Early instar nymphs hatch from mid-April to June. The early instar nymphs are very small and will grow larger through July when they molt into the 4th instar. (Photo by Lawrence Barringer, PA Dept of Agriculture, Bugwood.org)
4th instar nymphs can be found starting in July. They molt from the early instars and are distinctive because of their red coloration. (Photo by Alejandro Calixto, NYSIPM)
Adults are about 2.5 cm (1 inch) in length. The forewings are light brown with black spots. The hind wings are mainly red with black spots. The red color is especially noticeable when the insect flies. Adults can be found as early as July, and they will remain active until the first hard frost of the year, usually in November. The females begin laying eggs in September and conclude their egg laying by the first frost in November. (Photo by Lawrence Barringer, PA Dept of Agriculture, Bugwood.org)
SLF females prefer to lay their eggs masses on a host tree, however, they may also deposit eggs on a variety of flat surfaces including buildings, trailers, fence posts and vehicles. The eggs are laid in groups of approximately 30-50 and then coated with gray wax. When the wax has dried it can look similarly to a splash of mud making it difficult to notice them. The eggs typically hatch in the spring, usually in the first week of May. (Photo by Massachusets Department of Agriculture)
The following is a list of some of the host plants on which SLF has commonly been found to feed. This is not a complete list as they feed on over 70 plant species. Plants at risk can include:
- Tree-of-heaven
- Grape
- Black Walnut
- Red Maple
- Silver Maple
- Weeping willow
- Black Willow
Tree of heaven (Ailanthus altissima) is the primary host for SLF. They can be found feeding on tree of heaven at all life stages. More information on tree of heaven can be found here.
Damage
Nymphs and adults feed on plants, using their piercing mouthparts to suck sap from trunks and stems. This has been shown to cause stunted growth, localized damage, and reduced yields.
Additionally, as SLF feeds, it excretes a sugary substance called honeydew. Honeydew is attractive to ants, wasps, and bees and can develop an intense, rotten odor as it ferments. It is also readily colonized by black, sooty mold which can cover leaves and inhibit photosynthesis. Sooty mold can also cover manmade structures and can be difficult to remove.
It should be noted that although SLF have been found on crops such as corn, soybeans, and alfalfa, they haven’t been observed feeding on these plants.
Although SLF can be present in large numbers on host plants, SLF are not typically associated with host mortality. SLF is considered a stressor that may contribute to the decline of its host. The exception to this is grapes, which can suffer greatly reduced winter hardiness as a result of SLF feeding. It remains to be seen what effect lanternfly feeding will have on Maryland’s vineyards.
Management
The Maryland Department of Agriculture does not operate a residential spray program. We cannot offer to treat private residences for SLF, except within a narrow range of circumstances. If you qualify for treatment, you may be contacted by an MDA employee.
- Mechanical controls are non-chemical. They rely on killing SLF by hand or trapping. These options are the least environmentally impactful available. Please consider them first before choosing to use insecticides.
- Trapping - Traps are passive systems that can provide continuous control. They will need to be maintained. They can be erected as soon as early instar nymphs hatch, through until the end of the adult stage. Traps are ineffective once the adults have died off. Commercial traps are available. Do-it-yourself options are available on the internet. For example, a circle trap from Penn State University Extension.
- Chemical controls are insecticides.
- Be extremely cautious when choosing to apply insecticides! There is no insecticide that is specific to spotted lanternfly. Any application of insecticide has the potential to kill non-target insects.
- Insecticides are classed into two groups: contact and systemic.
- Contact - are mixed and applied directly to the pest insect.
- It is strongly recommended that you limit the use of contact insecticides to concentrations of SLF in order to reduce your environmental impact.
- Systemic - are mixed and applied to a host plant. The plant absorbs the insecticide and becomes toxic to the insects that feed on it.
- It is strongly advised that you limit the use of systemics to tree of heaven (Ailanthus altissima). Applying systemic insecticides to native plant species may result in substantial non-target losses.
- Do not apply insecticide to lawns! SLF does not reside in lawns.
- Specific information on chemical insecticides that are effective against SLF can be found by submitting a request to University of Maryland Extension at Ask Extension.
- A list of state-licensed applicators can be found here. You will need to know the type of applicator and the location within which you are seeking service.
- Cultural controls involve altering the way in which a property owner cultivates their property.
- The only recommended cultural control for SLF is removing their primary host, the tree of heaven. This will not eliminate SLF, but it makes a property less attractive to them.
- Removing tree of heaven can be laborious and expensive because its root system must be destroyed entirely to prevent suckering. For more information on controlling tree of heaven follow this link.
- The removal of other plant hosts is not recommended.
Marylanders should be aware that SLF is going to remain present in the landscape despite most management efforts. The extent of each
property owner's response will need to be measured against how much of a problem the SLF are. The Department of Agriculture cautions all Marylanders to please be judicious in your application of insecticides and to always adhere to the product label.
Additional information on lanternfly management for residents can be found at:
Permitting and Quarantine
The Secretary of Agriculture has issued a quarantine order for 20 Maryland counties. Businesses and institutions are required to be permitted if they move regulated articles from or within the quarantined area. Permitting is free and only needs to be undertaken by a single representative. That person can then train others on the identification and proper management of spotted lanternfly. Permits from other states are entirely reciprocal within Maryland. Be prepared to present your permit if questioned by an MDA inspector.
Persons found to be in violation of the Secretary’s quarantine order are liable for a civil penalty per each violation.
The list of regulated articles, the definition of persons required to obtain permits, as well as the parameters of the civil penalty can be found in the text of the Secretary of Agriculture’s quarantine order, here.
Residents should utilize the checklist for homeowners. Thoroughly inspect all items presented on this list for any type of spotted lanternfly life stage and destroy all lanternfly that you discover. This will help slow the spread of the insects to new areas. 