REARING IMPROVEMENTS FOR THE GERMAN-COCKROACH (DICTYOPTERA, BLATTELLIDAE)

Known-age cohorts of three strains of German cockroach, Blattella germ anica (L.), were mass-reared by establishing one rearing container eac h week (so that cockroaches within a container would be of known age). An average of 330-443 females was placed in oviposition units within these rearing containers. Percentage hatch of oothecae was 77.49-84.63 %, resulting in an average of 12,258-16,359 nymphs per rearing contain er. Development of nymphs was similar for the three strains. Survivors hip of nymphs to the adult stage was 19.95-29.56%; survivorship was si gnificantly higher for the strain most recently colonized from the fie ld. Adult emergence occurred at 6-7 wk, and average production per con tainer was 2,834-3,971 cockroaches.