Cactodera solani n. sp. (Nematoda: Heteroderidae), a new species of cyst-forming nematode parasitising tomato in Mexico

Summary A new species of cyst-forming nematode, Cactodera solani n. sp., from Mexico is described. The new species was found in a glasshouse in Mexico City parasitising tomato and common lambsquarter. This cyst nematode has light brown to almost black cysts, presents a small vulval cone with circumfenestra and morphologically it most resembles C. milleri. Cactodera solani n. sp. can be differentiated from C. milleri by having smaller cysts that are 417 (291-581) × 324 (204-505) vs 632 (515-730) × 506 (419-598) μm in size and a longer stylet in the second-stage juveniles of 25 (24-27) vs 22 (21-23) μm. Phylogenetic relationships within populations and species of Cactodera are given based on the analysis of the ITS rRNA and the partial COI gene sequences. The ITS rRNA and COI gene sequences clearly differentiated C. solani n. sp. from other Cactodera species. This new cyst-forming nematode has several generations per year and its life cycle can be completed in 49 days on tomato and in 40 days on common lambsquarter at 20-25°C.