Scymnus (Scymnus)

Yu, Guoyue, Montgomery, Michael E. & Yao, Defu, 2000, Lady Beetles (Coleoptera: Coccinellidae) From Chinese Hemlocks Infested With The Hemlock Woolly Adelgid, Adelges Tsugae Annand (Homoptera: Adelgidae), The Coleopterists Bulletin 54 (2), pp. 154-199 : 169-171

Key to Species of Scymnus (Scymnus) of China

1 Pronotum light without any dark marking ------------------------------------------------------- 2

1′ Pronotum black, or with anterior margin light, or pronotum light with black marking at base ---------------------------------------------------------------------------------------------- 8

2 Elytra yellow with M­shaped dark brown base; body length 1.8 to 2.3 mm ----------------------------------------------------------------------------- S. (Pullus) centralis Kamiya

2′ Elytra black, or with lighter apex ------------------------------------------------------------------------ 3

3 Elytra entirely black; body length 2.0 to 2.2 mm -------------------------------------------- --------------------------------------------------------------------------------- S. scapanulus Pang and Haung

3′ Elytra black with lighter apex ------------------------------------------------------------------------------- 4

4 Elytra black with less than 1/7 of apex lighter in color ----------------------------- 5

4′ Elytra black with more than 1/5 of apex lighter in color -------------------------- 6

5 Elytral apex and pronotum yellow; length of first abdominal sternum distinctly short, less than 1/4 width; postcoxal line incomplete, smooth arc; area enclosed by line finely punctate; body length 2.2 to 2.5 mm. ---------- ----------------------------------------------------------------------------------- S. notidanus Pang and Huang

5′ Elytral apex and pronotum brown, length of first abdominal sternum normal, about 1/3 width; postcoxal line complete, but last 1/3 weak, intermittent, tortuous; area enclosed by line with both fine and coarse punctutres; body length 2.4–2.7 mm ---------------------------------------- S. kabakovi Hoang

6 Prosternum with broad intercoxal carinae, length less than 2 times width at base; first three abdominal sterna with punctures on lateral area distinctly finer than on medial area; length 2.5 mm ---------- S. grammicus Yu

6′ Prosternum with narrow intercoxal carinae, length more than 2.4 times width at base; first three abdominal sterna with punctures similar on lateral and medial areas ------------------------------------------------------------------------------------------------ 7

7 First abdominal sternum with area enclosed by postcoxal line finely punctate and a few gross punctures, lateral sides coarsely punctate; tarsal claws short, 1/2 or less length of fourth tarsal segment; body length 1.8 to 2.3 mm ----------------------------------------------------------------------------- S. (Pullus) centralis Kamiya

7′ First abdominal sternum with lateral sides and area enclosed by postcoxal line finely punctate; tarsal claws very long, 2/3 length of fourth tarsal segment; body length 1.9 to 2.1 mm ------- S. dolichonychus Yu and Pang

8 Elytron black with one or two large lateral brownish spots, which may connect to sutural line, and a lighter apex ------------------------------------------------------- 9

8′ Elytra not as above, if with light spots, then spots very small ------------- 11

9 Pronotum brown with base black; body broadly oval, length 2.5 to 2.7 mm --------------------------------------------------------------------- S. manipulus Fürsch and Kreissl

9′ Pronotum black with anterio­lateral margin narrowly brown; body oval ------------------------------------------------------------------------------------------------------------------------------------------ 10

10 Elytron with one or two well­separated brown spots; median piece of tegmen distinctly thick at base; body length 2.8 to 3.0 mm ----------------------- ----------------------------------------------------------------------------------------------------- S. frontalis Fabricius

10′ Elytron with two brown spots, often joined; median piece of tegmen not distinctly thicker at base; body length 2.1 to 3.0 mm ------------------------------------ ------------------------------------------------------------------------------------------------ S. inderihensis Mulsant

11 Elytra light in color, with darker suture, lateral sides may also be dark; body length 2.2 mm --------------------------------------------------- S. nigrosuturalis Kamiya

11′ Elytra black, may have lighter apex or small brown spots --------------------- 12

12 Elytron with distinct rows of gross punctures forming sutural striae -- 13

12′ Elytron without distinct rows of gross punctures forming sutural striae ------------------------------------------------------------------------------------------------------------------------------------------ 15

13 Elytra entirely black without brown apex; body length 2.8 mm. -------------- -------------------------------------------------------------------------------------------------------- S. orientalis Mader

13′ Elytra black with brown apex ----------------------------------------------------------------------------- 14

14 Pronotum brown with base black; body length 1.9 to 2.2 mm. ----------------- ----------------------------------------------------------------------------------------------------- S. longmenicus Pang

14′ Pronotum black with narrow anterio­lateral margin light ------------------------ 15

15 Hind margin of fifth abdominal sternum distinctly emarginate in male; prosternum with parallel intercoxal carinae; body length 2.1 to 2.4 mm -------------------------------------------------------------------------------------- S. apiciflavus (Motschulsky)

15′ Hind margin of fifth abdominal sternum slightly emarginate in male; prosternal carinae distinctly convergent anteriorly; body length 2.1 to 2.2 mm ---------------------------------------------------------------------------------- S. dissolobus Pang and Huang

16 Elytral punctures nearly equal to those on pronotum -------------------------------- 17

16′ Elytral punctures much coarser than those on pronotum ------------------------- 19

17 Pronotum and elytra entirely black, area surrounded by postcoxal line finely punctate at anterior half and smooth at posterior half; body large, length 3.8 mm ----------------------------------------------- S. decemmaculatus Yu and Pang

17′ Pronotum yellow and subtriangular black spot at base; elytra black with apex dark brown; area surrounded by postcoxal line coarsely punctate ------------------------------------------------------------------------------------------------------------------------------------------ 18

18 First abdominal sternum widely smooth along postcoxal line, medial area with finer punctures than lateral area; body length 2.0 to 2.7 mm ------------ -------------------------------------------------------------------------------------------------------------- S. bifurcatus Yu

18′ First abdominal sternum narrowly smooth along postcoxal line, medial area with punctures similar to lateral area; body length 1.9 to 2.1 mm ------------------------------------------------------------------------------------------------------------ S. crinitus Fürsch

19 Elytra entirely black ------------------------------------------------------------------------------------------------ 23

19′ Elytra black with lighter apex, may have spots ------------------------------------------- 20

20 Elytra black with apical 1/6 or more brown ------------------------------------------------- 21

20′ Elytra black with narrow brown margin at apex, distinctly less than 1/6 elytral length -------------------------------------------------------------------------------------------------------------- 22

21 Elytron black often with 3 brown spots, but spots may be merged or missing; apical 1/3 of elytra brown, margin with black strongly arched; body length 2.2 to 2.5 mm. ---------------------------------------------------- S. najaformis Yu

21′ Elytron black without any spots; apical 1/6 brown, margin with black sinuous; body length 2.8 mm ----------------------- S. unciformis Yu , new species

22 Apex of sipho with a hook­shaped appendix; body length 2.2 to 2.5 mm. ------------------------------------------------------------------------------------------------------ S. folchinii Canepari

22′ Apex of sipho contracted at preapex, without distinct appendix; body length 2.1 to 2.3 mm --------------------------------------------- S. axinoides Ren and Pang

23 Pronotum black except for lighter anterior corners and lateral margins; body length 2.0 mm ------------------------------------- S. paracrinitus Yu , new species

23′ Pronotum yellow or brown with a black, triangular basal marking ----- 24

24 Postcoxal line of first abdominal sternum strongly arched; middle of sipho smooth without appendix; body length 2.0 to 2.2 mm. --------------------------------- --------------------------------------------------------------------------------- S. scapanulus Pang and Huang

24′ Postcoxal line of first abdominal sternum extending to lateral side evenly; middle of sipho with two fin­shaped appendices; body length 2.4 to 2.6 mm --------------------------------------------------------------------------- S. dipterydicus Ren and Pang