Observation on the host parasitoid interaction between Periplaneta americana, the American cockroach and Tetrastichus hagenowii, an oothecal parasitoid

Investigations were carried out on the host parasitoid interaction between Periplaneta americana, the American cockroach and Tetrastichus hagenowii, an oothecal parasitoid. This gregarious female parasitoid infected and or oviposited in only one host and caused 100 por cento mortality of the infected host. However, increase in parasitoid density decreased the progeny production and influenced the sex ratio. The progenies produced were male biased. When host preference was tested by offering oothecae of different species of cockroaches, T. hagenowii showed a predilection towards the oothecae of P. americana, suggestings its host specificity.

Cockroaches as transport hosts of the protozoan Toxoplasma gondii

Las cucarachas Eurycotis biolleyi y Blatella germanica ingieren heces de gato aún en presencia de azúcar, queso o masa de maíz. Además, los ooquistes de Toxoplasma pueden mantenerse viables externa e internamente en esos insectos hasta 19 días después de la exposición experimental. Se agregan así dos nuevos vectores mecánicos en la transmisión de T. gondii