There is no single scientific term for mildew. The term "mildew" actually encompasses several different types of fungi that cause various diseases in plants and other surfaces.

Here are some common types of mildew and their scientific names:

* Powdery mildew: Caused by various fungal species in the order Erysiphales.

* Downy mildew: Caused by fungi in the order Peronosporales.

* Black mildew: Often refers to sooty mold, which is caused by fungi that grow on honeydew produced by insects like aphids. The scientific name depends on the specific fungal species involved.

* Rust: Caused by fungi in the order Pucciniales.

So, the scientific term for mildew depends on the specific type of mildew you're referring to.