Amblycerus hoffmanseggi

Amblycerus hoffmanseggi (Gyllenhal, 1833)

(Figure 2 A–H)

Spermophagus hoffmanseggi Gyllenhal 1833, p. 105 (original description, distribution); Dejean 1837, p. 255 (catalogue, distribution); Schöenherr 1839, p. 134 (citation, distribution); Jekel 1855, p. 30 (citation); Gemminger and Harold 1873, p. 3218 (catalogue, distribution); Sharp 1885, p. 496 (citation); Pic 1913, p. 59 (catalogue, distribution); Pierce 1915, p. 9 (citation); Leng 1920, p. 306 (catalogue, distribution); Blair 1928, p. 679 (citation); Costa Lima 1928, p. 183 (host, distribution); Bondar 1931, p. 59 (citation, distribution); 1936, p. 34 (citation, distribution); Bosq 1943, p. 47 (distribution, host); Zacher 1952, p. 468 (host); Guérin 1953, p. 179 (citation, distribution, redescription); Kingsolver and Silva 1991, p. 414 (citation).

Amblycerus hoffmanseggi: Bridwell 1944; Blackwelder 1946, p. 762 (catalogue, distribution); Costa Lima 1955, p. 249 (host); Silva et al. 1968, p. 376 (distribution, host); Kingsolver 1970, p. 485 (redescription, distribution, male genitalia figure, key); Terán and L’Argentier 1981, pp. 61–70 (immature figure, ecology, host); Johnson and Kingsolver 1982, p. 410 (catalogue, distribution); Borowiec 1987, p. 187 (male genitalia figure); Udayagiri and Wadhi 1989, p. 10 (catalogue, distribution, type locality); Ribeiro-Costa and Marinoni 1992, pp. 149–175 (phenetic analisys); Ribeiro-Costa 1992, p. 153 (redescription, distribution, key, biology, host, male genitalia figure); Macêdo et al. 1992, pp. 331, 333 (biology, host); Johnson et al. 2001, pp. 37, 44, 45 (citation); Kingsolver 2004, p. 35 (citation).

Bruchus robiniae Olivier 1795, p. 7 (nec Fabricius, 1781, p. 75) (redescription); Gyllenhal 1833, p. 105 (synonym).

Diagnosis

Dimensions. Length (Pronotum-elytra) 4.04–5.35 mm. Width 2.36–3.12 mm.

Integument colour. Pronotum and elytra usually dark brown to black (Figure 2A). Antennae, edges and ventral region of pronotum dark brown (Figure 2A, B). Elytron with black longitudinal band on the external margin, rarely dark brown, from the tenth and eleventh or ninth to eleventh, or eighth to eleventh striae intervals (Figure 2A). Pygidium evenly dark brown (Figure 2D) or sometimes orange-red in lateroanterior areas. Abdominal ventrites usually with lateral rounded areas orange-red, rarely with the same colour (Figure 2B).

Pubescence. General pattern – Dense tuft of white pubescence posterior to the postocular lobe absent. Pronotum with dense yellow pubescence distributed in tufts, without forming distinct longitudinal bands or, sometimes, with dense pubescence forming a median band generally not reaching the anterior margin; white pubescence finely bordering edges; black pubescence scattered or in rare tufts (Figure 2A). Scutellum with dense white pubescence (Figure 2A). Elytron with intermixed light yellow and white pubescence with black tufts, the white and light yellow pubescence are distributed as follows: white on the inner margin, light yellow from the first to seventh striae intervals, white on eighth to eleventh, or light yellow on first to eighth and white on ninth to eleventh striae intervals, both intermixed with black tufts (Figure 2A). Pygidium with white pubescence denser at basal and lateral areas (Figure 2D). Pattern B – Pronotum with dense white pubescence laterally in tufts and, sometimes, on the midline forming a prescutellar band; rest with black scattered pubescence. Elytra with intermixed white pubescence and black tufts.

Ocular sinus shallow, not more than one-third of eye length (Figure 2C). Pronotum slightly convex, disc not sulcate in basal lobe (Figure 2A). Scutellum subtriangular (Figure 2A). Hind femur without teeth (Figure 2E). Hind tibia without carina and mucro (Figure 2F), a pair of spurs present, with internal spur about half the length of the external (Figure 2E, F). Last abdominal ventrite of male and female not emarginate at median region. Pygidium slightly concealed by elytra, lateral margins slightly straight with rounded apex (Figures 2B, D).

Male genitalia. Median lobe about five times longer than its median width, slightly expanded at the apex. Ventral valve (Figure 2G – VV) elongate and triangular, lateral margins sinuous near the opening of the internal sac. Basal region of internal sac (Figure 2G – BR) without spicules near base of ventral valve, with an anterior pair of small sclerites similar to teeth, posterior elongated, about six times its width, with apex rounded in ventral view; median region (Figure 2G – MR) with pair of lateral falciform sclerites with apexes varying in curvature, between them a median falciform sclerite about half the length of the lateral sclerites (Figure 2G). Tegmen with lateral lobes separated by shallow emargination, about 0.1 times the length of lateral lobes (Figure 2H).

Type material

According to Udayagiri and Wadhi (1989), the holotype is deposited at Swedish Museum of Natural History, Stockholm, Sweden (NHRS). Labels: “typus [red]” “Br: Robinia, Rio de Janeiro, V. Winther [handwritten, white]” “282, 69 [rose]”. In 1970, Kingsolver examined the type and redescribed Am. hoffmanseggi. Later, when Ribeiro-Costa (1992) established the hoffmanseggi group of Amblycerus, she redescribed this species again indicating the patterns of coloration, besides illustrating the male genitalia.

Additional specimens

BRAZIL: Rio de Janeiro: Arraial do Cabo: 10 / X / 1987, L.R.C. Souza col., in fruit of Senna bicapsularis, 1 specimen (DZUP). Itatiaia: 5 / X / 1924, Zikán col., no host plant, 1 specimen (FIOC). Teresópolis: P.N. Serra dos Órgãos, 2006, J.H. Viana col., in Senna neglecta var. oligophylla, 3 specimens (DZUP); VI / 2006, same collector and host plant, 43 specimens (DZUP); 22 / VIII / 2006, same collector and host plant, 12 specimens (DZUP); 05 / IX / 2006, same collector and host plant, 8 specimens (DZUP); 2007, same collector and host plant, 1 specimen (DZUP); 30 / VII / 2007, same collector and host plant, 1 specimen (DZUP); 12 / X / 2007, same collector and host plant, 1 specimen (DZUP); 14 / IX / 2007, same collector and host plant, 2 specimens (DZUP); 21 / IX / 2007, same collector and host plant, 1 specimen (DZUP); 26 / IX / 2007, same collector and host plant, 1 specimen (DZUP). Paraná: Curitiba: II / 1988, F. Giacomel col., Cassia alata, 2 specimens (DZUP); II / 1988, same collector, 1 specimen (DZUP); 02 / V / 1997, C.S. Ribeiro-Costa e J.M. Bobato col., Senna neglecta, 15 specimens (DZUP); VI / 1997, C.S. Ribeiro-Costa col., Senna neglecta var. neglecta, 9 specimens (DZUP); VI / 1998, same collector and host plant, 28 specimens (DZUP); Jardim Botânico, 20 / V / 2003, no collector and same host plant, 37 specimens (DZUP); UFPR – Prédio Ed. Física, 06 / VII / 2008, no collector and same host plant, 7 specimens (DZUP). Prudentópolis: 1 / XII / 1968, Moure & Dressler col., no host plant, 1 specimen (DZUP). Santa Catarina: Mafra: 08 / I / [19]93, D.T.R. Santos col., no host plant, 1 specimen (DZUP). Rio Grande do Sul: Viamão: 24 / II / 1986, M. Hoffmann col., 1 specimen (MCNZ). No locality: 5 / X / [19]24 | i. [not legible], Fedegoso, 1 specimen (FIOC).

Distribution

United States of America (erroneous record, Kingsolver 1970), Haiti and the Dominican Republic (erroneous record, Kingsolver 1970), Brazil (Bahia, Ceará, Espírito Santo, Pará, Mato Grosso, Goias, Minas Gerais, Rio de Janeiro, São Paulo, Paraná), Bolivia, Paraguay (San Pedro), Argentina (Corrientes, Entre Rios, Jujuy, Misiones, Salta, Tucuman).

New Records. Brazil (Santa Catarina, Rio Grande do Sul).

Host plants

Fabaceae: Caesalpinioideae: Gleditsia triacanthos, Senna alata, S. bicapularis, S. occidentalis, S. corymbosa, S. aphylla, S. bauhinioides, S. hirsuta; Faboideae: Platypodium elegans (doubtful record, Ribeiro-Costa 1992), Macroptilium atropurpureum.

Malvaceae: Malvoideae: Gossypium sp. (doubtful record, Ribeiro-Costa 1992).

New records – Fabaceae: Caesalpinioideae: Senna neglecta var. oligophylla and Senna neglecta var. neglecta.

Discussion

This species differs from all of the other bruchines occurring on S. neglecta by its larger size and by having a pair of spurs on the hind tibia. It has three pubescence colour patterns (Ribeiro-Costa 1992), although we found only two of them (the general pattern and pattern B) associated with S. neglecta. The general pattern was the most frequent in S. neglecta, and is presented and illustrated here; pattern B was the rarest, appearing in only one specimen. Later, Ribeiro-Costa (1992) established the hoffmanseggi group of Amblycerus and redescribed this species again, indicating the patterns of coloration and illustrating the male genitalia.