Facebook about Spittlebugs and the post read:
Dr. Bryan Unruh, UF/IFAS
Sticking to an IPM plan, at this current date spittlebug damage has not met the aesthetic threshold to put a control plan in place. Once the threshold has been met then cultural, mechanical, an chemical techniques need to be discussed to best take care of the issue. Since Dr. Unruh commented on spittlebugs there has been a dramatic increase in rainfall, so we can expect for the spittlebugs, to stay around a while longer. If you think you have an infestation that warrants treatment, call your local extension agent for treatment options.
by Matthew Orwat | May 9, 2013
Adult Scale – Image Courtesy Lyle Buss
Many different species of scale insect infect citrus in North Florida, and mid spring is usually when gardeners notice them on their fruit trees and ornamental shrubs. Many different species of scale affect Florida homeowners and cause a host of problems in the garden and landscape. Citrus is particularly prone to scale infestations in North Florida.
The Satsuma Tangerine, Citrus unshiu, is currently a fruit that is highly prized by home gardeners in North Florida. Now is the time to act to prevent heavy scale infestations since weather is warming and control methods cannot be used when daytime temperatures are very hot. This pest has already been observed at multiple locations throughout the Florida Panhandle in both home gardens and commercial production areas.
Scale often reduces tree vitality by ingesting sap that would otherwise be used by the tree for growth and fruit production. They may also cause premature fruit drop and defoliation. A secondary pest that may occur as result of Scale is Sooty Mold. Sooty Mold lives off of the surgery secretions of the scale and can cause citrus leaves to look black and eventually drop.
The good news is that Scale is relatively easy to control when managed in winter or early in the spring growing season. From October through mid-May growers should use Horticultural Oil to control scale, particularly horticultural oil containing petroleum products. These products deprive scale insects of oxygen. This will smother them, but dead insects will need to be washed off if complete removal is desired.
Cottony Cushion Scale – Image Courtesy Matthew Orwat
Applications should be timed correctly since horticultural oil applications can burn plants once the outdoor temperature reaches 94 ® F. A good rule of thumb is to apply horticultural oil on cool and cloudy days to minimize leaf damage. Always consult the label of each individual product before application and never apply more than the recommended amount. This last statement is especially crucial for horticultural oil applications, since increased rates are highly likely to damage plants. For more information, please consult this UF / IFAS publication on Citrus Scale and the Citrus Pest Management Guide.
Cottony Cushion Scale – Image Courtesy Matthew Orwat
