The Spotted Lanternfly (SLF) is an invasive pest that has been found to feed on a wide variety of plants, causing concern for agriculture and forestry. While the question “Can Flies See Red?” might seem unrelated, understanding insect vision and attraction to colors can be surprisingly relevant when managing pests like SLF. Although SLF is not a fly, but a planthopper, the question of color attraction is still pertinent in pest management strategies. This article, drawing upon expert information, will delve into the host plants of SLF, the damage they cause, and effective management techniques, providing a comprehensive guide for those affected by this invasive species.
SLF has been observed feeding on over 70 plant species, making it a polyphagous pest. Some of the commonly affected host plants include:
- Tree-of-heaven
- Grape
- Black Walnut
- Red Maple
- Silver Maple
- Weeping willow
- Black Willow
Alt text: Spotted Lanternfly nymphs and adults feeding on the bark of a Tree-of-Heaven, showcasing different life stages of the pest on its primary host.
Tree-of-heaven (Ailanthus altissima) stands out as the primary host plant for SLF. This invasive tree serves as a food source for SLF throughout all its life stages. Recognizing and managing Tree-of-heaven is crucial in controlling SLF populations. You can find more detailed information about Tree-of-heaven from resources like the University of Maryland Extension.
Damage Caused by Spotted Lanternfly
Both nymphs and adult SLF utilize their piercing-sucking mouthparts to feed on plant sap from trunks and stems. This feeding activity can lead to several detrimental effects on host plants, including stunted growth, localized damage, and reduced crop yields. The stress caused by SLF feeding can weaken plants, making them more susceptible to other diseases and environmental stressors.
Alt text: Visible feeding damage on a plant stem caused by Spotted Lanternfly, illustrating the piercing and sucking action of their mouthparts.
Furthermore, SLF excretes honeydew, a sugary substance, as they feed. Honeydew attracts other insects like ants, wasps, and bees. The fermentation of honeydew can also produce an unpleasant, rotten odor. Perhaps more concerning is that honeydew becomes a substrate for sooty mold. This black mold can cover leaves, branches, and even man-made structures beneath infested plants. Sooty mold on leaves inhibits photosynthesis, further stressing the host plant. Removing sooty mold from surfaces can also be a difficult task.
While SLF has been found on crops like corn, soybeans, and alfalfa, feeding on these plants has not been observed. This suggests that while SLF may be present in agricultural fields, their primary impact is on other host plants, particularly trees.
Although high populations of SLF can be alarming, they are not typically associated with causing immediate host plant mortality, with the notable exception of grapevines. SLF feeding can significantly reduce the winter hardiness of grapevines, potentially devastating vineyards. The long-term effects of SLF feeding on Maryland’s vineyards and other agricultural sectors are still under investigation.
Management Strategies for Spotted Lanternfly
It is important to note that the Maryland Department of Agriculture does not offer residential spraying programs for SLF. Management of SLF on private properties is primarily the responsibility of the property owner. Effective management strategies fall into several categories:
Mechanical Controls
Mechanical controls are non-chemical methods that focus on physically removing or trapping SLF. These methods are environmentally friendly and are recommended as a first line of defense.
- Hand-killing: Physically crushing or swatting SLF adults and nymphs can be effective for small infestations.
- Trapping: Various traps, such as sticky traps and circle traps, can capture SLF. However, be mindful of potential bycatch, as sticky traps can also capture beneficial insects and even small animals.
Alt text: A circle trap installed on a tree trunk to capture Spotted Lanternflies as they climb upwards, demonstrating a mechanical control method.
Chemical Controls
Chemical controls involve the use of insecticides. Caution is advised when using insecticides as no insecticide is specific to SLF, and any insecticide application can potentially harm non-target insects, including beneficial pollinators.
Insecticides are broadly classified into two types:
- Contact insecticides: These are applied directly to the SLF insect. It is recommended to use contact insecticides selectively and in areas with high SLF concentrations to minimize environmental impact.
- Systemic insecticides: These are applied to the host plant and are absorbed, making the plant toxic to SLF feeding on it. Systemic insecticides are best reserved for Tree-of-heaven to limit potential harm to native plants and non-target insects. Avoid applying insecticides to lawns as SLF does not typically inhabit lawns.
For specific insecticide recommendations, it is best to consult with the University of Maryland Extension or other local extension services. Licensed pesticide applicators can also provide professional treatment options.
Cultural Controls
Cultural controls involve modifying property management practices to make the environment less favorable for SLF.
- Tree-of-heaven removal: The most effective cultural control for SLF is the removal of Tree-of-heaven, their primary host. While this will not eliminate SLF entirely, it will make a property less attractive to them. Removing other host plants is generally not recommended.
Quarantine and Regulations
Maryland has implemented a quarantine order for several counties to slow the spread of SLF. Businesses and institutions operating within or moving goods from quarantined areas are required to obtain permits. Permitting is free and involves training personnel on SLF identification and management. Permits from other states are also recognized in Maryland. Violations of the quarantine order can result in civil penalties.
Residents within quarantined areas should utilize the homeowner checklist provided by the Maryland Department of Agriculture to inspect and destroy SLF in all life stages on items being moved. This vigilance is crucial in preventing the further spread of this invasive pest.
While SLF will likely remain a presence in the landscape, proactive management efforts can help mitigate their impact. Property owners should assess the level of SLF infestation and implement appropriate control measures, always exercising caution and adhering to product labels when using insecticides. By understanding SLF host plants, damage, and management options, communities can work together to minimize the impact of this invasive species.
