Saturday, May 21, 2016

Pest Alert - Some Bad Bugs in the VegHeadz Garden

Squash vine borer moth
Leon County UF/IFAS Extension Horticultural Assistant Kelly Thomas makes a tour through the vegetable garden most mornings.  This week she noted several "bad" bugs on plants and captured these photos.. 

The  squash vine borer moth is the guy responsible for the sudden collapse of seemingly healthy squash plants.  It lays its eggs on the base of the squash stem.  When they hatch, the larvae bore into the vine and feed there which eventually leads to the collapse of the plant as pathways for water and nutrients are severed by the larvae.  The borer hole can be seen, often with a little pile of frass (bug excrement and plant material) beside it.  Sometimes cutting a slit in the vine and removing the maggot will save the plant if detected early.  Wrapping tinfoil around the base of unaffected squash stems may prevent the borers from entering the stem.  Capturing and killing the moth is a preventive measure, but that is difficult.  However, they fly during the day unlike most moths which fly at night.  The moth resembles a wasp in flight.  They overwinter in the soil, emerging in the spring.  . 

Citrus flatid leaf hopper
The leafhopper or plant hopper at right is also a pest, but it doesn’t do much damage. Kelly found it on an eggplant.  It eats sap from the stem and produces honeydew that ants and bees feed on. The white material produced by the nymphs is sometimes mistaken for mealybugs.  The adults resemble a small white moth, and the nymphs are white also.  They can also be found on citrus and other woody trees and shrubs.  They may be prey for predator wasps. 

The real bad boys are the Leaf-footed bugs shown below.  Kelly says they are breeding like crazy in our garden. They come from a large family of sap-sucking bugs.  They get their name from the leaf-like enlargements or flaps on their hind legs.  They are closely related to stink bugs which are also sap-suckers.  They feed mostly on seeds of tomatoes and other plants such as pomegranates.   Their eggs are brown and cylindrical and laid in a string on a plant leaf or stem.  They should be located and destroyed when possible.    The adults live a relatively long life and lay eggs over a protracted period,  Major outbreaks occur after mild winters, and their population also depends on the amount of natural predators, weather, and food available.   They have piercing and sucking mouth parts which they use to probe into a tomato looking for seeds.  When they find one, they excrete an enzyme which liquifies the seed which they then suck out.  Their damage may destroy small tomatoes, but on larger ones, it leaves a small depression or discoloration in the fruit which does not affect its edibility.  They can be captured and drowned in soapy water.  They can be vacuumed with a hand vacuum.  Shaking the plant can sometimes dislodge nymphs which can be destroyed when they fall to the ground (lay down some paper or something light first so you can see them), but the adults will fly away.  Their predators include birds, spiders, some predator wasps, and tachinid flies.  Application of pyrethrins or other insecticides is problematic as the bugs usually appear when fruit is near harvest.  In addition, any insecticides which may be effective also kill beneficial insects which prey on these bugs and other pests. 

See the Pest Control Solutions chart from Native Nurseries . 

Leaf-footed bug

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