Larval stages of Heterodera avenae woll., H. cajani koshy and H. mothi Khan and Husain

The larval stages of Heterodera avenae, H. cajani and H. mothi have been compared. The second, third and fourth stage larvae of these species can be differentiated on the basis of body length, values of a, band c; shape of lip annule, spear size, spear knobs; lateral lines, opening of dorsal oesophageal gland and tail size. The development of fourth stage male larvae of H. avenae is different from other species because the posterior end of larvae remains attached to the third cuticle and larvae increase in length from anterior end, whereas in other species this larval stage gets completely detached itself from the cuticle at both the ends.