Fall is Egg-laying Season for the Spotted Lanternfly

The Spotted Lanternfly (SLF) continues to be a significant landscape pest in southeastern Pennsylvania.
Fall is Egg-laying Season for the Spotted Lanternfly - News

Updated: November 17, 2017

Fall is Egg-laying Season for the Spotted Lanternfly

Fresh spotted lanternfly egg masses. Photo: Emelie Swackhamer, Penn State

In addition to being a nuisance, it is clear that heavy infestations will harm landscape trees and impact orchard and vineyard businesses in the area. By October, the lanternfly population reached the adult (winged) stage. In some cases, intense adult clustering is still observed in several locations while in other areas SLF has redistributed in smaller groups.

Egg laying started early October. SLF will oviposit eggs on trees as well as any other hard surfaces (e.g., park benches, rocks, fence posts). The adult female deposits an average of 35 eggs in each egg mass. The eggs are laid in straight lines and covered with a waxy material. As the egg mass ages, it become well-camouflaged. The waxy material dries, cracks, and resembles a splash of dried mud. Females will continue to lay eggs until December when the temperatures are too cold for adult survival.

Spotted lanternfly egg mass on tree. Photo: Amy Korman, Penn State

During the fall season, the SLF management calendar continues to focus on restricting the movement of all living stages of the lanternfly. That is, the public should continue to avoid moving adults and egg masses outside the quarantine area. Businesses and residents in affected areas should continue inspection and vigilance in restricting further expansion of the SLF infestation. Some contact pesticides may be effective against the adult stage. Pennsylvania law requires pesticide labels to list the site(s) of the pesticide application; specific pests, such as SLF, are not required to be included on the label. The local Extension office can assist the public with questions regarding the appropriate use of pesticides against SLF.

Another option that should impact SLF is the removal of Tree-of-heaven (Ailathus altissima) from the property. Tree-of Heaven is the primary host of SLF and it is also an invasive plant species. A reduction in the availability of a primary host may impact the future growth of the insect population. Cutting the tree alone will not kill it. The stump must be treated with an herbicide to prevent new growth from sprouting from the stump. Read all pesticide labels carefully to ensure the products are used safely.

Mechanical control through egg removal is another opportunity to help to reduce next year’s population. Egg masses can be scraped into a plastic bag with liquid hand sanitizer and placed in the trash. Alternatively, eggs (within safe reach) can simply be smashed in place using the edge of a hard piece of plastic or other stiff material. The egg stage of many insects is hard to kill with chemicals and effective ovicides (a pesticide that kills eggs) for SLF have not been identified to date.

There are many opportunities to help stop the spread of SLF; however, community awareness is essential in controlling this invasive pest. The Green Industry and residents can help spread the word. If observed outside the quarantine area, report it to or call 1-866-253-7189.

Pennsylvania Department of Agriculture: Spotted Lanternfly