Attraction of mononchoides longicaudatus and M. fortidens (Nematoda: Diplogasterida) towards prey and factors influencing attraction

Abstract

The attraction of Mononchoides longicaudatus and M. fortidens towards prey and factors influencing their attraction were studied on agar plates. These predators were attracted towards excised and non-excised (live) prey in response to prey secretions, attractants. Predators also responded positively towards agar containing unidentified bacteria. M. longicaudatus and M. fortidens showed preference for the prey nematodes which were tested either alive or by cutting into two pieces (excised). Hirschmanniella oryzae, Tylenchorhynchus mashhoodi and Hoplolaimus indicus attracted predators most while Longidorus SP., and Helicotylenchus indicus elicited least response from the predators. The rest of the prey nematodes attracted predators moderately. Both species of predators were also attracted towards their own individuals. Different factors viz., prey number, temperature, incubation period of prey, starvation of predators and distance of predators from prey affected attraction of the predators towards Hirschmanniella oryzae and the second stage juveniles of Meloidogyne incognita. Both predators were attracted in maximum numbers when 50 prey nematodes were incubated for 12 h in Petri-dishes, at 25°-30°. Starvation of predators increased their attraction towards prey; increase in prey distance decreased attraction.