Mushroom fly pest incidence in four button mushroom (Agaricus bisporus) production centres of Zimbabwe-An exploratory study

Abstract

Mushroom fly pests are a serious deterrent to many wood-be button mushroom producers in
Zimbabwe due to their yield and quality degrading damage. Mushroom fly ubiquity is exacerbated
by conducive environmental factors, arguably the rampant food and fruit waste disposal in the
environment. Although modest fly pest management methods are available, expensive methods
are employed to contain pest spread and the subsequent damage they cause. The aim of this
exploratory study was to investigate prevalence, infestation sources, damage, seasonal severity and
control methods for mushroom fly pests on button mushroom farms in four production centres of
the crop. A farmer survey was conducted using a postal questionnaire to farmer respondents using
a mobile phone-integrated application. This study found that sciarid and phorid fly attack button
mushroom crop starting at the early spawn running phase through to the second crop flush with
rapid population build up if uncontrolled. The infestations were found to be high across four
surveyed sites with greatest infestations coinciding with the rainy season. Mushroom fly incidence
and the damage to button mushroom were not explained by location or farmer experience, making
these two variables insignificant in constructing a predictive model for the resultant fly pest
incidence or crop losses experienced. Hence production practices need to be re-evaluated to
develop sustainable methods of managing mushroom fly incidence and novel methods such as fly
repellents, baiting or manipulation of the mating mechanisms and overwintering disruption have
to be explored. From this study we found three species of mushroom fly as significant button
mushroom pests in the studied areas and hence appropriate pest management measures must be
taken to protect the crop to enable good quality and yield. Such adopted pest management methods
will go a long way in promoting and sustaining standard agro-ecological principles.