The brine shrimp Artemia reproduces either ovoviviparously, producing free-swimming nauplii, or oviparously, producing encysted embryos (diapause cysts) able to cope with harsh and complex habitats. When the cysts enter diapause they are encased in a complex external shell that protects them from certain extreme environments. The genomic comparison of oviparous and ovoviviparous ovisacs has bee...

The wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is one of the most serious pests of wheat worldwide. It overwinters as cocooned larvae in diapause and non-diapause forms. The cocoon is made of silk from the salivary glands. The silk glands, therefore, play an important role in the S. mosellana diapause. In the present study, the ultra-structures of the silk glands betw...

Embryos of the ground cricket, Allonemobius socius, enter diapause 4-5 days post-oviposition and overwinter in this dormant state that is characterized by developmental arrest. Suppressive subtractive hybridization and quantitative real-time PCR reveal eight candidate genes in pre-diapause embryos that show promise as regulators of diapause entry, when compared with embryos not destined for dia...

Diapause is a programmed state of developmental arrest that typically occurs as part of the natural developmental progression of organisms that inhabit seasonal environments. The brine shrimp Artemia franciscana and annual killifish Austrofundulus limnaeus share strikingly similar life histories that include embryonic diapause as a means to synchronize the growth and reproduction phases of thei...

The annual killifish Austrofundulus limnaeus survives in ephemeral pond habitats by producing drought-tolerant diapausing embryos. These embryos probably experience oxygen deprivation as part of their normal developmental environment. We assessed the anoxia tolerance of A. limnaeus embryos across the duration of embryonic development. Embryos develop a substantial tolerance to anoxia during ear...

Direct observation of 387 embryos in the early stages of development was combined with observations on breeding behaviour and reproductive biology obtained from the published literature, to estimate the timing of births, oestrus, ovulation and implantation, and to derive estimates of the duration of pregnancy, embryonic diapause and active gestation for crabeater seals (Lobodon carcinophagus). ...

The spider mite, Eotetranychus smithi Pritchard & Baker (Acari: Tetranychidae), exhibits a facultative diapause that occurs at the egg stage. Diapause was induced by low temperatures alone (≤ 17.5°C) and averted by high temperatures (≥ 20°C). Photoperiod had little effect on diapause induction. This is the first example of temperature-induced diapause in spider mites. The diapause eggs became l...

Diapause is a fundamental component of the life cycle in the majority of insects living in environments characterized by strong seasonality. The present study addresses poorly understood associations and trade-offs between endogenous diapause duration, thermal sensitivity of development, energetic cost of development and cold tolerance. Diapause intensity, metabolic rate trajectories and lipid ...