Agrilus jacobinus Horn 1891, Horn, 1891

Hespenheide, Henry A., Westcott, Richard L. & Bellamy, Charles L., 2011, Agrilus Curtis (Coleoptera: Buprestidae) of the Baja California peninsula, México, Zootaxa 2805, pp. 36-56: 45-49

publication ID 10.5281/zenodo.277078

persistent identifier

treatment provided by


scientific name

Agrilus jacobinus Horn 1891


Agrilus jacobinus Horn 1891  

(Figs. 67–68)

BCN, Ensenada, N.L.H. Krauss ( CAS); 4 mi S el Condor, 13 -VI- 81, Brown & Faulkner ( SDMC). Cazier (1951) recorded the species from Chihuahua, but we strongly suspect that was based on a misidentification. Otherwise, A.

jacobinus   has been known only from southern California. It belongs to a difficult group, which includes the aforementioned A. felix   , that is in need of revision.

Agrilus lacustris LeConte 1860   (Figs. 45–46)

We have seen only a few specimens from Baja California, and the only previous specific record is from San José del Cabo, BCS ( Horn 1894). We have examined specimens from the following localities: BCN, 49 mi SE Ensenada, E.L. Sleeper ( CAS); El Descanso, 27 -V- 68, D.S. Verity ( DSVC). BCS, Bahía de los Frailes, 14 -VIII- 55, J.P. Figg-Hoblyn ( CAS); San José Viejo, 17 -VII- 68; San José del Cabo, IX- 10 ( TAMU); near Santa Catarina. Elsewhere in Mexico it has been recorded from states in northern Mexico, and in Veracruz. It is widespread in the U.S., and occurs in Ontario, Canada. Adults have been collected on Croton pottsii (Klotzsch) Müll. Arg.   and C. punctatus Jacq.   ( Euphorbiaceae   ) and Solanum   sp. ( Solanaceae   ).

Agrilus lucanus Fall 1906   (Figs. 14–15)

On the peninsula this species is known only from the Cape Region, BCS, and was described from one specimen taken at El Taste. We have seen others, all from the vicinities of La Burrera, ± 23 ° 30 ’N, 110 °00’W, 580–900 m; and La Huerta, ± 24 °04’N, 110 ° 13 ’W, ± 410 m, collected during August to October ( CLBC, CHAH, RLWE, WFBM). One of us (RLW) beat a series from foliage of Diospyros californica (Brandegee) I.M. Johnston   var. californica   ( Ebenaceae   ), 7.5 km E La Burrera, nearby a stream in the canyon, 14 -X- 78. Sighting fresh emergence holes in a dead branch led to this collection, thus strongly implicating this plant as the larval host. Further evidence is that most if not all the other specimens mentioned here were also taken on that plant. No other host is known. This Mexican species of Agrilus   has also been recorded from Sinaloa, Zacatecas, Morelos and Oaxaca.

Agrilus paraimpexus Hespenheide 2007   (Figs. 57–58)

Specimens of this species from Baja California formerly were treated under A. addendus Crotch ( Horn 1894)   or A. impexus Horn   , but Hespenheide (2007) showed that three species are involved, with only A. paraimpexus   being found on the peninsula. We have seen specimens of this widespread and common beetle from as far north as San Matias Pass (ca. 31.31 °N, 115.50 °W) in BCN, south throughout the arid and semi-arid portions of the peninsula, from where adult collections are known only from leguminous trees and shrubs, notably mesquite, with a single, surely incidental collection on Eriogonum fasciculatum   . However, it has been reared only from dead twigs of Argythamnia   b. brandegeei Millspaugh (sometimes placed in the genus Ditaxis   ).” Dates of collection range from March to July in BCN, April to October in BCS ( Hespenheide 2007). Elsewhere A. paraimpexus   ranges widely, occurring from S California to SW New Mexico, southward to Costa Rica, and all adult collections and the single rearing record ( Pomaria jamesii (Torr. & A. Gray) Walp.   = Hoffmannseggia jamesii Torr. & A. Gray   are from plants in the family Fabaceae   .

Agrilus parvus californicus Westcott and Nelson 2000   (Figs. 49–50)

This subspecies is known on the peninsula from only a single locality in BCN near the southern end of the Sierra Juárez, 31 ° 52 ' 24 "N, 116 °05' 27 "W, taken in a malaise trap. Elsewhere it is known only from southern California, collected from its presumed host plant, Amorpha fruticosa   L. ( Fabaceae   ). The nominate subspecies is recorded from central Arizona eastward over much of the U.S.

PLATE 2. Dorsal and lateral views of species of Agrilus   from Baja California; scale bars = 1 mm: Figures 14–15, A. lucanus Fall   ; 16–17, A. fisherianus Knull   ; 18–19, A. fisherellus Obenberger   ; 20–21, (male), 22 (female) A. walsinghami Crotch   ; 23–24, A. quadriguttatus niveiventris Horn.  

Agrilus pectoralis Waterhouse 1889   (Figs. 59–60)

This species was recorded from as far north as 10 mi S of Punta Prieta, BCN, south to 20 mi W of Santa Rosalia, BCS ( Van Dyke 1942, as its synonym A. palmacollis Horn 1891   ). We have examined numerous specimens from near Penjamo, BCN southward to near Cabo San Lucas, BCS. Dates of collection range from March to November, the majority being taken from June through August. The only specimens with host data were beaten from Prosopis glandulosa   var. torreyana   . Outside Baja California, A. pectoralis   occurs from S. California to Texas, south through Mexico to Hidalgo and Guerrero. Larval and adult hosts all are trees in the family Fabaceae   .

PLATE 3. Dorsal and lateral views of species of Agrilus   from Baja California; scale bars = 1 mm: Figures 25–26, A. inhabilis inhabilis Kerremans   ; 27–28, A. inhabilis chalcogaster Van Dyke   ; 29–30, A. detractus Waterhouse   ; 31 –32, 33 (genitalia), A. coxalis Waterhouse   ; 34 –35, 36 (genitalia), A. auroguttatus Schaeffer   ; 37–38, A. politus (Say)   .

PLATE 4. Dorsal and lateral views of species of Agrilus   from Baja California; scale bars = 1 mm: Figures 39–40, A. arbuti Fisher   ; 41–42, A. angelicus Horn   ; 43–44, A. gibbicollis Fall   ; 45–46, A. lacustris LeConte   ; 47–48, A. harenus Nelson   ; 49–50, A. parvus californicus Westcott & Nelson.  

Agrilus peninsularis Van Dyke 1942   (Figs. 54–56)

This endemic is one of the most common species of Agrilus   on the peninsula, especially in BCS. Nevertheless, nothing about it has been published since the original description, at which time its habits were unknown. We have examined numerous specimens from just south of Punta Prieta southward throughout most of the peninsula all the way to Cabo San Lucas, a region that encompasses the collections recorded by Van Dyke (1942). That author recorded 17 paratypes; however, one of us (RLW) discovered that most of them had not been labeled as such. This has been corrected. As noted above, specimens from the two northernmost localities listed by Van Dyke (1942) for this species actually refer to A. abstersus   . The two species are very closely related, but seem to be reliably separated based on the characters given in the key. Whether or not their ranges overlap remains to be determined, although based on specimens we examined there is a distance of only about 70 km between them. Oddly, we have seen no records of A. abstersus   from northeastern BCN, although it is expected from there. Dates of capture for A. peninsularis   range from June to October, all those collected in the latter month being from the Cape Region. Adults have been collected only from shrubs and trees of the family Fabaceae   , mostly by beating, as follows: Cercidium   sp., Mimosa xantii Gray   , Olneya tesota A. Gray   , Ebenopsis confinis (Standl.) Britton & Rose   (= Pithecellobium confine Standley   ), and Prosopis glandulosa   var. torreyana   . A vast majority of the specimens bearing host data were collected on the latter plant.


CRAI - Universitat de Barcelona


California Academy of Sciences


W.F. Barr Entomological Collection














Agrilus jacobinus Horn 1891

Hespenheide, Henry A., Westcott, Richard L. & Bellamy, Charles L. 2011

Agrilus paraimpexus

Hespenheide 2007

Agrilus parvus californicus

Westcott and Nelson 2000

Agrilus peninsularis

Van Dyke 1942

Agrilus lucanus

Fall 1906

A. addendus Crotch ( Horn 1894 )

Crotch (Horn 1894

A. palmacollis

Horn 1891

Agrilus pectoralis

Waterhouse 1889