Q&A: When Will Spotted Lanternfly Eggs Hatch?

Spotted Lanternflies are black with white spots when they first hatch
Immature Spotted Lanterflies are black with white spots when they first hatch in mid-April to May. Photo: Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org

Q: When will Spotted Lanternfly eggs hatch? We’ve had such warm spells this season that I worry it’ll be early.

A: Spotted Lanternfly (SLF) egg hatch, like the activity of many insects, is greatly dependent on temperature. Predictions for egg hatch in an average year begin around mid-April but can continue into May, so while it may not be early per se at this point, it still will be soon. As such, this is your last opportunity to be vigilant for egg masses to squish before the active, hopping, hard-to-catch juveniles appear.

Don’t panic – juveniles cause little plant damage to gardens when young – but eliminate any egg masses within reach if possible because this is a serious agricultural pest (vineyards, mainly) and it might help you avoid an inundation of nuisance lanternflies later. To be fair, many eggs are laid high in tree canopies, making them inaccessible, but others can be laid on piles of stone, fencing, car hubcaps, grills, outdoor furniture, honey bee hive boxes, and so on.

Gray patches that look like dried mud are Spotted Lanternfly egg masses
Spotted Lanternfly egg masses on wood. Photo: Emelie Swackhamer, Penn State University, Bugwood.org

Be advised that the quarantine zones in Maryland have recently been expanded, and records indicate that the abundance of this pest has grown in our central counties. Check our Spotted Lanternfly web page and information updated on the Maryland Department of Agriculture website for more details. An MDA entomologist presented a refresher webinar about SLF this past winter, which you can find on the UMDHGIC YouTube channel as “Spotted Lanternfly Update from MDA.”

Spotted Lanternfly webinar (1 hour, 11 minutes)

If you haven’t seen Spotted Lanternflies in your neighborhoods yet, be prepared to see them in the next year or two as the population expands. I don’t want to scare you, just make you aware this will probably be something you’ll have to experience sooner or later, and I definitely discourage the use of any pesticide to combat this insect if its use can be avoided. Pesticides used to kill SLF have impacts on other insects and organisms and we don’t want to contribute to ecosystem damage by using them when the SLF damage done to most garden plants will be minimal.

By Miri Talabac, Horticulturist, University of Maryland Extension Home & Garden Information Center. Miri writes the Garden Q&A for The Baltimore Sun and Washington Gardener Magazine. Read more by Miri.

Have a plant or insect question? The University of Maryland Extension has answers! Send your questions and photos to Ask Extension. Our horticulturists are available to answer your questions online, year-roundYou can also connect with your local County/City Extension Office and Master Gardener local programs.

Spotted Lanternfly Moves Into New Areas This Year

spotted lanternflies
Adult and 4th Instar Juvenile Spotted Lanternflies. Photo: Richard Gardner, Bugwood.org

Spotted Lanternfly (Lycorma delicatula) arrived in Maryland last year. These invasive insects are being controlled now in 15 sites in Cecil County and several in Harford County. The Maryland Department of Agriculture has expanded its survey sites along the Pennsylvania and Delaware borders to monitor for this pest. They also are surveying in Washington County since Route 81 goes through there. A Spotted Lanternfly infestation was found along Route 81 in Winchester, Virginia.

The map below shows (in blue) where state quarantines for Spotted Lanternfly are in effect in Pennsylvania, New Jersey, Delaware, and Virginia. Permits are required for any commercial or university vehicles doing business in the quarantine zone or passing through quarantine areas. Here is a link to the Pennsylvania permit page. Maryland has reciprocity with Pennsylvania for permits.

map showing spotted lanternfly distribution

This is a potentially very devastating pest that has over 70 host plants including vegetables, garden plants, many trees, and especially invasive Tree of Heaven (Ailanthus altissima) which it may need to feed on to complete its life cycle. Lanternfly adults are very active now and are in the process of laying eggs. Please be vigilant and report any sightings to the Maryland Department of Agriculture at Dontbug.MD@Maryland.gov.

adult spotted lanternflies and an egg mass
Adult Spotted Lanternflies and an Egg Mass. Photo: Richard Gardner, Bugwood.org

For the latest information, check out Penn State Extension’s website on Spotted Lanternfly. They are the leader in research on this pest and have excellent information, photos, and videos.

By Mary Kay Malinoski, Extension Specialist, University of Maryland Extension, Home & Garden Information Center

Q&A: What Is Causing Trees to Lose Their Bark?

Several observations of tree bark damage like this have been reported to the University of Maryland Extension’s Home & Garden Information Center (HGIC) recently. 

Q: I was walking in the woods near my house and noticed bark trimmed off a tree. It looked like a buck rubbing with their antlers, but it was up high, about 10 feet. A couple weeks later, I was in my back yard and noticed the same thing on one of my trees. Can someone please help me figure out what is going on? Thanks!

A: This looks like damage from woodpecker feeding. Judging from the bark pattern of the tree, this looks like an ash tree. Many ashes in Maryland are becoming infested with the invasive emerald ash borer (EAB). Taking a close look at the photo, it appears there are borer holes in the trunk where the bark was removed. The EAB larvae that feed on the nutrient transporting layers under the bark are a good food source for birds such as woodpeckers. This woodpecker impact is being seen and reported more and more frequently.

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Spotted Lanternfly: A New Invasive Pest That is Too Close for Comfort

spotted lanternfly adult
Spotted Lanterfly Adult. Photo: Pennsylvania Department of Agriculture, Bugwood.org

Spotted Lanternfly (Lycorma delicatula) is an insect native to China that was first detected in Southeastern Pennsylvania in September 2014.  It has spread fairly rapidly since then. There were recent finds in Delaware and New York. Both were dead individual adults.

spotted lanternfly quarantin map of pennsylvania november 2017
A quarantine is in place in several counties of Southeastern Pennsylvania to restrict the spread of Spotted Lanternfly. Source: Pennsylvania Department of Agriculture

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