Moscito is a bidding or bridge system of the game of contract bridge

Contract bridge

Contract bridge, usually known simply as bridge, is a trick-taking card game using a standard deck of 52 playing cards played by four players in two competing partnerships with partners sitting opposite each other around a small table...

 invented by the Australian expert Paul Marston in the mid-1980s. According to him, this modification of his strong pass

Strong pass

In the card game of bridge, a strong pass is an opening pass that indicates a strong hand, typically with a minimum of 11-16 points. Strong pass bidding systems are of a quite different nature from the more typical "natural" systems, but share some similarities with strong club systems...

 systems came about because of political repression by the American faction in the World Bridge Federation. It has many variants. Most variants of Moscito uses the Symmetric Relay structure developed by Prof. Roy Kerr

Roy Kerr

Roy Patrick Kerr CNZM is a New Zealand mathematician who is best known for discovering the Kerr vacuum, an exact solution to the Einstein field equation of general relativity...

 for slam bidding.

In all variations of Moscito, 1 is used for strong hands, hence they are strong club systems like the precision club

Precision club

Precision Club is a bidding system in the game of contract bridge. It is a type of strong club system that was invented by C. C. Wei and used to good effect by Taiwan teams in the early 1970s...

. Usually the MAFIA (Majors First Always) principle is followed, such that a 4-card or longer major suit holding is always opened ahead of any minor suit however long or strong, but this has been slightly relaxed in later variants. Older versions typically have a special opening bid that shows both majors, while later versions use transfer bids in the openings.