Harborage width preferences of German cockroach (Dictyoptera: Blattellidae) adults and nymphs.
Adults and nymphal cohorts of the German cockroach, Blattella germanica (L.), were allowed 24 h to select preferred harborage widths from eight harborages between 1.59 and 12.72 mm (increments of 1.59 mm) in both individual and combined cohort studies. In individual cohort studies, 1- and 2-wk-old nymphs significantly preferred 1.59-mm-wide harborage, with 74 and 68%, respectively; 3- and 4-wk-old nymphs significantly preferred 3.18-mm-wide harborage, with 63 and 45%, respectively; 5-wk-old nymphs selected the 4.77-mm-wide harborage; and 6-wk-old nymphs were evenly distributed in 3.18- to 9.54-mm-wide harborages. Males were in 6.36- to 12.72-mm-wide harborages. Nongravid females (81%) were in 4.77-, 6.36-, and 11.13-mm-wide harborages; gravid females (94%) preferred 4.77- and 6.36-mm-wide harborages. The percentage of nymphs outside harborages decreased as cockroach age increased from 1 to 5 wk. In combined cohort studies, preferred harborage widths for all cohorts and sexes were 6.36-7.95 mm and 11.13-12.72 mm. The percentage of nymphs outside harborages was low and constant (< 4.57%) irrespective of age or sex.
Department of Entomology and Nematology, University of Florida, Gainesville 32611.
P G
PG
Koehler
C A
CA
Strong
R S
RS
Patterson
D000818:Animals; D001522:Behavior, Animal; D003058:Cockroaches / Q000254:growth & development / Q000502:physiology*; D005260:Female; D008297:Male; D009758:Nymph / Q000502:physiology