A bigger, bolder tick than the deer tick, brown with ornate whitish marbling on its shield, common on dogs and pant legs after grassy walks.
Where to look
Grassy road edges, field margins, and sunny trail sections
When
Most active April–August
Months
April to August
Easily confused with
Blacklegged (deer) tick is smaller and unpatterned, and the more serious disease risk here.
Do not touch
Same drill as every tick: prompt removal with tweezers, nightly checks. It can carry Rocky Mountain spotted fever. That's rare, but a fever with headache after a bite deserves a doctor.
A large glossy-black beetle spotted with white, and with long black-and-white banded antennae often longer than its own body; leaves round (not D-shaped) exit holes in bark.
Where to look
On hardwoods like maple; not yet found at GRSF, so any sighting matters
When
Adults active summer–early fall
Months
June to September
Easily confused with
Native long-horned beetles exist, but this one's big size, bright white spots, and round exit holes are distinctive. If unsure, photograph and report it.
Do not touch
PRIORITY INVASIVE — report immediately to USDA APHIS if found. Kills hardwoods including maple, birch, elm, willow.
Invasive
Not currently known to be established in Maryland. This is a watch-list species. If you think you see one (or its perfectly round exit holes in maple), photograph it and report to USDA APHIS; early detection is the whole game.
The deer tick: sesame-seed small, reddish body with black legs and a black shield behind the head. The nymphs in early summer are poppy-seed small and the real Lyme risk.
Where to look
Leaf litter, log edges, and grass along every trail. It finds you, not the reverse
When
Active spring through fall on any day above ~40°F, and warm winter afternoons too
Months
March to November
Easily confused with
American dog tick is bigger with white patterning and carries different (rarer) diseases; treat every tick the same way regardless.
Do not touch
This is the one to take seriously — it carries Lyme disease. Do a full tick check every night (kids, scalp, waistband, dogs). Remove attached ticks straight out with fine tweezers, then wash. A spreading bull's-eye rash or fever in the weeks after means a doctor visit. Mention the tick.
A brown, marbled, shield-shaped bug about the size of a fingernail, with tell-tale alternating black-and-white bands on the antennae and shield edges.
Where to look
On foliage and sunny walls; gathers on tents and gear as it cools off
When
Active spring–fall; crowds indoors and onto tents in fall
Months
April to October
Easily confused with
Native stink bugs lack the banded antennae; those black-and-white antenna rings are the giveaway.
Do not touch
Harmless to you, but it earns its name: if you squash or startle it, it releases a lasting skunky smell, so flick it off instead.
Invasive
An invasive farm pest. No need to report it (it's already widespread), but sweep or shake them off gear rather than crushing them, and don't pack them home.
An alarmingly large black-and-yellow wasp (up to two inches) cruising low over bare ground in high summer, or hauling a paralyzed cicada twice its weight back to its burrow.
Where to look
Bare sandy patches, road banks, and campsite edges. Look for the U-shaped dirt mounds at burrow entrances
When
July–September, during cicada season
Months
July to September
Easily confused with
European hornets are social, night-active around lights, and defend nests; cicada killers are loners that ignore you.
Do not touch
Scarier than it is: males can't sting at all (they just bluster), and females sting only if you literally grab one. Not a defender of nests like yellowjackets, so you can watch from a step away.
A soft-bodied beetle with a dark red-and-black shield over its head; by day it's easy to overlook, but at dusk the males float upward flashing a yellow-green 'J' of light.
Where to look
Rising over damp meadows, clearings, and forest edges after dark. It's the most common firefly here
A huge, heavy greenish-gray beetle blotched with black; the male sports a long curving horn like tiny rhino pincers. One of the largest beetles you'll find here.
Where to look
Drawn to lights at night; larvae grow for years in rotting wood
When
Adults Jul–August, mostly at night
Months
July to August
Do not touch
Impressively big but completely harmless: the horns are for wrestling rival males, not for you.
A big yellow butterfly with four bold black 'tiger' stripes on each forewing and tails on the hindwings; some females are entirely blackish instead of yellow.
Where to look
Sunny clearings, roadsides, and mud puddles all over GRSF. This is Maryland's state insect
A small, slender, brilliant metallic-green beetle about a half-inch long; you're far more likely to see its calling card: neat D-shaped exit holes in ash bark and dying ash crowns.
Where to look
On and around ash trees; watch for D-shaped holes and thinning, dying ash across GRSF
When
Adults active late spring–summer
Months
May to August
Invasive
This beetle has devastated ash trees across the region. Report signs to the MD DNR Forest Service (dnr.maryland.gov/forests). Most important thing you can do: don't move firewood. Buy it where you burn it, since firewood is how the larvae travel.
A big bright-orange summer butterfly with black chain-link patterning above. Underneath, silver spangles scatter across the wings like drops of mercury.
Where to look
Milkweed and thistle patches in sunny clearings; the caterpillars feed only on violets, at night
When
One long brood, June–September
Months
June to September
Easily confused with
Monarchs sail with flat wings and have white-spotted black borders; fritillaries flap-and-glide and flash silver beneath.
A shiny beetle about a half-inch long with a coppery back and a metallic-green head, with little white tufts of hair poking out along each side; often clustered feeding in groups.
Where to look
Skeletonizing leaves on many plants in sunny areas, often several to a leaf
When
Adults swarm June–August
Months
June to August
Easily confused with
The row of small white hair tufts along its sides separates it from native look-alike beetles.
Invasive
A widespread invasive plant pest. No need to report it, but don't move infested plants or soil that might carry its grubs.
A stunning pale-green moth as big as your palm, with long twisting hindwing tails and a translucent eyespot on each wing; a rare treat, usually seen at night near lights.
Where to look
Drawn to lights at night; adults live only about a week
A long, impossibly thin green or brown insect that looks exactly like a bare twig, with skinny legs held stiffly out; it barely moves and is easy to walk right past.
Where to look
On the leaves and twigs of oaks and cherries; look closely
Black body, red eyes, orange-veined wings: unmistakable, and in an emergence year, uncountable. Brood V owns this corner of Maryland and returns around 2033.
Where to look
Between emergences you'll only find shed nymph skins on trunks and old egg scars on twigs — then one May, everything, everywhere, all at once
When
Adults for about six loud weeks, May–June, in emergence years only
Months
May to June
Easily confused with
Dog-day (annual) cicadas are green-and-black, come every summer, and have dark eyes. Red eyes mean periodical.
Do not touch
Completely harmless. They don't bite or sting. Dogs will eat them until they regret it.
A slender green or brown mantis with folded 'praying' front legs and a swiveling triangular head; our smaller native mantis, usually under three inches.
Where to look
Meadows, brush, and sunny plants
When
Adults late summer–fall
Months
August to October
Easily confused with
Smaller than the introduced Chinese mantis, which can reach four inches and is more common in fields.
A dark butterfly crossed by bright red-orange bands on the forewings and along the hindwing edge, with white spots at the wingtips; often lands on people.
Where to look
Woodland edges, trails, and clearings; frequently basks on sunlit spots
You'll usually notice the caterpillars (dark and hairy with a double row of blue then red dots down the back) or the fuzzy tan egg masses stuck to bark; adult males are brown moths.
Where to look
On oaks, which the caterpillars can strip bare in outbreak years; egg masses on trunks, rocks, and gear
When
Caterpillars May–June; tan egg masses visible fall through winter
Months
May to July
Do not touch
The caterpillar's hairs can cause an itchy rash on some people, so don't handle them bare-handed.
Invasive
An invasive that defoliates oaks in cyclic outbreaks. Report heavy infestations to the MD DNR Forest Service (dnr.maryland.gov/forests). Check tents, gear, and vehicles for the fuzzy egg masses and scrape any off before you leave, so you don't spread it.
At rest, gray forewings with black spots; when it flushes, it flashes scarlet hindwings banded in black and white. Young nymphs are black (later red) with white spots.
Where to look
On tree-of-heaven and grapevines; egg masses look like smears of dried mud on trunks and flat surfaces
When
Adults Aug–November; spotted nymphs spring–summer
Months
June to November
Do not touch
It doesn't bite or sting people, but this one you should kill on sight, and scrape off any egg masses you find.
Invasive
A priority invasive and a serious threat to trees and crops. Report it right away to the MD Department of Agriculture (mda.maryland.gov). Squash adults and nymphs, scrape egg masses into a bag, and check your gear and vehicle so you don't carry it out.
A big gray armored assassin bug with a bizarre cog-wheel crest on its back, like a dinosaur shrunk to thumb size, stalking slowly through foliage after caterpillars.
Where to look
Shrubs, sunflower heads, and tree trunks. Often motionless, easy to mistake for bark
When
Adults most visible July–October
Months
July to October
Easily confused with
No other local insect has the cog-wheel. Leaf-footed bugs are browner, flatter, and harmless.
Do not touch
Look, don't handle. It's a gardener's friend, but its defensive bite is genuinely painful: most people rate it worse than a bee sting, and it can ache for days.
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