The Holguin Skipper Holguinia holguin has only been seen by a very select few observers. It is a very rare endemic to Cuba and has been seen in the hills at both ends of the island. Yosiel Álvarez has been doing targeted fieldwork to discover more about the island's rarest butterflies.
On 14 May 2023, a female Holguinia holguin was observed and photographed by Yosiel while ovipositing on fresh leaves of a climbing grass later identified as Tibisia farcta in the foothills of Alto de Florida, Baracoa, Guantánamo province. The location consisted of a dry serpentine-scrub woodland on the southern slope of a small hill accompanied in this highly diverse and endemic-rich habitat by the endemic skipper Bruner's Skipperling Oarisma bruneri.
The foodplant was previously unknown so well done to Yosiel for unlocking another mystery.

Another new butterfly species has been found in Cuba and the paper describing the event has recently been published. During a butterfly expedition to Cuba organised by Dr Marc Minno and the Tree Institute from Florida two female Pearl Crescent Phyciodes tharos were seen and photographed by Yosiel Álvarez on 26 June 2023 at Escaleras de Jaruco, Jaruco municipality in Mayabeque province, western Cuba.

This is a widespread species in the Americas and is found from Mexico up to Canada but has only once before been seen in the Caribbean, in the Bahamas which lie just to the north of Cuba (Rindge, 1952).
You can read the full details of this excellent find in the paper here (Álvarez, 2024).