Effect of alternative prey on development and consumption of Orius insidiosus (Say) (Hemiptera, Anthocoridae) and oviposition behavior on chrysantemum cultivars

This work aimed to evaluate the development time and the consumption of Orius insidiosus (Say, 1832) feeding on Aphis gossypii Glover, 1877 as well as its oviposition behavior on two chrysanthemum cut cultivars. The trials were conducted in climatic chamber at 25 ± 1 deg C, RH 70 ± 10% and 12h photo phase. Nymphs of the predator, less than 24h old, were kept individually in petri dishes (5cm) with 20 nymphs of A. gossypii (first, second and third instar) on leaf disc (4 cm) of each cultivar ('White Reagan' and 'Yellow Snowdon') in a layer of agar-water (1%). Petiole of each chrysanthemum cultivar as oviposition substrate was evaluated and the females were feeding on eggs of Anagasta kuehniella (Zeller, 1879). The predator complete its development feeding on A. gossypii kept in both cultivars. The duration of nymphal phase of O. insidiosus were 21.1 and 18.3 days on 'White Reagan' and 'Yellow Snowdon', respectively. The consumption of the females of O. insidiosus was higher (P<0.01) on A. gossypii in 'White Reagan' (2.63 nymphs) compared to the consumption in 'Yellow Snowdon' (0.7 nymphs). Females of O. insidiosus oviposited in petiole of both cultivars with 22.5 and 23.3 eggs/female on 'White Reagan' and 'Yellow Snowdon', respectively. Release of O. insidiosus on chrysanthemum crops could be important to decrease the A. gossypii population, as the predator completes its development having this aphid as prey, and the chrysanthemum cultivars offer conditions to colonization and establishment of O. insidiosus. (author)