My first goal on Isla Colon is always to do as much as possible in the short amount of time I have. Trips typically last less than two weeks, and opportunities for field work are always subject to the weather, which in the tropics is always subject to change. I have had week-long trips turned into two-day trips by ceaseless rain that drove almost all insect life underground (or, more accurately, under leaves). For this reason, I am constantly reviewing and revising the methods I use in an effort to be as efficient as possible. These are the main ways in which I have recorded insect species on Isla Colon:
The majority of my work in the field on Isla Colon has been at night, using lights to attract moths and other insects. In general this consists of setting up and monitoring a light rig of some kind throughout the evening. Most of the insects on this site were found at lights set up for the express purpose of attracting and collecting individuals in the hopes of improving the completeness of the inventory. Most of the moth specimens on this site were caught at a 160-watt mercury vapor lamp hung in front of a white sheet. There are two basic ways to set up a rig like this: on a rope strung between two trees, or freestanding using a bowed tent pole as a frame for the sheet. In wooded areas it’s not too difficult to find two well-spaced trees, put a clothesline between them, and set up a light in front. In treeless areas, like the pastures that border the old-growth rainforest on Isla Colon, the second method is necessary. The system I use now is lightweight, simple, and surprisingly sturdy. Here’s a link to similar rigs.
Other than lighting, baiting has been the most consistently rewarding method of acumulating records on Isla Colon. While this method is generally used for butterflies in the tropics (and several of the species represented here have been taken this way), it can also be effective in attracting moths that don’t come to lights and don’t fly in the day. Some groups, especially the Geometridae and the Noctuinae, are regular visitors to fruit bait left out all night. The photo below illustrates a method I came up with to keep the frequent rain from washing the bait away. I cut a piece of banana and tie it into a section of fabric from a pair of nylons. Even after the banana chunk is good and rotten (the way the moths like it), it stays more or less intact.
There are many moths, not to mention other groups, that do not come to lights or bait, and these often must be captured with a net. Some of these are diurnal (day-flying) moths that mimic other insects like wasps, flies, or true bugs. These species, along with butterflies and many other groups, must be sought during the day in bright sunny pasture and gloomy rainforest understory. Knee-high rubberized “jungle boots” are indispensable for this work, as is a copious amount of DEET. The margins of the forest and the overgrown areas of the machete-cut pastures on Isla Colon are the best places to search out day-flying moths and other insects. Unfortunately this habitat is also among the best place to find one of the deadliest snakes in the world, the fer de lance. Snakes aside, there are also plenty of Africanized bees, aggressive wasps, and huge venomous spiders, not to mention the countless plants that are protected by thorns and toxins. Never put your hand somewhere without looking first!
At the end of a typical 10-day trip, I’ll have pages of notes and narratives about the insects and conditions I've encountered, and between 300-500 specimens in glassine envelopes labelled with collecting data. I usually keep them in the ITEC freezer, which is without power during most of the day but still saves the specimens from the two biggest threats, ants and mold. These envelopes are packed into sturdy tupperware containers for the flight home. Once I arrive back at my basement “lab” in Chicago, the envelopes go straight into the freezer — this time one that doesn’t lose power — where they can be kept for weeks before the work of spreading and labeling can begin. This work involves placing each specimen on a black japanned insect pin, longer and thinner than regular dressmaker pins, along with a label with the collecting location, site type, collecting method, GPS data, date, and any other relevant information. In my collection, each insect gets a unique “location number” that makes it easier to find and refer to individuals that might otherwise get lost in the hundreds of individuals. Insects with wings must be “spread” and allowed to dry with the wings perpendicular to the body. so details like markings and wing venation can be seen. This is a delicate and demanding process, especially with some of the smaller and more delicate moths. Occasionally specimens are lost during this process, but as the years have gone by I’ve gotten better at saving even the most fragile and ragged individuals.
Once the specimen is spread and dried, it’s time to photograph and ID it for entry in the database. I use a CoolPix digital on macro and a basic home-made light rig, but the free Lightroom program does the real work for me, auto-correcting both white balance and exposure. Entering the record and photograph into this website is time-consuming, but the end result is worth it.
Finally, it's time to return specimens to Panama, to the Universidad de Panama collection, where other workers can use them for reference.