Insects and Composting

Composting is a great way to get rid of yard and vegetable waste in an environmentally sound manner. Not only do you keep the waste out of the landfill but in the end you gain a valuable product to add back to garden soil. Composting can be as simple or as involved as you want to make it. The simplest compost piles contain only yard waste which slowly breaks down without any additional inputs. It may take a year or longer to complete the decomposition process.

Hot composting

You can speed up decomposition by first chopping or shedding the yard waste which exposes more of the waste's surface to the decomposition process. Decomposition is even faster if the chopped yard waste is layered with soil, and confined to a compost bin. The soil adds necessary nutrients and microorganisms. Layered piles that are occasionally aerated by turning can become quite hot because of very rapid internal microbial decomposition. Compost piles that heat up because of rapid decomposition are call hot-composted.

Cold composting

Vegetable waste from the kitchen or garden, on the other hand, contains more water and nutrients then yard waste. The extra moisture greatly slows decomposition and the piles never heat up to the same degree as dry piles. Because the piles don't heat up internally they are called cold-composted.

Wet, cold composting piles typically contain large numbers of redworms, insect larvae and other microarthropods that could not survive hot-composting. In fact, redworms are sometimes added to the cold compost piles to start the process. Worm composting is called vermiculture.

Insects in compost bins

There are a number of insects that normally inhabit cold-composted piles especially those that contain large amounts of vegetable matter. The insects generally are no reason for concern, in fact they aid overall decomposition.

When vegetable-based kitchen waste is first added you may get a "bloom" of vinegar flies (fruit flies) until the mass of vegetable matter starts to break down. Vinegar flies lay their eggs in fruit and vegetable skins and the maggots feed on bacteria and fungi of the rotting plant matter.

Black soldier fly maggots (larvae, more information) [picture of black soldier fly maggot] can be found in some compost bins. These large maggots often startle those new to composting but they cause no harm. The maggots may indicate the presence of meat or fat in the compost, neither of which should ever be added to your bin.