Robinia leaf miner

[rick]

Michael Gochfeld wrote in message <1000906212038.ZM3742 at Gochfeld>...
>Therefore it was a shock this weekend, driving through Dutchess County,
>(southeastern) New York, to encounter endless stands of Black Locusts
>with dead leaves. I examined them and found evidence of total saturation
>(virtually 100% of the leaflets) by a leaf miner, which I later found
>out was a beetle, Odontota dorsalis (Thunberg).  This creature is
>apparently lethal to Black Locusts in the Ohio Valley and parts of
>southeastern U.S., and I never knew it was in the northeast.  Perhaps
>three mild winters in a row has allowed it to prosper.
>
>In this area in the 1950's we experienced the virtual extinction of
>wild Gray Birch by a leaf miner (a wasplet I believe).  So  the
>possibility of losing Black Locusts is very real.  I realize that this
>is often considered a weed tree, but that is another issue.
>
>Those of us for whom this Locust Miner is a new "pest" would be
>interested in the experience in areas where this miner has been endemic
>for a while.
>
>Michael Gochfeld
>
In northern Ohio, near Cleveland, Odontota dorsalis (Thunberg) has been a
regular on black locust.  When I lived there in the 60's and 70's, I
expected to find some on every black locust I inspected.   The locusts
exhibited minor miner (oops, isn't english great!) damage, not debilitating.
In 1998, I observed the same O. dorsalis abundance in the Cuyahoga River
Valley.  I do not know what keeps the population in check in northern Ohio,
but you may be experiencing a temporary plague which will trigger a local
response and bring the population to sustainable levels.

Rick