The condition caused by an increased production of a fungus normally resident in smaller numbers in the vagina is candidiasis.
1. Candidiasis, commonly known as a yeast infection, is caused by an overgrowth of the fungus Candida albicans, which is naturally present in the vagina in small quantities.
2. Factors such as hormonal changes, antibiotics, weakened immune system, diabetes, and poor hygiene can lead to an overgrowth of this fungus, resulting in symptoms like itching, burning, and abnormal discharge.
Therefore, in the given options, candidiasis is the one that is caused by an increased production of a fungus normally resident in smaller numbers in the vagina.