BioControl (2020) 65, 713-725

Fateme Ranjbar, J.P. Michaud, M. Amin Jalali and Mahdi Ziaaddini (2020)
Intraguild predation between two lady beetle predators is more sensitive to density than species of extraguild prey
BioControl 65 (6), 713-725
Abstract: Oenopia conglobata (Linnaeus) and Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae) are important predators of the pistachio psyllid, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae), a key pest of pistachio. The abundance of M. sexmaculatus has recently increased in pistachio orchards, while that of O. conglobata has declined. We designed laboratory experiments to (1) evaluate the potential for intraguild predation (IGP) between these two species, (2) detect any possible asymmetries in IGP interactions, and (3) characterize the sensitivity of IGP to varying densities of two extraguild (EG) prey, A. pistaciae and Aphis gossypii Glover (Hemiptera: Aphididae). We measured rates of IGP by fourth instar larvae and female adults (both starved for 12 h) on vulnerable immature life stages of the other species (eggs, first, and second instar larvae). IG and EG prey consumption were tallied after 12 h. All factors influenced rates of IGP, but species of IG predator, and life stage and density of EG prey, contributed the most variance. IGP decreased parabolically with increasing prey densities. IGP on eggs was higher than on first instars, which was higher than on second instars, suggesting palatability declined in later life stages. The larger M. sexmaculatus exhibited higher voracity than the smaller O. conglobata in both predation and IGP. Both species consumed more A. pistaciae than A. gossypii in all treatments, which may reflect either lower handling time or lower food value per prey.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): J.P. Michaud, M. Amin Jalali

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Agonoscena pistaciae	Pistachio nut and relatives (Pistacia)
Cheilomenes sexmaculata (predator)	Agonoscena pistaciae
Oenopia conglobata (predator)	Agonoscena pistaciae