Aphthona spp. 
<<back to leafy spurge
Common Name
Leafy spurge flea beetles
Weeds Impacted
Adult and larval beetles attack leafy spurge. Adults feed on leaves and flowers, and larvae feed on root hairs and young roots. Larvae cause the greatest impact by decreasing the availability of stored energy reserves. Larval feeding damage may also make plants more susceptible to infection and disease caused by soil-dwelling fungi. Some Aphthona spp. have been know to feed on a few other plants in the genus Euphorbia, including the native Rocky Mountain spurge (E. robusta), but no long-term impacts have been reported.
Insect Description
In the field, Aphthona spp. may refer to six different beetle species released for control of leafy spurge including A. adbominalis, A. cyparissiae, A. czwalinae, A. lacertosa, A. flava, and A. nigriscutus. Adults are small, oval beetles, ranging from 2 to about 3.5 mm (approximately 1/16 to 1/8 inch) long. They may be coppery brown, brown with markings and with or without transparent wing covers, or shiny black. Larvae are small, whitish, and either C-shaped (A. abdominalis) or worm-like, found either in or around young roots and root hairs within 5 cm (2 inch) of the soil surface.
Life Cycle
A general life cycle for Aphthona spp. begins with adults emerging in spring or early summer. Females lay eggs throughout the summer either on the soil surface next to the stems or on stems near the soil level. Eggs hatch in one to two weeks. Larvae feed on young roots and root hairs, overwintering in and then pupating within young roots. Pupation occurs in the spring or early summer.
Field Identification
Most small, oval beetles found on leafy spurge are likely to be Aphthona spp. The only other beetle agent released on leafy spurge is the much larger and elongate stem borer Oberea erythrocephala. The presence of Aphthona spp. in the field can be indicated by grayish patches of dead stems, often referred to as “a hole in the spurge” or "halos". Adult create shot-hole type feeding damage in the leaves.
Availability
Most Aphthona spp. are readily available; A. abdominalis was unavailable as of 2004. Adults are collected throughout the summer. To inquire about availability and to request this biocontrol agent, please download, complete and submit this form.
Comments
In stands where beetles are abundant, significant impacts can be observed in three to five years. Beetles can reduce leafy spurge cover, density, and biomass, allowing for increases in grasses and forbs. The most abundant and available Aphthona spp. are A. lacertosa and A. nigriscutis. A. lacertosa is effective in leafy spurge stands of moderate density, mesic moisture regime and intermediate stem height (40-50 cm) while A. nigriscutis is effective in somewhat lower stand densities, dryer moisture regimes and shorter stem heights.
Using the Agents: Integrated Weed Management
Leafy spurge is highly toxic, extremely difficult to control with herbicides, and nearly impossible to control with physical, mechanical or other methods. Roots can grow 3 to 7 m (10 to over 20 ft) deep, and new plants can sprout from pieces of roots as small as 1.3 cm (1/2 in) long and 0.25 cm (approx 1/8 in) thick. Thus, successful control of leafy spurge is usually a long-term process, and biological control is an absolutely critical component of effective management.
Aphthona spp. should be released where large infestations of leafy spurge occur. Some beetle species are susceptible to predation by ants and interference from grasshoppers, so initial releases should be avoided in areas where those insects are abundant.
Sheep and goats can feed safely on leafy spurge, and grazing by these animals can help slow spread of the weed. Do NOT, however, allow cattle to feed on leafy spurge. Ingestion of the plant by cattle can cause animal illness or death.
Small or satellite infestations should be sprayed annually, without skipping a year until control is over 90%. Consult with your county weed office, Extension office or an IWM practitioner to determine which herbicide treatments are safe and appropriate.
Any management of leafy spurge should include intensive revegetation with native or other desirable plants, especially grasses. Revegetation promotes plant competition, which stresses weeds and allows for more effective treatment. For more information about revegetation and IWM, click here.
For more information about integrated management of leafy spurge, follow the highlighted links in the references below:
References
Coombs, E. M., J. K. Clark, G. L. Piper, and A. F. Cofrancesco, Jr. 2004. Biological Control of Invasive Plants in the United States. Western Society of Weed Science, Oregon State Univ. Press, Corvallis.
Lym, R. G., and C. G. Messersmith. 2006. Leafy Spurge Identification and Chemical Control. North Dakota State University Extension Bulletin W-765. URL http://www.ag.ndsu.edu/pubs/plantsci/weeds/w765w.htm
Lym, R. G., and R. K. Zollinger. 1995. Integrated Management of Leafy Spurge. North Dakota State University Extension Bulletin W-866. URL http://www.ag.ndsu.edu/pubs/plantsci/weeds/w866w.htm
Photo Credits
Aphthona flava - Norman Rees, USDA Agricultural Research Service, bugwood.org (insectimages.org), http://www.insectimages.org/images/768x512/0025090.jpg
Aphthona lacertosa - Minnesota Department of Agriculture Biocontrol, http://www.mda.state.mn.us/plants/badplants/leafyspurge.htm
Secondary content using h2 tag. Column 2
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
Heading using the h3tag
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.