Bloodworm is a burrowing bristle worm (polychaete) known for its creamy pink color since its pale, almost transparent skin allow the red hemoglobin-containing body fluids to show through. This invertebrate pest affects your garden by burrowing and attacking newly sown seeds of most greenhouse crops and reducing germination efficiency. Though their burrowing may help improve soil aeration, in most instances it modifies the soil structure in manners that are prejudicial to the successful establishment of the roots of plants.
How to eliminate bloodworms using organic methods
1. Use Bacillus Thruringiensis
If you notice signs of bloodworms burrows in the seedbed in your greenhouse, apply Bacillus Thuringiensis (Bt) to help contain their spread and even eliminate the pests before they cause harm. Bt is a broad-spectrum biological pesticide that effectively controls crop pests that dwell in the soil. During sporulation, it produces crystal proteins that penetrate the delicate skin of bloodworms, harming and eventually killing the bloodworms.
2. Use Predatory Insects
Certain insects such as lacewing, dragonflies, and birds such as the American-dwelling Passeriformes feed on bloodworms. Fortunately, many of these do so without necessarily harming your crops in the greenhouse. If you live in an area susceptible to bloodworms attack then consider buying lacewing from vendors dealing in biological pest control agents. Release these in your greenhouse. Alternatively, you can set your greenhouse kits in a manner that allows for easy entry of predatory insects and birds.
3. Controlled Watering
Bloodworms thrive in wet soil or muddy conditions, especially if such soils are rich in organic matter. Reducing the amount of water you apply as well as watering in the morning instead of just before dusk makes the soil less favorable for bloodworms.
4. Use Beneficial Nematodes
Beneficial nematodes are an effective control measure against 200 species of soil-dwelling pests, bloodworms included. Luckily, the nematodes are not harmful to beneficial insects such as ladybugs and earthworms. The nematodes have symbiotic bacteria in their guts, which kills the target pests in 48 hours or less. To eliminate bloodworms using beneficial nematodes, spray the solution of water and the nematodes on the affected areas.