Southern root-knot nematode

Females of M. incognita are pear-shaped with no posterior protuberance. Their stylet ranges from 15 to 16 μm long, and knobs are rounded and offset. Perineal pattern is oval to rounded, typically with high dorsal arch, striae usually wavy, and lateral field absent or weakly demarcated. Males have a not offset head with an elevated labial disc without lateral lips (usually). Their stylet ranges from 23 to 26 μm long, and knobs are rounded to oval and offset. Juveniles' second stage body size ranges from 350 to 450 μm long. Their tail has a rounded tip and ranges from 43 to 65 μm in length with a 6 to 14 μm long hyaline region.

Meloidogyne incognita is widely spread around the globe and found in many different soil types.

Within the egg, the first molt occurs and a juvenile first state (J1) becomes a juvenile second stage (J2). Under favorable conditions (temperature, moisture, host stimulus) the J2 hatches, reaches and penetrates the host root. Root tips are the primary infection court. Once inside the roots, J2 migrate through cortical tissues towards the vascular zone where they establish a permanent feeding site called giant cell. At this point the nematode enlarges acquire a "sausage" shape and becomes sedentary. Three more molts occur, J2 becomes J3, J4 and then adult. M. incognita is sexually dimorphic. Females acquire a globose shaped body while males become vermiform and leave the roots. Upon maturity females lay eggs into a gelatinous mass that protect them against unfavorable environmental conditions, and the life cycle is repeated. It takes 37 days at 21 °C (70 °F) for M. incognita to complete its life cycle.