Early instar nymphs hatch in the first week of May. The early instar nymphs are very small. They will grow larger through July when they molt into the 4th instar. (Photograph by Lawrence Barringer, PA Dept of Agriculture, Bugwood.org.)
4th instar nymphs can be found starting in June. They molt from the early instars and are distinctive because of their red coloration. (Photograph taken 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 October and conclude their egg laying by the first frost in November. (Photograph by Lawrence Barringer, PA Dept of Agriculture, Bugwood.org.)
Spotted lanternfly females prefer to lay their eggs masses on a host tree, however; they have also been seen depositing eggs on a variety of flat surfaces such as 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 which can make them difficult to notice. The eggs typically hatch in the spring, usually in the first week of May.
Here is a list of some of the host plants on which SLF has commonly been found to feed. Please keep in mind that this is not a complete list because they feed on over 70 plant species. Some plants that are at risk:
grape, black walnut, red maple, silver maple, eastern white pine, weeping willow, black willow, black cherry, sycamore.
Tree of heaven (Ailanthus altissima) is the primary host for spotted lanternfly. They can be found feeding on tree of heaven at all life stages. More information on tree of heaven can be found here.
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 the spotted lanternfly feeds, it excretes a sugary substance called honeydew. Honeydew is attractive to ants, wasps, and bees. Honeydew 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 spotted lanternflies 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 vinyards.
The MD Dept. 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 lanternfly 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.
- Insecticides can be purchased commercially or applied by a state-licensed applicator.
- Specific information on chemical insecticides that are effective against spotted lanternfly 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.
Additional information on lanternfly management for residents can be found at:
Permitting and Quarantine
The Secretary of Agriculture has issued a quarantine order for 11 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. Destroy all lanternfly that you discover. This will help slow the spread of the insects to new areas.