Science and Research

Stick Insects in the Osa


Male of Calynda coronata

In early November 2015 we traveled to Osa in order to research the stick insect fauna of the Peninsula. It was due to the kindness of Max Villalobos, the Operations Manager of Osa Conservation, that we were allowed to search and collect in the Osa Conservation area.


Stick Insects (Phasmatodea) can be found in Costa Rica with 3000 species currently known in the tropics around the world.  They are herbivores and well-known for resembling twigs or branches. Therefore, they have great camouflage.  Brightly colored and well-flying winged insects also can be classified as Stick Insects. Stick Insects represent the world’s longest known insects, the largest of all being a Bornean species that measures 56.7 cm from the tips of the fore-legs to the tip of the abdomen. Some 60 species have so far been reported from Costa Rica, but the actual number of species occurring throughout the country is estimated to be much higher.

Spectacular startle display of a female Metriophasma diocles

Due to their good camouflage Stick Insects are most easily found during the night by searching the lower vegetation with torch lights. This method makes the insects easy to spot and often good numbers can be found with rich and diverse low vegetation throughout most of Costa Rica. Rainfalls during the afternoon or early evening usually increase the number of specimens encountered. Most species are night-active and start feeding shortly after dawn.

While only on Osa for eight days we have unfortunately chosen a fairly bad time. The strong El Niño in 2015 has caused a massive decrease of rainfalls in this particular area during the past months and our observations right away showed low numbers of insects. Only few specimens were seen, which was very disappointing for our studies. Almost all of the species observed were common ones, that also occur in other regions of Costa Rica. The most abundant species in the Osa Conservation area were the orange-winged Pseudophasma unicolor and the slender, wingless Calynda coronata.

Mating couple of Calynda coronata – females are either green or brown and bear crown-like spines on their head

Mating couple of Calynda coronata – females are either green or brown and bear crown-like spines on their head

Most of Osa Peninsula and the area of Osa Conservation represent perfect habitats for a diverse stick insect fauna and – mostly based on museum specimens – we know that there are many other species on Osa, but which we were not able to find. The very low abundance of these insects caused by El Niño during our stay in Osa has unfortunately not contributed much to our project, which is a forthcoming book on the stick insects of Costa Rica. Hence, we shall like to encourage all of you to look out for stick insects during your studies at Osa Conservation. Any information, records or photos are helpful and welcome. We will be very grateful for any support! Thank you!

Feel free to contact Frank and Oskar. Just have a look at:

Research conducted by: Frank Hennemann, Oskar Conle, Kenji Nishida & Yeisson Gutiérrez

Miscellaneous, Sustainable agriculture, Volunteers and Visitors

Going ‘nuts’ at Finca Osa Verde


Our Finca Osa Verde consists of 600 acres of pasture and forest, as well as 1.1 miles of sea turtle nesting habitat. Osa Verde includes a small farm that supplies Osa Conservation’s field station kitchen and dining halls with all types of fruits and veggies; from lettuce, to peppers, yucca, bananas, and rice.

peanit picking

This week we collected peanuts
from the Finca Osa farm and volunteers, research assistants, and staff members joined forces to create organic peanut butter for the very first time. The process is quite simple and the peanut butter is extremely delicious!



First thing you need to know is that peanuts don’t belong to the nut family, they are actually from the Leguminosae family which includes beans and peas. They develop underground in the plant roots, just like potatoes.


cooking nuts
Follow these steps and you will be eating organic peanut butter in no time:

  • Collect the peanuts from the ground by pulling the plants out and collecting the peanuts from the roots. Buying the peanut pods from a supermarket works just as well.
  • Sun dry the peanut: spread the pods on the floor and dry them for a few hours. Be aware of the rain, especially if you are in the rain forest. If you bought your pods, there is no need for drying them.
  • Roast the peanuts: this part of the process was quite fun and challenging since we have to light our own wooden oven. Looking for fallen dry wood, making the fire (which was easier said than done), waiting for the fire to become a bed of coal, and then roasting the peanut pods without burning them was quite an experience.
  • Peel the peanut pods to extract the roasted seeds. This was a daunting job but luckily, everybody at the Station gave a hand with this part of the process. We decided to call ourselves the “nut team”.
  • Grind the peanuts with a food processer.
  • Add salt or sugar according to your preferences.

eatingGrowing, making, and eating your own food is not only delicious, but it’s a way to minimize adverse impacts on the natural environment. We are what we eat. Here at Osa Conservation we care about the food that we eat and where it comes from. Think about the food you eat: how can it be better for our environment and ourselves?

Environmental Education, Miscellaneous, Science and Research, Volunteers and Visitors

A little luck and a fun(gi) story

Read about Grace Leppink’s experience in the Osa as she makes exciting fungi discoveries!

Fungi are found throughout the world, but some of the most amazing and diverse fungi are found in Costa Rica.  The combination of deeply shaded forests and a warm, humid climate makes Costa Rica the perfect incubator for fungi.  As a new mycologist, the opportunity to travel to Costa Rica was one that I could not pass up.  On my first day at the Piro Research Station I had an exciting and lucky encounter with fungi.


Staheliomyces cincta, fresh and erect.

We were in the thick of the forest on the Ajo Trail. As we rounded the corner we found our prey under the canopy of a giant tree. The intricate lacework of its body was accented by the few rays of light the canopy allowed through.  We had come across a stunning specimen – the strangled stinkhorn, Staheliomyces cinctus.  When I first laid my eyes on it, it seemed out of place compared to the brown and green hues surrounding it.  This white alien shape seemed to protrude out of nowhere, like some weird organic artifact. As my professor joked later, it was the best accessorized fungi he had ever met, as it wore a thick shiny black belt – of slime containing its spores.


collapsing fungi

Same fungus, same day. Starting to collapse! It was undetectable a day later.

This stinkhorn is uncommon and not well documented. One reason is due to the short time that the fruiting body exists.  The structure rarely lasts more than a day before turning into messy lump of black goo.  If my group had not gone out to that trail on that morning we might only have found a shriveled shadow of its former glory.

In the following weeks I hope to continue my documentation of the fantastic fungi by looking at the secondary and primary forests of the OSA peninsula!


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