By Richard Reardon and Rebecca Trigger

This article first appeared in the PA Forestry Association April newsletter--

Mile-a-minute vine (MAM. Persicaria perfoliata) is a fast-growing annual invasive plant native to Asia.  It has extensively invaded open areas, roadsides, utility rights-of-way and forest edges in the mid-Atlantic and northeastern states.

To combat this invasive plant, a weevil, Rhinoncomimus latipes, was introduced as a natural enemy.  It is a specialist insect feeding only on MAM.  Read more here.

Operationally, in an effort to control MAM, the weevils are hand-released close to the roads and trails.  However, the MAM in hard-to-access areas, e.g. steep hillsides, could not be managed by hand releases of the insect.

To access difficult terrain areas a research project was initiated in Southwest Pennsylvania to evaluate the use of drones with onboard sensors to map the locations of MAM.

The drones were further developed with an aerial release system to distribute the weevils with precision onto MAM sites.  The weevils are placed in a biodegradable container and released from the drone.

Results of field tests evaluating the system showed no negative effects on survivorship and feeding ability of the weevils after release.

The weevils were very successful in controlling MAM in the release sites as well as in surrounding sites.

One of the woodland study sites, owned by Rebecca Trigger, had MAM infested sites that were both easy and difficult to access.  Hand and aerial release of the weevils were utilized on the property.

The weevils were very successful in controlling MAM at both release sites as well to surrounding sites, R. Trigger states. “It’s a wonderful feeling seeing the mile-a-minute patches decrease in size, knowing the weevils are munching away.”

The weevils can be collected from previous release sites and released into new sites by hand or drone, depending on the accessibility of the site within the same state.

Dr. Yong-Lak Park, Professor of Entomology at West Virginia University, has developed a low cost, logistically practical and effective system to map MAM and release weevils for use in hard to access areas (Park et al, 2018 Pest Management Science 74: 141-148).

If you don’t know anyone with weevils on a MAM site, you may be able to purchase them. 

For information on weevil purchases for MAM control, depending on your state, contact the Philip Alampi Beneficial Insect Rearing Laboratory in New Jersey.  This lab has  New Jersey Department of Agriculture 526 permit that also covers sales to Pennsylvania and West Virginia.

-- Richard Reardon, Entomologist, USDA Forest Service (Retired)

-- Rebecca Trigger is a tree farmer from Greene County 

(Reprinted from PA Forestry Association April newsletter.  Click Here to sign up for your own copy - bottom of page.)

Related Article:

-- DCNR Blog: Weevils To The Rescue, Helping To Reduce Spread Of Mile-A-Minute Invasive Plant

[Posted: April 7, 2022]

4/11/2022