Advisor(s)
Abstract(s)
1. Autoparasitoids are intraguild consumers that attack and kill heterospecific
and conspecific parasitoids as well as immature stages of hemipteran hosts, such
as aphids, whiteflies and soft scales. Field experiments assessing the importance of
interspecific competition between autoparasitoids and primary parasitoids, as well as
its impact on herbivore suppression, are scarcely found in the ecological literature.
2. Using field data from 40 olive orchards, this study examined the mechanisms that
regulate: (i) the interspecific competition between primary parasitoids of the genus
Metaphycus and the autoparasitoid Coccophagus lycimnia; and (ii) the density of their
shared herbivore host, the soft scale Saissetia oleae.
3. Metaphycus parasitoids used smaller hosts than C. lycimnia, yet did not outcompete
C. lycimnia. On the other hand, C. lycimnia preferred to use Metaphycus females as
secondary hosts for producing males rather than their own females. This preference
might explain why the autoparasitoid negatively affected the density of the primary
parasitoids.
4. Parasitism by the autoparasitoid C. lycimnia at the beginning of the season was
the sole variable positively related to host mortality throughout the season, showing its
greater effect on herbivore suppression.
5. In this study, an autoparasitoid, inferior at resource exploitation, was shown to
outcompete a primary parasitoid without disrupting herbivore suppression.
Description
Keywords
Coccophagus Exploitative competition Interspecific competition Intraguild predation Metaphycus Soft scales
Pedagogical Context
Citation
Marrao, Rosalina; Frago, Enric; Pereira, José A.; Tena, Alejandro (2020). An autoparasitoid wasp, inferior at resource exploitation, outcompetes primary parasitoids by using competitor females to produce males. Ecological Entomology. ISSN 0307-6946. p. 1-14