Description
Dicyphus hesperus is a generalist predatory mirid bug used to control whitefly, spider mites, thrips, moth eggs and aphids. It is similar to Macrolophus caliginosus which is currently being used in Europe. Adults are slender, 6mm long and are black and green with red eyes. Adults are highly mobile and can rapidly fly throughout the greenhouse. Nymphs are green with red eyes.
Note: Dicyphus will also feed on plants and should not be used with crops that suffer from cosmetic damage, like Gerbera. Most work with Dicyphus has been on vegetable crops such as tomato, pepper and eggplant.
Target Pests
Greenhouse whitefly (Trialeurodes vaporariorum), Tobacco whitefly (Bemisia tabaci). Dicyphus will also feed on two-spotted spider mite (Tetranychus urticae), thrips and moth eggs, but will not control these pests.
Life Cycle
Development from egg to adult takes 5 weeks at 77°F and 8 weeks at 68°F. Adult females lay 3 eggs per day, for a total of 88 eggs over a 20–30-day span. Eggs are laid in the tissue of plant stems and leaf veins and are not easily seen. They hatch in 2 weeks.
Use in Biological Control
- Dicyphus is best used in conjunction with other biocontrol agents in greenhouse crops.
- Release Dicyphus early in the season or as soon as whiteflies are found, in batches of 100 adults.
- Add supplementary food (Ephestia eggs) if whitefly populations are low. Dicyphus need large numbers of prey for reproduction to occur.
- This predator obtains water from feeding on plants and can survive for long periods without food but will not reproduce without adequate prey. Feeding damage to plants is superficial and usually not noticeable until populations of Dicyphus exceed over 100/plant.
- The use of banker plants such as mullein (Verbascum Thapsus) and eggplant is useful for increasing Dicyphusnumbers as well as for monitoring pests.
- Adults and nymphs move quickly and hide in plant material. They are often found on the middle leaves.
- It takes 8-12 weeks to establish a population of Dicyphus.
Introduction Rates
Use early in the season at a rate of 0.25 – 0.5 bugs/10 sq. ft. Repeat in 2-3 weeks.
Using Pesticides
Spreader-stickers, insecticidal oils and soaps are harmful to Dicyphus upon contact but have little residual activity. Most pesticides used for whitefly, including systemic pesticides, are harmful to Dicyphus. Check a chemical compatibility chart for pesticide side effects, which are similar to Orius.
Content Courtesy of Applied Bio-nomics Ltd