Pamphagus batnensis Benkenana & Petit, 2012

Benkenana, Naima, Harrat, Abboud & Petit, Daniel, 2012, The Pamphagidae (Orthoptera) from East Algeria and description of a new species, Zootaxa 3168 (1), pp. 22-38 : 29-36

Description of Pamphagus batnensis Benkenana & Petit

Holotype. Male. National park of Belezma , Batna Wilaya, 1200 m, 03/06/2010, MNHN-EO-CAELIF592 (fig. 5).

Paratypes. 1 male, National park of Belezma , Batna Wilaya, 1200 m, 03/06/2011, MNHN-EO-CAELIF593 ; 1 female, El-Hamma , Khenchela Wilaya, 1200 m, 15/04/2010, MNHN-EO-CAELIF594 (fig. 4N) ; 1 male, El- Hamma , Khenchela Wilaya, 983 m, 15/04/2010, Mentouri University: 40K (fig. 3H, 3K) ; 1 female, El-Hamma , Khenchela Wilaya, 983 m, 15/04/2010, Mentouri University: 41K ; 1 male, El-Hamma , Khenchela Wilaya, 983 m, 02/04/2010, Limoges University: 21K ; 1 female, El-Hamma , Khenchela Wilaya, 983 m, 02/04/2010, Limoges University: 22K .

Body. The vertex of the head has a median keel well pronounced, unlike P. elephas in which it is obliterated. Carinae of the vertex frontally are closed by an acute angle, like in P. djelfensis , and less obtuse than in P. auresianus . Pronotum is less raised and laterally compressed than in P. elephas , and interrupted by a transverse sulcus in its forth to fifth distal part. There are 2 light stripes at the pronotum base, the median one larger than the more ventral one. In the female, the caudal edge of the pronotum is laterally decorated with a series of 4-7 white spots, unlike P. cristatus and P. elephas which have not. The tegmina slightly exceeds the first abdominal tergite in male, shorter or equal in the female, and there is a light stripe on the posterior edge. In the male, Krauss’ organs are granulose and roughly streaked. The overall coloration is very close to the one usually observed in P. djelfensis and P. auresianus .

Male genitalia. The valve width is thinner in P. batnensis than in P. auresianus in ventral view, and quite similar to what is observed in P. djelfensis . In lateral view, the phallic complex is less curved than in P. auresianus , and is close to the one of P. djelfensis . The echinule number on the epiphallus in P. batnensis is lower than in P. auresianus and P. djelfensis .

In order to discriminate the species in the group P. djelfensis-P. auresianus and P. batnensis ( P. djelfensis complex), morphometric measurements were undertaken (table 4). It appears that the length of abdomen and the width over length ratio in hind femur are globally greater in P. auresianus than in the two other species. The epiphallus characters allow to distinguish the three species, as the number of echinules is lower in P. batnensis (around 6 and 7) than in P. auresianus (around 9–11) and P. djelfensis (around 12–14). The echinules are arranged in left and right rows that make more open angle in P. auresianus than in the two other species. The valve width over phallic complex length ratio is greater in P. auresianus than in the two other species.

Abbreviations. ThL: thorax length; Thw: thorax width; PL: Pronotum length; Pw: Pronotum width; Abd: abdomen length; Teg: tegmina length; FL: hind femur length; Fw: hind femur width; Ech: echinule number; Angle: angle between echinulate series; Vw/PCL: valve width/phallic complex length; VL/PCL: valve length/phallic complex length.

We used the table 4 of morphometrics data to perform a principal component analysis for the males. The aim was to test if the three species can be objectively defined and to appreciate the degree of overlapping between species envelopes. The first ordination plane expresses 46% of total variance. Ellipses were drawn from the clustering on the three first scores, with Euclidean distance as a measure of similarity (data not shown). It appeared that three groups of individuals are well separated, that could correspond to three different species, and that genitalia and hind femur shapes are the most discriminant characters (fig. 6). P. auresianus is characterized by a high width over length ratio for hind femur, and a high angle between echinule series on epiphallus plate. In contrast, P. djelfensis and P. batnensis are distinct by the weaker number of echinules and longer hind femur in P. batnensis than in P. djelfensis . Moreover, the valve length over the phallic complex length ratio is higher in P. batnensis than in P. djelfensis . The same ratio for the valve width is higher in P. auresianus than in the two other species.