Macrolophus pygmaeus (Heteroptera: Miridae) induces systemic resistance in tomato against Meloidogyne spp

The ability of Macrolophus pygmaeus to induce systemic resistance in susceptible and Mi1.2 resistant tomato against Meloidogyne spp. was evaluated in pot experiments. The susceptible cv. Roma and the resistant cv. Caramba were exposed to 15 M. pygmaeus nymphs per plant in mesh bags for 48h and then were inoculated with 1 second-stage juvenile (J2) of M. incognita or 3 J2 cm ^− 3 of soil of a mixed community of M. arenaria, M. hapla , and M. javanica . Tomato plants were maintained in a growth chamber during 40 days. Then the number of egg masses and eggs per plant were determined. In addition, the preference of the insect was estimated confronting nematode-infected vs. non-infected plants in a Y-tube olfactometer and in insect cages, where 10 females were released into each cage containing resistant or susceptible tomato plants. After 1, 2, 4, 24, 48 and 72h, the number of M. pygmaeus was counted as well as the offspring after 14 days. M. pygmaeus reduced the infectivity and reproduction by 37% and 53%, in the susceptible tomato inoculated with M. incognita and by 52% and 37% when inoculated with the nematode community but no effect was observed in the Mi1.2 resistant tomato irrespective of the nematode inoculum. The preference and the offspring of M. pygmaeus was not negatively affected by the nematode infection or the tomato cultivar. In conclusion, pre-induction of tomato plants with M. pygmaeus reduces RKN infectivity and reproduction in susceptible but not in Mi1.2 resistant tomato.