By Matt Bertone & Cynthia Music
Photo legend: Can you spot the bark vs. ambrosia beetles in the photo above? Top: an ambrosia beetle, Ambrosiodmus sp. (Scolytinae); Center: an ash bark beetle, Hylesinus aculeatus (Scolytinae); Bottom: pinhole borer or ambrosia beetle, Euplatypus compositus (Platypodinae)
Taxonomy is an ever-changing landscape of how we name organisms. When common names are created and approved, or taxonomists split/lump taxa, the NPDN National Data Committee is there to keep host and pest names in the NPDN National Repository (https://npdn.ceris.purdue.edu/) as accurate as possible. One recent update resulted in numerous changes to entries in the repository, so we’d like to explain how those changes came about.
When I (Matt) was a new entomology student (at the turn of the century!), we had to learn our beetle families, including two called Scolytidae (bark and ambrosia beetles) and Platypodidae (pinhole borers or ambrosia beetles). These small beetles are common, and some are extremely important economically. In the years since then, much work has been done on the phylogenetics of these groups resulting in them being firmly placed within the already massive family of “true” weevils, Curculionidae. Despite lacking the distinct snout of their close relatives, both molecular evidence and the morphology of the larvae, for example, lead to this change. Although some people still refer to these beetles using their previous names (mostly due to tradition), the majority of workers currently refer to them as the subfamilies Scolytinae and Platypodinae.
As for common names, therein lies some complexity. Scolytinae contains species that feed in numerous plant parts and have very diverse biologies. Often, they live in woody plants and trees, usually those that are declining or dead. Many of these beetles tunnel just below the bark, creating galleries along the wood, vertically. The larvae and adults will feed directly on the plant material, so we call these types “bark beetles.” Then, there are those (especially the important and species rich Xyleborina) that tunnel straight into the heartwood, across the grain. These beetles don’t feed on the plant material itself; rather, they bring fungal spores with them to grow inside the tunnels. These taxonomically disparate fungi are collectively referred to as “ambrosia fungi,” thus the insects are called “ambrosia beetles,” To further complicate things, Platypodinae is more uniform and consists only of fungus-growing “ambrosia beetles.” They are also often called pinhole borers due to their small size and characteristic holes they make in wood (though, again, some Scolytinae also have this name). Thus “ambrosia beetle” does not represent a taxonomic group but rather a functional or biological group. [As another aside, there are also some beetles in other groups outside of Curculionidae called “bark beetles,” so it becomes tough sometimes…]
Of course, there are also many species within these groups that have approved common names, like the Southern pine beetle (Dendroctonus frontalis), redbay ambrosia beetle (Xyleborus glabratus), and camphor shot borer (Cnestus mutilatus). We took these into consideration when updating the common names, thus we either have specific approved common names or two general common names for these beetles, depending on their biology: “ambrosia beetle” or “bark beetle.”
If you find any names in the database that need updating or other attention, please feel free to contact someone on the committee. It may be a simple change, or we’ll have a committee discussion to decide what changes best reflect our current understanding of these names. We hope these changes make our network and job as diagnosticians better by helping to communicate names in the most accurate way possible!
Photo legend: Can you spot the bark vs. ambrosia beetles in the photo above? Top: an ambrosia beetle, Ambrosiodmus sp. (Scolytinae); Center: an ash bark beetle, Hylesinus aculeatus (Scolytinae); Bottom: pinhole borer or ambrosia beetle, Euplatypus compositus (Platypodinae)
Taxonomy is an ever-changing landscape of how we name organisms. When common names are created and approved, or taxonomists split/lump taxa, the NPDN National Data Committee is there to keep host and pest names in the NPDN National Repository (https://npdn.ceris.purdue.edu/) as accurate as possible. One recent update resulted in numerous changes to entries in the repository, so we’d like to explain how those changes came about.
When I (Matt) was a new entomology student (at the turn of the century!), we had to learn our beetle families, including two called Scolytidae (bark and ambrosia beetles) and Platypodidae (pinhole borers or ambrosia beetles). These small beetles are common, and some are extremely important economically. In the years since then, much work has been done on the phylogenetics of these groups resulting in them being firmly placed within the already massive family of “true” weevils, Curculionidae. Despite lacking the distinct snout of their close relatives, both molecular evidence and the morphology of the larvae, for example, lead to this change. Although some people still refer to these beetles using their previous names (mostly due to tradition), the majority of workers currently refer to them as the subfamilies Scolytinae and Platypodinae.
As for common names, therein lies some complexity. Scolytinae contains species that feed in numerous plant parts and have very diverse biologies. Often, they live in woody plants and trees, usually those that are declining or dead. Many of these beetles tunnel just below the bark, creating galleries along the wood, vertically. The larvae and adults will feed directly on the plant material, so we call these types “bark beetles.” Then, there are those (especially the important and species rich Xyleborina) that tunnel straight into the heartwood, across the grain. These beetles don’t feed on the plant material itself; rather, they bring fungal spores with them to grow inside the tunnels. These taxonomically disparate fungi are collectively referred to as “ambrosia fungi,” thus the insects are called “ambrosia beetles,” To further complicate things, Platypodinae is more uniform and consists only of fungus-growing “ambrosia beetles.” They are also often called pinhole borers due to their small size and characteristic holes they make in wood (though, again, some Scolytinae also have this name). Thus “ambrosia beetle” does not represent a taxonomic group but rather a functional or biological group. [As another aside, there are also some beetles in other groups outside of Curculionidae called “bark beetles,” so it becomes tough sometimes…]
Of course, there are also many species within these groups that have approved common names, like the Southern pine beetle (Dendroctonus frontalis), redbay ambrosia beetle (Xyleborus glabratus), and camphor shot borer (Cnestus mutilatus). We took these into consideration when updating the common names, thus we either have specific approved common names or two general common names for these beetles, depending on their biology: “ambrosia beetle” or “bark beetle.”
If you find any names in the database that need updating or other attention, please feel free to contact someone on the committee. It may be a simple change, or we’ll have a committee discussion to decide what changes best reflect our current understanding of these names. We hope these changes make our network and job as diagnosticians better by helping to communicate names in the most accurate way possible!
