Predation of Orius insidiosus (Hemiptera: Anthocoridae) on Chaetosiphon fragaefolii and Aphis gossypii (Hemiptera: Aphididae) in strawberry

RIZZO ESTEFANÍA; ALONSO, MARIÁNGELES; FRANCESENA NATALIA; PASCUA, MARIANA; ROCCA MARGARITA; GRECO NANCY

Denver

Congreso; International Congress of Entomology 2017-ESA; 2017

Chaetosiphon fragaefolii and Aphis gossypii are strawberry pests in several countries. Different parasitoids attack A. gossypii in this crop, but no field parasitism has been observed on C. fragaefolii throughout the world, so other mortality factors such as predation deserve more attention for the latter. Orius insidiosus, mainly thrips predator, also feeds on aphids. We investigated the daily consumption rate of O. insidiosus fed on C. fragaefolii and A. gossypii as well as predator preference and searching time. A randomized design was used with 14 replications per treatment: species and stage of prey (nymph and adult). The experimental unit was a Petri dish, containing a strawberry leaflet over agar. A female predator and 12 aphids as prey were added. The number of prey consumed was recorded after 24 hours. O. insidiosus consumed fewer nymphs (2.66±0.15) and adults (3.72±0.14) of C. fragaefolii, than nymphs (7.29±0.20) and adults (4.64±0.19) of A. gossypii. The predation rates were: 0.29±0.05 and 0.24±0.05 on nymphs and adults of C. fragaefolii, respectively; 0.58±0.08 and 0.40±0.06 on nymphs and adults of A. gosypii, respectively. When both species were offered together, O. insidiosus preferred adults of A. gosyppii (Manly?s Index > 0.5). The searching time was significantly less for nymphs of A. gossypii than for nymphs of C. fragaefolii, and both species produced exudates. Although O. insidiosus fed on C. fragaefolii, the consumption rate was low and did not show preference for this aphid. However, this predator could complement the biological control by aphidophagous in strawberry.