Key to Platystoma species of Israel
1. Legs pale (yellow or reddish). Wing pattern pale (Figs. 32, 38).................................................. 2
- Legs dark (dark brown to black). Wing pattern dark (Figs. 30, 31, 33–37, 39)...................................... 3
2. Legs yellow. Abdomen densely and uniformly microtrichose. ♂: T5 shorter than T3 and T4 combined. Terminal filaments no more than 4 times as long as glans. ♀: T3 slightly longer than T4.................................. P. torridum n. sp.
- Legs reddish. Abdomen sparsely microtrichose. ♂: T5 longer than T3 and 4 combined. Terminal filaments more than 10 times as long as glans. ♀: T3 slightly shorter than T4............................................. P. dimidiatum Hendel
3. Gena height about 0.33 of eye height (sometimes more)....................................................... 4
- Gena height less than 0.33 of eye height.................................................................... 5
4. Ventral half of face shiny black. Ocellar triangle more than 0.33 times as long as frons (between anterior ocellus and lunule, medially), clearly setulose (Fig. 17).................................................... P. trigonum n. sp. (part)
- Ventral half of face microtrichose medially. Ocellar triangle shorter, without setulae (Fig. 12).............. P. geula n. sp.
5. Ventral half of face completely shiny black, without microtrichia................................................ 6
- Ventral half of face microtrichose at least medially........................................................... 7
6. Clypeus shiny black (Fig. 14). Abdomen entirely black, without microtrichia...................... P. nitidiventre Hendel
- Clypeus at least marginally microtrichose (Fig. 17). Abdomen densely microtrichose............. P. trigonum n. sp. (part)
7. Postocellar seta present.................................................................................8
- Postocellar seta absent................................................................................. 10
8. Wing with a distinct hyaline transverse band over crossvein DM-Cu (Fig. 30). Scutum and scutellum mostly black or just weakly microtrichose. Scutum with thin, grayish, inconspicuous longitudinal lines of microtrichia. Abdomen black, without microtrichia............................................................................ P. arcuatum Loew
- No such band on wing (although hyaline dots are present in this area). Scutum with wide, conspicuous lines of microtrichia. Abdomen microtrichose at least partially on T5..............................................................9
9. ♂: T5 shorter than T3 and T4 combined. ♀: T3 slightly longer than T4; T4 slightly longer than T5. Two spermathecae present..................................................................................... P. pubescens Loew
- ♂: T5 three times as long as T3 and T4 combined. ♀: T4 longer than T3 and longer than T5. Three spermathecae present............................................................................................. P. dalia n. sp.
10. Ventral half of face only medially microtrichose. Clypeus microtrichose only marginally (Fig. 11). ♂: T5 more than 4 times as long as T3 and T4 combined............................................................. P. elizabethae n. sp.
- Ventral half of face densely and almost completely microtrichose. Clypeus densely microtrichose (Fig. 13). ♂: T5 shorter than T3 and T4 combined................................................................... P. malatiense Hennig