LABS

The 20th’s mission was to protect troops against non-human enemies … diseases. The entomology lab was broken into identifying mosquito larvae (my job) and adult mosquitos caught in traps. The idea was to pinpoint where disease-carrying mosquitos like Anopheles and Aedes aegypti were breeding so that ground or aerial spraying missions could reduce their populations. We discovered that the standard key book had mixed up the larval vs. adult identifications of an entire genus. We sent specimens of larvae, pupae and adults to the Smithsonian in hopes of getting that corrected. We produced a “library” of sample larval slide mounts of just about every mosquito species in Vietnam for reference and teaching of future lab personnel. We reared out larvae and prepared slide mounts of all stages of development and paired those with mounts of the adults for reference.

Marquardt in the water lab: The water lab tested water samples from various military units and from village water supplies. The usual standard test was to use Petri dishes to check for bacteria. E. Coli, a serious threat from fecal contamination, was always a concern. Whatever might grow in the dishes was examined by microscope (note the binocular scope on the counter). The Vietnamese often used human excrement to fertilize their rice crops. Photo by Bruce Hoff

There were several “labs” in the headquarters unit including ones for environmental sanitation (inspection of mess halls, etc.), vector control (identification of disease-carrying critters), epidemiology (investigation of disease outbreaks such as plague), water lab (including water quality assessments) and entomology (my lab for mosquito larvae identification and a lab for identifying adult mosquitos caught in traps, both for targeting control efforts such as spray missions).