2nd Place: A peek at how different oyster mushroom (Pleurotus spp.) hunting strategies can impact fungus gnat (Lycoriella spp.) management

Fungs gnats (Lycoriella spp.) are a major pest of mushroom production. Oyster mushrooms (Pleurotus spp.) are a nutritious gourmet mushroom and second most widely produced mushroom worldwide. At present, pest management strategies on oyster mushroom farms have been informed by research done in button mushroom systems (Agaricus spp). However, oyster mushrooms display carnivory towards nematodes, a biological control agent used against fungus gnats, while button mushrooms do not. This led us to our main question. Are fungus gnat loads impacted by different species of oyster mushrooms? We evaluated three species of oyster mushrooms (P. ostreatus, P. columbinus, and P. djamor). Mushrooms bioassay containers were infested with six gravid female fungus gnats that were allowed to lay eggs for 72 hours. Separate containers were used to evaluate larvae and adults. The containers were held for 4 weeks at 21 C and 80% RH in Martha fruiting chambers. The containers were destructively sampled weekly to analyze larval populations. At week three, daily numbers of adult emergence were recorded. Significant differences were found between the mushroom species, leading to our second question. Are oyster mushrooms displaying carnivory upon fungus gnat larvae? Petri dishes with PDA agar were inoculated with the three species of oyster mushroom, then infested with 5 first instar larvae. These petri plates were held for three days then number of traps were recorded. Significant differences were noted which matched the results from the first experiment. This is the first instance in which mushroom carnivory towards fungus gnats has been reported.