Little Lari - Taking a bite out of Hemlock Woolly Adelgid!
We’ve been talking a lot about hemlocks here at the Catskill Center this past year. They’re an iconic part of the Catskills, whether they are providing ideal trout stream habitat, stabilizing steep slopes, or just perfectly framing an aesthetic waterfall getaway. Unfortunately, hemlocks in the Catskills (and elsewhere along the East coast) have been struggling to overcome an attack by an invasive insect: the hemlock woolly adelgid.
Hemlock woolly adelgid, or HWA, is a tiny relative of the aphid that uses piercing mouth parts to suck nutritious sap from hemlocks. Individually these insects don’t cause much harm, but when hundreds (or more) attack a hemlock, it can be difficult for the tree to recover. Usually the tree cannot fight off these insects on their own; they need a little help.
Last month, our local hemlocks got a little of that help. the Catskill Regional Invasive Species Partnership (CRISP), in partnership with the New York State Hemlock Initiative headed by Mark Whitmore, released Laricobius nigrinus, or little Lari, on to several Catskills hemlock trees which were severely infested with HWA. It was a cold, snowy day, but these insects are no stranger to low temperatures – they’re most active in the winter!
Lari is itself a relatively small insect, about the size of an exclamation point in the newspaper. But this small bug packs a huge punch – Lari is a predator beetle that only eats hemlock woolly adelgid. Where HWA is native Laricobius nigrinus is one of several insects that helps keep the populations under control. We hope that Lari will do something similar here in the Catskills.
As with any biological control, there was extensive research before anyone could release Lari in the East coast. Many years of testing occurred to be sure that Laricobius nigrinus will only eat hemlock woolly adelgid, only after which it was approved for release. We’ll be monitoring our new population of L. nigrinus closely for the next several years, to make sure that it has everything it needs to succeed.