Derobrachus hovorei
Santos-Silva, 2007
Palo Verde Root Borer, Palo Verde Beetle, Palo Verde Borer Beetle
Derobrachus hovorei is a large longhorn beetle native to the southwestern United States and northern Mexico. It was formally described as a distinct by Santos-Silva in 2007, having been previously confused with D. geminatus for over a century. are among the largest beetles in North America, reaching up to 3.5 inches in length. The species is named for its larval association with palo verde trees (Parkinsonia spp.), though it has been observed feeding on roots of various other tree species in urban environments.
Pronunciation
How to pronounce Derobrachus hovorei: //dɛɹ.oʊˈbɹeɪ.kəs ˈhoʊ.vəˌraɪ//
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Identification
Distinguished from the related D. geminatus by taxonomic revision (Santos-Silva 2007); prior to 2007, literature incorrectly applied the name geminatus to this . Among North American cerambycids, the combination of very large size (up to 88 mm), black to brown coloration, thoracic spines, and association with Parkinsonia plants supports identification.
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Habitat
Native to desert and semi-arid regions of the southwestern United States and northern Mexico. In urban areas, found in parks, college campuses, cemeteries, and residential landscapes where trees are present or where susceptible ornamental trees have been planted.
Distribution
Southwestern United States (Arizona, New Mexico, Texas, California, Nevada, Utah) and northern Mexico. GBIF records confirm presence in both MX and US.
Seasonality
emerge in summer to mate. Mature beetles active during summer months. Field observations from July 2021 document adults at light sheets during this period.
Diet
Larvae feed on roots of trees. In natural settings, primarily associated with palo verde (Parkinsonia spp.), including P. florida, P. microphylla, and P. sonorae. In urban areas, has been observed feeding on roots of Siberian elm, white and fruitless mulberry, various cottonwoods, and citrus in warmest desert areas.
Host Associations
- Parkinsonia - primary larval natural in wild; includes P. florida, P. microphylla, P. sonorae
- Ulmus pumila - larval Siberian elm; urban areas
- Morus alba - larval white mulberry; urban areas
- Morus - larval fruitless mulberry; urban areas
- Populus - larval cottonwoods; urban areas
- Citrus - larval warmest desert areas only
Life Cycle
hatch into that live underground for up to three years. Larvae are cream colored to pale green with brown . Larval feeding on tree roots can cause branch dieback. emerge from in summer.
Behavior
can fly, though has been described as awkward. Adults have been observed crawling on sand near light sources at night. Adults will bite in self-defense if handled.
Ecological Role
Larval root-boring activity can cause significant dieback of tree branches. As a long-lived root feeder, larvae represent a substantial component in subterranean desert .
Human Relevance
Not harmful to humans, though capable of defensive biting. Large larvae are frequently uncovered by gardeners during routine yard maintenance, particularly in flower beds surrounding lawns with susceptible trees. Can cause damage to ornamental and landscape trees through larval root feeding.
Similar Taxa
- Derobrachus geminatusHistorically confused with D. hovorei; D. hovorei was not recognized as distinct until Santos-Silva's 2007 revision. Essentially all literature prior to 2007 incorrectly uses the name geminatus for this .
More Details
Taxonomic history
For over 100 years, this was confused with Derobrachus geminatus. Santos-Silva formally described D. hovorei as a new species in 2007, making essentially all prior literature on 'D. geminatus' from the southwestern US and northern Mexico referable to this species instead.