Calligrapha (Zygogramma)

Clark, Shawn M., Douglas, Hume B. & Cavan, Daniel J., 2024, Notes on Calligrapha Chevrolat (Subgenus Zygogramma Chevrolat) and Tritaenia Motschulsky (Coleoptera: Chrysomelidae: Chrysomelinae), The Coleopterists Bulletin 78 (2), pp. 281-295 : 289-290

KEY TO SPECIES OF ADULT CALLIGRAPHA (ZYGOGRAMMA) FROM CANADA AND UNITED STATES

1. Lateral, impunctate interstria of elytron, between outermost row of punctures and epipleural ridge, dark in distal half, contrasting with pale basal half; epipleuron of similar dark color .................................................... 2

1′. Lateral, impunctate interstria of elytron pale for most or entire length of elytron; epipleuron dark or pale ........................................... 4

2. Discal dark markings of elytra consisting of straight or evenly arcuate stripes of approximately even width, without isolated spots ( Fig. 1D ); pronotum evenly convex from right lateral edge to left lateral edge, without depression in sublateral area; pronotum without area of very coarse punctures (largest punctures not wider than narrow part of antennomere 3); anterolateral areas of pronotum usually paler than head .......................... .................................. C. continua (LeConte)

2′. Elytral markings irregular in shape, including isolated spots and/or stripes with abrupt curves and transverse portions ( Figs. 1K, L ); pronotum usually with large, shallow depression in area of very coarse sublateral punctures (largest punctures wider than wide part of antennomere 3); anterolateral areas of pronotum usually not paler than head ......... 3

3. Head, prothorax, and at least anterior legs usually paler than dark brown mesothorax, metathorax, abdomen, and elytral maculae; humeral marking usually not connected to sutural marking; dark areas without bluish tint; habitus as in Fig. 1K .............................. ........................................... C. piceicollis Stål

3′. Head, thorax, abdomen, and elytral maculae black, with faint blue tint in many specimens (or, in paler specimens, at least posterior part of prothorax near midline black); humeral marking often extending postero-mesad, connecting with sutural marking near elytral mid-length; habitus as in Fig. 1L .................. ..................................... C. signatipennis Stål

4. Lateral, impunctate interstria of elytron, adjacent to epipleuron, with elongate dark area near mid-length; discal elytral dark markings consisting of abruptly sinuous stripe, plus small maculae; epipleuron dark; habitus as in Fig. 1J .................................... C. opifera Stål

4′. Lateral, impunctate interstria of elytron entirely pale; discal elytral markings and epipleuron variable...................................... 5

5. Epipleuron darker than pale areas of elytral disc; elytral dark markings, including sutural and median stripes, sinuous, irregular in width; many small spots also present on elytra; habitus as in Fig. 1A ............................... ................................ C. arizonica (Schaeffer)

5′. If epipleuron darker than pale areas of elytral disc, then elytral markings consisting of dark stripes of regular width and at most one or two small spots............................................ 6

6. Pronotum, at least in anterolateral areas and along anterior edge, pale, like pale areas of elytra............................................................ 7

6′. Pronotum much darker than pale elytral areas, at most with anterolateral corners only vaguely paler than rest of pronotum ........... 9

7. Dark markings including multiple stripes on each elytron, regularly shaped, extending most of elytral length; stripes unusually obsolete or interrupted, but then position of stripes indicated by punctures; isolated spots often present on lateral and distal declivities of elytron; pronotum clearly bicolored in most specimens, with darker areas distinct ...8

7′. Elytra without stripes or with only subsutural dark stripe; other dark markings consisting of numerous, mostly elongate but short maculae, each circumscribed by punctures; short elytral maculae not confined to declivities; pronotal dark markings variable, weak or absent in some specimens; habitus as in Fig. 1C .............................. C. pallida (Bland)

8. All dark elytral stripes distally separate from each other, usually clearly visible (except sutural stripe sometimes obsolete); lateral-most stripe short, joined basally, on humerus with adjacent stripe, usually represented distally by isolated spot near mid-length of elytron; epipleuron usually darker than pale areas of elytral disc; habitus as in Fig. 1G .................. ........................ C. exclamationis (Fabricius)

8′. Elytra with dark sutural and subsutural stripes normally confluent with each other in posterior half, sometimes obsolete (but their positions then outlined by punctures); third and fourth stripes usually joined with each other on elytral declivity; lateral-most stripe sometimes short (as above), sometimes represented by single, isolated spot, but not represented by both short stripe and isolated spot near mid-length of elytron; epipleuron not darker than pale areas of elytral disc; habitus as in Fig. 1B .............. C. conjuncta (Rogers)

9. All elytral stripes regular in shape, extending most of elytral length (lateral-most stripe, present in other species, absent); median and sublateral stripes sometimes coalescing to form combined, broad stripe; habitus as in Figs. 1M, N ............ C. suturalis (Fabricius)

9′. At least lateral-most elytral stripe shortened or represented by only isolated spots ........ 10

10. Elytron with sutural and subsutural dark stripes joined together along at least apical third; remaining elytral markings either very abruptly curved and intertwined with each other, or composed of numerous isolated spots ...........................................................11

10′. Sutural and subsutural dark stripes separate from each other, except sometimes at extreme apex; remaining elytral markings few in number and more or less vittate, although often interrupted, shortened, or obsolete... 13

11. Apart from combined sutural and subsutural dark stripes, other elytral markings consisting of many isolated spots; habitus as in Fig. 1F ................................... C. estriata (Schaeffer)

11′. Dark areas of each elytron including winding, elongate marking extending most of elytral length ............................................. 12

12. Dark areas of body (e.g., pronotum) redbrown; elytron with epipleural ridge dark brown; elytron with subsutural stripe usually separate from sutural stripe for at least half length; habitus as in Fig. 1O ......................... ...................................... C. tortuosa (Rogers)

12′. Dark areas of body black or nearly so, often with slight brassy or golden green reflections; epipleural ridge yellow; subsutural and sutural stripes confluent with each other along distal two-thirds; habitus as in Fig. 1I ........... ............................................... C. malvae Stål

13. Elytral dark stripes (or normally interrupt- ed remnants) often only outlined with dark color, with interior areas of markings yellow (unusually, elytral stripes uninterrupted, with dark interior areas); subsutural stripe separated from stripe on its lateral side by distance less than twice width of each stripe; lateral-most stripe usually represented by only isolated dots, only unusually including short stripe joined on humerus with preceding stripe; habitus as in Fig. 1H .................... ................................ C. heterothecae (Linell)

13′. Elytral dark markings solid, not only outlined with black; subsutural stripe separated from following stripe by distance much greater than twice width of each stripe; lateral-most stripe short, confluent on humerus with preceding stripe, usually followed distally by one or two isolated spots; habitus as in Fig. 1E ...................................... C. disrupta (Rogers)

Figures

Fig. 1. Dorsal habitus of Calligrapha (Zygogramma) and Tritaenia species. A) C. (Z.) arizonica, B) C. (Z.) conjuncta, C) C. (Z.) pallida, D) C. (Z.) continua, E) C. (Z.) disrupta, F) C. (Z.) estriata, G) C. (Z.) exclamationis, H) C. (Z.) heterothecae, I) C. (Z.) malvae, J) C. (Z.) opifera, K) C. (Z.) piceicollis, L) C. (Z.) signatipennis, M) C. (Z.) suturalis, N) C. (Z.) suturalis, O) C. (Z.) tortuosa, P) T.(Ithygramma) cognata, Q) T.(Tritaenia) quinquevirgata. Scale bars = 2 mm.