June Bug / Beetle (Phyllophaga spp.)

Terrestrial, hatching June–July, active in water between 58 and 75°F, and imitated at #10–14. Recorded from northern lower Michigan, southern lower Michigan and the Upper Peninsula, where 1140 Michigan rivers on this site carry a page.

Chunky brown scarab beetles that fly clumsily at dusk in early summer and land in the water regularly — size 10 to 14 and heavier than they look. Only the adult matters: a dusk fly on tree-lined water, fished with a deliberate splash rather than a delicate one. A big clumsy beetle on a warm June evening is a mouthful worth a trout leaving cover for. The peak falls in June and July, and the active water-temperature band runs 58 to 75 degrees, which covers cold-transitional, cool and warm streams. Patterns are all bulk and float: a Foam Beetle at 12 to 18, a Chubby Chernobyl at 8 to 14, or a Stimulator at 8 to 16. The records behind this entry span northern and southern lower Michigan, the Upper Peninsula, the Wisconsin driftless, northern Wisconsin, and the Virginia and North Carolina mountains — a coarse picture of where the insect turns up, and no more specific than that.

#10–14Hook size
58–75°FWater, active
Jun–JulPeak months
1Life stage fished

Subbasins with trout water where it is on record: 42 of Michigan's 59.

See Michigan's trout water on the live map → Every reach coloured by water temperature — the water these hatches come off.

What it is

Terrestrial · Phyllophaga spp. · adult

Chunky brown scarab beetles that fly clumsily at dusk in early summer and land in the water regularly. Size 10 to 14 and heavier than they look.

A big clumsy beetle on a warm June evening is a mouthful worth a trout leaving cover for.

When it hatches

Peak is June–July. The pale months either side are the shoulder — the app widens a peak by one month in each direction and recommends the bug there, and no further: that widening is bounded so that a bug peaking in May is never offered in August.

JFMAMJJASOND

peak shoulder not recommended

Water conditions

The band is a water temperature, not an air temperature, and it is the range in which this insect is worth fishing — for a mayfly that is the emergence window; for a scud or a midge it is simply the range trout will still eat one in.

58°F 75°F

Active from 58°F to 75°F. On this map that is cold-transitional, cool, warm water — the band crosses 2 of the three breaks the river colours use. Breaks at 58, 64 and 70°F.

Stages

What the insect is doing, and what that means for what you tie on.

Stage	What it is
adult	A dusk fly on tree-lined water. Fished with a deliberate splash.

Matching flies

3 patterns in this book imitate the June Bug / Beetle, across its stages. Which one to tie on follows the stage the water temperature says it is in — the app makes that call on a live reading; this page lists the whole set.

Where to find it right now

The rivers with a page here that sit in this insect's regions, with a USGS gauge reporting water temperature. This list is re-ranked against the reading each gauge is sending now and today's date, so it is live — the fallback below it, if the readings do not arrive, is each river's measured July mean.

Regional presence

Regions, not collection records. This insect is recorded from the coarse regions below; nobody has surveyed which named river it has been caught on, and this page will not pretend otherwise.

northern lower Michigan MI
southern lower Michigan MI
the Upper Peninsula MI
the Wisconsin driftless WI
northern Wisconsin WI
the Virginia mountains VA
the North Carolina mountains NC

Rivers in these regions with a page here

Related hatches

Same family, or overlapping this one's calendar on the same water.

Open the trout map →Every trout stream near you, coloured by today's water temperature.