Most of the insects you’ll encounter in Costa Rica are more of an annoyance than a safety concern, but some can carry diseases.
Mosquitoes are the most significant threat, but not because of malaria which pops to mind when people think of the tropics but is uncommon in Costa Rica. Instead, mosquito borne dengue fever (bone break fever) is on the rise throughout the world and is becoming more common in the Guanacaste and Caribbean regions of Costa Rica.
The dengue virus is spread by Aedes aegypti mosquitoes which hunt most actively at dawn and dusk, in shady areas, or when the weather is cool and cloudy.
There is no treatment for dengue fever. Fluid replacement is important to prevent dehydration and Acetaminophen (Tylenol) helps control the fever (Do Not take aspirin).
Purrujas (no-see-ums) are mosquito’s super evil microscopic twins that can transmit encephalitis – very rarely transmitted to humans in Costa Rica.
Africanized bees are present. We saw a miniature stampede down the main street of Puerto Jiménez when a group of horses being prepared for a tour group disturbed a hive. Dodging back and forth while running is better than running in a straight line (but don’t trip), get inside a building car or tent as quickly as possible. The Warner Brothers® standby of diving in the pond and breathing through a reed until the bees move on is not recommended since the bees can be very patient.
Scorpions like to snuggle into your shoes or crumpled up clothing while you sleep, so shake them out before you put them on.