Climate Change and Caterpillars

Expedition Briefing

Download Packing List for Costa Rica       Download Packing List for Ecuador

Click on the images to view full size!

The Research

Caterpillars eat an incredible amount of plant matter—some caterpillars can eat up to 27,000 times their body weight in just a few weeks (the equivalent of a 150-pound person eating over four million pounds of food). One of the main environmental checks to this ravenous hunger is a group of insects called “parasitoids.” This group, which includes many species of wasps and flies, kills caterpillars by using them as a nursery for their larvae. Using a special organ called an ovipositor, these insects deposit their eggs either onto the backs or into the bodies of living caterpillars. This ensures a safe environment for the eggs to develop and plenty of food, as the larvae consume their host once they’ve outgrown the nursery. This relationship creates a system of checks and balances in the ecosystem: the parasitoids keep the caterpillar population from growing too large and, therefore, prevent them from overeating their host plants.

This intricate interaction involves three levels of the food chain (plants, caterpillars, and parasitoids), making it a ‘tri-trophic’ interaction. These multi-level relationships are essential to keeping many environments healthy and functioning, but increasing climatic variability is poised to disrupt these interactions. Climate-driven shifts in the timing of plant and herbivore seasonal development will likely throw off the signals that govern these relationships. Studying these types of multilevel ecosystem interactions is a new approach to understanding biodiversity and is quickly expanding our understanding of the interplay between ecosystem function, biodiversity, and climate change.

While studying the impacts of climate change on this delicate ecosystem, you will have the chance to experience fascinating and spectacular diversity—and, like many Earthwatch teams before you, you may even have the chance to encounter species new to science!

Earthwatch volunteers have assisted in this collaborative project every year since 1996, including over 1,000 volunteers aiding in long-term research [Dyer et al. 2012]. The data collected in Costa Rica and Ecuador is complemented by similar research being conducted around the world. Other Earthwatch teams on this project conduct work throughout the year in Arizona, Nevada, California, and Peru. Although interaction diversity is a new area of exploration, using information from Earthwatch projects and collaborators, we have learned that interaction diversity is particularly sensitive to climate change.

Changes in global temperatures and levels of CO2 because of climate change are likely to disrupt how ecosystem elements interact with each other. Because these changes will affect many different interactions between organisms, interaction diversity is likely to decline at a higher rate than species diversity [Stireman et al. 2005]. These changes in interaction diversity are likely to have a strong effect on ecosystem stability and function [Thompson 1996, Dyer et al. 2005]. By understanding the mechanics of the plant-caterpillar-parasitoid interaction and how climate variations alter it, we can better understand the dynamics of ecosystem interactions and how they could potentially be impacted. Staying ahead of the actual impacts is one of the best ways to be able to mitigate those impacts if and when they occur.

Parasitoids provide an essential, yet little studied, ecosystem service. By collecting natural history information and the results of long-term studies, this project will maximize the effectiveness of plant-caterpillar-parasitoid diversity databases and their analyses globally. Quantifying these relationships and collecting further data will give scientists the knowledge they need to enhance, restore, or maintain these relationships.

Climate Change and Caterpillars

Print page

How You Will Help

Volunteers will spend much of their time in the field, experiencing this rich diversity while working on this project. The rest of their time will be spent at the field station, aiding in rearing caterpillars and data entry. Volunteers will be involved with almost all aspects of the project. The project especially welcomes anyone with computer and web design skills. As part of this team, you will:

COLLECT AND IDENTIFY CATERPILLARS

You will spend about 70% of your time in the field, experiencing the rich diversity of Ecuador and Costa Rica. You will be trained to recognize evidence of caterpillar activity and will conduct visual searches, collecting any caterpillars encountered along with some of the plants they were found on.

COLLECT AND IDENTIFY PLANT MATERIAL

During long-term experiment data collecting, you will search plants for caterpillars in designated areas, then collect host plants, quantify leaf abundance, and collect material for laboratory or computer analyses.

PROCESS AND MONITOR CATERPILLARS

You will spend the rest of your time in the lab helping rear caterpillars. Rearing caterpillars involves placing them in clean bags, checking them for parasitoids, moving pupae to different bags, and collecting adults or parasitoids from the bag. Adult specimens are either released or preserved for further identification. Your interaction with different life stages of caterpillars and parasitoids will vary depending on their development during your time there. The station has a laboratory as well as an outdoor tent for caterpillar rearing, which has lines for hanging caterpillar bags, tables for processing and observing caterpillars, and spectacular views.

RECORD AND ENTER DATA

You will spend some time helping to enter data recorded in the field and observed in the lab by your team.

Climate Change and Caterpillars

Print page

Accommodations and Food

* Please note that not every expedition has couples’ or singles accommodations available. Please call or email Earthwatch to check for availability prior to reserving your space(s) on the team.

COSTA RICA

SLEEPING

La Selva Biological Station: La Selva is a large and very modern research facility, and the accommodations are considered luxurious by most tropical biologists (bear in mind that a tropical biologist’s idea of luxury may not match your own!). Team members will stay in shared accommodations. Sheets and towels are provided. At La Selva, each room also has a lockable cabinet for valuables.

* Earthwatch will honor each person’s assertion of gender identity respectfully and without judgment. For both teen and adult teams, where logistics dictate single-sex accommodations or other facilities, participant placements will be made in accordance with the gender identity the participant specified on their Earthwatch Participant form and/or preferences indicated in discussions with Earthwatch.

BATHROOMS

Bathrooms at both field stations are unisex and shared. They have flush toilets and private shower stalls with changing anterooms. Showers have electric hot water heads that usually work, while the sinks have only cold water.

ELECTRICITY

All rooms have electricity at both sites. It is 120 volts, 60 hertz, and uses plugs with two flat prongs (some also have a third-round grounding pin). These are the same as U.S. outlets.

PERSONAL COMMUNICATIONS

La Selva Biological Station: Free Internet access is usually available. There are also public telephones; international phone cards can be purchased at the station’s gift shop.

The study areas usually have some cell coverage (Verizon and AT&T seem to be the best).

Please note: Personal communication with outsiders is not always possible while participating in an expedition. Earthwatch encourages volunteers to minimize outgoing calls and immerse themselves in the experience; likewise, family and friends should restrict calls to urgent messages only.

FACILITIES AND AMENITIES

La Selva Biological Station: Laundry facilities (washers and dryers) are available in the afternoons and evenings for a fee of ~$8 USD per load.

DISTANCE TO THE FIELD SITE

La Selva is a one-kilometer (0.6 miles) walk from the caterpillar lab down a paved trail through the forest. Not all volunteers will need to walk to this lab every day.

FOOD AND WATER

At La Selva, staff will cook primarily typical Latin American food. Food at both sites is varied due to the international crew of researchers. The cooks are amazing, and meals are always enjoyable and communal. For long field days, bagged lunches consist of sandwiches, fruit, juice, and cookies.

TYPICAL MEALS

The following are examples of foods you may find in the field. Variety depends on availability. We appreciate your flexibility.

• Breakfast: Beans, rice, eggs, fruit, cereal, and coffee
• Lunch and Dinner: Beans, rice, soup, potatoes, salad, meat (substitute for vegetarians), vegetables, fruit, dessert
• Snacks: Cookies, ice cream, and yogurt available for sale at La Selva
• Beverages: Water, fruit juices (beer and soft drinks available at La Selva at your own expense). Please bring a reusable personal bottle for carrying drinking water to field sites. Tap water throughout La Selva is potable.

SPECIAL DIETARY REQUIREMENTS

Please alert Earthwatch to any special dietary requirements (e.g., diabetes, lactose intolerance, nut, or other food allergies, vegetarian or vegan diets) as soon as possible, and note them in the space provided on your volunteer forms.

ECUADOR

SLEEPING

The station has dormitory-style rooms that house two to five individuals (usually of the same gender) in bunk beds. There are no guarantees that couples will have private rooms, and there are no options for single rooms. The beds are comfortable, and sheets and blankets are provided, although you will need to bring your own bath towel and hand towel and/or face cloth.

* Earthwatch will honor each person’s assertion of gender identity respectfully and without judgment. For both teen and adult teams, where logistics dictate single-sex accommodations or other facilities, participant placements will be made in accordance with the gender identity the participant specified on their Earthwatch Participant form and/or preferences indicated in discussions with Earthwatch.

BATHROOMS

Bathrooms and showers are unisex and shared. They have three flush toilets and sinks with only cold water. The two showers have gas-generated warm water and anterooms for changing.

ELECTRICITY

The station is connected to an electrical grid that is usually operational at 120 volts, but sometimes electricity is limited or fails due to natural events. All electrical equipment (e.g., digital cameras and battery chargers) can be used when electricity is available. High humidity may cause fungal growth on the lenses of cameras, and power for charging batteries is very limited.

PERSONAL COMMUNICATIONS

The Internet is available on your own devices but may experience outages for several days due to weather or technological failure.

Please note: Personal communication with outsiders is not always possible while participating in an expedition. Earthwatch encourages volunteers to minimize outgoing calls and immerse themselves in the experience; likewise, family and friends should restrict calls to urgent messages only.

FACILITIES AND AMENITIES

Laundry facilities are not available, but locals will wash clothing for a small fee; this service usually takes three to five days. Lights are usually out by 10:00 p.m. The station is small and can be noisy late at night, so earplugs can be helpful if you are a light sleeper. 

DISTANCE TO THE FIELD SITE

The research station is in the middle of the project’s research area, so the study sites will typically be reached by walking. Occasionally some team members may travel to more distant sites in a project vehicle.

FOOD AND WATER

Research station staff will cook meals. Food will be varied due to the international crew of researchers; however, it will consist mainly of typical Latin American meals. Meat is usually not included, so you may want to bring supplemental snacks if you are not accustomed to a meatless diet. The cooks are excellent, and the meals are always enjoyable. Everyone eats together in a large outdoor dining room. You should bring any special food items, and you may wish to bring an insulated travel tea or coffee press for hot drinks.

TYPICAL MEALS

The following are examples of foods you may find in the field. Variety depends on availability. We appreciate your flexibility.

• Breakfast: Rice and beans, eggs, fruit, cereal, pancakes
• Lunch/Dinner: Rice and beans, soup, potatoes, salad, vegetables, fruit, dessert
• Snack: You can buy snacks and beverages at a store in the nearby town of Cosanga
• Beverages: Fruit juices, coffee, cocoa mix, beer, and soft drinks are available at your own expense
• Water: The tap water at Yanayacu is potable

SPECIAL DIETARY REQUIREMENTS

Please alert Earthwatch to any special dietary requirements (e.g., diabetes, lactose intolerance, nut, or other food allergies, vegetarian or vegan diets) as soon as possible, and note them in the space provided on your volunteer forms.

Climate Change and Caterpillars

Print page

Project Risks and Precautions

COSTA RICA

TRANSPORTATION

The bus that takes volunteers from San José to La Selva travels on a wet, winding, paved mountain road that is subject to minor landslides. Participants must wear seat belts whenever they are available and may not drive project vehicles.

TERRAIN

The terrain at La Selva and Tirimbina is very hilly, and some trails are quite steep. The cement and wood trails can get very slippery, and the mud trails are sometimes difficult to navigate due to water and deep mud. Walking slowly and carefully can prevent injury. Bring appropriate footwear and remember that the hiking can be as strenuous or easy as you feel is appropriate.

ANIMALS/PLANTS

There are poisonous snakes, some irritating plants, and plenty of biting and stinging insects. Snakebites are not common at La Selva, but the use of tall rubber boots in the field and flashlights at night are necessary precautions. Insect repellent can be used to ward off mosquitoes, chiggers, biting flies, and other insects. Most of the plants are harmless to people, but there are some plants that are poisonous and can cause rashes, and these will be pointed out to the volunteers.

CHIKUNGUNYA VIRUS (CHIKV), DENGUE OR ZIKA VIRUS

These viruses are present in Costa Rica and carried by the Aedes mosquito, which is active during the daytime. Long sleeves and insect repellant should be worn to protect against bites. Participants who are pregnant should consult their doctors before traveling due to the adverse effects the Zika virus could have on the fetus.

CLIMATE/WEATHER

There will be a lot of rain, so please bring appropriate rain gear. When it is not raining, the sun will be very intense; therefore, a wide-brimmed hat, sunscreen (SPF 30 or higher), and staying well hydrated are critical.

Because of the high humidity, those persons using a hearing aid device may find it doesn’t work properly. You should consider purchasing a hearing aid dehumidifier.

PROJECT EQUIPMENT

Volunteers will use pruning clippers, which can cause injuries. You will be instructed in their proper use to minimize the risk of injury.

PERSONAL SECURITY

Some volunteers have had items stolen that they stored at the hotel or left unsecured in their rooms at the station. Please leave valuables at home where possible or properly secured while at the hotel or research site.

Take personal safety precautions while traveling both before and after the expedition. Use common sense in urban centers (San Jose) due to the risk of petty or violent crime. Avoid traveling alone and displaying money or other valuables, use caution when withdrawing money from ATMs, take taxis, and avoid traveling at night. When walking in San Jose, do not walk with a big backpack; use small bags, and consider putting your money inside your shoes. A money belt or waist pouch is also highly recommended (neck pouches are not as they can be easily spotted). It is always best practice to leave unnecessary valuables at home. Take caution in tourist areas and crowded marketplaces. 

At the project site, do not wander off by yourself. It is possible to get lost, and the temperature, rainfall, and dampness can make this uncomfortable and dangerous.

DISTANCE FROM MEDICAL CARE

This project site is remote, with limited emergency response in case of medical concerns. If you are pregnant or have other conditions that could require emergency medical care, you should discuss this with your physician before joining this project.

DISEASES

All volunteers should see a travel doctor before leaving to discuss immunizations and other precautions to take against tropical diseases.

COVID-19 DISEASE RISKS

Earthwatch strongly encourages you to stay up to date with your vaccinations, including receiving booster doses if available and to continue to limit your exposure before your program, such as wearing a mask during travel and frequently washing your hands. Persons with a higher risk of severe illness from COVID-19 should consult with their healthcare provider before participation. 

If you, or another person on site, display symptoms of illness or test positive for COVID-19, you may be required to wear a mask, test for COVID-19, seek medical advice, isolate/quarantine on- or off-site, cease or limit participation in program activities, and/or take other precautions. If local conditions or recommendations from authorities change, additional requirements may be implemented. 

If you must isolate or depart from a program due to COVID-19 or other illness, you will not be entitled to a refund of the contribution for the program, nor any expenses resulting from your participation in the program or a disruption of your travel plans. We strongly encourage you to purchase travel insurance that will cover this eventuality.

ECUADOR

TRANSPORTATION

The road system in Ecuador can be risky by Western standards due to fast and reckless drivers, rain, poor or no lighting, and poor road conditions. The bus ride from Quito to Yanayacu takes a wet, winding mountain road that is very steep in sections, has long unpaved sections, and is frequently subject to landslides. Driving at night will be avoided. Seat belt use is required whenever possible. Volunteers are not permitted to drive.

TERRAIN

The trails where volunteers will collect caterpillars are steep, muddy, and slippery. Wear appropriate footwear (hiking boots with ankle support or Wellington boots with good tread; see the packing checklist). Always walk slowly and carefully, be aware of your surroundings, and heed staff instructions. Hiking can be as strenuous or easy as you feel is appropriate since caterpillars can be found everywhere.

ALTITUDE SICKNESS

Different people react in different ways to working at high altitudes. Even people who are very fit at sea level can find themselves struggling as they walk at higher altitudes. Take the first few days slowly (project staff will provide activities that require less exertion at the beginning of the expedition), and report any illness (headache, lethargy, appetite loss, nausea, etc.) to staff immediately. Also, remain well hydrated. The sun is strong at these altitudes, so a high-factor sunscreen and protective clothing (wide-brimmed hat, sunglasses, and long sleeves) are essential. If you have any condition that might be affected by increased sun exposure or if you are sensitive to heat, please consult a physician. Many common prescription medications can increase your sensitivity to sun and heat. Illnesses that may be aggravated by altitude include sickle cell anemia and chronic heart and lung diseases. Those with asthma or other breathing problems may experience altitude-related discomfort and may wish to consult with their doctors in advance.

ANIMALS/PLANTS

There are no large, dangerous animals or poisonous snakes in the area. There are few biting and stinging insects, but some visitors choose to bring insect repellent to ward off the occasional mosquito. Anyone allergic to wasps, bees, or ant stings should bring medications as appropriate with them (e.g., at least two Epi-Pens).

CHIKUNGUNYA VIRUS (CHIKV), DENGUE OR ZIKA VIRUS

These viruses are present in Ecuador and carried by the Aedes mosquito, which is active during the daytime. The mosquitos that carry the Chikungunya and malaria viruses do not reside in the cloud forest where Yanayacu is. They are found in the lowlands, like on the beach. Nonetheless, long sleeves and insect repellant should be worn to protect against bites. Volunteers should ask their doctors about preventative medicine for Malaria based on their travel plans. Participants who are pregnant should consult their doctors before traveling due to the adverse effects the Zika virus could have on the fetus.

CLIMATE/WEATHER

Due to the altitude, the climate, and the demanding nature of the research activities, take care to avoid dehydration. Always carry and drink plenty of water throughout the day and get enough to eat. Do not overexert yourself. Inform a staff member right away if you feel tired or ill. There will be a lot of rain, so bring appropriate gear. The risk of sunburn is also high; bring a wide-brimmed hat, sunscreen (30 SPF or higher), and appropriate clothing. Because of the high humidity, people who use hearing aids may find that they don’t work properly. You should consider purchasing a hearing aid dehumidifier.

PROJECT TASKS/EQUIPMENT

Volunteers will use pruning clippers. You will be instructed in their proper use to minimize the risk of injury.

POLITICAL

Roads are sometimes closed due to protests in the area. These protests do not generally pose a risk but should be avoided wherever possible.

PERSONAL SECURITY

Take personal safety precautions while traveling both before and after the expedition. Use common sense in urban centers (Quito, Tena, Guayaquil) due to the risk of petty or violent crime. Avoid traveling alone and displaying money or other valuables, use caution when withdrawing money from ATMs, take taxis, and avoid traveling at night. When walking in Quito, do not walk with a big backpack; use small bags, and consider putting your money inside your shoe. A money belt or waist pouch is also highly recommended (neck pouches are not as they can be easily spotted). It is always best practice to leave unnecessary valuables at home. Take caution in tourist areas and crowded marketplaces. In Quito, in particular, the old city center, city parks, Virgin of the Panecillo (El Panecillo) shrine, Calle Morales (often referred to as Calle La Ronda), El Tejar, Parroquia San Sebastiçn (old city), Gonzalez Suarez (old city), Avenida Cristùbal Colùn (new city), and the districts of La Mariscal, La Carolina, La Floresta, and La Marin should be avoided at night due to the high risk of petty crime. Also, avoid hiking in the areas surrounding Volcan Pichincha and the Teleferico (cable car). At the project site, do not wander off by yourself. It is possible to get lost, and the temperature, rainfall, and dampness can make this uncomfortable and dangerous.

DISEASES

All volunteers should see a travel doctor before leaving to discuss immunizations and other precautions to take against tropical diseases.

COVID-19 DISEASE RISKS

Earthwatch strongly encourages you to stay up to date with your vaccinations, including receiving booster doses if available and to continue to limit your exposure before your program, such as wearing a mask during travel and frequently washing your hands. Persons with a higher risk of severe illness from COVID-19 should consult with their healthcare provider before participation. 

If you, or another person on site, display symptoms of illness or test positive for COVID-19, you may be required to wear a mask, test for COVID-19, seek medical advice, isolate/quarantine on- or off-site, cease or limit participation in program activities, and/or take other precautions. If local conditions or recommendations from authorities change, additional requirements may be implemented. 

If you must isolate or depart from a program due to COVID-19 or other illness, you will not be entitled to a refund of the contribution for the program, nor any expenses resulting from your participation in the program or a disruption of your travel plans. We strongly encourage you to purchase travel insurance that will cover this eventuality.

Climate Change and Caterpillars

Print page

Resources

BOOKS

• Wagner, D.L., 2010. Caterpillars of eastern North America: a guide to identification and natural history. Princeton University Press.

ARTICLES

• The first article is highly recommended. Link to these papers: wolfweb.unr.edu/~ldyer/papers.htm
• Dyer, L.A., Wagner, D.L., Greeney, H.F., Smilanich, A.M., Massad, T.M., Robinson, M. Fox, M., Hazen, R., Glassmire, A., Pardikes, N., Fredrickson, K., Pearson, C., Gentry, G.L., and J.O. Stireman III. 2012. Novel insights into tritrophic interaction diversity and chemical ecology using 16 years of volunteer supported research. American Entomologist 58:15-19.
• Stireman, J.O. III, L.A. Dyer, D.H. Janzen, M.S. Singer, J.T. Lill, R.J. Marquis, R.E. Ricklefs, G.L. Gentry, W. Hallwachs, P.D. Coley, J.A. Barone, H.F. Greeney, H. Connahs, P. Barbosa, H.C. Morais, and I.R. Diniz. 2005. Climatic unpredictability and parasitism of caterpillars: Implications of global warming. Proceedings of the National Academy of Sciences 102:17384-17387.

PROJECT-RELATED WEBSITES

• caterpillars.org

LITERATURE CITED

• Dyer, L.A., M.S. Singer, J.T. Lill, J.O. Stireman III, G.L. Gentry, R.J. Marquis, R.E. Ricklefs, H.F. Greeney, D.L. Wagner, H.C. Morais, I.R. Diniz, T.A. Kursar, and P.D. Coley. 2007. Host specificity of Lepidoptera in tropical and temperate forests. Nature 448:696-699.
• Dyer, L.A., T.R. Walla, H.F. Greeney, J.O. Stireman III, and R.F. Hazen. 2010. Diversity of interactions: A metric for studies of biodiversity. Biotropica 42:281-289.
• Dyer, L.A., and D.K. Letourneau. 2013. Can Climate Change Trigger Massive Diversity Cascades in Terrestrial Ecosystems? Diversity 5:1-35.
• Forister, M. L., Novotny, V., Panorska, A. K., Baje, L., Basset, Y., Butterill, P. T., Cizek, L., Coley, P. D., Dem, F., Diniz, I. R., Drozd, P., Fox, M., Glassmire, A., Hazen, R., Hrcek, J., Jahner, J. P., Kama, O., Kozubowski, T. J., Kursar, T. A., Lewis, O. T., Lill, J., Marquis, R. J., Miller, S. E., Morais, H. C., Murakami, M., Nickel, H., Pardikes, N., Ricklefs, R. E., Singer, M. S., Smilanich, A. M., Stireman, J. O., Villamarín-Cortez, S., Vodka, S., Volf, M., Wagner, D. L., Walla, T., Weiblen, G. D., and L. A. Dyer. 2015. Global distribution of diet breadth in insect herbivores. Proceedings of the National Academy of Sciences 112:442-447.
• Glassmire, A. E., Jeffrey, C. S., Forister, M. L., Parchman, T. L., Nice, C. C., Jahner, J. P., Wilson, J. S., Walla, T. R., Richards, L. A., Smilanich, A. M., Leonard, M. D., Morrison, C. R., Simbaña, W., Salagaje, L. A., Dodson, C. D., Miller, J. S., Tepe, E. J., Villamarin-Cortez, S. and Dyer, L. A. (2016), Intraspecific phytochemical variation shapes community and population structure for specialist caterpillars. New Phytologist 212:208-219.
• Long, Z. T., J. F. Bruno, and J. E. Duffy. 2007. Biodiversity mediates productivity through different mechanisms at adjacent trophic levels. Ecology 88: 2821-2829.
• McCann, K. S. 2000. The diversity-stability debate. Nature 405:228-233.
• Rodríguez-Castañeda, H.G. Connahs, T.R. Walla and L.A. Dyer. 2010. Tropical forests are not flat: How mountains affect herbivore diversity. Ecology Letters (in prep).
• Smilanich, A.M., L.A. Dyer, and G. L. Gentry. 2009. The insect immune response and other putative defenses as effective predictors of parasitism. Ecology 90:1434-1440.
• Stireman, J.O. III, L.A. Dyer, D.H. Janzen, M.S. Singer, J.T. Lill, R.J. Marquis, R.E. Ricklefs, G.L. Gentry, W. Hallwachs, P.D. Coley, J.A. Barone, H.F. Greeney, H. Connahs, P. Barbosa, H.C. Morais, and I.R. Diniz. 2005. Climatic unpredictability and parasitism of caterpillars: Implications of global warming. Proceedings of the National Academy of Sciences 102:17384-17387.

Climate Change and Caterpillars

Print page