Measures to eliminate pests on holly plants in the garden start with cultural control — maintaining the holly strong and healthy so it can withstand and recover from pest infestations. Biological controls include beneficial insects already present or introduced into the garden that prey on insects that are dangerous. Sometimes, infestation and damage to the holly is intense enough to warrant using pesticides. When that happens, start your pest control schedule using the least toxic pesticides available and utilize poisonous chemicals only as a last resort.
Horticultural Oils
One of these less toxic pesticides available for holly plants is olive oil. This pesticide, sprayed thoroughly with special attention to the undersides of the leaves, smothers insects on the holly. Horticultural oil — also known as narrow-range, superior or supreme oil is made of oil products. Sprays are usually most successful during the dormant season or from late winter to summer. The product poses no known risk to fish from runoff and is considered low-impact as far as valuable mammals are involved. Horticultural oil does not have any residual impact, killing just those insects it contacts through program. To avoid harming honeybees, the oil needs to be utilised in early morning or at night, before bees become busy in the garden.
Insecticidal Soap and Neem Oil
Like olive oil, insecticidal soap and neem oil are touch killers that smother just those insects present in the time of program. Repeat sprays are occasionally required to finish off the majority of the pests. Natural predators may then take over to finish the task for you. Some insecticidal soaps include pyrethrins for more killing power. Insecticidal soaps and neem oil controls aphids, mites and other sap-sucking insects that may infest holly plants, in addition to larval forms of leafminers and other damaging insects. This product has a marginally higher sensitivity to honeybees, so spraying during the night or early morning minimizes the risk. Spraying in bright sunlight may burn the plant.
Sticky Tape and Baits
Because ants shield sap-sucking insects that excrete honeydew, controlling ants infesting the holly plant allows beneficial insects to become in the aphids, soft-scale insects and other damaging pests. Sticky tape wrapped around the lower stems of the holly prevents ants from climbing into the foliage. You may also wrap the stems with masking tape, paper or especially manufactured fabric wrap for coat and trees the stuff with sticky stuff. Ant baits contain both the attractant and a pesticide that ants carry back to their divisions, killing the rest. Although baits act more gradually, pesticide sprays are confined to killing just the ants present in place of the colony.
Other Chemical Pesticides
Insecticides containing chemicals such as carbaryl, organophosphates or pyrethroids kill aphids, holly leafminers, scale insects, mites, and the larval stages of beetles and moths. These goods have a residual effect that not only eliminates the target pest, but also beneficial insects that attempt to prey on them. Runoff in rural regions may pose a hazard to water supplies. Spray is usually best beginning in mid-May, according to the University of California Statewide Integrated Pest Management site. This is when pests like holly leafminer start to lay eggs. Products containing spinosad or imidacloprid (or both) are somewhat toxic to beneficial insects and honeybees. Acephate is highly toxic to honeybees. All three products work on aphids, scale insects, leafrollers, and moth larvae.
Systemic Pesticides
A narrower approach to target pesticides is to work with imidacloprid as a systemic pesticide. This might be applied to the soil, by injection to the primary stem or as a foliar spray. The pesticide is absorbed by the holly and spread throughout the plant, killing all insects feeding everywhere around the plant. Soil applications are usually best, according to the UC Statewide IPM site, avoiding the harm brought on by stem injection and hazard of spray drift inherent in foliar sprays. Imidacloprid is readily absorbed by the holly’s roots for flow to the foliage and stems.