Cnemidochroma phyllopus (Guérin-Méneville, 1844)

Valle, Néstor G., Ibarra-Polesel, Mario G., Cherman, Mariana Alejandra, Monné, Marcela L. & Damborsky, Miryam P., 2021, First record of Cnemidochroma phyllopus (Coleoptera: Cerambycidae) in the province of Corrientes, Argentina and potential distribution in the southern part of South America, Zootaxa 5082 (1), pp. 53-64 : 55-58

Cnemidochroma phyllopus (Guérin-Méneville, 1844)

( Fig.1 )

Material examined. ARGENTINA: Corrientes: Mburucuyá, Department Mburucuyá , 28º2’29’’S; 58º13’49’’W, 81 m above sea level, 1 male, body length 30.0 mm; width 8.1 mm, 25.X.2018, N. G. Valle leg. (CARTROUNNE 9063) .

Species distribution model. Excluding the new locality record, fifty-five occurrence records ranging from 1944 to 2020 were assembled, mostly concentrated in Brazil (n = 42). Based on the thinned process, 43 unique georeferenced records persisted, and were eligible for Maxent modelling ( Table 1 ; Fig.2A ). The calibration area for the species (M), was established from the projection area and the records were recognized in six biogeographical provinces: Caatinga, Atlantic, Araucaria and Parana Forest, Pampean, and Chacoan ( Fig. 2B ).

Twenty-one candidate models were generated based on all possible combinations of the regularization multipliers and the features classes (3 RM x 7 FC). Three models met the criteria of statistical significance, with values of the area under the curve ( AUC), partial ROC (pROC) and omission rate significantly different from random. One out of the three models with a lowest AICc value (delta AICc = 0) was selected. The best model was built under optimized settings, a regularization multiplier value of 2, a quadratic (Q) feature class and a set of three principal components ( Table 2 ).

The final distribution map obtained by the model enabled to identify highest suitability for C. phyllopus occurrence in the southeast coastal areas of Brazil (Espírito Santo, Rio de Janeiro, São Paulo, Paraná and Santa Catarina) mostly concentrated on the Atlantic biogeographic Province. The climatic suitability conditions continue and ranged over the southwestern Brazil, Paraguay and towards the northeastern to the central regions of Argentina which correspond to the Parana Forest, Araucaria Forest and Chacoan biogeographic Provinces ( Fig. 3A ) .

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Suitability gradually decreased towards Uruguay and southern Argentina and did not extend beyond 10°S in Brazil. Based on continuous and binary maps, the favorable area for the species may be larger, extending over the westernmost region of Paraguay, southeastern Bolivia and northwestern Argentina, which is located in the Chacoan biogeographic province ( Figs. 3 A-3B).

Figures

FIGURE 1. Cnemidochroma phyllopus, dorsal (A), ventral (B) and lateral (C) habitus of male, deposited in the Universidad Nacional del Nordeste (CARTROUNNE 9063). Corrientes, Argentina.

FIGURE 2. A) Geographical distribution of C. phyllopus allocated to countries. Occurrence records are shown as white circles; white square is the new locality record. Countries are identified with different colors: Argentina (light blue), Brazil (green), Paraguay (yellow) and Uruguay (purple). B) Model calibration map (test data are shown as red circles- and training data as -blackcircles). Calibration area (M) marked in yellow around the records. Biogeographic provinces are indicated with different colors: Caatinga (red), Araucaria Forest (blue), Atlantic (green), Pampean (brown), Chacoan (light blue) and Parana Forest (lilac).

FIGURE 3. A) Potential suitable areas throughout the historical distribution for C. phyllopus based on the best model. Warmer colors (e.g., red) indicate areas of higher climatic suitability, whereas cooler colors (e.g., green) represent areas with lower climatic suitability. B) Binary map showing habitat suitability for C. phyllopus. Biogeographic provinces, as they are shown in figure 2B, are delimited by lines. Occurrence records are shown as black circles; white square is the new locality record.