by Randy Sweeney, Science Teacher, Jefferson High School, LAUSD, Project ISSUES

Background/The Issues
The populations of butterflies, and other flying insects, varies throughout the year. Not all species of butterflies fly in the vicinity of highway, but many do. It is possible to get an idea of the relative numbers of butterflies at various times of the year, by sampling the numbers of various species which end up trapped (and killed) on the radiators of your car during car trips. This investigation will outline some procedures which can be used to gather data on the relative sizes of populations of flying insects during different times of the year. A system of reporting the data in a "standardized" format will also be presented.

Problem Statement
It is difficult to get a "measure" of the numbers of flying insects in an area, and the sizes of these populations vary throughout the year.

Hypothesis
A car's radiator, because it draws in air at a rapid rate and insects have little time to avoid being sucked in, can be used as a tool to get an estimate of the relative sizes of populations of flying insects. The numbers kinds and the numbers of each kind of flying insects caught on a radiator will vary through the year.

Procedure
To do this experiment a person will have to clean off the front of the radiator of their car before they make a car trip. All insects must be removed, and the front end of the car must be cleaned of all insects which might have fallen off the radiator while it is being cleaned.

Care must be taken to carefully record the mileage on the car's odometer (the mileage gage) before you leave on your trip, and also when you arrive. It is also important for you to record the biome types through which you drive (chaparral, grasslands, evergreen forest, desert...), along with the date and times (particularly how many hours of the trip was driven in daylight...and how many hours were driving in the dark) of your trip.

When you arrive at your destination record the car's mileage and carefully remove (with tweezers if necessary) all the insects which were "captured" on your car's radiator. Carefully store the insects on paper towels in a box (where they can not get broken up during the rest of your trip).

Just prior to your "return home" trip, carefully clean your radiator as you did before you left your house. Record the date, mileage, biome types, etc. (as you did on the trip away from home). After you arrive home, and you have recorded the mileage for your trip.

Observations
Keep the collection of insects caught in your trip going away from home separated from the collection of insects caught on the way back to your house. Keeping these two groups separated, separate each of the same kind of insect. Count how many of each type of insect was caught on your car's radiator. Do this for each of the two trips, and record the data separately.

Identify each group of insect, as much as you can. Describe the type of insect in more general terms when you are unable to identify it by name. Write these descriptions with the data for the numbers of individuals in each group.

Calculate the average number (even a decimal part of an individual insect is OK) of each kind of insect caught per mile traveled.

Analyzing Your Results
Compare the data and observations for your trip away from your home with the data and observations for the trip back home.

Was each trip taken during the same hours of the day? (approximately...daylight?...night?)

If the trips were driven during the same times of the day, how closely did your data and observations compare with one another?

If the trips were driven at different times of the day (daylight versus night (dark)), were the data and observations significantly different from one another?

If you travel the same route at different times of the year, how do the data and observations compare with data and observations taken at different times of the year?

Communicate Your Results
Send (email) a copy of your results to target@lalc.k12.ca.us, to add to a data base of the number of individuals of each kind of insect caught per mile of trip during each month of the year.