Page 23 - Griffin Gazette Q4 2017
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sanitation products such as Greenshield II, Kleengrow, SaniDate 5.0
and Zerotol 2.0 can be used to finish the job and ensure a clean start.
Control options
Chemical control of fungus gnats and shoreflies should target the
larval stage because the control of the adults is not very effective
with the available pesticides. Table 1 lists products recommended
by GGSPro. Check the Digital Gazette for more details on these
products including rates, REIs and more. All treatments are made
to the soil.
Biological control often begins with soil treatments with nematodes,
which are highly successful in controlling the larval stages of
fungus gnats and shoreflies. S. feltiae is used for fungus gnats and
S. carpocapsae for shoreflies. Nematode treatments are generally
effective for about 3 weeks and can be applied to all types of crops
and most types of growing media. Following treatment, the number
of adults will decline gradually as the adults die off and fewer
emerge from the soil to replace them. Dalotia coriaria, (aka Atheta
or rove beetle), is a small beetle with a huge appetite for many soil
dwelling pests, including fungus gnat and shorefly larvae, with the
thrips pupae control as an added bonus. Once established in a
cool moist location, they will often establish themselves in the crops.
Stratiolaelaps scimitus, formerly known as Hypoaspis miles, is a
tiny predator mite that patrols the soil surface and feeds on many
of the same soil dwelling pests that Dalotia does. In greenhouses
where pesticides are seldom used, the aptly named Hunter fly
(Coenosia attenuate) will sometimes appear as a welcome ally.
Hunter flies consume adult fungus gnats and shoreflies along will
some other flying insects. They are not commercially available at
this time but they have been introducing themselves to commercial
greenhouses in the northeastern U.S. Use yellow sticky cards to
monitor for adult fungus gnats and shoreflies and deploy the BCAs
at the first sign of pest pressure. Certain compatible pesticides
can be safely used in conjunction with biological control agents.
Contact GGSPro for assistance. The Digital Gazette contains
trade names, application rates and tips for success with all of the
mentioned BCAs. Bulletins with the same information are available
upon request.
Read and follow all label directions. The label is the law! Products
other than those mentioned may be safe and effective. Some
pesticides may be restricted use or unregistered in certain states.
YOUR FIRST LINE OF DEFENSE
Bioline is a company active in
the field of biocontrol.
Image 1- Fungus gnat Image 2- Fungus gnat Image 3-Shorefly adult
damage on dahlia leaf larvae with distinctive displaying spots on the
black head capsule- wings
Photo credit: Bioline
Agrosciences
Image 4- Shorefly Image 5- Dalotia Image 6- Hunter Fly
pupae- Photo credit: adult feeding on (Coenosia attenuata)
Bioline Agrosciences fungus gnat larvae- Photo credit: Leanne
Photo credit: Bioline Pundt, UConn
Agrosciences
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