Jars and bags. Containers such as jars or vials (smaller jars) could arguably be the most useful collecting tool for many insect species. They can be used to collect specimens by placing the jar lip over the insect to capture it and then using a card to slide under the inverted jar to seal the insect inside before placing the lid on it. Non-flying or startled insects can be beaten from plant foliage into the jar to capture them, or hand-picked insects can be placed directly in the container. One method for sampling insects in cotton fields, called a beat bucket, uses a 5-gallon plastic bucket. Terminal ends of cotton plants are “beaten” in the bucket to dislodge insects where they can be counted or collected. Home gardeners have simply used an empty coffee can to beat pest insects like Colorado potato beetle larvae from plants as a control measure!
Zip-lock sandwich bags are excellent containers for use in field collections. Many can be carried easily, requiring minimal space. Specimens can be separated by groups so that large active insects do not damage smaller fragile specimens, and once in the bag, air can be removed to limit mobility of the specimens to prevent injury. The bags containing specimens can be frozen before further processing.
Cockroach trap. An easy way to collect cockroaches is to prepare a trap made from a jar. Any clean clear glass jar is suitable. Mix mineral oil with Vaseline® to thin the Vaseline and use the mixture to coat the inner surface of the jar in a layer from the top of the jar to about 1 to 2 wide. Put an attractive food such as peanut butter and/or bananas in the jar and place it in an area where cockroach activity has been observed or is suspected such as along a wall or in a corner of the garage or kitchen. Leave it at least overnight. Cockroaches climbing into the jar will be unable to escape by scaling the jar’s vertical inner surface. The jar can then be put in a freezer to kill the specimens for mounting of preservation in alcohol (for immature stages such as nymphs), or they can be kept alive to start a culture. The advantage of this trap over commercially available box-type sticky traps is that specimens collected are clean and living.
Food-baited jars (decaying fruit, animal products). Use of various materials may make baited jars suitable to collect other groups of insects. For instance, placing an over-ripe banana in a jar will attract fruit flies (Drosophila) to lay eggs on the “bait”, and decomposing canned meat products such as tuna fish will attract house and bottle flies to lay eggs on the substrate (carrion). In this way immature stages (maggots) of these insects can be obtained. Excrement attracts insects as well, including dung beetles! Simply leaving a bucket (or bird bath) filled with rainwater outside will attract egg-laying female mosquitoes and soon you will have a culture of mosquito larvae! Certain moths, butterflies and beetles can be attracted to various concoctions of fermenting material like over-rip bananas, brown sugar and beer blended together and painted on tree trunks or used in traps (see section, “Baiting for moths and beetles”).
Cricket cages. Sporting goods stores frequently sell cricket cages that are designed to store live crickets used for fishing bait. These are cylindrical wire-mesh containers with a plastic sleeve in the middle of the top that allows fishermen to reach in to retrieve specimens while preventing escape of crickets.
Sorting trays. If collection methods result in mixtures of soil, plant materials or other debris, specimens will need to be extracted live or after de-mobilizing them (e.g., with CO2 or cold temperatures). White metal or plastic trays are ideal for this purpose unless the insects are still alive and actively crawling. In that case the inner sides of the tray can be coated with some type of material that the insects can not climb, such as a dusting of talcum powder (baby powder), a mixture of petroleum gelly (Vaseline®) and mineral oil (liquid paraffin), of special Teflon®-like coatings like Fluon™ (ICI Fluro Polymers, Bayonne, NJ). Heat strips (greater that 135 degrees F) and electric grid systems have also ben used to form barriers insects will not cross.