You can do photography at set intervals, as used in bird studies :)

You could also use environmental DNA techniques, but it may be more difficult to infer abundances.

As you are working primarily as an educator, I think that you have some wiggle room. As part of classes in the past, I have observed discrete areas for one hour. However, my main recommendation is to use dry pit traps in your area of interest. Shallow, wide, plastic pits are effective ways of gathering insects for educational purposes. I use pitfall traps in my research and shallow plastic containers are very cheap. Many insects are, of course, predatory, so you should think carefully about the timeframe that they will be in the trap. I would recommend deployment for about 24hrs with sufficient cover (litter in the trap). This should help you safely avoid bycatch (mice and lizards often become stuck in the traps and will dehydrate quickly if you are not careful) and will provide a rough idea about the insect diversity and abundance in your area of interest. Pit traps are certainly not without their own problems and will over and under-estimate certain groups, however, I have many happy memories of students pouring dry traps into collection trays and seeing a variety of invertebrates scurry out. Simply remove the litter from the tray carefully, count your organisms of interest, and return them to your study area. Hope this helps, message me if I can help further.

There is no universal method that works for all taxa. With undergraduates in the tropics we have successfully used: 1 hour of observations in pairs of an area or flowering plant, ideally using an identification sheet for the taxa of interest, such as butterflies or bees; observations for an hour of baits (tuna and honey, or see what your local ants like) put on the ground for ants, identifying to morphospecies unless you have an ant expert or good keys; collection of litter samples into a plastic bag and then sorting in white trays in the lab.

A typical pitfall trap can be used with a small amount of water as a preservative solution for dung beetles. So it will make their wings wet and less likely to escape from the trap. Then, after the identification, they can return to the same locality Enoka Kudavidanage . In addition, some camera traps were developed with specific focal lengths to capture the image of small insets. That would be a perfect nondestructive method to measure pollinator diversity and abundance. Akihiro Nakamura Mark Jun M. Alcantara