Laemosaccus andersoni 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 : 916-917

Laemosaccus andersoni Hespenheide , new species

Zoobank.org/ urn:lsid:zoobank.org:act:076ABC07-A500-4138-BA00-2DD19122783F ( Figs. 7, 8 , 19 )

Description. Holotype Male. Length 3.6 mm, width 1.75 mm ( Figs. 7, 8 ). Robust, subcylindrical in cross section, slightly obovate, abruptly rounded and nearly transverse behind, attenuate and narrowly rounded in front, black except each elytron with large, oval, red-orange spot on anterior 2/3 and just interior of lateral margins nearly to suture; pronotum and elytra glabrous, thorax and abdomen ventrally with punctures each with a silvery seta, nearly covering the ventral surface except for small area along posterior portion of metasternum along midline, setae semierect on abdominal ventrite 5, head with sparse, inconspicuous setae on sides of rostrum between eyes and antennal insertions and behind eyes, setae more slender and semi-erect on femora, long, hair-like, and semierect on tergite 8; tergite 7 with small, scale-like setae on basal margin, otherwise glabrous. Head hemispherical, 0.8 mm wide, rostrum rounded-terete, moderately coarsely punctate with distinct medial carina, 0.6 mm long, antennae inserted at middle. Pronotum globose from above, nearly flat in lateral view, constricted before anterior margin, 1.25 mm long, 1.4 mm wide, broadest at basal third, lateral margins conspicuously arcuate, finely, evenly punctate, punctures rounded and separate on basal half, somewhat elongate and nearly confluent near midline on apical half, with distinct, fine medial carina on basal 3/4. Elytra distinctly wider than pronotum at base, 2.3 mm long, 1.75 mm maximum width, elytral striae narrower than intervals, striae distinctly, finely punctate, intervals raised and rounded, intervals 3 and 5 very weakly toothed. First abdominal ventrite very slightly concave along midline, with setae less conspicuous. Pygidium conspicuously convex (“domed”) at middle, postpygidium with broad, raised, polished prominence along basal half of midline. Profemora with very small, forward-directed, acute ventral tooth beyond middle. Genitalia as in Fig. 19 ; aedeagus 1.10 mm long.

Allotype Female. As male but 3.45 mm long, 1.45 mm wide, rostrum subcylindrical, more finely punctate; abdominal ventrites broadly glabrous along postero-medial margins, ventrite 5 subequal to ventrite 4 at middle, expanded at sides and equal to ventrites 3 + 4; tergite 7 very strongly convex, granular, glabrous except with erect, hair-like setae at apical fifth.

Specimens Examined. Holotype: Arizona: Cochise Co., Chiricahua Mts. , 2.5 mi. SW Portal, 5000’, 10.08.1983, R. S. Anderson ( CMNC) . Allotype: Same data as holotype ( CMNC) . Paratypes: USA: Arizona: Santa Rita Mts. , 5 to 8000 ft, July, F. H. Snow (9, SEMC) , 12.07.1950, P. P. Cook (1, SEMC) . Cochise Co., 2.5-5 km W Portal , 1646 m, 23.07.1989, R. S. Anderson, 89-12 (2, CMNC) ; same data as holotype (3, CMNC) ; Chiricahua M., 15.06.1939, 24.07.1955, D. J. & J. N. Knull (2, OSU) ; Chiricahua Mts., Horseshoe Can. , 6000’, 4.07.1977, S. McCleve (1, TAMU) ; Chiricahua Mts., Rucker Cyn. Dam , 25.07.2005, C. W. O’ Brien (1, ASUHIC) ; Cave Ck. Canyon , 8.08.1974, A. J. Gilbert, H. E. Gilbert (1, ASUHIC) ; Cava [sic] Cr , 3.09.1943 (1, EMEC) ; Chiricahua Mountains, South Fork Cave Creek , 31°52.47’N 109°10.92’W, 5440’, 23.07.2003, S. M. Clark (1, ASUHIC) ; Douglas , 7.08.1933, 1.08.1936, W. W. Jones (5, EMEC, USNM) ; Bisbee, Quarry Cyn. , 5600’, 7-8- 1978 (1, SWRS) ; Huachuca Mts., Copper Canyon , 1737-1829m, 26.07.1989, R. S. Anderson, 89-23 (1, CMNC) ; Coconino Co., Oak Cr. Can., 21.07.50, D. J. & J. N. Knull (1, OSU) ; Oak Creek Cyn., Manzanita Camp , 30.07.1950, B. E. White (7, CASC) ; Gila Co., Sierra Ancha Mts., Workman Creek , 5.08.1977, S. McCleve (1, TAMU) ; Pima Co., Mt. Lemmon Hwy. , mi. 1-17, 1.08.2000, J. Huether (1, CMNC) ; [Pinal Co.] Oracle , 7-7, Hubbard & Schwarz (1, USNM) ; Santa Cruz Co., Pena Blanca , 14.07.2000, F. W. Skillman Jr. (2, ASUHIC) . Mexico: Chihuahua: Basaseachi Falls , 1950 m, 28°11’N 108°13’W, 5440’, 5.07.2006, D. Furth (3, CHAH) ; Coahuila: nr Jame , 33 mi. SE Saltillo, 7500’, 25.07.63, A. T. Howden (2, CMNC) ; Durango: 3 km W El Palmito , 2- 3.10.1976, E. Giesbert (1, EMEC) ; 25 km SW La Ciudad , 7300’, 22.06.1991, J. Rifkind, Pine / Oak (1, WFBM) ; 36 mi. W Cd. Durango , 9.06.1967, [A. R. Moldenke], on Ceanothus buxifolia (3. BMNH, CHAH, USNM) . Estado de México: Santa Catarina del Monte ± 12 km (air) ESE Texcoco , 2800 m, 20.06.2000, R. L. Westcott, beating Quercus sp. (1, TAMU) ; Nuevo León: Chipinque Mesa, Zoo , 3700’, 21.06.1983, C. W. & L. O’ Brien & G. B. Marshall (1, ASUHIC) .

Host. Adults of L. andersoni have been collected on Quercus sp. and Ceanothus “ buxifolia ” [= Ceanothus buxifolius Willd. ex Schult. f., Rhamnaceae ] in Mexico.

Etymology. This species is named in honor of Robert S. Anderson, the collector of the holotype and major collector and student of the Curculionidae (e.g., Anderson 1989, 2002).

Discussion: This is one of the most distinctive of the L. nephele group of species in both the domed pygidium of both sexes and the form of the male genitalia. Some fresher specimens have a few postscutellar setae on the first elytral interval. Males vary in size from 2.85 to 4.10 mm (mean = 3.46 mm, n = 17); females vary from 3.10 to 4.40 mm (mean = 3.92 mm, n = 20).

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.