Establishment of the Armored Scale,Rhizaspidiotus donacis1, a Biological Control Agent ofArundo donax

2011 ◽  
Vol 36 (3) ◽  
pp. 373-374 ◽  
Author(s):  
John A. Goolsby ◽  
Alan A. Kirk ◽  
Patrick J. Moran ◽  
Alex E. Racelis ◽  
John J. Adamczyk ◽  
...  
Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 588
Author(s):  
Charles A. Braman ◽  
Adam M. Lambert ◽  
A. Zeynep Özsoy ◽  
Ellen N. Hollstien ◽  
Kirsten A. Sheehy ◽  
...  

Arundo donax (giant reed) is invasive in Mediterranean, sub-, and tropical riparian systems worldwide. The armored scale Rhizaspidiotus donacis is approved for biocontrol in North America, but an adventive population was recently discovered in southern California. We documented this population’s distribution, phylogeny, phenology, potential host spillover to Phragmites spp., and potential for parasitism by a common biocontrol parasitoid of citrus scale. The adventive scale was found within a single watershed and is genetically closest to Iberian scale genotypes. Rhizaspidiotus donacis developed on Phragmites haplotypes but at much lower densities than Arundo. The adventive population is univoltine, producing crawlers from March-June. Aphytis melinus parasitoids exhibited sustained interest in R. donacis during choice and no-choice trials and oviposition resulted in a small second generation. Rhizaspidiotus donacis appears limited in distribution by its univoltinism and sessile adult females. This presents challenges for broad biocontrol implementation but allows for targeted application. The genetic differentiation between imported biocontrol samples and adventive populations presents an opportunity for exploring benefits of hybrids and/or alternative genotypes where establishment has been difficult. While unlikely to occur in situ, spillover to vulnerable endemic Phragmites or deleterious parasitoid effects on scale biocontrol agents warrants consideration when planning use of R. donacis.


HortScience ◽  
2013 ◽  
Vol 48 (1) ◽  
pp. 60-62 ◽  
Author(s):  
Thomas E. Marler ◽  
Ross Miller ◽  
Aubrey Moore

Container-grown Cycas micronesica seedlings were purposefully infested with Aulacaspis yasumatsui and then installed at 0, 75, or 150 cm above the ground to investigate effects of infestation height on predation by Rhyzobius lophanthae. Significantly more scales on elevated seedlings were attacked by the predator. Our results indicate that lower predation at ground level by R. lophanthae may partly explain why the predator is not effectively controlling this armored scale epidemic on Guam. Ephemeral outbreaks of A. yasumatsui documented in quarterly surveys from Sept. 2006 until Aug. 2012 confirm the inadequate biological control. Our results illuminate the importance of fully evaluating the reliance on an alien predator as a solo biological control agent for an alien pest.


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