Phoretic relationship between the myceliophagous mite Microdispus lambi (Acari: Microdispidae) and mushroom flies in Spanish crops

We studied the role played by the phorid Megaselia halterata (Wood) and the sciarid Lycoriella auripila (Winnertz) in the phoretic dispersion of the myceliophagous mite Microdispus lambi (Acari: Pygmephoridae). Twenty‐four crops were monitored during 18 months in commercial mushroom farms in Castilla‐La Mancha (Spain). Adults of both species were collected weekly and the mites they carried were counted and identified. Both phorids (19.6%) and sciarids (4.4%) carried the mite M. lambi. The calculated load of each was 3.4 M. lambi mites per phorid and 1.9 per sciarid. The same percentage of male and female phorid was used as vector, but the load was slightly higher for females (1.86 mites per female compared with1.48 mites per male). A mean of 7.2% of the phorids examined in winter were vectors of M. lambi, while in spring and autumn of the first year the average was more than 22%. The mean load did not vary significantly between seasons. Inside the mushroom farms, less than 10% of a small initial population of phorids carried mites (less than two mites per phorid). As the cycle progressed, more than 35% of a larger population of emerging flies did so (average 3.5 mites per phorid vector). At the end of the growth cycle, the flies may fly off to colonise nearby farms, favouring the propagation of M. lambi from infested to uninfested crops. Megaselia halterata is the principal vector of M. lambi in the mushroom farms of Castilla‐La Mancha due to their high numbers, the high percentage carrying mites and the number of M. lambi they carry.info:eu-repo/semantics/acceptedVersio

Cultivation of Agaricus bitorquis mushroom as an strategy for the Integrated Pest Management of the myceliophagous mite Microdispus lambi

BACKGROUND: The phorid fly Megaselia halterata Winnertz (Diptera: Phoridae) is the principal vector of Microdispus lambi (Acari: Pygmephoroidea) in Spanish Agaricus bisporus Lange (Imbach) mushroom farms. This myceliophagous mite does not appear to be a pest in Agaricus bitorquis (Quél.) Sacc mushroom crops. This study explores the role of phorid flies as vectors of Microdispus lambi in Agaricus bitorquis mushroom crops. RESULTS: The incidence of M. lambi in A. bitorquis growing substrates did not reach appreciable levels at any point during the growing cycle. The presence of phorid flies in A. bitorquis farms was normally higher than that in the case of Agaricus bisporus Lange (Imbach) species. The percentage of phorid vectors did not statistically differ between both Agaricus crops during infection periods. However, by the end of the crop, this percentage had increased only in A. bisporus crops, coinciding with a high incidence of mites in the substrate of this mushroom species; Megaselia halterata emerging from the mushroom substrate of A. bitorquis summer crops did not carry mites as they were absent from compost and casing. CONCLUSION: M. halterata is a pest in Spanish A. bitorquis mushroom crops, meanwhile M. lambi, its phorectic mite, has shown not to be a pest of this species mushroom farms during the spring–summer growing season. A. bitorquis crops could potentially be used as an IPM measure to decrease the incidence and prevent the propagation of the myceliophagous mite M. lambi in A. bisporus mushroom growing farms.info:eu-repo/semantics/acceptedVersio