Ghosts and witches for Halloween

VIC LEIPZIG AND LOU MURRAY

The witching season is upon us and it’s time for ghost stories.

Incredibly enough, nature can provide us with stories of ghosts and

witches. But don’t get too frightened. The story we’re about to tell

is really about shrimp and moths.

While searching for a seasonal topic, we latched first onto ghost

shrimp. These crustaceans live in underwater burrows at the Bolsa

Chica and Huntington Wetlands in Talbert Marsh, where they feed on

plankton and detritus. You can see the openings of their burrows,

especially on the western shore of Inner Bolsa Bay. The burrows look

like gray underwater anthills. In fact, a single ghost shrimp lives

in each burrow, which is actually a long, branching, complex

underwater network of tunnels. These burrows, which the shrimp work

on constantly, can go as deep as 30 inches beneath the mud.

Ghost shrimp don’t look much like the shrimp that we eat. They

grow up to four or five inches long and look more like a translucent

little lobster, with one large claw and one small one, and a

decidedly lobster-like tail.

Some fishermen use a sucking device to pull ghost shrimp out of

their burrows. But they don’t eat them; they use them for bait. One

study showed that nearly 6,000 pounds of ghost shrimp are taken by

fishermen annually from Los Angeles and San Diego counties.

It’s really too bad that fishermen use them for bait. Ghost shrimp

are beneficial to the ecosystem. These crustaceans mix the sediment,

oxygenate the mud, and provide homes in their burrows for pea crabs,

scale worms and other small invertebrates, which in turn provide food

for migratory shorebirds. Fishermen would do well to use a different

kind of bait and leave the ghost shrimp alone.

The other part of our Halloween tale involves the black witch

moth. This huge, dark moth is spreading its range northward from

Mexico into Southern California. The black witch moth is the largest

known moth with a wingspan of seven inches. It lives mainly in the

New World tropics, plus southern parts of Texas and Florida.

This July, two specimens from Orange County were reported to Mike

Quinn, a Texas scientist who is keeping records of black witch moth

sightings. One of the moths was found in Fullerton and the other in

Costa Mesa.

Just last month, someone brought a mysterious dark moth in to

Cerritos College, where Vic was teaching. Vic had never seen a moth

that large and didn’t know what species it was. Another faculty

member took the monstrous-sized moth to an entomologist, who

identified it as a black witch moth. When we learned how rare this

moth is, Vic e-mailed the finding to Quinn to be included in the

database.

So little is known of the migratory habits of this moth that all

U.S. sightings are important. This year seems to be a banner year for

black witch moths, with more sightings out of its normal range than

ever before. Although there were only 10 reports of a black witch

moth east of the Mississippi this year, there have been hundreds of

sightings west of the Mississippi, and as far north as British

Columbia, Montana and Minnesota.

The main migration season for this moth seems to be in June and

July, with fewer sightings in the fall and none after November.

In California, there have been only two sightings in June, 11 in

July, two in August, one in September and two in October. Those

aren’t sightings from this year. That’s the grand total of all

recorded sightings in California.

This is one rare moth, but your odds of seeing one are improving.

Sightings between 1958 and the 1990s averaged two per decade.

Sightings since June of this year have averaged two per week. The

black witch moth seems to be expanding it range northward, at least

temporarily. Is this a permanent expansion, or merely an unusual

irruption? Only time will tell.

Like most moths, black witch moths fly at night. They are likely

to roost in garages, under eaves or even under cars. They don’t hang

around and will fly off the next day, so if you’re lucky enough to

find one, take a photograph quickly. Even if the moth were to hang

around in one spot, it wouldn’t be there long because adult moths

only live three to four weeks.

You’re even less likely to see a black witch moth caterpillar. The

smooth, gray caterpillars feed mainly on acacia trees and mesquite,

so we’re not likely to find any caterpillars in Orange County.

Maybe it’s a good thing that we don’t usually see black witch

moths. The moth has been known in Mexico since Aztec times as the

butterfly of death. Legend has it that if one flies into your house,

someone will die. Another legend says that if the moth flies over

your head, you will lose your hair. We’d better not let any of those

moths fly over Vic. He’s lost enough hair already.

Keep your eyes peeled for one of these very dark, huge moths,

especially next summer. If you see one, report it to Mike Quinn at

mike.quinn@tpwd.state.tx.us. Meanwhile, we hope all of your ghosts

and witches are shrimp and moths.

* VIC LEIPZIG and LOU MURRAY are Huntington Beach residents and

environmentalists. They can be reached at vicleipzig@aol.com.