Identification of predator–prey relationships between coccinellids and Saissetia oleae (Hemiptera: Coccidae), in olive groves, using an enzyme-linked immunosorbent assay

Abstract

A polyclonal antiserum (AS) was developed and characterized for the detection of immature stages of the black-scale, Saissetia oleae, in whole body homogenized field-collected coccinellid species, using an indirect enzyme-linked immunosorbent assay (ELISA). The indirect ELISA showed to be sensitive to the S. oleae AS, detecting a protein content between 0.118 and 0.0374 lg mL -1 . The specificity of the ELISA was tested by assaying a range of sympatric predators and alternative preys with the S. oleae AS. Coccinellid larvae obtained the highest cross-reaction and a positive-negative threshold was established at 0.674 lg mL -1 protein. A total of 1,322 coccinellids were field-collected in three olive groves located in Trás-osMontes (northeast of Portugal) by the beating technique and were analyzed to detect S. oleae proteins in their guts. Fieldcollected coccinellids which attained a S. oleae protein concentration equivalent higher than the threshold were considered as a positive reaction. In the overall collected coccinellids, 21.2% reacted positively with the S. oleae AS. Chilocorus bipustulatus and coccinellid larvae obtained the highest percentages of positives with 43.4 and 40.8%, respectively. The greatest frequency of positive responses occurred at the beginning of July, mid-August, and midOctober coinciding with the occurrence of the first, second and third instar nymphs of S. oleae, respectively. Thus, in this study, the role of coccinellids as natural control agents of S. oleae was highlighted by the number of individuals and species that tested positive for S. oleae AS.

Food Relationships

“…Crook & Sunderland 1984, Sunderland et al 1987, Hagley & Allen 1990. A double antibody method that can be scored by eye (Stuart & Greenstone 1990, Greenstone & Trowell 1994 is still used (Santos et al 2009 ).…”

Species abundance patterns of coccinellid communities associated with olive, chestnut and almond crops in north‐eastern Portugal

“…According to Giorgi et al (2009), scale insects are the primary prey of most species of these three tribes and these species are known predators of S. oleae (Argyriou & Katsoyannos, 1977;Ba M'Hamed & Chemseddine, 2001;Santos et al, 2009;Santos et al, 2010). The coccinellid community in olive was mainly dominated by the species belonging to the tribes Scymnini, Coccidulini and Chilocorini such as S. mediterraneus, R. chrysomeloides and C. bipustulatus, respectively.…”

“…The coccinellid community in olive was mainly dominated by the species belonging to the tribes Scymnini, Coccidulini and Chilocorini such as S. mediterraneus, R. chrysomeloides and C. bipustulatus, respectively. According to Giorgi et al (2009), scale insects are the primary prey of most species of these three tribes and these species are known predators of S. oleae (Argyriou & Katsoyannos, 1977;Ba M'Hamed & Chemseddine, 2001;Santos et al, 2009;Santos et al, 2010).…”

Response of coccinellid community to the dimethoate application in olive groves in Northeastern Portugal

“…C. bipustulatus) will ingest more preys and hence more insecticide than smaller species. In the treatment, the community was reduced to four dominant species, while in the control there were five, due to the significant decline of C. bipustulatus, which is one of the most important predators of Saissetia oleae (Olivier) either in the olive or citrus groves (Limón et al, 1976;Argyriou and Katsoyannos, 1977;Santos et al, 2009). Therefore, the significant reduction of this species from the treated grove can have negative consequences for the natural control of olive pests, which can increase rapidly resulting in pest outbreaks.…”