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Brownheaded leafrollers - Mortality |
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| No comprehensive analysis has been carried out of the importance and role of mortality factors affecting brownheaded leafroller populations in apple orchards in New Zealand. The following Table summarises the limited results of several studies on apples. | |
| Mortality factor | Mortality | Causes |
| Unfulfilled fecundity | ?Unknown | Mainly weather, host plant, larval density |
| Infertility | <1% | |
| Inviability | 2.5% | Weather |
| Egg predation/parasitism | 3-12% | Predatory bugs, Anystis baccarum, Trichogramma spp. |
| Predation and losses of young larvae (between hatching and larval establishment on apple trees) | 88-94% | Spiders, earwigs, predatory bugs, Anystis baccarum, emigration, weather, birds |
| Parasitism of larvae, all species | ?Unknown | Complex of parasitoids |
| Larval/pupal parasitism | ?Unknown | Pales spp. and complex of introduced parasitoids. |
| Emigration
from orchards - probably minor Immigration to orchards - probably major |
High populations on nearby host plants causing immigration into low resident density in orchards |