Scymnus (Scymnus)
Creators: name: Yu, Guoyue
name: Montgomery, Michael E.
name: Yao, Defu
Publisher: name: Zenodo
Year: 2000
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Coccinellidae
Scymnus

description: 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
description: Published as part of 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), pp. 154-199 in The Coleopterists Bulletin 54 (2) on pages 169-171, DOI: 10.1649/0010-065X(2000)054[0154:LBCCFC]2.0.CO;2