Exema Lacordaire, 1848

Chamorro-Lacayo, Maria & Konstantinov, Alexander, 2009, Synopsis of warty leaf beetle genera of the world (Coleoptera, Chrysomelidae, Cryptocephalinae, Chlamisini), ZooKeys 8 (8), pp. 63-88 : 74-76

Exema Lacordaire

( Figs. 1 F ; 2 E ; 3 E ; 4 E ; 5 E )

Exema Lacordaire, 1848: 844 ; Type species: Chlamys intricata Kollar, 1824 , by subsequent designation of Jacoby, 1908: 278; Karren, 1966: 1 (revision of North American species north of Mexico).

Diagnosis. Length 2.18-3.45 mm, width 1.36-2.72 mm. General body shape cylindrical, widest near shoulders. Antenna serrate beyond 5 th antennomere, 3 rd, 4 th, and 5 th antennomeres slightly widened, but not dilated distally. Pronotum medially elevated, with various bumps and short ridges. Pronotal base opposite mesoscutellum (posterior pronotal lobe) concave, usually without well differentiated notch. Prosternum gradually narrowing posteriorly, at about middle abruptly narrowing to thin parallel sided ridge. Anterior margin of metasternum concave. Mesoscutellum short, transverse. Metascutellum not exposed. Elytral suture serration complete. Elytral tubercules well developed. Males with spines or spinulae on first ventral abdominal segment. Tibiae slightly curved, flattened, with sharp dorsal edge. Fore- and midtibial apices with spine in males, but lacking them in females. Tarsal claw from simple to appendiculate. Ejaculatory guide (part of internal sac of aedeagus) short, tubular, sclerotized.

Distribution. Nearctic, Neotropical, and Oriental Regions ( Monrós, 1952; Karren, 1966).

Remarks. This genus may be distinguished from Chlamisus by the following characters: males with spines or spinulae on first ventral abdominal segment; 5 th antennomere much smaller than 6 th; sutural serration of elytra complete (in Chlamisus males without spines or spinulae on first ventrite and 5 th antennomere nearly as large as 6 th; sutural serration of elytra usually incomplete); ejaculatory guide short, single, tubular, and sclerotized (elongate and paired in Chlamisus ). Lacordaire (1848) established Exema for species of Chlamisus that have a very abrupt antennal “club”, the first serrated antennomere (6 th) is much wider than 5 th.

Exema was designated a junior synonym of Chlamisus by Gressitt and Kimoto (1961) based on their study of Oriental species; however, Exema continues to be treat- ed as valid ( Karren 1966, 1972; Riley et al. 2003; Seeno and Wilcox 1982).

A total of 26 species are included in Exema ; 9 Nearctic, 7 Oriental, and 10 Neotropical ( Monrós 1952; Karren 1966).

Material examined.

Exema canadensis Pierce :

1) a. [ USA] Lakehead Md, 21.VII.06/ b. Ex. Coll. Knab/ c. Exema canadensis

Pierce det. Karren 1966.

Exema elliptica Karren :

1) a. [ USA] Houston, Tex. 25. V.49, T. L. Ward, Baccaharis halinifolia / b. Para-

type Exema elliptica Karren.

Exema variopicta Monrós :

1) a. [ Argentina] R.A. Salta, San Bernardo, 30.I.950, Willink & Monrós/ b.

1181/ c. F. Monrós Collection, 1959/ d. Exema variopicta Monrós F. Monrós

det. 1954.

Figures

Figure 1. Chlamisini, dorsal view. A, Aulacochlamys distincta (Achard). B, A. costicollis (Lacordaire. C, Carcinobaena pilula (Klug). D, Chlamisus foveolatus (Knoch). E, Diplacaspis prosternalis (Schaeffer). F, Exema elliptica Karren. G, Fulcidax coelestina (Lacordaire). H, Hymetes javana Lacordaire. I, Melittochlamys specula (Klug). Į, Neochlamisus insularis (Schaeffer). K, N. velutinus Karren. L, Pseudochlamys megalostomoides Lacordaire ♀.

Figure 2. Chlamisini, lateral view. A, Aulacochlamys distincta (Achard). B, A. costicollis (Lacordaire). C, Chlamisus foveolatus (Knoch). D, Diplacaspis prosternalis (Schaeffer). E, Exema elliptica Karren.F, Fulcidax coelestina (Lacordaire). G, Hymetes javana Lacordaire. H, Melittochlamys specula (Klug). I, Neochlamisus insularis (Schaeffer). Į, N. velutinus Karren. K, Pseudochlamys megalostomoides Lacordaire ♁. L, P. megalostomoides ♀.

Figure 3. Chlamisini, ventral view. A, Aulacochlamys costicollis (Lacordaire). B, Carcinobaena pilula (Klug). C, Chlamisus foveolatus (Knoch). D, Diplacaspis prosternalis (Schaeffer). E, Exema elliptica Karren. F, Fulcidax coelestina (Lacordaire). G, Hymetes javana Lacordaire. H, Melittochlamys specula (Klug). I, Neochlamisus insularis (Schaeffer). Į, N. velutinus Karren. K, Pseudochlamys megalostomoides Lacordaire ♁. L, P. megalostomoides ♀.

Figure 4. Chlamisini, frontal view. A, Aulacochlamys costicollis (Lacordaire). B, Carcinobaena pilula (Klug). C, Chlamisus foveolatus (Knoch). D, Diplacaspis prosternalis (Schaeffer). E, Exema elliptica Karren. F, Fulcidax coelestina (Lacordaire). G, Hymetes javana Lacordaire. H, Melittochlamys specula (Klug). I, Neochlamisus insularis (Schaeffer). J, N. velutinus Karren. K, Pseudochlamys megalostomoides Lacordaire ♁. L, P. megalostomoides ♀.

Figure 5. Chlamisini, caudal view. A, Aulacochlamys costicollis (Lacordaire). B, Carcinobaena pilula (Klug). C, Chlamisus foveolatus (Knoch). D, Diplacaspis prosternalis (Schaeffer). E, Exema elliptica Karren. F, Fulcidax coelestina (Lacordaire). G, Hymetes javana Lacordaire. H, Melittochlamys specula (Klug). I, Neochlamisus insularis (Schaeffer). Į, N. velutinus Karren. K, Pseudochlamys megalostomoides Lacordaire ♀.