Comparison of the performance of an eriophyid mite, Aceria salsolae, on nontarget plants in the laboratory and in the field

Authors: MARINI, FRANCESCA - Biotechnology And Biological Control Agency; VIDOVIC, BILJANA - University Of Belgrade; LONIS, SIMONE - Biotechnology And Biological Control Agency; Wibawa, Maria - Irene; DE LILLO, ENRICO - Bari University; KASHEFI, JAVID - European Biological Control Laboratory (EBCL); CRISTOFARO, MASSIMO - Enea Casaccia Research Center; Smith, Lincoln

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/31/2021
Publication Date: 10/11/2020
Citation: Marini, F., Vidovic, B., Lonis, S., Wibawa, M.I., De Lillo, E., Kashefi, J., Cristofaro, M., Smith, L. 2020. Comparison of the performance of an eriophyid mite, Aceria salsolae, on nontarget plants in the laboratory and in the field. Biological Control. 152. Article 104455. https://doi.org/10.1016/j.biocontrol.2020.104455.
DOI: https://doi.org/10.1016/j.biocontrol.2020.104455

Interpretive Summary: Russian thistle, common tumbleweed, is an invasive weed in the western USA that originates from Central Asia. Because of its widespread distribution this plant is the target of a biological control program. An eriophyid mite has been discovered in the Mediterranean Region that attacks this plant and prevents seed production. This mite appears to be highly specific to Russian thistle, but it was able to persist and/or develop on some nontarget plants in the laboratory. We conducted experiments in the laboratory and in the field in Italy to assess the risk of this mite to nontarget plants. The results indicate that the mite can sometimes reproduce in the laboratory on a few nontarget plants that are closely related to Russian thistle, but that it does not reproduce on any of these plants under field conditions. These results indicate that this mite should be safe to use as a biological control agent in the U.S.

Technical Abstract: There is increasing interest in the possibility of using eriophyid mites as biological control agents of invasive alien weeds; however their small size and our lack of knowledge about their general biology present challenges to evaluating their risk to nontarget plants. Aceria salsolae has been proposed as a candidate agent for Russian thistle (Salsola tragus) in the USA. During host specificity testing this mite could sometimes persist and possibly multiply on a few nontarget species under laboratory conditions. We conducted a series of no-choice laboratory experiments and a field experiment to try to delineate the physiological and ecological host ranges of this mite and assess its risk to nontarget plants. In the laboratory, A. salsolae increased exponentially on S. tragus, multiplying about 80 fold in 5 weeks. A little reproduction was observed on some plants of Atriplex coronata, Bassia hyssopifolia, B. prostrata, Kochia scoparia and Suaeda calceoliformis in the laboratory during 5 weeks, but mean mite densities remained low (less than 6 fold increase). In a field experiment in which plants were inoculated with mites in June and then harvested when they began to produce seed, mites persisted on A. coronata up to 64 days after inoculation, but at extremely low densities, and with no evidence of reproduction. No mites persisted on A. truncata, B. hyssopifolia, or S. calceoliformis. No signs of damage were observed on any of the nontarget plants in the laboratory or the field experiments. We conclude that this mite is not likely to multiply on any of these plants under field conditions, and that it is not expected to pose a risk to any nontarget plants in the contiguous USA.