Diomini, Gordon, 1999

Vandenberg, Natalia J. & Hanson, Paul E., 2019, Overview of the lady beetle tribe Diomini (Coleoptera: Coccinellidae) and description of a new phytophagous, silk-spinning genus from Costa Rica that induces food bodies on leaves of Piper (Piperaceae), Zootaxa 4554 (1), pp. 255-285 : 262

Key to World genera of Diomini sens. nov.

(excluding Erratodiomus and Magnodiomus ( Hyperaspidini ) ( Figs. 1–2 ))

1. Antenna with 10 antennomeres........................................................................... 2

1’. Antenna with 11 antennomeres........................................................................... 4

2. Species restricted to the New World....................................................................... 3

2’. Species occurring outside the New World............................................... Diomus Mulsant , in part

3. Female genitalia ( Fig. 5 ) with sperm duct generally long, convoluted; spermatheca vermiform throughout, lacking bulbous basal chamber. Male genitalia ( Fig. 7 ) with main tube of penis completing half to three-quarters turn or more within basal ½, somewhat spiraliform; penis bearing long or short apical flagellum; penis capsule ( Figs. 7, 11–12 ) with long slender inner arm that may be strongly procurved ( Fig. 12 ); outer arm truncated or obliterated ( Fig. 11 ), leaving large oval orifice to mark its place; some species with fragment of outer arm present but not enclosing ejaculatory duct ( Fig. 12 ). Predators on Sternorrhyncha ( Pseudococcidae , Coccidae , Diaspididae , Monophlebidae , Ortheziidae ). Larvae free-living......... Decadiomus Chapin

3’. Female genitalia ( Fig. 6 ) with sperm duct of moderate length, may be weakly sinuous; spermatheca with bulbous basal chamber. Male genitalia ( Figs. 8 , 29–32 ) with main tube of penis completing half turn within basal ½, forming fishhook shape; penis lacking apical flagellum; inner and outer arms of penis capsule ( Fig. 10 ) equally well developed, broadly consolidated into fanlike shape with sinuous distal margin; ejaculatory duct enters penis capsule through small opening in outer angle of capsule. Parasites of Piper plants that feed on food bodies. Larvae develop in silken tents constructed between leaf veins ( Figs. 40–42 ).................................................................................. Moiradiomus gen. nov.

4. Length of terminal antennomere approximately equal to twice width, longer than basal 3 antennomeres combined................................................................................................. Andrzej Ślipiński

4.’ Length of terminal antennomere ( Figs. 1a,b ) less than twice width (except in Diomus sedani ), much shorter than basal 3 antennomeres combined..................................................................................... 5

5. Pronotum with sharp submarginal carinae separating the anterolateral pronotal angles from the disc. Australia..................................................................................................... Dichaina Weise

5.’ Pronotum without submarginal carinae..................................................................... 6

6. Prosternum T-shaped, long anterior to coxal cavities (subequal to length of cavity), with short carinae not extending to apex. Female genitalia with bulbous base to spermatheca, with distally tapered sclerotized sheath in basal half of sperm duct (similar to Moiradiomus ; Fig. 6 ). Restricted to the New World........................................ Heterodiomus Brèthes

6.’ Without the above combination of characters. Distributed world wide................................ Diomus Mulsant

Figures

FIGURES 1–2. Diagrammatic representation of major diagnostic features of Diomini and Hyperaspidini: 1, Diomini: a, ventral view of head capsule showing position of maxillary palp when retracted; b, left antennal club from dorsal view when extended; c, apex of mesothoracic leg showing trimerous tarsus; d, left half of first abdominal ventrite showing configuration of postcoxal line. 2, Hyperaspidini: a, ventral view of head capsule showing position of maxillary palp when retracted (left side of image) or extended (right side of image); b, left antennal club from dorsal view when extended (left image), same rotated 90 degrees counter clockwise to show membranous sensory patches of last two antennomeres (right image); c, apex of mesothoracic leg showing cryptotetramerous tarsus; d, left half of first abdominal ventrite showing various configurations of the postcoxal line.

FIGURES 3–12. Genitalia of Diomini and Selvadiina (Hyperaspidini): 3–6, female genitalia, dorsal view (spermatheca shaded gray): 3, Selvadius nunenmacheri Gordon 1970 (Hyperaspidini: Selvadiina), showing distal end of sperm duct and spermatheca, accessory gland not shown (after Gordon 1985); 4, Erratodiomus brindisi Gordon 1999 (Hyperaspidini: Selvadiina), bursa through spermatheca, accessory gland not shown (after Gordon 1999); 5, Decadiomus hughesi Gordon & Hilburn 1990 (Diomini), bursa through spermatheca (note long convoluted sperm duct); 6, M. lachesis (Diomini) (A.g.= accessory gland); 7–12, male genitalia of Diomini, left lateral view of penis: 7, D. hughesi; 8, M. lachesis; 9, Diomus donatus Gordon (capsule); 10, M. lachesis (capsule); 11, Decadiomus bigemmeus (capsule); 12, Decadiomus liebecki (capsule)

FIGURES 29–32. Male genitalia of Moiradiomus species (a, left lateral view of phallobase; b, ventral view of phallobase; c, left lateral view of penis; d, apex of basal lobe, enlarged): 29, M. clotho; 30, M. lachesis; 31, M. atopos; 32, M. nanita.

FIGURES 40–42. Tents of Moiradiomus spp.: 40, M. lachesis on Piper lanosibracteum; 41, M. nanita on P. reticulatum; 42, M. atropos on P. friedrichsthalii.