red spider
US /ˌred ˈspaɪ.dər/
UK /ˌred ˈspaɪ.dər/

1.
ragnetto rosso
a tiny red or reddish-brown mite that feeds on the sap of plants, often causing damage to crops and garden plants
:
•
The leaves of the rose bush were covered in tiny red spiders.
Le foglie del cespuglio di rose erano coperte da minuscoli ragnetti rossi.
•
You need to treat your plants for red spider infestation.
Devi trattare le tue piante per l'infestazione da ragnetto rosso.