aphid

Stekolshchikov, Andrey V., 2022, A contribution to the aphid fauna (Hemiptera, Aphidoidea) of Republic of Mali, Zootaxa 5183 (1), pp. 423-438 : 431-432

A key to the aphid species of Republic of Mali

1. Cauda very broadly rounded, less than 0.5 times as long as its basal width. Siphunculi as short cones. Antennae 3-, 4-, 5- or 6-segmented, with processus terminalis less than 1 times as long as base of last antennal segment. Eyes of apterae threefacetted............................................................................................. 2

- Cauda triangular, tongue- or finger-shaped, much more than 0.5 times as long as its basal width. Siphunculi conic, subcylindrical or tubular. Antennae 5- or 6-segmented, with processus terminalis more or less than 1 times as long as base of last antennal segment. Eyes of apterae multifacetted................................................................. .... 3

2. Abdominal tergite VII without processes. All legs of apterae with one tarsal segment. Forewing veins of alatae isn’t thickly black-bordered. On roots of different Poaceae ........... Tetraneura (Tetraneurella) fusiformis fusiformis Matsumura, 1917

- Abdominal tergite VII with a pair of long, pointed backwardly-directed processes. All legs of apterae with two tarsal segment. Alatae have thickly black-bordered forewing veins. On young shoots, leaves and stems of woody Euphorbiaceae or Phyllanthaceae , and often but accidentaly alatae on plants of another families... Schoutedenia ralumensis Rübsaamen 1905

3. Lateral abdominal tubercles on segment VII placed posterior and level with or dorsal to the spiracle, i.e. on or dorsal to an imaginary line drawn through the abdominal spiracles........................................................ 4

- Lateral abdominal tubercles on segment VII situated posterior and ventral to the spiracle on that segment, i.e. on the outside of an imaginary line running through the abdominal spiracles..................................................... 6

4. Siphunculi as long as or shorter than the cauda. On Sorghum , also sometime can colonizing Saccharum and Zea mays ............................................................................ .. Melanaphis sorghi ( Theobald, 1904)

- Siphunculi longer than the cauda......................................................................... 5

5. Processus terminalis of 6th antennal segment 4.5–8.3 times as long as base of segment. Cauda pale. Hindwing with only 1 oblique vein. On Poaceae ................................................. Hysteroneura setariae ( Thomas, 1878)

- Processus terminalis of 6th antennal segment 1.7–2.8 times as long as base of segment. Cauda pigmented, brownish. Hindwing with 2 oblique veins. On Poaceae ............................................. Rhopalosiphum maidis ( Fitch, 1856)

6. Processus terminalis shorter than base. Cauda longer than the siphunculi. On Peganum , Calligonum , Calotropis and others, mostly xerophytic plants..................................................... Brachyunguis harmalae Das, 1918

- Processus terminalis longer than base. Cauda shorter than the siphunculi....................................... ...7

7. Abdomen with dark transverse bands on all tergites, usually a solid dark shield, sometimes reduced (in alatae), but present at least on the tergites IV and V. Cauda black like siphunculi, bearing 4–9 setae. On different plants, but with a strong preference for Fabaceae .................................................................. Aphis craccivora Koch, 1854

- Abdomen in apterae lacking such dorsal pigmentation on tergites I–V, dark transverse bands may be present on tergites VII and VIII, sometimes on VI as well; in alatae sometimes with small transverse bands on some or all tergites, but never with any kind of a solid dark shield. Cauda pale, dusky or black, bearing 4–20 setae............................................ 8

8. Siphunculi of apterae mainly pale or dusky, only dark towards apices, cauda pale. Fifth antennal segment of alatae with 0– 2 secondary rhinaria. Processus terminalis 1.2–3.5 times as long as base of last antennal segment. Cauda with 4–12 setae. Polyphagous................................................................ Aphis nasturtii Kaltenbach, 1843

- Siphunculi of apterae dark, cauda pale, dusky or dark. Fifth antennal segment of alatae without secondary rhinaria. Processus terminalis 2.0–4.8 times as long as base of last antennal segment. Cauda with 4–20 setae............................. 9

9. Hind tibiae mainly dark. Cauda dark, with 8–20 setae. Processus terminalis 3.0–4.8 times as long as base of last antennal segment. On different plants, but with a strong preference for Asclepiadaceae and Apocynaceae .......................................................................................... .. Aphis nerii Boyer de Fonscolombe, 1841

- Hind tibiae pale for more than half of length. Cauda pale, dusky or dark, with 4–8 setae. Processus terminalis 2.0–3.5 times as long as base of last antennal segment. Very widly polyphagous......... .... ................ Aphis gossypii Glover, 1877