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Intra‐ and interspecific interactions between aphidophagous ladybirds: the role of prey in predator coexistence
Author(s) -
Rocca Margarita,
Rizzo Estefanía,
Greco Nancy,
Sánchez Norma
Publication year - 2017
Publication title -
entomologia experimentalis et applicata
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.765
H-Index - 83
eISSN - 1570-7458
pISSN - 0013-8703
DOI - 10.1111/eea.12527
Subject(s) - intraguild predation , biology , interspecific competition , predation , cannibalism , guild , predator , intraspecific competition , larva , ecology , competition (biology) , instar , coccinellidae , habitat
Cannibalism ( CANN ) and intraguild predation ( IGP ) may provide energy and nutrients to individuals and eliminate potential competitors. These negative competitive interactions could also affect the coexistence of predatory species. The co‐occurrence of aphidophagous ladybird species in crops creates opportunities for CANN and IGP , especially when aphids become scarce. The Lotka–Volterra model predicts the coexistence of two species if intraspecific competition is stronger than interspecific interference interactions. C ycloneda sanguinea L. and E riopis connexa ( G ermar) (both C oleoptera: C occinellidae) coexist in sweet pepper crops in La Plata (Argentina) consuming mainly M yzus persicae ( S ulzer) ( H emiptera: A phididae). The present study used laboratory experiments to estimate levels of CANN and IGP by adults and larvae on eggs, and by adults on larvae, in both the presence and absence of prey (i.e., M . persicae ), to explain the effect of prey on coexistence of these two predators. Levels of CANN by C . sanguinea and E . connexa were high in the absence of aphids, and decreased when prey was present. Intraguild predation was bidirectional and asymmetric. Adults and larvae of E . connexa were more voracious IG predators of C . sanguinea than vice versa, the former being the stronger IG predator and interference competitor. E riopis connexa always won when larvae of the same instar were compared, whereas the larger larva always won when larvae were of different instars, regardless of species. In the presence of prey, CANN by both species decreased, but IGP by E . connexa on C . sanguinea remained high, suggesting that E . connexa could displace C . sanguinea via interspecific interference competition. Other factors potentially affecting the coexistence of C . sanguinea and E . connexa in sweet pepper crops are discussed.