regulates regulation of developmental process biological regulation haustorium mother cell formation regulation of haustorium mother cell formation biological_process regulation of haustorium mother cell formation on or near host Any process that modulates the frequency, rate or extent of symbiont haustorium mother cell formation. The host is defined as the larger of the organisms involved in a symbiotic interaction. GO:0075193 Note that this term should not be used to annotate gene products of the host. It should only be used to annotate those gene products from the symbiont involved in this process.