Incidence of non-immunological defenses of soil white grubs on parasitism success of Mallophora ruficauda larva (Diptera: Asilidae).

CASTELO, M.K.; CRESPO. J.E.

Insects

MDPI

Lugar: Basel; Año: 2012 vol. 3 p. 692 - 708

2075-4450

White grubs are larvae of Coleoptera of the family Scarabaeidae. They areknown because of their intensive feeding habits on crop roots. Mallophora ruficauda(Diptera: Asilidae) is a dipteran parasitoid whose larva is a natural enemy for white grubs.This species is a solitary ectoparasitoid, where both female and larva realize different stepsin the host location process. Female place its eggs in high grasslands and then, the larvafinds and parasitizes the host in the ground. There are nine potential hosts in the area ofaction of this parasitoid; however a high preference for Cyclocephala signaticollis has beenobserved (87% of field parasitism). It is known that many insects have developeddefensive and immunological mechanisms when attacked by a parasitoid, which can bebehavioral, physiological, chemical or genetic. The objectives of this work were toinvestigate what kind of defense and non-immunological associated mechanisms the whitegrubs have against this parasitoid and to understand why M. ruficauda have such a highpreference for masked chafer grubs or Cyclocephala species. In particular, for each whitegrub species, we asked: (1) If there is a differential behavioral reaction when a parasitoidattack is simulated; (2) If body attributes of white grubs species have influence on defensebehavior, and particularly for the masked chafer C. signaticollis; and (3) Why this speciesis the most selected by M. ruficauda. It was found that behavioral defenses of white grubs would explain the parasitism pattern of M. ruficauda larvae and its preference for C. signaticollis.