More is not necessarily better: the interaction between insect population density and culture age of fungus on the control of invasive weed water hyacinth

摘要: The possibilities of a positive or negative impact the biocontrol agents may have on each other as well control weed itself, inspired us to study interactions between mirid, Eccritotarsus catarinensis and phytopathogen, Acremonium zonatum, water hyacinth, Eichhornia crassipes. Observations were made disease initiation time A. zonatum grown for different durations with insect densities hyacinth. In absence mirids, lowest (3.1 days) highest (5.1 was observed using 21 42 days old culture respectively. treatments involving shortest (1.78 longest (13.22 by hyacinth 10 20 mirids/plant By 30th day, maximum percentage damage (77.9%) in treatment day fungal mirid density/plant despite initial delay initiation. This result suggests an development plant defense response due feeding delaying pathogen from establishing. Extensive studies multitrophic should be essential part pre-release assessments enhance success rates biological weeds.