Study summaries: four well-established findings, carefully stated
Each summary below states what was found, why it matters for practice, and the limits of the finding. Specific citation (authors, journal, year) is given only for the study this desk can cite with certainty; the others are described generally from the established literature, without invented figures.
1. Glucose aversion in German cockroaches — Wada-Katsumata et al., Science, 2013
Citation: Wada-Katsumata, A., Silverman, J., & Schal, C., Science, 2013 — cited with specifics because this desk is certain of it.
Finding. Populations of German cockroaches that avoided glucose-containing baits were shown to have an altered gustatory response: glucose stimulates bitter-taste receptor neurons in addition to sweet ones, so glucose-averse roaches perceive the bait component as bitter and reject it. The trait is heritable — a behavioural resistance mechanism selected by bait use itself.
Practice implication. Bait failure is not always under-application. Rotating bait matrices and active ingredients, and confirming feeding, matters as much as placement.
Limits. The study characterises a mechanism in studied populations; the prevalence of glucose aversion in any given building is a local question answered by monitoring, not assumption.
2. Cockroach allergen reduction through targeted intervention — described generally
Citation discipline: described from the inner-city asthma intervention literature generally; no single-study figures are quoted here.
Finding. Interventions that actually reduced cockroach infestation — targeted baiting within an IPM programme, combined with resident education and cleaning — reduced cockroach allergen levels in homes, while allergen persisted where infestation persisted. The pattern across studies is that allergen tracks live infestation, not cleaning effort alone.
Practice implication. For allergen goals, the endpoint to measure is allergen in settled dust alongside pest counts, and the intervention must include population control.
Limits. Allergen held in dust reservoirs persists for months after an infestation ends, so short follow-up windows overstate success; and the interventions were bundled (baiting plus education plus cleaning), so the contribution of any single component cannot be isolated from these studies.
3. Pyrethroid resistance surveys in bed bugs — described generally
Citation discipline: described from the survey literature generally; prevalence varies by collection and no single percentage is asserted.
Finding. Field-collected bed bug populations surveyed in the published literature have repeatedly shown sodium-channel (kdr-type) mutations and increased detoxification-enzyme activity, with bioassay survival after pyrethroid exposure far above that of susceptible laboratory strains.
Practice implication. Treatment plans that assume pyrethroid susceptibility fail predictably; current professional guidance builds in heat, desiccants, encasements, and non-pyrethroid options.
Limits. Surveys sample collected populations, not a census of all bed bugs; resistance levels vary by city, by building, and over time, so no survey result licences assuming either susceptibility or resistance in a specific room.
4. Heat lethality for bed bugs — described in ranges from the literature generally
Citation discipline: temperature ranges below are the broadly reported lethal ranges in the thermal-mortality literature, stated as ranges, not as a single study's data points.
Finding. Bed bugs and their eggs die when exposed to sufficiently high temperatures for sufficient time; the literature generally reports lethality beginning around 45–50 °C (113–122 °F), depending on exposure duration and life stage, with eggs requiring the more demanding end of time–temperature combinations. Whole-room heat treatments therefore aim to hold every harborage — including insulated refuges — within the lethal range long enough, verified with sensors.
Practice implication. “The room felt hot” is not a treatment record; sensor-verified time-at-temperature in the coldest harborage is.
Limits. The ranges are composites across studies, species of test chamber, and exposure setups; they state where lethality begins, not a field protocol, and real treatments succeed or fail on the coldest harborage, not the room average.