Baryscapus rugglesi (Rohwer, 1919) (Hymenoptera: Eulophidae) discovered in western North America: Redescription, notes on biology, and implications as a parasitoid of its host, Agrilus cuprescens (Ménétries, 1832) (Coleoptera: Buprestidae)
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... Contrary to Raghuvir and Davis though, when canes were held at RH levels below their estimated thresholds (Davis & Raghuvir, 1964;Raghuvir, 1962), it did not delay or prevent progression through phenological stages to preclude or postpone adult emergence. Considerable year-to-year variability in damage to both wild hosts and cultivated Rubus has also been observed, as were instances of considerable larval mortality (O'Dea et al., , 2023 similar to what was observed by Garlick (1940), Mundinger (1941) and Larson (2009). ...
... Additionally, multiple caches of eulophid larvae were found in the terminus of some galleries lacking a viable A. cuprescens larva, similar to Garlick (1940) and Mundinger (1941). Numerous larvae recovered from A. cuprescens galleries from disparate locations over 4 years were reared and all identified to be B. rugglesi (Rohwer, 1919), the same species previously found parasitizing A. cuprescens by Mundinger (1941); this species was previously not known to occur in western North America (O'Dea et al., 2023). Baryscapus rugglesi appears to be the predominant parasitoid of A. cuprescens in the PNW and may play significant role in attenuating A. cuprescens populations in this region, although accurate estimations of the magnitude of its effect has not yet been determinable. ...
... Current research in the PNW region on A. cuprescens control has been targeted at building on the phenological work begun by Raghuvir and Davis in order develop a more comprehensive IPM program for it (O'Dea et al., , 2023 ...
Agrilus cuprescens (Ménétries, 1832), the rose stem girdler, is a Palearctic Buprestidae (Coleoptera) pest of Rosa and Rubus species. Its introduction and consequent spread across North America may now make it the most widely distributed Agrilus species, globally.
No evidence reviewed indicated A. cuprescens was present in North America long before it was first reported on Rosa in New Jersey, USA, in 1913. The species incrementally progressed westward, reaching the Pacific coast in Washington, USA, 101 years later. Future spread is most likely within the northern Canadian prairies and the Pacific Northwest regions. Its presence in the latter region poses a contemporary threat to epicentres of Rubus production in both the United States and Canada. As of 2022, confirmed spread within the region extended nearly to the Canadian border in Washington and the southern Willamette Valley in Oregon.
The most comprehensive, foundational investigations of A. cuprescens in North America were conducted in the late 1930s and early 1940s in New York, USA, and in Utah, USA, during the late 1950s and early 1960s following damaging outbreaks on Rubus . Ongoing research in the Pacific Northwest is attempting to refine information on this pest as it progresses towards naturalization within a new North American ecological and agricultural context.
This review aggregates and clarifies the geographical progression, biological understandings and management of this species in North America, which has been fraught with a convoluted history of misidentifications, and varying degrees of consideration given to it as a pest of concern.
Purpose of Review
The invasion of North America by the Asian beetle Agrilus planipennis has caused severe economic and ecological damage to ash (Fraxinus) tree populations. Agrilus planipennis has recently entered eastern Europe and is spreading there. Many other Agrilus species can potentially become invasive pests due to the cryptic nature of their immature stages that can be inconspicuously transported within infested plant material. We review the ecology, economic impacts, and management strategies of Agrilus worldwide and highlight research gaps.
Recent Findings
Much has been learned in recent decades about the basic biology and control tactics for a few Agrilus species, especially A. planipennis.
Summary
The genus Agrilus has over 3,341 described species, making it the largest genus in the Animal Kingdom. Most Agrilus are univoltine and have a narrow host range. Chemical, tactile, and visual cues of host plants are used by adult Agrilus to select suitable hosts for consumption by adults and larvae. Most Agrilus larvae develop within the cambial region, constructing galleries that effectively girdle the host plant. Mechanisms of host plant resistance are being explored. Diverse groups of natural enemies attack all life stages of Agrilus species, with some coevolved specialist parasitoids being introduced successfully to suppress A. planipennis in North America. Climate change, leading to warmer and drier conditions, will influence the distribution and population dynamics of many Agrilus species. Many research gaps still exist in the areas of biocontrol, host plant resistance, and sustainable management strategies for this important group of plant pests.
The study was carried out in а raspberry plantation (2013-2015) in the experimental field of the Institute of Agriculture – Kyustendil. The purpose of this study is to investigate the effect of organic fertilizer application on the stock larvae of Agrilus aurichalceus and population management, using biological plant protection products. According to the results of this study, it has been proved that fertilizing with organic fertilizers has a reductive effect on the survival of the A. aurichalceus population and does not affect the population of the larval endoparasitoid Ttrastichus heeringi in the cultivars Willamette and Lyulin. The relationships between A. aurichalceus and T. heeringi in the conditions of organic raspberry production have been studied. The established degree of parasitism of the larvae by T. heeringi (32.7-68.4%) is capable of reducing and controlling the population of A. aurichalceus in the Willamette without chemical control. Two treatments with bioinsecticides have been carried out for the protection of plants from cultivar Lyulin due to a significantly lower degree of parasitism (18.1-50.0%). The most effective insecticides to the control of adults of A. aurichalceus have been identified: Pyrethrum FS EC-0.05% and NeemAzal®-T/S - 0.3 %. The adult control scheme involves two treatments with bioinsecticides of infested shrubs. The first treatment should be done during the buttoning, the second treatment during the mass flight of beetles (only at an established density of 3-4 beetles/m2).
A wide range of beneficial insects controlling raspberry cane pest populations has been
identified since the first surveys on the arthropod fauna of the plant were carried out. As far as the
parasitoids of the raspberry cane midge (Resseliella theobaldi) and the rose stem girdler (Agrilus
cuprescens) are concerned, a large number of references on different parasitoid species can be found
in the literature dealing with the biology and control of the pests. In some cases, the specimens of the
reared or collected parasitoids were identified by former or present-day specialists, but the citation of
species names from old publications without checking them also seems to be quite widespread. As it
has turned out that in many cases invalid, ambiguous or incorrect names are mentioned in
publications, the aim of the authors of this paper was to give a review of the cited parasitoids of the
two, above-mentioned raspberry cane pests together with making their taxonomic status clear so as to
help researchers and plant protection engineers use the correct, presently accepted names of these
beneficial insects. This work has been carried out within the scope of an international cooperation in
which curators and specialists of national insect collections and researchers of plant protection
institutes from Europe helped the investigations. On the basis of this study, the most frequently cited
natural enemy of raspberry cane midge is Tetrastichus inunctus, while those of rose stem girdler are
Tetrastichus heeringi and T. agrilorum. However, the type of T. inunctus is lost so this species name is
now ambiguous, and the specimens earlier reared from the larvae of rose stem girdler and identified as
T. agrilorum need to be re-examined. According to the authors’ rearing experiments, Aprostocetus
epicharmus proved to be the primary parasitoid of raspberry cane midge, while it was Tetrastichus
heeringi which parasitized the larvae of rose stem girdler significantly. Further studies on this topic are
in progress.
Agrilus corylicola Fisher, A. carpini Knull and A. pseudocoryli Fisher are newly elevated in status from subspecies to species. Agrilus fulgens LeConte and A. torquatus LeConte are considered to be full species as originally described, and all are contrasted with their similar species.
The rose stem girdler, Argilus rubicola communis Obenberger, has been an important pest of raspberries near Salt Lake City, Utah, since 1955. Injury often exceeds 90% destruction of susceptible canes. Control can be achieved through a combination of pruning plus burning before the adults leave the canes, followed by an insecticide treatment applied during the early part of the adult flight. Control ranging from 90 to 99% can be obtained through these combination treatments.