The action spectrum for breaking diapause in the oak silkworm, Antheraea pernyi Guer., and the codling moth, Laspeyresia pomonella (L.), was determined from 400 to 700 nm with a wedge-interference spectrograph. Insects were exposed to ten hours of white light, followed by six hours of spectral light each day for 45 days. The portion of the spectrum between 400 and 500 nm was found to be the mos...

Field studies over 3 yr demonstrated that overwintering populations of the Colorado potato beetle in upstate New York and on Long Island are composed of adults from both the first and second summer generations. The two populations from the climatically different regions differ in their responses to environmental factors that influence voltinism. The critical photoperiod for aestival diapause in...

Changes in nucleolar ultrastructure were studied in preimplantation rat embryos before diapause (d 5), during diapause (d 6, 7 and 8) and after reactivation brought about either by in vitro culture for 24 h (d 7 and 8) or by estradiol-17 beta treatment of the mothers (d 11). Before diapause, fully developed nucleoli contained several low-density fibrillar centers surrounded by a dense fibrillar...

-UNIFORMITY OF SUCCESSIVE POPULATIONS OF AN ALPINE GRASSHOPPER WITH A TWO YEAR DIAPAUSE. Aeropedellus clavatus (Thomas), an abundant grasshopper in the alpine tundra of Colorado, has a two-year diapause. This suggests the possibility of two distinct populations in successive years. Statistical analysis of samples from three alpine localities on Mount Evans, Colorado, collected in 1958, 1959, an...

A hyperparasitic system with prolonged diapause for host is investigated. It is assumed that host prolonged diapause occur at larval stage, and parasitoid attack is limited to egg stage before the initiation of host diapause. Such behavior has been reported for many ichneumons. Hyperparasite only attacks the parasitoids that parasitize the hosts. Hyperparasitic system is often used in biologica...

Embryos of the crustacean, Artemia franciscana, undergo alternative developmental pathways, producing either larvae or encysted embryos (cysts). The cysts enter diapause, characterized by exceptionally high resistance to environmental stress, a condition thought to involve the sHSP (small heat-shock protein), p26. Subtractive hybridization has revealed another sHSP, termed ArHsp21, in diapause-...

The paper presents an extention of analytical reviews concerning the dormant stages in life cycles of representatives of the complex group of chelicerate arthropods, named the Acari or Acarina. The previous reviews were devoted to the comparative and evolutionary aspects of dormant stages distribution in life cycles of mites and ticks in comparison to mandibulate arthropods — insects and crusta...

Laboratory-reared western corn rootworms, Diabrotica virgifera virgifera, from colonies maintained at the North Central Agricultural Research Laboratory (NCARL) in Brookings, SD, are used extensively by many researchers in studies of the biology, ecology, behavior, and genetics of thismajor insect pest.Anondiapause colonydeveloped throughartiÞcial selection in theearly 1970s is particularly att...

Ann. Entomol. Sm. Am. 92(3): 362-395 (1999) ABSTRACT This study examines the diapause response among boll weevils collected as immatures in squares at different times of the summer and held under simulated field photoperiods and temperatures of northern Mississippi. The percentage of adults exhibiting prediapause increased seasonally, starting with the 1st generation in July and achieving a max...

Trehalase, which specifically hydrolyses trehalose into glucose, plays an important role in the metabolism of trehalose. Large amounts of trehalose are stored in the diapause encysted embryos (cysts) of Artemia, which are not only vital to their extraordinary stress resistance, but also provide a source of energy for development after diapause is terminated. In the present study, a mechanism fo...