Chironomids (Diptera: Chironomidae) are the most widely distributed and often the most abundant insect in freshwater. They undergo a complete metamorphosis of four life stages, of which the egg, larva, and pupae are aquatic and the adult is terrestrial. Chironomid egg masses were found to be natural reservoirs of Vibrio cholerae and Aeromonas species. To expand the knowledge of the endogenous b...

1. The development of the amphiaster is associated with the formation of two semisolid masses within the more fluid egg substance. 2. The elongation of the egg during cleavage is possibly produced as a consequence of the mutual pressure of these two growing semisolid masses. 3. The division of the egg into two blastomeres consists essentially in a growth, within the egg, of two masses of materi...

Parasitoid longevity, utilization of Homalodisca coagulata (Say) (Hemiptera: Cicadellidae) eggs of diVerent ages, and progeny survival rates were determined in the laboratory for Gonatocerus ashmeadi Girault, Gonatocerus triguttatus Girault, and Gonatocerus fasciatus Girault (Hymenoptera: Mymaridae). Ovipositional behavior and aggression between females were investigated when all three species ...

Cytoplasmic rearrangements which follow fertilization were monitored in inverted eggs. A set of yolk compartments was resolved by cytological analyses of both normally oriented and inverted eggs. Those compartments were characterized by their yolk platelet compositions and movement during egg inversion. In addition to the major yolk masses which contain either small, intermediate or large plate...

The Southern Ocean is one of the coldest, most stable marine environments on Earth and represents a unique environment for investigating metabolic consequences of low temperature. Here we test predictions of a new diffusion-reaction model of O(2) distributions in egg masses, using egg masses of the Antarctic nudibranch mollusk, Tritonia challengeriana. When warmed from -1.5 degrees to +1.5 degr...

A maturation-rate relationship for Meloidogyne incognita on Lycopersicon esculentum 'Rutgers' was derived and used to estimate harvest dates for maximum egg hatch from laboratory cultures at ambient temperatures. Daily maturation increments were totaled (nematode maturation total, NMT) and correlated with hatch from isolated white, yellow, and amber egg masses. Hatch per mass fluctuated periodi...

T h e infectivity of second-stage larvae of Meloidogyne spp. is a function of soil temperature, aeration, moisture, texture, and density, as well as a funct ion of the distance the second-stage larvae have to travel pr ior to root penetra t ion (3, 4). Because eggs may require up to 2 weeks to hatch under greenhouse conditions, infection periods with larvae are normal ly shorter than those with...