The raids and piracy of the VIIIth to Xth century in the western Mediterranean basin were quite different in the sense that they didn't attacked ships, as only Romans having a fleet worth of mention in the region since the fall of Vandals, but were raids expeditions that sometimes happened by land, sometimes crossed the sea; sacking cities and establishing outposts. On this regard, they were closer to Viking and Hungarian raids, than later Barbary coast piracy.

Not all of them originated from Africa, and if Arabo-Andalusian raids in Gaul were significantly less important in scope and importance after the triparte battles of Toulouse-Tours-La Berre (721-732-737) and critically the loss of Narbonne in 759, Arabo-Andalusians still led raids in Languedoc and Provence either trough Languedoc, or using naval hit-and-run raids trough Balearic Islands and Corsica.
Relatively spaced out chronologically, these raids are ravaging enough that the ability of Boso to repeal or prevent them is what allows him (among other factors) to forge a semi-Carolingian kingdom in Provence.
Shortly thereafter, Arabo-Andalusians manage to hold part of the Provencal coast, in a place called "Fraxinetum" or Jabal al-Qilal (possibly modern La Garde-Freinet) in the 880's, from where they would be able to raid and ransom the region, efficiently blocking communications between southern France and Italy including by taking over some Alpine passes (if these Saraceni aren't some indigenous population whom semi-paganism would have owed them the name).
Far from being just a seasonal or permanent raider camps as Viking hold-outs were in the Atlantic coast of Western Francia, Fraxinetum is a real extension of Arabo-Andalusian marches; included in its general sphere against Franks, Abbasid and Romans.

It would last almost a century as such, and it's quite probable that at the root of this longevity is not only this political and strategical role; but the capacity of the local population to coexist if not mix in this Islamic frontier.

Situation in Italy was quite similar, and happened not after the Arabo-Islamic conquest of Africa, but in the same time : as soon as the mid-VIIth century, Saracenic piracy in Sicily is recorded (although in very short and scarce mentions) by Latin sources even before Carthage falls into Arab control. There too, it's to be considered in the context of the wars between Romans and Arabs for the control of the Mediterranean basin and its islands would it be to ensure supply of westernmost holdings; Arabo-Africans and Arabo-Andalusians raiding periodically Corsica or Sardinia.
The conquest of hold-outs in Sicily and Italy since the 830's (best represented by the Emirates of Sicily and Bari; but as well coastal establishments comparable to Fraxinetum near Rome on the Garigliano) obeyed to the same logic that presided in Arabo-Andalusian raids in Provence : the establishment of frontier outposts to securise Arabo-African and Arabo-Siculan presence, agreements and negotiations with local powers and populations (Sigurd of Benevent, Docibilo of Gaeta, etc.) at the benefit of the Aghlabid dynasty.

With the reinforcement of regional aristocracies, civil wars and inner conflicts in al-Andalus and al-Ifriqiya; these outposts became more vulnerable, local agreements less relevant, and they were wiped out in the Xth century.
It didn't stop Saracenic piracy, and raids continued well into the XIIth century on the coast : but that's really with the XIVth century that Arabo-African attacks targeted Christians ships, after the naval development of Italian maritime cities (partly due to the necessities of acting against VIIth-Xth centuries Saracenic piracies and the Byzantine-Arab naval wars) since the Xth.

Not that Barbary Corsairs didn't made several hit-and-run raids in Europe, of course : but while made in accordance with a really broad Ottoman strategy, they weren't seen as a military and political extension of the Dar-al-Islam.

- Fraxinetum : An Islamic frontier state in tenth-century Provence; Mohammed Ballan; 2002

- Provence et piraterie sarrasine; Philippe Sénac; 1988

- Muslims of Medieval Italy; Alex Metcalfe*; 2005*