This was my second trip to Costa Rica, having organised and led a small group tour there in 1992. The trip was deliberately timed to coincide with the Costa Rican rainy season, a time when butterflies emerge en masse in the seasonally dry Guanacaste region in the north. The price to be paid of course was that the regions I visited further south were heavily inundated, so butterfly watching in these areas was confined to mornings and early afternoons, before the arrival of the torrential daily rains.

I spent the first 4 days at the American owned Rancho Naturalista at Tuis, Turrialba. The small rancho is set in mid-elevation transitional rainforest at circa 1400m altitude, with short trails through relict primary forest, secondary forest and a regenerating clearing.

On sunny mornings butterflies appeared in reasonable numbers, with about 95 species recorded. The highlights included Morpho helenor, patrolling regularly along the tracks; the near-fluorescent orange Dryadula phaetusa, and the stunning black and orange Longwing Heliconius hecale. The most exciting species however was an immaculate dazzling iridescent blue Skipper Astraptes fulgerator, which basked in the morning sun for just long enough for me to take one photo. A few moments earlier I had come across a group of about 30 Phoebis sennae roosting in a small bush. They made a beautiful sight, with the golden morning sunlight streaming through their wings.

At night the forest was alive with the chirping of myriads of frogs and insects. I left a tungsten lamp switched each night, hoping to attract a few moths onto the verandah. Each morning I awoke before dawn to investigate, and found the walls and ceiling covered in several hundred moths. The variety of shapes, cryptic patterns and strange resting postures adopted by the moths was amazing. There were many beautiful Geometrids, a mass of brightly coloured "Micros", lots of very attractive Tussocks, Prominents and Leopards, some stunning Hawkmoths, and a couple of Automeris Bull's-eye Silkmoths. Certainly the greatest moth bonanza in all my years of travelling. 

From Rancho Naturalista I then transferred by road to Los Innocentes, a hacienda set below Volcan Orosi in the dry Guanacaste region. For 4 days I was able to explore a variety of habitats including lush grassland, flowery cattle pastures, relict riverbank forest and an orchard where fermenting fruit attracted many butterflies. Splendid species abounded including the Crackers Hamadryas feronia,  februa and the incredibly beautiful calico blue Hamadryas amphinome, all basking head-downwards on the tree trunks. Other species included the brilliant orange Dryas iulia nectaring at Lantana, a stunning blue Skipper Paches loxus, the dazzling blue Morpho helenor, and the gorgeous green and brown Malachite Siproeta stelenes. 

Along the muddy edges of a stream a group of Phoebis sennae congregated at cattle urine. Other puddling species included the Queen Swallowtail Heraclides androgeus, banded with cream on a chocolate ground colour; and the gorgeous Red Daggerwing, Marpesia petreus, probably the most beautifully shaped butterfly in the world. One of the most unusual butterflies was the white skipper Atarnes sallei, prettily marked with orange and black. As well as butterflies, Los Innocentes had helicopter damselflies, some beautiful cicadas, and several very large and attractive cricket species. 

My next destination was Selva Verde lodge, situated on the banks of the Sarapiqui river, and surrounded by primary and secondary forest, cattle pasture, and banana and palm plantations. Torrential rain every afternoon reduced my butterfly-watching time considerably, but in the mornings I had about 4 hours to explore the surrounding forest.

The primary forest behind the lodge was not particularly productive, but across the road there were a few hectares of mildly degraded forest, where dozens of beautiful  species flew along the main track, and on the plethora of narrow forest trails. These included Morpho helenor, some nice Pyrgine skippers, the very beautiful transparent Satyrines Cithaerias pireta and Dulcedo polita, and the stunning Metalmark Eurybia lycisca, seen nectaring at Heliconia flowers. I was also very fortunate to get close to a small group of Parides childrenae whose black wings are marked with patches of scarlet and metallic green. To see these lovely butterflies fluttering around bushes at the edge of the forest was certainly one of the highlights of the trip.

I rounded off the trip with a relaxing 3 days at Marenco, a coastal biological station on the Osa peninsula. Butterflies here were generally scarcer than at the other sites, but included a few species such as Pierella luna, Euptoieta hegesia and Heliconius sapho that I had not seen elsewhere.

The behaviour of Heliconius erato, as observed by myself at Marenco, was fascinating to watch. I found a group of males aggressively jostling around a chrysalis, attempting to copulate with it. A frantic battle took place the instant the female hatched from the chrysalis, as all the males struggled to copulate with her, not even allowing her time to expand and dry her wings. One of the males succeeded, and the mated pair then had to endure the attention of the remaining males, which were extremely persistent, trying to prise the pair apart. Eventually, as dusk approached, the unsuccessful males started to disperse. I found the pair again the next morning, still copulated, with 2 persistent males that had returned and were continuing to harass them.