Common whiteflies aren't hard to miss — as their name implies, they're white, and the vast majority of insect pests that affect greenhouse crops are brown and black. Whiteflies are also rarely seen singly, preferring to travel in swarming patterns instead. Their eggs are also white and somewhat resemble a fungal pathogen known as powdery mildew when they're on the surface of a leaf. Whiteflies lay their eggs on the undersides of leaves, so be sure to check that area when monitoring for insect pests.
Whiteflies and Greenhouse Crops
Whiteflies are a major problem with commercially grown.
Poinsettias, tomatoes, and a variety of herbaceous annuals and perennials
Isolated whitefly infestations won't do much more than cosmetic damage to otherwise healthy plant material, but whiteflies that have gotten out of control have the potential to decimate entire greenhouse crops. Fortunately, there are strategies designed to minimize and even eliminate whitefly populations that don't fall outside of the perimeters of organic growing practices.
Preventing Whitefly Infestations
Preventive measures are the most important part of whitefly control in commercial greenhouses because these insects are far easier to prevent than they are to eradicate once they gain a foothold on your greenhouse crops. The following are five preventive measures you can take.
- The first step is to thoroughly inspect your greenhouse for any signs of openings in which the insects may potentially gain access from the outside. Make sure that any opening, no matter how small, is securely closed.
- Practice weed control on the outside of your greenhouse. Whiteflies love common weeds, and they'll be more likely to access the interior greenhouse if large populations exist near the exterior.
- Implement a monitoring program that entails checking for whiteflies on a daily basis, especially when crops are known to be vulnerable to this pest. Apply an insecticidal soap that's certified for use in organic growing on leaves if insects or their eggs are discovered.
- Provide plants with good air circulation. Make sure to have pass-through fans running and to provide at least six inches of room between the outer leaves of each individual plant. Whiteflies love dense foliage and dank conditions.
- Release ladybugs. Ladybugs are an effective natural control against whiteflies in their adult, pupa, and larva stages. Some growers use them even before they notice whiteflies as a way of hedging their bets.
The good news about whiteflies is that they can't withstand winter weather conditions in anywhere but the tropics, which means you can get an early start on controlling them because most greenhouse crops are planted in late winter.
For more information, contact an organic greenhouse production service.