Dicyphus hesperus is an omnivorous generalist predator similar to Macrolophus caliginosus and Nesidiocoris tenuis, which are being used in Europe and Africa to control whitefly, spider mites, moth eggs and aphids. It is best used along with other biological control agents in greenhouse tomato crops that have, or (because of past history) are expected to have whitefly, spider mite, or thrips problems. Dicyphus should not be used on its own to replace other biological control agents.
Development from egg to adult takes five weeks at 77°F (25°C) and eight weeks at 68°F (20°C). Adult females lay their eggs inside plant tissue and are not easily seen. After about two weeks, nymphs will hatch which are green with red eyes. Both nymph and adult stages are predacious.
Use in Biological Control
Use Dicyphus to control greenhouse whitefly (Trialeurodes vaporariorum) & tobacco whitefly (Bemisia tabaci). Dicyphus will also feed on two-spotted spider mite (Tetranychus urticae), Thrips, Aphids and Moth eggs but will not control these pests.
The development time of Dicyphus is relatively long for an insect and it takes a few generations before its population is large enough to offer control. Therefore the recommended release strategy is to apply Dicyphus to mullein banker plants to develop when planting your crop. Another strategy is to apply as soon as whiteflies are detected at a rate of 1-2 /10 ft2 (/m2) of infested area; repeat in 2-3 weeks. Add supplementary food (frozen moth eggs Ephestia k.) to these areas weekly.
Dicyphus needs large numbers of prey to reproduce so releases should only be made in areas where pests have been detected or where supplementary food is being added.
This predator obtains water from plant feeding and can survive for long periods without food, but must have insect food to reproduce. Feeding damage to the plant or tomato fruit is superficial and not usually noticeable unless population levels exceed 100 Dicyphus/plant.
The use of mullein banker plants (Verbascum thapsus) and supplemental feeding is highly recommended for increasing Dicyphus numbers.
Since Dicyphus is also a plant feeder it should not be used on crops which can be damaged. An example is Gerbera crops where nymphs and adults may feed on the developing flower buds and cause distortion and spoilage of the flowers.
Adults and nymphs move quickly and hide in plant material when approached. On mature tomato plants adults and nymphs are often found on the middle leaves.
Most pesticides used for whitefly including systemic pesticides are harmful to Dicyphus. Check with your supplier or with a chemical effect list before using any pesticide.