Weakening Beetle's Protection is Bad Science, Groups Say

Valley elderberry longhorn beetle | Photo: USFWS/Flickr/Creative Commons License

The U.S. Fish and Wildlife Service is proposing to take a California beetle off the Endangered Species Act's Threatened list, but two leading environmental groups are charging that the move is based on politics rather than science.

The Center for Biological Diversity and the Xerces Society for Invertebrate Conservation on Tuesday urged USFWS to abandon its move to delist the Valley elderberry longhorn beetle, found only in a few stands of blue elder shrub along riverbanks in the Central Valley of California.

The groups charge that the scientific justification for the proposal to remove the beetle from ESA protection is flawed, based on shoddy and unsubstantiated records of the beetle's presence, as well as factually inaccurate statements from real estate developers in beetle habitat.

The beetle, Desmocerus californicus dimorphus, was listed as Threatened under ESA in 1980. That's long been resented by real estate and related interests in the Valley, who perceive the insect as an obstacle to developing historic flood plains and riverbanks for ill-advised residential developments. Taking the beetle off the Threatened list has been a goal of anti-environmental interests since at least the opening days of the 104th Congress in 1995.

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As I mentioned here last month, the valley elderberry longhorn beetle depends on blue elders of a relatively advanced age to rear its larvae, which burrow through the larger stems of the native shrubs. Elders are associated with streamside or "riparian" thickets, a biome of which California has lost a good 90 percent in the last century.

Nonetheless, USFWS proposed delisting the beetle in 2012 in response to a 2010 suit from the conservative, anti-environmental group Pacific Legal Foundation.

"Removing protections for an imperiled beetle and its vanishing habitat before the species is actually recovered is not what the Fish and Wildlife Service is supposed to do," said CBD's Jeff Miller. "The agency's own scientific peer review casts serious doubt on claims that numerous additional populations of the beetle have been found."

That peer review, conducted at the behest of USFWS by the consulting firm Atkins North America, tapped four experts in Central Valley landscapes and invertebrate ecology to look over the agency's scientific justification for removing the beetle from protection.

Among the most damning finds of the peer review groups were the revelation that a large number of the supposed recent sightings of the beetle were based on biologists' observation of larval exit holes in elder stems with no insects nearby for positive identification. The problem is, larvae of the closely related and still-abundant California elderberry longhorn beetle, Desmocerus californicus californicus, leave virtually identical exit holes in elder stems when they emerge to start life as adult beetles. Without an insect present, said the peer reviewers, misidentification of the subspecies responsible for the exit holes is a virtual certainty.

What's more, the peer reviewers found that of the 26 locations USFWS claims hold populations of valley elderberry longhorn beetle, eight show no indication of the beetles' presence after 2000. The reviewers also said USFWS may have artificially inflated the number of formal populations of the beetle by splitting local clusters of exit holes into more than one "occurrence" of the subspecies.

Perhaps most troubling, the groups challenging the delisting charge that USFWS was swayed in its decision to delist the beetle by political pressure from real estate developers. In a letter to USFWS dated Tuesday, CBD's Executive Director Kieran Suckling and Sarina Jepsen, Endangered Species Program Director of the Xerces Society say that a Freedom of Information Act (FOIA) request revealed improper interference in the agency's scientific assessment of the beetle's status:

"There's just not sufficient information, and no valid population data, to move forward with delisting the Valley elderberry longhorn beetle," said Jeff Miller. "Delisting criteria, including how many populations are needed for recovery, have never been developed. Objectives that were established by a 1984 recovery plan have not been met."

USFWS's final ruling on the delisting proposal is expected soon.

For ongoing environmental coverage in March 2017 and afterward, please visit our show Earth Focus, or browse Redefine for historic material.
KCET's award-winning environment news project Redefine ran from July 2012 through February 2017.

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