Double-occupancy college dormitory rooms of ∼38 m3
were used. Each room contained similar furniture consisting
of two beds with wooden frames, waterproof mattresses and
no box springs, a dresser, two wooden desks and two wooden
desk chairs. All furniture was arranged in a similar manner in
each of the 12 rooms used in this study (Fig. 1A). Experiment
rooms were located on the third floor of the dormitory building.
A preliminary experiment was performed in which paper cups
containing 10 adult crickets [Achaeta domesticus (Linnaeus)
(Orthoptera: Gryllidae)] were placed in the four corners (where
pipes and electrical lines connected the rooms) of the floor
in all rooms located above, below and adjacent to the treated
rooms to determine if dichlorvos leaked from the treated rooms
to rooms not being used in the experiment. Similar cups were
also placed in treated rooms during the experiment. Crickets,
which are target insects listed on the dichlorvos Nuvan
Prostrips® label and are known to be susceptible to very low
concentrations of dichlorvos (Harris & Mazurek, 1964), died
in all treated rooms in