Which pests the vector district covers — and which it doesn't
Azusa is one of 26 member cities of the San Gabriel Valley Mosquito & Vector Control District, a public agency formed in 1989. The district monitors and treats mosquitoes and black flies. It does not respond to rats, mice, cockroaches, bees or fire ants; for those it refers residents to other agencies or to private pest control.
Knowing that split saves time. Biting flies along the river or a neglected green pool next door are district matters — call them at (626) 814-9466. Droppings in the garage, roaches in the kitchen, bed bugs in a bedroom or a wasp nest under the eaves are problems on your own property, and those are the jobs PesPro inspects and treats.
Sources: [2]
Spring black flies from the San Gabriel River
In March 2026, Los Angeles news outlets reported a surge of small, biting black flies across the San Gabriel Valley foothills, and Azusa appeared on every list of affected communities. Black fly larvae need fast, oxygen-rich water, and they develop in the San Gabriel River. The vector district said its traps jumped from single-digit counts the year before to more than 500, and that it treats larval habitat in the river and at upstream sites such as Morris Dam.
Coverage linked the spikes to spring water releases from the dams upriver. The flies swarm around the face and bite, but the district said they are not known to transmit disease in the area. Its practical advice: wear a mesh head net outdoors, use a DEET-based repellent, and switch off decorative fountains for 24 hours once a week so larvae cannot settle in moving water at home.
PesPro does not offer black fly control — treating the river is the district's work, and reporting heavy activity to them helps them target it. If biting flies are your main complaint this spring, the district is the right call, not an exterminator.
Sources: [11][12][13][2]
West Nile virus keeps returning to Azusa traps
The district has trapped West Nile–positive mosquitoes in Azusa in five of the last six seasons: 9 samples in 2021, 2 in 2022, 6 in 2023, 1 in 2024 and 5 in 2026, when the first Azusa detection was logged on July 15. The only gap was 2025, a quiet year across the entire district with just eight positives, none of them in Azusa. In 2026 the district counted 219 positive samples overall, so the virus is circulating widely again.
The California Department of Public Health also lists both invasive Aedes species — Aedes aegypti and Aedes albopictus — as present in Azusa. Unlike the native mosquitoes that bite at dusk, these bite during the day and lay eggs in very small amounts of water: plant saucers, buckets, toys and clogged gutters. The district asks residents to empty standing water every week and to use a repellent with DEET, picaridin, IR3535 or oil of lemon eucalyptus.
Mosquito control is not a PesPro service. What we do on every visit is point out leaky hose bibs, sweating pipes and puddled planters, because the moisture that breeds mosquitoes outdoors also keeps American cockroaches and ant colonies thriving along a foundation.
Sources: [9][8][7][5][4][3][10][6]
Life at the mouth of the canyon: coyotes, fruit and roof rats
The city calls itself the gateway to the San Gabriel Canyon and the Angeles National Forest, reached by Highway 39, and it asks canyon visitors to carry their trash back out. Homes near that wildland edge share space with coyotes — enough that Azusa runs a coyote management program with the San Gabriel Valley Council of Governments.
The city's coyote guidance doubles as rodent advice: keep garbage in bins with tight lids, pick up fallen fruit, and bring bird feeders in at night because spilled seed draws rodents, which in turn draw coyotes. If you have fruit trees, a patio feeder or pet food outdoors, those are the first things we look at — before we start hunting for entry gaps.
Rodents also carry fleas. Los Angeles County recorded 220 flea-borne typhus cases in 2025, a record for the county as a whole (not an Azusa figure), and it recommends year-round flea control for pets and keeping animals out from under decks and homes.
Sources: [17][16][14]
Older central Azusa vs. newer Rosedale
Census figures put Azusa's median year built at 1970, and just under half of the city's 15,580 housing units are detached houses. About a third are in buildings with two or more units, 656 are mobile homes, and 45% of occupied homes are rented. Many households therefore share walls, plumbing chases and laundry rooms with neighbors — a major factor for German cockroaches and bed bugs, both of which move from unit to unit.
At the north end of the city, the planned Rosedale community (built under the Monrovia Nursery Specific Plan) has 1,227 of its 1,250 approved homes completed and occupied, according to the city. Newer construction generally starts out with tighter seals and screened vents, so the weak spots shift to garage doors left open and gaps around later additions like cable or solar lines. Homes from the 1960s and '70s are more likely to have torn vent screens, cracked stucco and openings around original plumbing.
Sources: [1][15]
Hablamos español — plus Chinese and Spanish web pages
About 43% of Azusa residents age five and older speak Spanish at home, and roughly 2,400 speak Chinese, most of them with limited English, according to the Census. Our technicians explain findings, preparation steps and estimates in English or Spanish, and you can read our website in Spanish at pespro.com/es or in Chinese at pespro.com/zh.
Sources: [1]
