Seeing is Believing, A Fourteen-Year Study on Efficacy and Economics of Visual Inspections to Protect A Large Mammal Collection from Insect Pests

Abstract

In response to the cessation of use of in-case fumigants, from 1995–2009 the Smithsonian Institution, National Museum of Natural History's Division of Mammals (DOM) applied a consistent voluntary visual inspection protocol over a period of 14 years. On average, per-case inspections required about 7 minutes. Inspections categorized case pest activity as clean, soiled, signs of life, and live insects. These categories compartmentalized levels of uncertainty about pest activity and directly led to remedial treatment and cleaning actions performed at a case level. Evidence of recurrent reinfestation led to case renovation or replacement. In order for an integrated pest management (IPM) method to be successful, it has to demonstrate a predatory efficacy better than the replacement and recruitment rates of the pests. With at most 1.5% of staff time devoted to IPM, case infestations of Thylodrias contractus (Motschulsky 1839) Coleoptera: Dermestidae and Necrobia rufipes (De Geer 1775) Coleoptera: Cleridae were lowered to near zero within 3 years. Rebound toward initial rates occurred after a forced 3-year hiatus in inspections and was similarly dealt with by a following round of inspections. The hourly investment of time is comparable with that of previous case repellant or fumigation regimes, but without the aggregated loss of access to collections during enclosure and out-gassing of fumigant, thus allowing longer and safer access to collections over a year, and instilling greater knowledge of specimen condition across the collection regardless of current research focus. The study also includes an economic comparison to historical methods of case level pest suppression with fumigants against two other comparably large collections documented within the last half century.