The first real storm hits in early July and the desert empties itself onto your porch. Swift Pest fields a wave of calls every year in the days after that first rain, usually from someone standing well back from a beetle the size of a cigar. Most of what arrives during monsoon season is harmless and gone in a few weeks. One of the swarmers is not, and telling them apart matters more than anything else you do about the situation.
What is the enormous beetle on my patio?
A palo verde beetle, properly the palo verde root borer (Derobrachus hovorei). Adults run three to three and a half inches long, dark brown to black, with very long antennae and small spines along the sides of the thorax.
They emerge after the first monsoon rains, fly at dusk, and orient toward lights. Flight is loud and erratic, and they land on people by accident rather than intent. They do not sting and do not carry disease, though the mandibles can pinch if you pick one up. Adults live roughly a month, which is why the invasion feels intense and then simply stops.
Are palo verde beetles killing my tree?
The adults are not. The larvae do the damage, and by the time you see a beetle, the feeding happened years ago.
Grubs live underground for several years, commonly three to four, feeding on the roots of palo verde, mesquite, olive, elm, and citrus. They tend to exploit trees already stressed by drought, shallow watering, trunk injury, or trenching. Killing adults accomplishes nothing for the tree. Deep, infrequent irrigation that drives roots down, mulch kept off the trunk, and avoiding string trimmer wounds do more than any product.
What are the loud metallic green beetles?
Green fig beetles, also called figeater beetles (Cotinis mutabilis). About an inch and a quarter, metallic green, and famously bad at flying.
They are after ripe and fermenting fruit, so they cluster around figs, peaches, grapes, and fallen citrus. The larvae develop in compost, manure, and thick mulch, and crawl on their backs, unsettling to find in a garden bed but harmless. Turning compost and picking fruit promptly does more than spraying.
Which monsoon swarmer actually signals a problem?
Termite alates. Desert subterranean termites (Heterotermes aureus) send out winged reproductives after monsoon rains, and a swarm near your house means a colony is established nearby.
Swarms usually happen in the afternoon or evening following a rain, from July into September. The flight itself is brief. What you find afterward is more telling: small piles of shed wings on window sills, in spider webs under eaves, or at the base of a slab. Wings on the interior side of a window are worth an inspection promptly.
How do you tell a termite swarmer from a flying ant?
Look at the waist, the wings, and the antennae. Termites have a broad, straight-sided body with no pinched waist, four wings of roughly equal length, and straight beaded antennae.
Flying ants have an obvious narrow waist, forewings noticeably longer than the hind wings, and elbowed antennae with a bend in the middle. Ant swarms also occur after monsoon rains and are common enough that plenty of people call about the wrong insect. If you are unsure, save a few specimens in a sealed bag rather than sweeping them up.
Why does everything end up at the porch light?
Most monsoon swarmers navigate by light and will orbit the brightest source they can find, which puts them at your entry doors.
The fix is placement more than wattage. Move the light off the door and light the walkway instead, switch entry fixtures to warm or yellow bulbs, and close the garage before dusk on the nights after a storm. Check screens for tears and door sweeps for gaps, since a three-inch beetle only needs an open slider for a few seconds.
Spraying flying insects in the air is wasted effort. They are not breeding on your patio, and the population outside is far larger than anything a can of product will touch.
How Swift Pest handles monsoon swarm season
Identification first, treatment second. A palo verde beetle call usually ends with a conversation about tree watering and exterior lighting rather than a chemical application. A call about wings on the window sill turns into a termite inspection of the slab line, block wall, and any wood in contact with soil.
Most of what shows up after the first storm is a nuisance with a short shelf life. The exception is the one with straight antennae and four matching wings. Swift Pest identifies what is actually flying around Tucson properties during monsoon season and inspects for desert subterranean termites when the swarm points that direction. Reach out through the site if you found wings and want to know what left them.