L'Immacolata in question has nothing to do with the Immaculate Conception. In fact, in the first phrase of the following paragraph it says that "the Immacolata è una Madonna potente e vittoriosa", meaning that the "Immacolata" is the Virgin Mary.

I'm posting this separately because all this naturally won't fit on the "agree" line.
However, the reference here is to the Immaculate as indicated in the papal bull of 1854.

Here are some excerpts, but you can find the entire text of the papal bull at the site referenced below.

Pius IX
THE IMMACULATE CONCEPTION
Apostolic Constitution "Ineffabilis Deus"
December 8, 1854

...The same Roman Church, therefore, desired nothing more than by the most persuasive means to state, to protect, to promote and to defend the doctrine of the Immaculate Conception.

VENERATION OF THE IMMACULATE
Our predecessors, indeed, by virtue of their apostolic authority, gloried in instituting the Feast of the Conception in the Roman Church. They did so to enhance its importance and dignity by a suitable Office and Mass, whereby the prerogative of the Virgin, her exception from the hereditary taint, was most distinctly affirmed. As to the homage already instituted, they spared no effort to promote and to extend it either by the granting of indulgences, or by allowing cities, provinces and kingdoms to choose as their patroness God's own Mother, under the title of "The Immaculate Conception."

... Consequently, following the examples of our predecessors, and desiring to proceed in the traditional manner, we announced and held a consistory, in which we addressed our brethren, the cardinals of the Holy Roman Church. It was the greatest spiritual joy for us when we heard them ask us to promulgate the dogmatic definition of the Immaculate Conception of the Virgin Mother of God.[28]

Therefore, having full trust in the Lord that the opportune time had come for defining the Immaculate Conception of the Blessed Virgin Mary, Mother of God, which Holy Scripture, venerable Tradition, the constant mind of the Church, the desire of Catholic bishops and the faithful, and the memorable Acts and Constitutions of our predecessors, wonderfully illustrate and proclaim, and having most diligently considered all things, as we poured forth to God ceaseless and fervent prayers, we concluded that we should no longer delay in decreeing and defining by our supreme authority the Immaculate Conception of the Blessed Virgin.

L'Immacolata here refers to Mary the Immaculate (she who conceived immaculately).

In English one says "Mary Immaculate"
(You'll find this in many websites).