Key to species of Cactodera (modified from Subbotin et al., 2010, Cid Del Prado Vera & Subbotin 2014) 1 Cyst generally two times or more longer than wide, mean L/W ratio = 2.3................................. C. estonica - Cyst usually less than twice as long as wide, mean L/W ratio = 1.1–1.8........................................... 2 2 Eggshell punctate...................................................................................... 3 - Eggshell smooth..................................................................................... 10 3 Mean stylet length of J2s ± 26 µm......................................................................... 4 - Mean stylet length of J2s 3.5.................................................................. 7 7 Female L/W ratio <1.4, mean hyaline region of J2s <22 µm............................................... C. cacti - Female L/W ratio ± 1.4, mean hyaline region of J2s ± 22 µm................................... C. chenopodiae sp. n 8 Fenestral diam. <25 µm................................................................................ 9 - Fenestral diam. ± 25 µm....................................................................... C. galinsogae 9 Hyaline region of J2s = 4–8 µm..................................................................... C. rosae - Hyaline region of J2s = 16–23 µm.................................................................. C. evansi 10 Mean J2s tail length <40 µm........................................................................... 11 - Mean J2s tail length ± 40 µm............................................................................ 13 11 Mean J2s body length <406 µm, mean hyaline region <16 µm........................................ C. amaranthi - Mean J2s body length ± 406 µm, mean hyaline region ± 16 µm................................................. 12 12 Cyst with distinct vulval cone, J2s stylet length =21.0–23.0 µm....................................... C. torreyanae - Cyst without distinct vulval cone, J2s stylet length =23.4–25.0 µm......................................... C. salina 13 J2s stylet knobs anterior surface concave, DGO = 4.5–5.6 µm................................................. 14 - J2s stylet knobs anterior surface convex, DGO = 2.5–3.0 µm........................................... C. acnidae 14 Vulval denticles present, J2s tail length = 43–50 µm..................................................... C. weissi - Vulval denticles absent, J2s tail length = 46–60 µm................................................... C. radicale

Published as part of Feng, Yaxing, Wang, Dong, Xiao, Dongxue, Pereira, Tiago José, Xuan, Yuanhu, Wang, Yuanyuan, Liu, Xiaoyu, Chen, Lijie, Duan, Yuxi & Zhu, Xiaofeng, 2018, Cactodera chenopodiae (Nematoda: Heteroderidae), a new species of cyst nematode parasitizing common lambsquarter (Chenopodium album) in Liaoning, China, pp. 361-375 in Zootaxa 4407 (3) on page 373, DOI: 10.11646/zootaxa.4407.3.4, http://zenodo.org/record/1216588