Laemosaccus arizonensis Hespenheide, 2019

Hespenheide, Henry A., 2019, A Review of the Genus Laemosaccus Schönherr, 1826 (Coleoptera: Curculionidae: Mesoptiliinae) from Baja California and America North of Mexico: Diversity and Mimicry, The Coleopterists Bulletin (MIMICRY AND LAEMOSACCUS In an earlier paper (Hespenheide 1996), I presented the hypothesis that species of Laemosaccus of the L. nephele group with red humeral spots on the elytra were Batesian mimics of members of the Chrysomelidae in the subfamily Clytrinae. There is no evidence that Laemosaccus species are distasteful, and what is either L. nephele and / or L. obrieni have been reported as prey items of birds (Beal 1912). In Cave Creek Canyon, Cochise County, Arizona, 21 forms (species and “ subspecies ”) of Clytrinae were hypothesized to be the primary models of 22 species of mimics in the families Anthribidae (one species), Bruchidae (two species), Buprestidae (four species), Chrysomelidae, subfamily Cryptocephalinae (three species), Coccinellidae (six species), Curculionidae, subfamily Baridinae (one species), and Laemosaccus (five species). Of these, the coccinellids and the cryptocephaline chrysomelids are probably distasteful Mullerian co-mimics. Ecologically, the species of Laemosaccus co-occurred with their clytrine models on both desert legumes and canyon oaks, although more clytrine species occurred in the desert and more Laemosaccus species occurred in the canyons. Species of clytrines showing the mimetic pattern are common throughout Mexico (Bellamy 2003, who renamed the Mexican buprestid genus Acherusia Laporte and Gory, 1837 as Mimicoclytrina Bellamy to reflect their resemblance to clytrines), but decline in numbers of species and in the proportion of the clytrine fauna through Central America to Panama (Hespenheide 1996, fig. 2). Laemosaccus seems to follow a similar pattern. Mimicry is more common in large faunas, especially in wet tropical areas (Hespenheide 1986, 1995); because the largest clytrine fauna is in Mexico, the clytrine mimicry complex is also larger there (Hespenheide 1996). This complex has more members than I first enumerated and deserves further study. The evolution of mimicry produces resemblances between unrelated species (Laemosaccus and other putative mimics, with clytrines and perhaps other Chrysomelidae and Coccinellidae as models; see Hespenheide 1976, 1996) and selects against the divergence of related species. In Batesian mimicry - hypothesized to be the form of relationship between Laemosaccus and clytrines - the selection for precision of mimicry is stronger on the mimic (Laemosaccus), so that resemblances among them should be closer, regardless of ancestry. Close morphological resemblances based on ecology rather than ancestry may be termed mimetic homoplasy (Hespenheide 2005) and can make recognition of species difficult (as in Laemosaccus) or complicate phylogenetic analyses. I have speculated (Hespenheide 1996) that the sympatric “ subspecies ” of the clytrine models (Moldenke 1970) may in fact be reproductively isolated sibling species. It will be interesting to see whether or not genomic studies show the closeness of relationships among Laemosaccus species that the morphology suggests) 73 (4), pp. 905-939 : 917-918

Laemosaccus arizonensis Hespenheide , new species

Zoobank.org/ urn:lsid:zoobank.org:act:C0F9822F-3C24-493E-A4F5-246EDB1F5CD3 ( Figs. 9 , 20 )

Description. Holotype Male. Length 2.9 mm, width 1.3 mm wide ( Fig. 9 ). Robust, subcylindrical in cross section, broadly rounded behind, more narrowly so in front, black except each elytron with large red-orange spot on anterior 3/4 from near lateral margins to anterior margin and suture and broadly rounded behind; pronotum, elytra, and propygidium glabrous; thorax and abdomen ventrally with punctures each with a silvery seta except in transverse oval glabrous area across midline of metasternum and anterior section of abdominal ventrite 1, head with few inconspicuous setae on rostrum above antennal insertions and behind eyes, setae more slender and semi-erect on basal half of femora, hair-like and semi-erect on ventral half of tergite 8 and in dense tufts on either side of the midline on abdominal ventrite 1. Head hemispherical, 0.7 mm wide, rostrum rounded-terete, densely, finely punctate, 0.4 mm long, antennae inserted at middle. Pronotum gibbous, convex at base in lateral view, less convex in cross section, constricted before anterior margin, 0.95 mm long, 1.2 mm wide, broadest at middle, with lateral margins more rounded in front than behind, finely, evenly punctate, punctures longitundinally confluent, with fine medial carina on basal half. Elytra slightly wider than pronotum at base, 1.9 mm long, 1.3 mm maximum width, elytral striae subequal to intervals, striae moderately coarsely punctate, intervals rounded-angulate, interval 3 weakly toothed on middle third, interval 5 weakly toothed on apical half. Abdominal ventrite 5 half as long at middle as at lateral margins. Profemora with acute ventral tooth before middle. Genitalia as in Fig. 20 ; aedeagus 0.80 mm long.

Allotype Female. As male but 2.75 mm long, 1.2 mm wide; rostrum forming conspicuous obtuse angle with front, subcylindrical, polished, very finely, sparsely, inconspicuously punctate, 0.4 mm long; area on either side of midline of posterior half of metasternum and abdominal ventrites 1 and 2 glabrous and more or less polished; tergite 7 convex, coarsely punctate, with semi-erect, hair-like setae on ventral fifth.

Specimens Examined. Holotype: Arizona: Cochise Co., Chiricahua Mountains, Onion Saddle , 7600’, 31°56’N 109°16’W, 22.07.1981, H. A. Hespenheide, Quercus (USNM) . Allotype: Arizona: Cochise Co., E. Turkey Creek , 6.5 mi. W Portal, 6400’, 31°54-55’N 109°15’W, 20.07.1981, H. A. Hespenheide, oak ( USNM) . Paratypes: USA: Arizona: Cochise Co., Chiricahua Mts. , 07.06.1908, V. Owen (1, LACM) ; Pinery Cyn., Chiricahua Mts., below Onion Saddle , 7200’, 31°56’N 109°16’W, 25.06.1999, H. A. Hespenheide, on leaves of Quercus gambelli Nutt. (7, BMNH, CHAH) ; Cave Ck. Cyn., Chiricahua Mts., Sunny Flat , 5100’, 31°53’N 109°10’W, 23.06.1984, 23, 24, 26.05.1985, H. A. Hespenheide, on Quercus sp. (17, CHAH, TAMU) , 30.05.1982, H.A. Hespenheide, Quercus (2, CHAH) , 20.05.1985, H. A. Hespenheide (1, CHAH) ; Cave Ck. Cyn., Chiricahua Mts. , 5 mi. WSW Portal, 5900’, 31°54’N 109°13-14’W, 24.06.1999, H. A. Hespenheide (1, CHAH) ; Cave Ck. Cyn., Chiricahua Mts., Herb Martyr Dam , 5800’, 31°52’N 109°14’W, 30.05.1997, L. M. LaPierre (1, CHAH) ; Chiricahua Mts., E. Turkey Creek , 6.5 mi. W Portal, 6400’, 31°54-55’N 109°15’W, 16.07.1981, H. A. Hespenheide (1, CHAH) ; Chiricahua Mountains, Onion Saddle , 7600’, 31°56’N 109°16’W, 21.07.1981, H. A. Hespenheide (1, CHAH) ; Cave Ck. Cyn., Chiricahua Mts. , 2 mi. WSW Portal, no date (1, CHAH) ; Miller Can., Huachu [ca] Mts. , 9, 10, 11, 12.07.1907, H. A. Kaeber (4, USNM) ; Copper Cyn., Huachuca Mts. , 25.07.1984, W. F. Barr, Quercus (1, WFBM) ; [Pima Co.], Catalina Mts., Htchck. Hwy. mi. 10, 19.06.1958, C. O’ Brien (1, ASUHIC) ; Santa Cruz Co., Madera Canyon, Josephine Saddle Trail , 26.07.1989, R. Turnbow (1, CMNC) , Madera Canyon, Santa Rita Mts. , 10- 15.07.1975, A. E. Lewis (1, ASUHIC) , Madera Canyon , 28.07.1967, R. A. Tilden (1, ASUHIC) ; S. Rita Mts. , 11.06, Hubbard & Schwarz (1, USNM) . Mexico: Oaxaca: Hwy 175, 22 mi. NE Oaxaca,7900’, 26.08.1982, C. & L. O’ Brien & G. Wibmer (1, ASUHIC) .

Hosts. Adults have been collected on Quercus gambelli Nutt. and on undetermined oaks.

Etymology. This species is named for the state in which it was first collected.

Discussion. Males of L. arizonensis are easily recognizable by the external secondary sexual character of the two tufts of semi-erect setae on the first abdominal ventrite. Females have a short, polished, peg-like rostrum at an angle with the frons, large posthumeral orange spots and medially glabrous first abdominal ventrite. Although widely disjunct, the specimen from Oaxaca shares this character and the equally distinctive genitalia. This is one of the smallest Laemosaccus in the L. nephele group of species; males vary in length from 2.20 to 2.90 mm (mean = 2.60 mm, n = 26); females vary from 2.45 to 3.10 mm (mean = 2.73 mm, n = 13).

Figures

Figs. 7–12. Laemosaccus species. 7–8) L. andersoni, dorsal and lateral habitus, respectively; 9) L. arizonensis, dorsal habitus; 10) L. bimaculatus, dorsal habitus; 11–12) L. burkei, dorsal and lateral habitus, respectively.

Figs. 19–24. Laemosaccus species, dorsal and lateral views of aedeagus and paramere. 19) L. andersoni; 20) L. arizonensis; 21) L. bimaculatus; 22) L. burkei; 23) L. clytrinoides; 24) L. howdenae.