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Biting Flies This Fall

We often consider the end of summer a time when nuisance insects are decreasing in numbers, but there is one insect that is reaching peak numbers at this time of year.  The Stable Fly or Dog fly, Stomoxys calcitrans,  can occur at all times of the year, but populations are heaviest in late Summer through early Winter along the Gulf Coast.

Resembling the common house fly,  stable flies are persistent pests in their search for a blood meal.  They have a painful bite due to specialized mouthparts that resemble sharp thorns that rasp the skin.    Luckily, most people do not have an allergic reaction following a bite.

Stablefly_JFButler

Stable flies breed in many types of moist or decaying vegetation, including seaweed deposits along the beach.  Each female can lay about 500 eggs and the typical fly maggots feed in the vegetation before pupating into the adult.  The entire life cycle takes several weeks.

Spraying a pesticide to control adult stable flies outdoors is not a practical option for homeowners.  Rather, control methods should be directed at their breeding sites to reduce numbers.  This includes allowing manures, plant debris, or crop residues to dry quickly by spreading them thinly over an area or composting them properly.

Following hurricane events, local agencies may manage stable fly populations with pesticides, but these flies do not often warrant the use of such limited resources for control.

For more information, consult this UF / IFAS publiction about the Stable Fly.

What is that Web in my Pecan Tree?

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.

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Photograph by James Castner, University of Florida.

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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

Asian Cockroach – Is it a Pest of the Home or the Garden?

German cockroach (left), Asian cockroach (right). Credit: Dina L. Richman, University of Florida

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.

 

 

Why is My Squash Wilting?

Why is My Squash Wilting?

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

Squash Vine Borer larva. Image Credit Matthew Orwat

 

Adult Moth. Image Credit Theresa Friday

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

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.

 

Tree Cattle are Harmless

Tree cattle webbing. Photograph by Douglas L. Caldwell, University of Florida

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

Tree cattle. Photograph by Jim Castner, University of Florida

Spittlebugs: an IPM approach

Spittlebugs: an IPM approach

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

Dr. Bryan Unruh, UF/IFAS

facebook spittlebugs

 

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.