These are not desired, not welcomed and unwanted. But these always come, feed , grow, multiply and live in your gardens.
After realizing that some leaves are getting yellowish, I thought its worth to give a close look on the leaves as what is going on in there, I used my kids toy (45X zoom small magnifier) and to my surprize I found mites attack... red,black,grey, yellow on my plants.
the next step is to grab some Neem oil......
but believe me these little magnifying toys cheeply available online "made in china" are very helpful in gardening