Laboratory trials were carried out in order to determine biological traits and predation activity of four Orius species - the paleartic Orius majusculus (Reuter), O. laevigatus (Fieber) and O. niger Wolff and the neartic O. insidiosus (Say) - using Ephestia kuehniella (Zeller) eggs and Frankliniella occidentalis (Pergande) adults as prey. The intrinsic rates of natural increase (rm) were calculated for the four Orius species on the two preys and the rm was 0.094 (on F. occidentalis) and 0.068 (on E. kuehniella) for O. laevigatus, 0.097 (on F. occidentalis) and 0.080 (on E. kuehniella) for O. majusculus, 0.116 (on F. occidentalis) and 0.101 (on E. kuehniella) for O. insidiosus, 0.035 (on F. occidentalis) and −0.003 (on E. kuehniella) for O. niger, respectively. The kill-rate (km), a parameter that we designed to take into account the age-specific predation both during the nymphal and the adult stages, was calculated in order to compare the predation capacity of the Orius species. The km on the prey species F. occidentalis was 0.23 for O. laevigatus, 0.21 for O. majusculus, 0.25 for O. insidiosus, 0.19 for O. niger, respectively. In all species, the females that fed on E. kuehniella showed greater longevity and higher reproduction than those fed on F. occidentalis. O. niger was the most difficult species to rear, both during immature stages and as adults. O. niger showed a high preimaginal mortality, high consumption of E. kuehniella eggs, low predation of F. occidentalis adults, long development time, low fecundity and low rm on both preys. The development time of O. majusculus and O. laevigatus was similar when feeding on F. occidentalis. The total consumption of E. kuehniella eggs was significantly higher for O. laevigatus. O. majusculus showed a higher fecundity compared to O. laevigatus when fed E. kuehniella eggs, but no differences were recorded when both species were fed F. occidentalis adults. Most data for the neartic O. insidiosus were similar to those of O. laevigatus and O. majusculus. Performance of O. laevigatus was best at 26 °C. A mass-rearing method for O. laevigatus was developed and the main quality control parameters for this species were defined.
Biological traits and predation capacity of four Orius species on two prey species
BURGIO, GIOVANNI
2004
Abstract
Laboratory trials were carried out in order to determine biological traits and predation activity of four Orius species - the paleartic Orius majusculus (Reuter), O. laevigatus (Fieber) and O. niger Wolff and the neartic O. insidiosus (Say) - using Ephestia kuehniella (Zeller) eggs and Frankliniella occidentalis (Pergande) adults as prey. The intrinsic rates of natural increase (rm) were calculated for the four Orius species on the two preys and the rm was 0.094 (on F. occidentalis) and 0.068 (on E. kuehniella) for O. laevigatus, 0.097 (on F. occidentalis) and 0.080 (on E. kuehniella) for O. majusculus, 0.116 (on F. occidentalis) and 0.101 (on E. kuehniella) for O. insidiosus, 0.035 (on F. occidentalis) and −0.003 (on E. kuehniella) for O. niger, respectively. The kill-rate (km), a parameter that we designed to take into account the age-specific predation both during the nymphal and the adult stages, was calculated in order to compare the predation capacity of the Orius species. The km on the prey species F. occidentalis was 0.23 for O. laevigatus, 0.21 for O. majusculus, 0.25 for O. insidiosus, 0.19 for O. niger, respectively. In all species, the females that fed on E. kuehniella showed greater longevity and higher reproduction than those fed on F. occidentalis. O. niger was the most difficult species to rear, both during immature stages and as adults. O. niger showed a high preimaginal mortality, high consumption of E. kuehniella eggs, low predation of F. occidentalis adults, long development time, low fecundity and low rm on both preys. The development time of O. majusculus and O. laevigatus was similar when feeding on F. occidentalis. The total consumption of E. kuehniella eggs was significantly higher for O. laevigatus. O. majusculus showed a higher fecundity compared to O. laevigatus when fed E. kuehniella eggs, but no differences were recorded when both species were fed F. occidentalis adults. Most data for the neartic O. insidiosus were similar to those of O. laevigatus and O. majusculus. Performance of O. laevigatus was best at 26 °C. A mass-rearing method for O. laevigatus was developed and the main quality control parameters for this species were defined.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
