Toxoptera chaetosiphon, Qiao & Wang & Zhang, 2008

Qiao, Gexia, Wang, Jianfeng & Zhang, Guangxue, 2008, Toxoptera Koch (Hemiptera: Aphididae), a generic account, description of a new species from China, and keys to species, Zootaxa 1746, pp. 1-14 : 3-4

Key to the species of Toxoptera (Apterous viviparous females)

1. Siphunculi usually 0.4–0.7 times as long as cauda in length; abdominal tergite VIII with at least 4 hairs; antennal segment III with at least 17 hairs................................................. 2

- Siphunculi usually 0.9–1.9 times as long as cauda in length; abdominal tergite VIII with 2 hairs, occasionally 3; antennal segment III with at most 11 hairs........................................... 4

2. Dorsal hairs of body with distinct sclerotizations at base; antennal segment III with 15–18 hairs; ultimate rostral segment 1.7–1.9 times as long as second hind tarsal segment; siphunculi with 6–8 hairs; cauda with 18–28 hairs; on Camellia oleifera ............................... Toxoptera chaetosiphon sp. nov.

- Dorsal hairs of body without sclerotizations at base; antennal segment III with at least 28 hairs; ultimate rostral segment usually shorter 1.6 times than second hind tarsal segment; siphunculi without hairs, or occasionally 1 hair; cauda bearing at most 22 hairs; on various plants........................... 3

3. Base of antennal segment VI with 5–7 hairs; dorsal hairs of body shorter than widest diameter of antennal segment III; ultimate rostral segment with 2 or 3 pairs of accessory hairs.......... T. victoriae Martin

- Base of antennal segment VI with 2 hairs; dorsal hairs of body longer than widest diameter of antennal segment III; ultimate rostral segment with 1 pair of accessory hairs.......... T. odinae (van der Goot)

4. Antennal segments III–IV pale; length of hairs on antennal segment III mostly longer than widest diameter of the segment................................................... T. citricidus (Kirkaldy)

- Apical part of antennal segment III and apical part of segment IV brown; length of hairs on antennal segment III mostly shorter than widest diameter of the segment...... T. aurantii (Boyer de Fonscolombe)

(Alate viviparous females)

1. Fore wing usually with two-branched media............................................... 2

- Fore wing usually with one-branched media................... T. aurantii (Boyer de Fonscolombe)

2. Abdominal tergite VIII bearing only 2 dorsal hairs, occasionally 3 ones; siphunculi almost always longer than cauda in length.................................................. T. citricidus (Kirkaldy)

- Abdominal tergite VIII bearing 4–12 dorsal hairs; siphunculi either subequal to or shorter than cauda in length.............................................................................. 3

3. Dorsal hairs of head many, about 30-32 ones; siphunculi with 5 or 6 long and pointed hairs............................................................................ T. chaetosiphon sp.nov.

- Dorsal hairs of head fewer, less than 20 ones; siphunculi without or (rarely) with 1 hair............. 4

4. The base of antennal segment VI with 5–7 hairs; dorsal hairs of body shorter than widest diameter of antennal segment III; ultimate rostral segment with 2 or 3 pairs of accessory hairs... T. victoriae Martin

- The base of antennal segment VI with 2 hairs; dorsal hairs of body longer than widest diameter of antennal segment III; ultimate rostral segment with 1 pair of accessory hairs....... T. odinae (van der Goot)