The study, published Monday, observed three American female cockroaches and found their egg cases, or oothecae
, matured faster when the females were together than when they were isolated, (http://www.
2004) confirmed this observation by recording oviposition dates in the field, later collecting and refrigerating egg cases until 1 April and then reporting that earlylaid oothecae
hatched significantly earlier than those laid later, indicating a development period that begins at fertilization and oviposition.
americana can lay 51 oothecae
in 25 months, generating about 816 descendants within two years (GALLO et al.
Descriptive figures of oothecae
and genitalia of some collected species are shown.
Adult mantises can't survive frigid temperatures, but the eggs inside oothecae
Effects of three insecticide formulations in the removal and hatching of oothecae
of Blatella germanica.
Also recorded was a large number of spider webs without spiders (n = 215) and a few live spiders and oothecae
(n = 18).
Twenty controls and eight treated oothecae
were assessed, and we observed that the number of eggs per ootheca decreased according to the rank of egg-laying (Fig.
pelios Order No of gizzards Type found in which were found Araneida 7 Spiders Coleoptera 10 Beetles Dermaptera 2 Adult earwigs Dictyoptera 6 Cockroaches Dictyoptera 3 Oothecae
Diptera 6 Larvae Hymenoptera 14 Formicidae--Ants Hymenoptera 2 Apidae--Honeybees Isoptera 20 Adult Termites Lepidoptera 11 Larvae Neuroptera 3 Adult Lacewings Odonata 1 Adult damsel fly Orthoptera 34 Acrididae--Adults or nymphs Orthoptera 2 Gryllidae--Adults.
Mantids were already present in this field, but we removed all oothecae
from the plot area before the experiment.
Our results are consistent with the status of the blaberids as a highly derived cockroach family with distinctive life-history modifications, including retention of oothecae
Effects of four physical treatments of oothecae
of Periplaneta americana on parasitism and development of parasitic wasp Evania appendigaster.