Delaware Wildlife Alert: The Dangerous Pests You Need to Watch Out For Right Now

From the Brandywine Valley down to the beaches of Sussex County, here is what you need to know to stay safe this month.

1. The Spotted Lanternfly: Hatch Season Is Here

Delaware remains under a high-alert status for the Spotted Lanternfly (SLF). As of mid-April 2026, we have entered the transition period where the mud-like egg masses begin to hatch into tiny, flightless nymphs.

• The Threat: These sap-suckers target over 70 host plants, including Delaware's vineyards, fruit orchards, and hardwood trees like the Black Walnut.
• What to Look For Now: You are looking for the "first instar" nymphs—tiny, black insects with white spots. They are often mistaken for small ticks or spiders.
• Action Plan: If you see egg masses (gray, mud-like smears) on your car, fence, or trees, scrape them into a bag of rubbing alcohol immediately. If you find nymphs, "squish on sight" is the standing recommendation from the Department of Agriculture.

2. Box Tree Moth: A New Border Threat

On March 6, 2026, the Maryland Department of Agriculture issued an emergency quarantine that includes several counties bordering Delaware. Official surveys have now confirmed established populations of the Box Tree Moth within Delaware's borders.

• The Danger: This invasive moth from East Asia can completely defoliate and kill boxwood shrubs in a single season.
• Detection: Check your ornamental boxwoods for heavy webbing and bright green caterpillars with black stripes.
• The Rule: Avoid moving boxwood plants or clippings between counties. If you suspect an infestation, report it to the Delaware Department of Agriculture's Plant Industries office.

3. Ticks: A "Higher Prevalence" Year

Delaware health officials are warning of an aggressive tick season in 2026. Following a "rollercoaster" spring with alternating warm and cool days, the first Deer Ticks of the year were active as early as March 9th.

• The Nymph Alert: In April and May, we see the emergence of nymphal ticks. These are the size of a poppy seed and carry a significantly higher risk of transmitting Lyme Disease because they are so difficult to detect on the skin.
• Where They Hide: Particularly prevalent in the tall grasses of New Castle County's parks and the brushy "edge" habitats of the southern coastal forests.
• Prevention: Wear light-colored clothing to spot them more easily and perform a thorough "pressure check" (feeling for small, stationary bumps) after any outdoor activity.

4. Venomous Residents: Copperheads on the Move

Delaware has only one medically significant venomous snake: the Northern Copperhead. As daytime temperatures consistently reach 60°F this April, they are leaving their winter dens to find food.

• Identification: Look for the unmistakable "Hershey Kiss" or hourglass patterns on their sides. They blend in perfectly with the dried leaves and mulch common in Delaware gardens.
• Hiding Spots: They are frequently found near woodpiles, stone walls, and the edges of freshwater ponds.
• Safety Tip: Most bites occur when a person accidentally steps on or reaches near a hidden snake. Use a stick to move leaf litter before reaching into garden beds this spring.

5. Emerald Ash Borer: A Growing Forest Threat

While ash trees make up a small percentage of Delaware's forests, the Emerald Ash Borer (EAB) has seen a massive surge in activity. Recent aerial surveys mapped over 3,300 acres of damage, a significant jump from previous years.

• The Warning: As of April 2026, outside firewood is strictly prohibited in all Delaware State Park campgrounds.
• Action: To protect the State remaining ash trees, "Buy It Where You Burn It." Moving firewood is the primary way this pest hitches a ride into uninfested parks like Trap Pond or Lums Pond.

Summary Checklist for Delaware Residents

1. Inspect Your Boxwoods: Watch for webbing or green caterpillars to stop the Box Tree Moth.
2. Scrape and Squish: Mid-April is the final window to destroy Spotted Lanternfly egg masses before the nymphs take over.
3. Leave the Firewood: Only use heat-treated or locally sourced wood at state campgrounds to prevent the spread of EAB.
4. Tick Hygiene: Perform a full-body check on yourself and your pets every time you come in from a walk in the woods or tall grass.