Contents: By Damage and Image
Rose stem girdler
Rose stem girdler, Agrilus cuprescens Ménétriés, is a key pest of caneberries and roses and can be quite damaging. It is thought to have been established in the United States sometime in the 1870's. It was first noted on rose and blackberry foliage in Olympia, Washington June 4, 2014 and confirmed as rose stem girdler. A few days after, on June 11, 2014, an image of an adult rose girdler was submitted to BugGuide from Davenport in eastern Washington (Westcott. et al., 2015). Rose stem girdler was also caught in a trap in southern Washington near Castle Rock in 2014 and in the Portland area in 2015 (there was an earlier detection, 1994, in Oregon east of the Cascades). Damage from the borer was first confirmed in the Willamette Valley in caneberries at the North Willamette Research and Extension Center in August of 2017. We have reports of damage as far south as Woodburn, OR as of the spring of 2018.
Potential for this borer to become a key pest in caneberry production exists. The beetle has been in Utah since 1955 and is considered a common pest of caneberries and wild roses (Alston, 2015). In Hungary, this pest became a dominent raspberry production pest with regular infestations in well maintained farms. Sources for these infestations were abandoned, not-pruned blocks with high weed coverage (Veszelka and Fajcsi, 2001).
Hosts include plants in the genera, Rubus spp., and Rosa spp. There were prior reports of damage on Ribes spp. but those reports appear to be based on mistaken identity with a similar Agrilus species (Westcott. et al., 2015).
There is one generation per year. The beetles overwinters in the pith of the canes as fourth generation larvae. Pupation occurs as temperatures average 55 degrees F. Adults emerge from the canes in May through June in Utah (Alston 2015) [Samples of infested canes are currently being monitored in rearing cages at the North Willamette Research and Extension Center in Aurora, Oregon, to assess adult emergence during spring of 2015].
Adult beetles are copper-coloured and narrow, tapering toward the end of their abdomen. They are most active (feeding, mating, and egg laying) in the morning, prefering to rest on foliage during the evening. The adults must feed prior to egg laying. Eggs require four-to-fourteen days to hatch depending on temperature. The larvae emerge through the base of the eggs and chew through to the cambiem of the stems.
The larvae are narrow, flattened, and segmented with an enlarged prothorax which covers most of its tiny black head capsule. The larvae continue to feed in the cambien with a spiraling tunnel that often girdles the stem causing the shoot to flag or wilt. Additional symptoms are a swollen node where the spiral tunnel is located. The bark may be discolored, more woody, or cracking in this area. These stems tend to break easily. The third and fourth instar larvae move into the pith of the plants and remain there until they pupate and emerge as adults. Damage can occur on both primary and secondary canes of caneberries.
Vétek et al. (2008) looked at natural enemies of the rose stem girdler. There has been research on biological control in Europe. A parasitoid wasp, Tetrastichus agrili Clwt., caused 57.6% mortality of rose stem girdler larvae in a Hungarian raspberry plantation (Reichart 1968). Additional Tetrastichus spp. have been discovered in Bulgaria. One, a larval parasite, caused 43-92% mortality in the rose stem girdler larvae while another species was an egg parasite.
Management focuses on good plant health (proper fertilization and irrigation), sanitation (removal and destruction of infested canes), and insecticide application times to kill the emerging adults prior to egg laying. Váňová et al. (2008) have looked at within cane distribution of the borer and might be helpful to design infested cane removal strategies. Adult beetle emergence may overlap flowering periods so use appropriate pollinator protection strategies. (More information on management in caneberries is available from Alston et al. (2015) and the Pacific Northwest Insect Management Handbook (2018).
Alston, D. 2015. Rose stem girdler [Agrilus cuprescens]. [pdf]. Utah State University Extension. Ent. 178-15. January 2017.
Davis, D. W., and N. N. Raghuvir. 1964. The biology of the rose stem girdler, Agrilus rubicola communis, on raspberries in Utah (Coleoptera:Buprestidae). Annals of the Entomological Society of America 57 (2): 154-159.
Cane fruit: rose stem girdler. Pacific Northwest Insect Management Handbook. 2018 Edition. <18 April 2018>
Váňová, M., P. Tóth, and J. Lukáš. 2008. Patterns in the within-cane distribution of the gall-like swellings caused by Agrilus cuprescens (Coleoptera: Buprestidae) and the rate of raspberry infestation. [pdf]Integrated Plant Protection in Soft Fruits. IOBC/wprs Bulletin 39, 2008. pp. 77-84. <24 April 2018>
Veszelka, MS. and M Fajcsi. 2001. Changes of the dominance of arthropod pest species in Hungarian raspberry plantations. [pdf]. In Proceedings of the IOBC Working group “Integrated Plant Protection in Orchards” Subgroup “Soft Fruits”. Dundee, Scotland. 18-21 September 2001. <24 April 2018>
Vétek, G. , C. Thuróczy, and B. Pénzes. 2008. Notes on the parasitoids of the raspberry cane midge, Resseliella theobaldi (Barnes, 1927) (Diptera: Cecidomyiidae) and the rose stem girdler, Agrilus cuprescens (Ménétriés, 1832) (Coleoptera: Buprestidae). [pdf].Integrated Plant Protection in Soft Fruits. IOBC/wprs Bulletin 39, 2008. pp. 51-64. <24 April 2018>.
Richard L. Westcott, Chris Looney and Megan Asche. 2015. Agrilus cuprescens (Ménétries) (Coleoptera: Buprestidae), the
Created <18 April 2018>
Current update 24 April 2018
Author: R.L. Rosetta, Extension Nursery Integrated Pest Management, Department of Horticulture, Oregon State University
Rose stem girdler damage on raspberry canes. Note swollen, woody, and cracked bark.