Loopers

About 30 different species of aphids can be found in greenhouses, depending on the crops grown. Aphids are generally less than 1/8 inch long and can occur in large colonies on new plant growth, the base of buds, or the undersides of mature leaves. There are many species of Aphids which range in colour from greenish-yellow to very dark green, dark brown to black and even pink. In large group some have wings, which are transparent.

Damage

Aphids are insects that suck away at the plant sap and cause distorted growth. Aphids void waste as a sugar-rich liquid called honeydew, which attracts ants and promotes growth of black-coloured fungi called sooty mold. In addition, some aphids can also transmit viral plant diseases.

Detection and Monitoring

Cleanliness is an important part of Aphid control. To prevent the introduction of new Aphid species into your greenhouse, carefully inspect all new plants before placing them in the growing areas. Eliminating all weeds in or near the greenhouse can be useful because it will help suppress potential pools from which Aphids might enter the crop. Signs of an Aphid infestation include the presence of white cast (molted) skins, honeydew, and black sooty mould fungi. Yellow sticky cards can capture winged Aphids that have entered the greenhouse from outdoors, particularly during spring and early summer.
Insecticides with contact, Tran’s laminar, or systemic activity can be used to control Aphids. Trans laminar is a means by which after application, the material penetrates leaf tissues and forms a reservoir of active components within the leaf. This provides protracted lasting activity even after spray residues dissipate. Insecticide applications must be initiated early in the cropping cycle, when plants are small. Surfactants help to cover plant areas with wettable or soluble powder
Insect growth regulators and pyrethroid-based insecticides also provide control of Aphids.
Initial extended control of Aphids can be contained by using Systemic insecticides, including neonicotinoid-based insecticides

Biological Control
Aphids have many natural enemies and several groups have been studied as potential biological control agents for release in greenhouse crops. Aphids are vulnerable to many natural enemies, both predators and parasitoids, which may serve as effective biological control agents in greenhouses. Aphid predators include ladybird beetles, lacewings, and predatory midges. There are several biological control options for greenhouse aphid pests. Some common biological control agents (BCAs) include green lacewings (Chrysoperla carnea, C. rufilabris,Chrysopa spp.), Aphid midges (Aphidoletes aphidimyza), parasitic wasps (Aphidius colemani and Aphidius matricariae) and lady beetles (Hippodamia convergens). At all temperatures, Aphidoletes is the best of the four at controlling aphids. However, the predatory midge is not effective during short-day conditions.

Entomopathogenic fungus:
The entomopathogenic fungus, Beauveria bassiana, is most effective when Aphid populations are low. This fungus may not be compatible with the convergent ladybird beetle (Hippodamia convergens) depending on the concentration of spores applied.
Biorational Pesticides

Strains of the fungus Beauveria bassiana provide good control of Aphids, including green peach Aphids. The fungus works by attaching to the exterior of the pest, then penetrating the body and killing it.

Insect Growth Regulators

Insect growth regulators (IGRs) are another least toxic Pesticide control option for pests. IGRs typically kill insects by disrupting their development.