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Biological Control : A Guide to Natural Enemies in North America Anthony Shelton, Ph.D., Professor of Entomology, Cornell University

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Rhinoncomimus latipes
(Coleoptera: Curculionidae)

by J. Hough-Goldstein, Department of Entomology & Wildlife Ecology, University of Delaware, Newark, DE 19716

Mile-a-minute weed, Persicaria perfoliata (Polygonaceae), is an annual vine that has been a pest in the eastern United States since its accidental introduction from Asia into York County, Pennsylvania, in the 1930s. It forms dense monocultures, scrambling over and suppressing other plants and preventing tree regeneration. The host-specific weevil, Rhinoncomimus latipes, occurs over a wide geographic range in China, Japan, Korea and the Russian Far East. Following intensive host-range testing, R. latipes was approved for release in North America in 2004. It was first released in Delaware and New Jersey, and has subsequently been released in nine other states.


Adult weevils are about 2 mm long and are black when they first emerge, but become coated with an orange-brown substance apparently derived from plant sap after they have been feeding on P. perfoliata for several days. Weevils are typically found near the actively growing plant terminals. Feeding damage consists of characteristic small holes in leaves. Eggs are laid singly on the leaves, stems, or buds of P. perfoliata, and are yellowish, peanut-shaped, and covered with a small strip of frass. Larvae are rarely seen because they develop inside P. perfoliata stems, but scars or small holes are often visible on plants near nodes, where larvae have entered the stem or exited for pupation.


Rhinoncomimus latipes is found only on P. perfoliata, both in its native and introduced range. Persicaria perfoliata is primarily riparian in its native range in Asia. In North America it grows in full sun or partial shade, with typical habitats including roadsides, edges of woods, reforestation clear-cuts, utility rights-of-way, open meadows (if unmowed), and stream banks.

Pests attacked

Host range studies in both China and North America have shown that this insect is extremely host-specific, with no egg-laying or larval survival on any plant species except P. perfoliata. Adult weevils feed minimally on several related Polygonaceae, but only under laboratory no-choice conditions.

Life cycle

Adult weevils overwinter in the soil or leaf litter. They emerge in early spring when P. perfoliata seedlings are about 6 inches tall, and begin mating and laying eggs. Newly hatched larvae bore into the plant stem at nodes and feed internally. Once they are full grown, larvae crawl or drop out of the stem and pupate in the soil under the host plant. Adult weevils emerge from the soil about one week later, crawl up nearby stems and mate on the host plant, feed on its leaves, and initiate egg-laying. The complete R. latipes life cycle from egg to adult takes about one month, and at least three to four overlapping generations occur during the growing season in the mid-Atlantic region. Egg laying ceases between mid-August and mid-September, as weevils prepare for overwintering.

Relative effectiveness

Although it is too soon for a complete assessment of the effectiveness of R. latipes in controlling mile-a-minute weed, initial indications are very positive. Weevils have overwintered and established at virtually all sites where they have been released, and P. perfoliata populations have declined substantially at many sites. Weevils disperse at a rate of more than 4 km per year after the first year of release. They locate both large and small mile-a-minute weed patches and establish new populations.

Pesticide susceptibility

This weevil is susceptible to commonly used insecticides and thus should not be exposed to insecticidal sprays. It is not directly affected by commonly used herbicides, but larval development is indirectly affected by herbicides if the plant dies before larval feeding is completed.

Commercial availability

Rhinoncomimus latipes has been reared since 2004 at the New Jersey Department of Agriculture Phillip Alampi Beneficial Insect Rearing Laboratory, Trenton, NJ, and the laboratory expects to begin selling the weevils in 2011. Weevils can also be collected from mile-a-minute plants where a population has established, by shaking the plant terminals into a large funnel with the small end inserted into a container. The adult weevils can then be transported to another mile-a-minute patch, as long as it is within the same state (otherwise a permit from USDA-APHIS is required).


Ding JQ, Fu WD, Reardon R, Wu Y, Zhang GL (2004) Exploratory survey in China for potential insect biocontrol agents of mile-a-minute weed, Polygonum perfoliatum L., in Eastern USA. Biol Control 30:487-495

Frye MJ, Lake EC, Hough-Goldstein J (2010) Field host-specificity of the mile-a-minute weevil, Rhinoncomimus latipes Korotyaev (Coleoptera: Curculionidae). Biol Control 55:234-240
Hough-Goldstein J, Lake E, Reardon R, Wu Y (2008a) Biology and biological control of mile-a-minute weed. USDA Forest Service FHTET-2008-10

Hough-Goldstein J, Morrison P, Reardon R, Robbins G, Mayer MA, Hudson W (2009) Monitored releases of Rhinoncomimus latipes (Coleoptera: Curculionidae), a biological control agent of mile-a-minute weed (Persicaria perfoliata), 2004–2008. Biol Control 51:450-457

Korotyaev BA (2006) A review of the weevil genus Rhinoncomimus Wagner (Coleoptera: Curculionidae: Ceutorhynchinae). Entomologische Abhandlungen 63:99-122

Lake EC, Hough-Goldstein J, Shropshire KJ, D’Amico V (2011) Establishment and dispersal of the biological control weevil Rhinoncomimus latipes on mile-a-minute weed, Persicaria perfoliata (Polygonaceae). Biol Control 58:294-301

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Top: Brachypterolus pulicarius adults.  R.Richard, USDA-APHIS

Rhinoncomimus latipes adult weevil, newly emerged.

PHOTO: Kelsey Paras

Top: Brachypterolus pulicarius adults.  R.Richard, USDA-APHIS

Rhinoncomimus latipes adult weevil, after feeding on P. perfoliata

PHOTO: Amy Diercks

Top: Brachypterolus pulicarius adults.  R.Richard, USDA-APHIS

Characteristic adult feeding damage

PHOTO: Ellen Lake

Top: Brachypterolus pulicarius adults.  R.Richard, USDA-APHIS

Scar at node indicating larval feeding

PHOTO: Ellen Lake

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