Dr. Marie Sarin
Urban Entomologist — Integrated Pest Management Consultant
My path is fairly straightforward: a Bachelor's degree in Organismal Biology in Montpellier, a Master's in Ecology and Environmental Management, then a Doctorate in Entomology focused on pyrethroid resistance in urban populations of Blattella germanica. That question — why some treatments fail while others succeed — became the through-line of my career.
For eight years, I worked as a consultant for municipal sanitation departments: managing infestations in social housing, writing intervention protocols, training technicians. I then joined a private Certibiocide-certified pest control company, where I oversaw projects ranging from single-studio apartments to 200-unit residential buildings.
I have seen families sleeping in their car because of bed bugs, or too scared to turn on their kitchen light. My observation, based on hundreds of interventions: 90% of treatment failures stem from an incorrect initial diagnosis or an active molecule unsuited to the resistance level of the target population.
Area of Specialization
My specialization covers two complementary areas: urban entomology (behavior of pest species in built environments, reproduction cycles, dispersal vectors) and insecticide resistance phenomena.
This second area is particularly critical: German cockroach populations in urban environments now show levels of pyrethroid resistance that render the majority of retail products ineffective. Recommending a permethrin-based spray on a resistant population is, at best, useless and, at worst, counterproductive (increased selection pressure). This is why every product evaluation begins with an analysis of the active molecule, not the brand.
Treatment Philosophy: Integrated Pest Management (IPM)
The Integrated Pest Management (IPM) framework is the methodological approach I apply systematically. The principle: intervene at the lowest possible level of the action pyramid.
Mechanical & Preventive
Sealing entry points, monitoring traps, managing food sources. Stopping the infestation at its source before any treatment.
Physical & Thermal
High-temperature steam, cryogenic cold, diatomaceous earth. Proven efficacy, no possible resistance, zero chemical residue.
Targeted Chemical
As a last resort: active molecule chosen for its mode of action, at the minimum effective dose, with rotation of chemical families to prevent resistance.
What 15 Years in the Field Taught Me
These observations come from direct hands-on work and documented field interventions, not from manufacturer product sheets.
The Reality of Temperature in Steam Treatments
When I evaluate a steam cleaner against bed bugs, I measure the outlet temperature at 2 inches from the nozzle with an infrared thermometer. The lethal threshold for Cimex lectularius is 118°F in direct contact for 90 seconds. A unit advertised as delivering "300°F" at the outlet may deliver only 126°F at the actual contact point on a box spring joint — not enough to reach eggs nestled in cracks. Steam pressure (measured in bar) and flow rate (g/min) are just as critical as the nominal temperature rating. That is why I always compare these three parameters before recommending a model.
Diatomaceous Earth: Food-Grade vs. Filter-Grade
The difference is not visible on an Amazon product listing — you feel it when you handle it. Food-grade diatomaceous earth (amorphous, cold-process silica) has a characteristic powdery fineness, slightly greasy to the touch, a sign of high active amorphous silica content. Filter-grade (used in pool filters) is more crystalline, abrasive to the touch, and potentially irritating to the respiratory tracts of occupants and pets. In the field, I exclusively use food-grade with a particle size under 10 microns: it adheres to insect appendages and effectively destroys the waxy cuticle.
Field Report: Multi-Unit Infestation
In 2022, I assisted the sanitation department of a municipality in the Hérault region for an infestation of American cockroaches (Periplaneta americana) entering from the sewer network into 12 residential buildings. Protocol applied: three treatment cycles combining insecticide gel (indoxacarb / fipronil rotation) and a residual barrier in the basement. Result at Day 60: a 95% reduction confirmed by monitoring traps. This type of intervention validates in the field the superiority of gel over powders for highly mobile species, and the indispensability of active molecule rotation across long treatment cycles.
How Do I Select Products?
Every recommendation on ClearHomePests follows a four-step protocol:
- 1 Active Molecule Analysis: Is the molecule (indoxacarb, fipronil, imidacloprid, brodifacoum…) scientifically recognized for its efficacy on the target species? What is its mode of action? What documented resistance exists in US populations?
- 2 Formulation Testing: Is the product palatable to the target species? Does the formulation withstand typical humidity and storage temperatures? Do the texture, viscosity, and scent meet professional standards?
- 3 Field Network Feedback: I consult my network of certified pest control technicians for their feedback from real-world jobs in the past 12 months. A product can be excellent in laboratory conditions and disappointing in real-world advanced infestation conditions.
- 4 Independence: I select products for their active molecule and their efficacy/safety ratio, not for their brand. Some links are Amazon affiliate links, which is clearly disclosed — this does not bias the rankings.
No More Ineffective Products
Ultrasonic gadgets, broad-spectrum fumigants, traps with no active molecule: I debunk the scams with data.
Professional Protocols
I only recommend what certified pest control technicians use on their jobs.
Accessibility
Making professional knowledge accessible to homeowners in distress, without unnecessary jargon.