Dryocosmus, Giraud, 1859

Cerasa, Giuliano, Verde, Gabriella Lo, Caleca, Virgilio, Massa, Bruno, Nicholls, James A. & Melika, George, 2020, Description of the sexual generation of Dryocosmus destefanii (Hymenoptera: Cynipidae: Cynipini) and disclosure of its life cycle, Zootaxa 4742 (2), pp. 359-374 : 362-363

Key to the Western Palaearctic Dryocosmus species

1 Females............................................................................................. 2

- Males............................................................................................. 11

2 Mesoscutellum entirely smooth and glossy or at least the central area of mesoscutellar disc up to the area proximal to the foveae always smooth and glossy; at most a very narrow strip laterally and posteriorly along emarginated edges sculptured....... 3

- Mesoscutellum entirely and uniformly coriaceous or rugose.................................................... 6

3 Scutellar foveae more or less distinct, separated by distinct median carina ( Fig. 36 )................................. 4

- Scutellar foveae absent, anteriorly only a transverse impression present ( Fig. 38 )........................... D. tavakolii

4 All metasomal tergites without micropunctures, mesopleuron without striae marking transepisternal line; axillula delicately coriaceous........................................................................................... 5

- All metasomal tergites, except 2nd, with distinct uniform dense micropunctures, mesopleuron with very few delicate indistinct striae marking transepisternal line not surpassing 1/2 of mesopleuron length; axillula strongly sculptured especially at posterior end ( Fig. 15 ); hindwing with narrow infuscate stripe on the anterior margin, starting from hamuli and extending along the margin for more than 3/4 of its length ( Fig. 24 )................................................. D. destefanii , sexual

5 Pedicel and scape 1.5–1.7 times broader than flagellomeres ( Fig. 37 ); all flagellomeres nearly of the same width; scutellar foveae subtriangular, separated by wide and short median carina, with diverging sides, this short median carina occupies 1/8 of mesoscutellum length ( Fig. 36 )......................................................... D. destefanii , asexual

- Pedicel and scape at least 2.2–2.5 times broader than flagellomeres; flagellomeres towards the apex broadened, F8–F12 at least 2.0 times as broad as preceding flagellomeres ( Fig. 39 ); scutellar foveae subquadrangular, separated by distinct narrow median carina with non-diverging sides, this long median carina occupies 1/4 of mesoscutellum length ( Fig. 40 )...... D. caspiensis

6 Gena not or inconspicuously broadened behind eye, not visible in anterior view.................................... 7

- Gena strongly broadened behind eye, easily visible in anterior view ( Fig. 41 ).................... D. cerriphilus , asexual

7 Entire body reddish brown to light yellowish brown.......................................................... 8

- Entire body black or brownish black...................................................................... 9

8 Eye large, silvery, transfacial distance nearly equal to height of eye, body uniformly light brown to yellowish...... D. mikoi

- Eye small, black, transfacial distance longer than height of eye; head and mesosoma reddish brown, metasoma darker ( Fig. 42 )........................................................................................ D. jungalii

9 All metasomal tergites, except 2nd, with distinct uniform dense micropunctures; mesoscutellar disk reaching mesoscutum in the center, very narrow anterior scutellar depression present only on both sides of this attachment point ( Fig. 43 )................................................................................................... D. kuriphilus

- All metasomal tergites, including 2nd, without micropunctures; mesoscutellar disk never reaching mesoscutum; broad complete transverse anterior scutellar depression present across mesoscutellum...................................... 10

10 Mesoscutellum distinctly longer than broad, rugose to coriaceous, elongate, sides nearly parallel, with narrow median carina reaching mesoscutum and dividing medially smooth glossy broad anterior scutellar depression; body usually black or dark brown........................................................................................ D. mayri

- Mesoscutellum as long as broad or only slightly longer than broad, dull rugose, without median carina, with rugose anteriorscutellar depression; body usually brown to reddish brown...................................... D. cerriphilus , sexual

11 Body entirely yellow, except dark brown or black head...................................................... 12

- Body black or dark brown............................................................................. 13

12 Mesoscutellum smooth, glossy, without sculpture; head black.......................................... D. jungalii

- Mesoscutellum uniformly coriaceous, head brown..................................................... D. mikoi

13 Mesoscutellar disk alutaceous or very delicately coriaceous; mesopleuron uniformly smooth glossy or delicately alutaceous. .................................................................................................. 14

- Mesoscutellar disk uniformly coriaceous to rugose; mesopleuron smooth glossy, with delicate longitudinal striae in medioanterior part................................................................................... D. cerriphilus

14 Diameter of lateral ocellus about equal to or slightly greater than OOL ( Fig. 30 ); all metasomal tergites, except 2nd, with distinct uniform dense micropunctures; malar space very short, 0.11-0.12 times as long as height of eye ( Fig. 28 ); metasomal petiole longer than wide; hindwing with narrow infuscate stripe on the anterior margin, starting from hamuli and extending along the margin for more than 3/4 of its length ( Fig. 29 )............................................. D. destefanii

- Diameter of lateral ocellus at least twice OOL; all metasomal tergites without micropunctures; malar space extremely short, 0.06-0.07 times as long as height of eye ( Fig. 27 ); metasomal petiole as long as broad......................... D. mayri

Figures

FIGURES 36–43. 36–37, Dryocosmus destefanii asexual female: 36, mesoscutellum (dorsal view), 37, antenna; 38, D. tavakolii, mesoscutellum, dorsal view; 39–40, D. caspiensis, asexual female: 39, antenna, 40, mesosoma, dorsal view; 41, D. cerriphilus, asexual female, head, anterior view; 42, D. jungalii, female, head, anterior view; 43, D. kuriphilus, mesoscutellum, dorsal view.

FIGURES 8–16. Dryocosmus destefanii, sexual generation: 8, head, female (front view); 9, head, female (posterior view); 10, head, female (lateral view); 11, first antennal segments, male, the arrow shows the first flagellomere, excavated in basal half; 12, antenna, female; 13, mesosoma, female (dorsal view); 14, head, female (dorsal view); 15, mesosoma, female (lateral view); 16, mesosoma, female (latero-ventral view).

FIGURES 17–26. Dryocosmus destefanii, sexual generation, female: 17, pronotum, (anterodorsal view); 18, mesosoma (lateroventral view); 19, posterodorsal view of mesosoma; 20, mesosoma (ventral view); 21, metascutellum and propodeum, posterodorsal view; 22, forewing; 23, metasoma (lateral view); 24, hindwing, the arrows show the infuscation on the anterior margin; 25, ventral spine of hypopygium (lateral view); 26, ventral spine of hypopygium, ventral view.

FIGURES 27–35. 27, Dryocosmus mayri sexual generation, head, male (front view); 28–35, D. destefanii, sexual generation: 28, head, male (front view); 29, hindwing, male, the arrows show the infuscation on the anterior margin; 30, head, male (dorsal view); 31, metasoma, male (lateral view); 32, foreleg, female, the arrow shows the magnification of simple tarsal claws; 33, metasoma, male (ventral view); 34, mid tarsus and mid tibial spur, female; 35, hind tarsus and hind tibial spur, female.