Blightbeetle — ruling 1

Blightbeetle doesn’t remove any +1/+1 counters already on creatures your opponents control.

Blightbeetle — ruling 2

Creatures your opponents control won’t receive +1/+1 counters as they enter the battlefield.

Blightbeetle — ruling 3

If a replacement effect allows a player to modify or replace an event by putting +1/+1 counters on a creature affected by Blightbeetle, that player may apply that replacement effect, but they won’t get counters. If the original event is entirely replaced (such as by applying Vigor’s replacement effect), the entire original event simply doesn’t happen.

Blightbeetle — ruling 4

If the cost of an ability or an additional cost of a spell requires putting +1/+1 counters on a creature affected by Blightbeetle, that cost can’t be paid. If a resolving spell or ability says that a player may put +1/+1 counters on that creature, that player can’t choose to do so.

Blightbeetle : règles, fonctionnement et interactions (MTG)

Blightbeetle is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Protection from green (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything green.) Creatures your opponents control can't have +1/+1 counters put on them.

How it works : Blightbeetle

Original English text — Wizards of the Coast / Scryfall

#1July 12, 2019· Wizards of the Coast
Blightbeetle doesn’t remove any +1/+1 counters already on creatures your opponents control.
No other card is named in this ruling.
#2July 12, 2019· Wizards of the Coast
Creatures your opponents control won’t receive +1/+1 counters as they enter the battlefield.
No other card is named in this ruling.
#3July 12, 2019· Wizards of the Coast
If a replacement effect allows a player to modify or replace an event by putting +1/+1 counters on a creature affected by Blightbeetle, that player may apply that replacement effect, but they won’t get counters. If the original event is entirely replaced (such as by applying Vigor’s replacement effect), the entire original event simply doesn’t happen.
No other card is named in this ruling.
#4July 12, 2019· Wizards of the Coast
If the cost of an ability or an additional cost of a spell requires putting +1/+1 counters on a creature affected by Blightbeetle, that cost can’t be paid. If a resolving spell or ability says that a player may put +1/+1 counters on that creature, that player can’t choose to do so.
No other card is named in this ruling.