Purple Triangles in the Trees

Purple Triangles in the Trees

From time to time I am reminded of how little I know.  Honestly, I am reminded on a daily basis. A few weeks ago someone asked me about the purple things hanging from the trees. Luckily, the person gave me some good southern directions on where I could find one of these things hanging around in Marianna. So I drove out to the site to get a better look. What I saw hanging in the tree was a three-sided, purple triangle about two feet tall and a foot wide.  It looked to me like someone got a box kite stuck in a tree. Upon further research, it was determined this box kite like thing was a monitoring trap for the emerald ash borer (EAB).

A woman hanging an emerald ash borer trap in a tree. Photo Credit: Texas A&M University

A woman hanging an emerald ash borer trap in a tree. Photo Credit: Texas A&M University

The emerald ash borer (EAB) is a destructive, exotic wood-boring beetle native to Asia. It was first discovered in North America in July 2002 and has made a home in Michigan, Ohio and Ontario, Canada. Millions of ash trees have been killed by the EAB in Michigan and invested ash tree nursery stock in other states indicates the potential for increased spread of the pest. EAB has made its way to the south and has been found in Louisiana and Arkansas.

Monitoring traps are not the only means of EAB detection. A proactive approach utilizing observant citizens can help keep an eye out for potential populations. You can use these tips to monitor your community for emerald ash borers:

Ash Tree Identification – Ash trees are identified by their (1) opposite branching pattern, (2) compound leaves with 5-9 leaflets, and (3) diamond shaped bark ridges on mature trees.

A compound leaf of an ash tree. Photo Credit: FDACS

A compound leaf of an ash tree. Photo Credit: FDACS

Woodpecker Damage – Of course, not all woodpecker damage on ash trees is associated with EAB infestation, but woodpecker damage in the upper part of the tree can indicate their presence.  The woodpecker damage is usually accompanied by vertical cracks in the bark.

Canopy Thinning – As the attack progresses, bark cracking continues and the canopy in the upper half of the tree begins to thin.

Michigan ash tree showing decline due to Emerald ash borer. Photo Credit: USDA

Michigan ash tree showing decline due to Emerald ash borer. Photo Credit: USDA

Tunnels and Holes – The emerald ash borer makes distinctive S-shaped tunnels that differ from damage from other borers.

EAB Damage (left) VS Other Borer Damage. Photo Credit: Texas A&M University

EAB Damage (left) VS Other Borer Damage (right). Photo Credit: Texas A&M University

This beetle hitchhikes on firewood and infests new areas at an alarming rate.  Although the EAB has not yet been detected in Florida, transporting firewood from other states puts Florida ash trees at risk. Your help is needed to detect possible infestations so they can be quickly eradicated. The information available at the following links will help you identify the EAB, EAB host trees, and infestation symptoms.

 

Tent Caterpillars: An Unwelcome Spring Guest

Tent Caterpillars: An Unwelcome Spring Guest

Uninvited guests can sometimes be fun and entertaining, bringing spontaneity to an otherwise predictable schedule. Sometimes the surprise guest is just an unpleasant distraction with no redeeming virtues.

The unanticipated knock on the door can bring both scenarios to mind. Almost everyone has an enjoyable cousin who regales listeners with amusing tales, and picks up the check for dinner.

Likewise, there are those potential callers with parasitic qualities, the appetite of a market hog, and initiative of a sloth. The Eastern Tent Caterpillar is one such visitor in north Florida.

These native caterpillars build large, thick nests on the branch forks and crotches of many kinds of trees, seeming to always choose the prized specimens highly valued by the homeowner. The silky tent shaped nests are easy to see and identity in host trees.

The caterpillars emerging in the spring of 2015 were laid in the spring of 2014. The adult moth lays her eggs in a single batch in May to July in the panhandle. There are 200 to 300 eggs laid in the group.

The mass of eggs are shiny, reddish-brown and look like dried foam. They are ordinarily about six inches back from the tip of a thin twig in host tree.

In approximately three weeks the eggs contain fully formed caterpillars, but the small caterpillars remain in the eggs until the following spring.

In late-February to mid-March they chew their way through their egg shells ready to eat their host tree that is entering the spring budding period with plentiful tender vegetation.

The voracious larvae immediately infest and, if in sufficient numbers, defoliate plum, cherry and many others. Normally the trees recover after a few weeks, but weakened or diseased trees may die.

When not eating, the newly hatched caterpillars construct their silk tent. The caterpillars use a pheromone trail to guild them back home when foraging is done.

A social insect, the eastern tent caterpillars congregate at their specific tent during the night and in rainy weather, expanding it to accommodate their growing size. These caterpillars do not feed within their nests.

The caterpillars disperse to colonize new areas when maturity is reached. They construct cocoons in protected places once they have sufficiently scattered.

Birds are not attracted to these hairy caterpillars. If they have a heavy concentration of black cherry leaves in their diet, the caterpillars will have a bitter acrid taste.

Parasitic wasps and weather are the two most common causes of caterpillar death. These caterpillars are especially susceptible to cold weather once they have emerged from their eggs.

About two weeks later, an adult moth emerges to begin the process again. Mating and egg laying commonly occur within 24 hours of the moths emerging from their cocoons

These brown moths are nocturnal and are seen flying only at night. They are an inch to two inches wingtip to wingtip at maturity and easy to overlook.

Tent Caterpillars are quick to hatch and eat their way through home landscapes.

Tent Caterpillars are quick to hatch and eat their way through home landscapes.

Unfortunately, once they arrive for a visit they always overstay their welcome.

Contact your local UF/IFAS County Extension Office to learn more about Eastern Tent Caterpillars in north Florida.