Biology Of Mastrus Ridibundus (Gravenhorst), A Potential Biological Control Agent For Area-Wide Management Of Cydia Pomonella (Linneaus) (Lepidoptera: Tortricidae)

The codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) is a serious pest of pome fruit crops. A natural enemy of codling moth, the larval ectoparasitoid Mastrus ridibundus (Gravenhorst) (Hymenoptera: Ichneumonidae) has been imported into South America from the USA but little is known about the biology and ecology of the wasp, knowledge that is needed to design an efficient strategy of release and establishment. Experiments were carried out to assess important traits of the biology of the parasitoid in relation to its possible use as a biocontrol agent for codling moth. When M. ridibundus females were offered larvae ranging in weight from 37 to 78 mg, they oviposited more eggs on heavier hosts. In another study, the adult wasps were offered honey, diluted honey (10%) or pollen in paired choice tests and both males and females preferred honey over the other two foods. Females preferred 10% honey over pollen, while the males showed the opposite preference. Honey-fed females lived longer than starved females. Adults died rapidly at 35 degrees C, while they lived 20 days at 25 degrees C and 12-17 days at 15 degrees C. Female wasps had on average 25 +/- 14 and 18 +/- 11 progeny at 15 and 25 degrees C, respectively, but they did not had progeny at 35 degrees C. The development time (egg to adult emergence) was on average 44 +/- 7 and 24 +/- 2 days at 15 and 25 degrees C respectively. Immature insects did not reach the adult stage at 35 degrees C.