At Work While Surveying Moths
This page is dedicated to give a glimpse of the work we do in the field while surveying moths in the Keys.
The Light Rig
David setting up the lights at Watsons Hammock, Big Pine Key
David at Crocodile Lake NWLR, 2004
Larry Fine checking out some bugs
Shining bright in Big Pine Key
Luis and Christian Vinals checking out some bugs
The Fine family, the Vinals family and Jeff Denis having a good time
A loaded light sheet at the Nike Missile Site in Crocodile Lake National Wildlife Refuge (May, 2008)
Lorenzo Fine - the next generation of Lepidopterist!
Cold and rainy - we'll still check it out!
What a family!!!!
The light rig is my favorite way of surveying moths. It's quite simple. You basically set up some UV lights such as mercury vapor bulbs set up on a tripod in front of a white bed sheet and wait for them to come in. Most moths navigate at night by flying at a specific angle to moonlight which is a constant angle due to how far away the moon is. When light of a similar spectrum is given from a bulb, as a moth flies by the bulb, the angle of the light changes causing the moth to adjust its course as it flies by. This is what leads them to spiral in towards the light sorce. The white bed sheet reflects the light and when the moth eventually hits the sheet they usually grab onto it and come to rest. This makes observing them very easy. Only species that are desired are taken, the rest safely fly away once the light is turned off. This is also a a great way to collect live female specimens for the purpose of obtaining eggs for life cycle documentation.
Using a light rig requires your presense for surveying and is quite laborious in its set up as opposed to the bucket light traps that are set out and then are retrieved in the morning so it requires more time and attention. It has been, however, a tremendous opportunity for fellowship and relationship building as quality time is spent with friends, family and colleagues as we await incoming moths
Bucket Light Traps
7746 - Automeris io lileth
6670 – Phrygionis auriferaria
7704 -Eacles imperialis
Many times, moths come to the light but don't make it into the bucket. Visible here are the following: 6670 – Phrygionis auriferaria, 7746 - Automeris io lileth and (in the background) 7704 -Eacles imperialis
If you're ever walking down a path in the Keys and see one of these - don't be alarmed. Just a bug trap! My phone and permit number will be on the trap!
OOOH! Syntomaea syntomoides!!! Scrore!!!
Bucket light traps have proven to be a highly effective way to continue survey work on evenings when time is limited. A 15 watt UV light bulb is mounted on top of a bucket with a funnel and powered by a small battery. They can be placed in late afternoon and then retrieved in the morning. As insects approach the light source and hit the aluminum plates next to the bulb, they drop down through a funnel an into the bucket.
Bucket light traps are a wonderful way to obtain specimens of micro Lepidoptera. Large species can be collected as well but usually on a much lesser volume than are attracted to the mercury vapor lights at the light rig. In any given area, there are usually multiple micro-habitats. Having several bucket light traps placed in various different micro habitats has proven to be a way to get the most out of a moth collecting evening as you are able to survey species that remain local due to close host plant association or other factors.
various styles of bait traps
various styles of bait traps
A green anole is thinking really big for dinner! I think a black witch might be a little to much to swallow!
20 Plus - Black Witch moths in a single bait trap - Big Pine Key
various styles of bait traps
Bait traps can be an incredible recourse for surveying certain types of insects. Many species of moths do not readily come to lights and must be observed using other methods. Various moths in the noctuid family can be abundant in a habitat but you will never see one at a UV light however put some fermenting fruit out and you will be surprised what you may find. Typically bait traps work far better in the dry season down in the Keys. Once consistent rainfall comes, they seem to be much less effective, however in the fall, winter and early spring months, I've found hundreds of moths in a trap only after a single evening.
Leroy Koehn has been my mentor with bait trapping for moths so many thanks to my dear friend for showing me this stuff! While there is no magical moth elixir - I chop up a few bananas, a few apples add some sugar and water and place them in a gallon zip lock bag about 3 days prior to a collecting trip. I squeeze all the air out of the zip lock back and then leave it in the sun. In a few days, fermentation will take place and the bag will fill up with gas. This is when you know that your bait is ready!
There are a few tricks to effectively using bait traps. First of all, you need to make sure you hang them high enough so critters don't get to your bait. I've seen deer standing on their hind legs and sticking their long tongue into the trap scooping fruit out from the pan. Raccoons, opossums, rats and others will all see your moth bait as a tasty desert! Sometimes ants will find their way into your trap as well which is really not good. Other pests can find their way into the traps as well such as wasps and hornets (which makes sticking your hand into the trap a little awkward) as well as tree frogs - which no doubt are entering the trap because they see the moths - not for the fruit! I've found 6 Cuban Tree Frogs in one bait trap before. Their tummies were quite full! While there is some trial and error involved in bait trapping for moths, the rewards can be well worth it. This is one of the best ways to check out the "black witch" 8649 - Ascalapha odorata up close and personally. Various moths species would have gone unseen over the 13 years of surveying without the bait traps; moths such as the (white witch) - 8647 – Thysania zenobia, and various species in the genus Zale. When things are really dry, you may find moths that you typically never see in bait traps simply because they are looking for something sweet and moist to drink. I've found up to 5 8224 – Calidota laqueata in a trap before. This moth has proven to be quite rare and I've never found more than one or two at a light trap. One of the best things about bait trapping is that all specimens can be released without harm.
Looking for Larvae
Mark Walker searching for caterpillars
David Fine back in the year 2000 looking for caterpillars
Learn what to look for!
Larval tent of 2nd instar
Polygonia leo larva
Hunting for immature stages of Lepidoptera can be very challenging. They are really good at hiding for the most part. For someone that starts out looking for moth larvae, you will find it time consuming and possibly quite frustrating. I would encourage you to stick with it though! Educating yourself on a particular species of moth as to the proper host plant, the time of year when they would be most likely to be found, and if possible, larval habits, will be very helpful to you as you go on the hunt. The important thing to keep in mind is to be patient and as your eyes adjust to the "ordinary" you will eventually train yourself to "notice" things that are out of the ordinary. Little by little, you will begin to notice visual ques that will lead you to success. As you educate yourself and train your eyes to hunt for larvae, you will begin to become more and more efficient and successfull.
Some of my best finds in the field have not come at a light or bait trap, they have come through finding larvae, raising them through to adulthood and now you have an immaculate specimen to photograph. Photographically documenting immature life-cycle stages has become my favorite angle to this project and is perhaps the best way to add scientific value to the project as there are lifecycles of many species of moths that have never been documented.
(Grape Root Borer Moth)
Using Pheromone traps is very usuful way to encounter moths of the family Sesiidae. They are a rarely seen, day flying family that strongly mimic wasps and hornets. These species rarely come to lights and are not seen at fruit traps. Instead, they can be attracted by an artificially created sex pheromone that is placed in the center of the trap under the lid. Males can sense the pheromone from miles away and in the right time of year can show up in abundnace at your trap. Once they are attracted to the sent and aproach the center of the trap, they naturally wind up falling down through the funnel into the bucket. Only 2 species of Sessiids have been reported from the Keys, both in North Key Largo: (2530 – Vitacea polistiformis and 2614 – Carmenta texana)