A beautiful Lasaia agesilas (Riodinidae) photographed in Caçapava, SP, Brazil. This species is found exclusively in the neotropics (from Mexico to Paraguay). They are small butterflies, averaging about 30mm in wingspan. Males have extremely reflective wing scales, shimmering in metallic turquoise, blue or steely grey according to species. Females are rarely seen. They are generally a dull earthy brown color. Both sexes have a similar pattern of black spots.
The butterflies are strongly attracted to human sweat. So when you come across them, get ready because they will not stop harassing you.
Pristimantis gaigei (Craugastoridae) is a nocturnal species of primary humid lowland forest, and secondary forest. Adults are found under surface debris and in leaf-litter, its range often associated with caves or rocky stream banks. It breeds by direct development. This species is native to Colombia; Costa Rica, and Panama [source].
If you go diving in the western Atlantic Ocean from the Chesapeake Bay to the Dominican Republic, you may run into this gorgeous crab, the Calico Box Crab, Hepatus epheliticus. It lives in shallow water at depths of up to 46 metres (151 ft) on sandy and muddy substrates. It often carries the sea anemone Calliactis tricolor on its back, or lies buried in the sand, with only its eyes exposed.
Cruziohyla calcarifer (Hylidae) from Sarapiquí, Heredia, Costa Rica.
This species was previously within the genus Agalychnis but was moved to the new genus Cruziohyla in 2005.
The Splendid Trrefrog is native to Colombia, Costa Rica, Ecuador, Honduras, Nicaragua, and Panama. This species is often considered to be rare, although more likely it is under-recorded, since it is a canopy frog and has a very soft call. Only occasional individuals are seen from time to time.
Urbanus proteus(Hesperiidae - Pyrginae) is a very particular butterfly by the white spots are distinguished at their upper wings are actually translucent sections. If you are lucky enough to see it perched on a flower, you can distinguish the colorful flowers through these “windows” on their wings.
Their size ranges from 37 to 55 mm. It is a butterfly medium size easily recognizable by expansions in the form of its hind wings tail. The back of his body takes on a blue-green iridescent tone due to the dense and bright hairs that extend to the base of their wings. How others of its kind, has big eyes and antennae with a slight hook .
This butterfly can be found from Argentina north through Central America, the West Indies, and Mexico to peninsular Florida and South Texas. Occasionally strays and colonizes north to Connecticut, southern Illinois, eastern Kansas, southern Arizona, and southern California .
Caterpillars feed on leaves and live in shelters of rolled leaves.
Megasoma elephas (Coleoptera - Scarabaeidae - Dynastinae) is one of the giants of the insect world. It is a large and distinctive tropical beetle known from southern Texas, southern Mexico, Central America, and South America.
The most distinctive feature of this beetle is what gives it its name, the long rhinoceros-like and upward-curving horn that males have. This horn has a furry covering and it splits into two at the tip. In addition to the long horn on the head, the pronotum of the male elephant beetle bears a smaller, central horn and a triangular horn on each side. The female elephant beetle is distinguished from the male by its lack of horns
This beetle ranges in size between 7–12 cm (2.75-4.75 in); males are sometimes even bigger .
Curious fact: the Elephant beetle is one of the species that has been used in military application experiments conducted at the University of California, Berkeley, and sponsored by the Pentagon (US), for implanting radio-equipped miniature neural stimulating power systems and remotely control the flight of the insect, creating the prototype called "cyborg beetle" which may serve as useful models for “micro air vehicles” 
Some tropical flowers reflect sound so nectar-seeking bats can find them more easily.
by Susan McGrath
Nature’s inventiveness knows no bounds. Consider the case of the nectar-drinking bat and the night-flowering vine whose lives intertwine in the lowland tropical forests of Central America.
Glossophaga commissarisi, a tiny, winged mammal with a body no bigger than your thumb, flits among the flowers of Mucuna holtonii, lapping nectar, much as hummingbirds and bumblebees do. In exchange it pollinates the plant. In daylight flowers can flaunt their wares with bright colors such as scarlet and fuchsia, but at night, when even the brightest hues pale to a moonlit silver, Mucuna flowers resort to sound to catch the ear of nectar bats.
At La Selva Biological Station in northern Costa Rica a vigorous old Mucuna has woven a leafy ceiling above a forest clearing and lowered dozens of flowers into the opening on long, green stalks. The flowers dangle at staggered heights in the vaulted clearing like chandeliers in a shadowy ballroom, each palm-size inflorescence a whorl of pale yellow, pea-pod-shaped buds on arched stems…
… are a type of march fly (not a true but, but indeed a fly, despite the common name), found in the southeast US and parts of Central America.
They get their common name from their mating behavior - pairs remained coupled for up to days at a time during copulation. Males are smaller than females, but have larger eyes that perhaps help them better locate a mate.
The adults emerge in large flights in late spring and late summer, which may number hundreds of thousands over the course of a few weeks, though individuals only live for a few days each. These swarms often occur in roadside habitats, becoming a nuisance to motorists when they hit the windshield.
Adults feed on nectar during their brief lifespan; the larvae feed on decaying vegetation.
photo by Florida Fish and Wildlife (MyFWCmedia) on Flickr
It has taken me three trips to Panama to find and photograph this bird! The Resplendent Quetzal, reputed to be the most beautiful and ornate bird in the western hemisphere. The breeding male has gleaming emerald tail feathers that can be more than 65cm long. They are the party streamers of the rainforest.