Heterodiomus Brèthes, 1925

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 : 263

Heterodiomus Brèthes, 1925

Heterodiomus Brèthes 1925:155 . Type species: Heterodiomus darwini Brèthes, 1925 , by subsequent designation of Korschefsky 1931.

Diagnosis. This genus was described but not diagnosed by Brèthes (1925). The species currently included ( Gordon 1999; Gordon & González 2003) are distinguished from other members of the New World Diomini by the combination of: antennae composed of 11 antennomeres, prosternum shaped like a short stemmed T, long anterior to coxal cavities (subequal to length of cavity), intercoxal process with carinae short, not extending to anterior margin, and suture between abdominal ventrites 1 and 2 partially obliterated. Members of Heterodiomus are strongly united by the shape of the female genitalia which have a bulbous base to the spermatheca and distally tapered sclerotized sheath in the basal half of the sperm duct (= “thorn-like infundibulum” sens. Gordon 1999). Although this combination of genital characteristics does not occur in the other Diomini illustrated in Gordon (1999), the corresponding structures in most species have not yet been evaluated, and a very similar configuration ( Fig. 6 ) is found in the new genus described herein.

Figures

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)