Survival Rate in Larvae (Apis mellifera L.) Additively Fed With Pleurotus ostreatus

D´ARCANGELO, V.; MOLINÉ, M. P.; MORAN GIARDINI, P.; DOMINGUEZ, E.; DAMIANI, N.; QUINTANA, S.; PAREDES, N.; GENDE, L.

Congreso; 3th International Congress on Bee Science; 2024

Honeybees are vital pollinating agents for both agricultural and natural ecosystems. However, their population are declining deu to the interplay of various stressors notably including pathogens, pesticides, and inadequate nutrition. Pleurotus ostreatus were shown to have the potential to mitigate the impact of some of these stressors. The aim of this study was to assess the short-term effects of feeding Apis mellifera larvae with different concentration of ethanol mushrooms extract in conjunction with their regular larval diet. Common oyster mushroom collected on Mar del Plata, Buenos Aires, Argentina, were used. First, Pleurotus spp. was genetically identified by semi-nested PCR with primers ITS1 and ITS4. Subsequent GenBank bioinformatic analysis revealed a 98% homology with a Pleurotus ostreatus sequence isolate CC389.After the genetic identification, ethanolic extract was prepared. 70 g of mushroom powder was dissolved in 70 ml of ethanol 50% and incubated at 25°C for 5 days. Mushroom extract was filtered and evaporated .The effect of ethanolic mushrooms extract on larval survival was assessed using a total of 144 individuals (24 per diet group). The control group was fed with a diet composed of yeast extract, glucose, fructose, royal jelly, and water , while the experimental groups received extract concentrations ranging from 80 mg/ml to 8 mg/ml instead of water. Larvae in all groups were feed and monitored daily until reaching the final stage, with their survival recorded. The survival analyses were made according to the Kaplan–Meier method. Survival curves were created in function of the number of larvae alive versus time per treatment. Differences among curves were analyzed using the Log-Rank test at a significance level of α = 0.05. Larvae fed with P.ostreatus did not exhibit a significant change in their survival proportions (Log Rank Test: Statistical: 6.447, df= 5; p= 0.265) compared to larvae fed with the control diet. The mean survival time of larvae fed with the control diet was 5.750 ± 0.239 days, while those fed with other diets had mean survival times of 5.708 ± 0.282days (8mg/ml), 6.667 ± 0.244 days (20mg/ml), 6.000 ± 0.000 days (40mg/ml), 5.333 ± 0.351 days (60mg/ml) and 5.583 ±0.237   days (80mg/ml). In conclusion, the tested mushroom extract proved to be harmeless to honeybee’s larvae