Key to species of Sadoletus from Laos, Thailand and adjoining countries

1 Body length less than 3.5 mm ................................................................. S. montanellus

- Body length more than 3.5 mm ........................................................................... 2

2 Labium slightly exceeding posterior margin of prothorax, not reaching mesocoxae; corium with black area in both sexes; hemelytra with dark markings at inner angle of corium and hemelytral membrane...................................... 3

- Labium reaching at least mesocoxae; corium without black area in female; hemelytra lacking dark marking at inner angle of corium and hemelytral membrane......................................................................... 4

3 Posterior lobe of pronotum with 2 pale brown markings; hemelytral membrane with pale brown transverse marking at middle; abdominal sterna reddish brown; ovipositor straight from ventral view; posterior margin of pygophore and cuplike sclerite not fused; paramere narrow and acute at apex.................................................... S. laosensis sp. nov. - Posterior lobe of pronotum with 2 dark brown markings arranged transversely and 2 dark spots at lateral angle; hemelytral membrane with black circular marking at middle; abdominal sterna black; ovipositor strongly curved from ventral view; posterior margin of pygophore and cuplike sclerite fused together; paramere sickle-shaped at apex......... S. melasmus sp. nov.

4 Antennal segment III blackish; corium with black to dark brown area at least in male; each abdominal laterotergite in both sexes unicolored (connexiva entirely brown or black)......................................................... 5

- Antennal segment III yellowish; corium without black to dark brown area in both sexes; each abdominal laterotergite in both sexes bicolored (pale brown anteriorly and black posteriorly)................................................... 7

5 Antennal segment I black; ground color of posterior lobe of pronotum dark brown; pro- and mesofemora and tibiae entirely black......................................................................................... S. corvus

- Antennal segment I yellow; ground color of posterior lobe of pronotum brownish yellow; pro- and mesofemora and tibiae brownish yellow...................................................................................... 6

6 Posterior lobe of pronotum without dark longitudinal marking; apical half of corium without black area in female; femora and tibiae without annulations......................................................................... S. bakeri

- Posterior lobe of pronotum with dark longitudinal marking; apical half of corium black in female; femora and tibiae with annulations................................................................................... S. ryukyuensis

7 Rostrum reaching metacoxae; hemelytra not surpassing apex of abdomen; corium subhyaline; posterior margin of sternite VI sinuate; apex of paramere laminated........................................................... S. subpellucidus

- Rostrum not reaching metacoxae; hemelytra surpassing apex of abdomen; corium white; posterior margin of sternite VI concave; apex of paramere laminated......................................................................... 8

8 Antennal segment II more than twice longer than segment I; posterior lobe of pronotum more than 1.5 times longer than anterior lobe; profemur without dark markings; basal one-third of paramere twisted............................. S. valdezi

- Antennal segment II less than twice longer than segment I; posterior lobe of pronotum less than 1.3 times longer than anterior lobe; profemur with dark markings; basal one-third of paramere not twisted................................ S. validus