Scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the superfamily Coccoidea. Adult females typically have soft bodies and no limbs, and are concealed underneath domed scales, extruding quantities of wax for protection.

https://en.wikipedia.org/wiki/Scale_insect#As_pests

Los cocoideos o insectos escamas (Coccoidea) son una superfamilia de pequeños insectos del orden de los hemípteros conocidos vulgarmente como cochinillas.

Varían mucho en apariencia, desde organismos muy pequeños (1-2 mm) de cubiertas cerosas, hasta objetos brillantes de unos 5 mm y criaturas cubiertas con cera melosa.

https://es.wikipedia.org/wiki/Coccoidea

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Note added at 1 hr (2020-07-02 21:02:58 GMT)
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In my area of Spain, it's called cochinilla.

So it´s very sad to see these proud warriors smothered and suffocated by the white blanket that is dactylopius coccus or the cochineal scale insect.

For a few years now this insect has been gaining ground and this year it is like a white plague – given a huge impulse by the exceptionally hot summer this year. Ironically, this insect was introduced to the plants and farmed for the natural cochineal dye that can be extracted.

https://www.viverosflorena.com/the-white-plague-of-the-chumb...

Dejan manchas en las hojas, de color transparente, que se ven a simple vista parece mojado, una mancha de líquido espeso o de una consistencia melosa, debido al mielato que desprenden.

https://greenwolfgrow.com/identificar-y-eliminar-cochinillas...