Diorhabda elongata (Brulle, 1832)

Tracy, James L. & Robbins, Thomas O., 2009, Taxonomic revision and biogeography of the Tamarix-feeding Diorhabda elongata (Brullé, 1832) species group (Coleoptera: Chrysomelidae: Galerucinae: Galerucini) and analysis of their potential in biological control of Tamarisk, Zootaxa 2101 (1), pp. 1-152 : 40

Key to the Species of the Diorhabda elongata Group: Adult Females

1. Vaginal palpi (VP) wider than long, with a width to length ratio (LP/WP) of 0.46–0.94 ( Figs. 34–36 ). If width to length ratio of vaginal palpus 0.94, then the width of the widest lobe on the stalk (WLS) of internal sternite VIII (IS VIII) less than or equal to 0.10 mm ( Figs. 34 , 39 ). Length 4.9–8.4 mm. Circummediterranean, Senegal, Yemen, Portugal, Bulgaria, Macedonia, S. Ukraine, Turkey, Syria, Transcaucasus, C. Asia (east to Kazakhstan and Pakistan), Iraq, Iran, W. North America (introduced) ............................................................................................... 2

- Vaginal palpi about as long as wide or longer, with a width to length ratio of 0.94–1.36 ( Figs. 37, 38 ). If width to length ratio of vaginal palpus 0.94, then the width of the widest lobe on the stalk of internal sternite VIII greater than or equal to 0.11 mm ( Figs. 37 , 42 ). Length 4.8–7.0 mm. S. Russia, Transcaucasus, Syria, Iran, C. Asia, Pakistan, N.W. and N.C. China, S.W. Mongolia, W. North America (introduced) ................................................... 5

2(1). Vaginal palpi (VP) broadly rounded ( Fig. 34 ). Width of the widest lobe on the stalk (WLS) of internal sternite VIII (IS VIII) from 0.06–0.11 mm ( Fig. 34 , 39 ). Subsutural (SSV) and submarginal elytral vittae (SMV), if present, never extending from apical half of elytra into the basal half ( Fig. 1 ). Length 5.8–7.7 mm. Circummediterranean, Portugal, Bulgaria, Macedonia, S. Russia (Dagestan Republic), W. North America (introduced), commonly collected from coastal C. Turkey to Italy.......................................................................................... elongata (Brullé)

- Vaginal palpi triangulate, narrowly rounded ( Figs. 35–36 ). Width of the widest lobe on the stalk of internal sternite VIII from 0.08–0.18 mm ( Figs. 35–36 , 40–41 ). Subsutural and submarginal elytral vittae, if present, often extending from apical half of elytra into the basal half ( Fig. 5 ). Length 4.9–8.4 mm. Portugal, Spain, France, N. Africa, Senegal, Yemen, S. Ukraine, Turkey, Syria, Transcaucasus, C. Asia (east to N.W. China and Pakistan), Iraq, Iran, W. North America (introduced) ......................................................................................................................... 3

3(2). Stalk of internal sternite VIII (IS VIII) with tips of both lobes (TL) strongly curved inward away from apical lobe, and tips of lobes rounded or pointed, not quadrate ( Fig. 40 —Baghdad, Ashgabat, and Pul-e Charki). Length 5.1–8.4 mm. S. Ukraine, Turkey, Syria, Transcaucasus, C. Asia (east to N.W. China and Pakistan), Iraq, Iran, W. North America (introduced) ...................................................................................................... carinata (Faldermann)

- Stalk of internal sternite VIII with tip of at least one lobe not strongly curved inward away from apical lobe, and tips of lobes rounded, quadrate or pointed ( Figs. 35–36 , 40 – Lagodekhi and Ardanuc, 41 – Biskra, Tamri, Ndiol, and Perpignan) ............................................................................................................................................................ 4

4(3). Stalk of internal sternite VIII (IS VIII) with tips of lobes (TL) either not curved or curved outward towards apical lobe, and tips of lobes rounded or quadrate, not pointed ( Fig. 41 - Ndiol, Perpignan, Kom Ombo). Length 4.9–7.4 mm. Portugal, Spain, France, N. Africa, Senegal, Yemen, Iraq, W. North America (introduced) ............................... ....................................................................................................................................................... sublineata (Lucas)

- Stalk of internal sternite VIII with tip of at least one lobe curved at least slightly inward away from apical lobe, and tips of lobes rounded, quadrate or pointed ( Figs. 35–36 , 40 – Lagodekhi and Ardanuc, 41 – Biskra and Tamri). Length 4.9–8.4 mm. ( Iraq is area of range overlap) .......................... carinata (Faldermann) and sublineata (Lucas)

5(1). Width of stalk (WST) of internal sternite VIII (IS VIII) 0.36–0.57 mm and this width 0.49–0.77 times the width of the apical lobe (WAL) ( Figs. 37 , 42 ). Length 5.0–7.0 mm. S. Russia, Transcaucasus, Iran, C. Asia, N.W. and N.C. China, S.W. Mongolia, W. North America (introduced) ...................................................... carinulata (Desbrochers)

- Width of stalk of internal sternite VIII 0.22–0.33 mm and this width 0.33–0.48 times the width of apical lobe ( Figs. 38 , 43 ). Length 4.8–6.4 mm. Syria, Iran, Pakistan......................................................... meridionalis Berti & Rapilly

Figures

FIGURES 34–38. Female genitalia: internal sternite VIII (IS VIII), vaginal palpi (VP), and spermatheca (SP). 34—Diorhabda elongata, 35—D. carinata, 36—D. sublineata, 37—D. carinulata, 38—D. meridionalis. AL—apical lobe of IS VIII, LP—length vaginal palpus, PA—pointed appendage of SP, ST—stalk of IS VIII, TL—tips of lobes of IS VIII, WAL—width apical lobe of IS VIII, WLS—width lobe of stalk of IS VIII, WP—width vaginal palpus, WST—width stalk of IS VIII. Scale bar 1.0 mm.

FIGURES 39–43. Female internal sternite VIII (IS VIII). 39—Diorhabda elongata, 40—D. carinata, 41—D. sublineata, 42—D. carinulata, 43—D. meridionalis. AL—apical lobe, ST—stalk, TL—tips of lobes of stalk, *—IS VIII distinctly identifiable as D. carinata, **—IS VIII distinctly identifiable as D. sublineata. Scale bar 1.0 mm.

FIGURES 1–9. Dorsal habitus of males (dead - top row, living - bottom row) of the Diorhabda elongata species group (tamarisk beetles): 1–2—D. elongata (Mediterranean tamarisk beetle), 3–4—D. carinata (larger tamarisk beetle), 5–6—D. sublineata (subtropical tamarisk beetle), 7–8—D. carinulata (northern tamarisk beetle), 9—D. meridionalis (southern tamarisk beetle). SSV—subsutural elytral vitta, SMV—submarginal elytral vitta. Scale bar 5.0 mm.