Boll weevil in South America.

bitstream/item/145707/1/1994FL001-CAmpanhola-boll-2405.pd

Some phytoseiid mites from the South Pacific, with descriptions of new species and a definition of the Amblyseius largoensis species group.

Species of Phytoseiidae collected in Fiji, Vanuatu (New Hebrides) and New Caledonia in 1979 and Cook Islands in 1981 are listed. Amblyseius fijiensis n. sp. and A. herbicoloides n. sp. belong to the largoensis species group, which, as defined, comprises 9 species, 7 of which are Known only from the Southern Hemisphere. Amblyseius (Indoseiulus) hebridensis n. sp. is also described

Suitability of the spider mite Tetranychus evansi as prey for phytoseiulus persimilis.

Experiments conducted to evaluate the suitability of T. evansi as a source of food for P. persimilis revealed that the primary factor responsible for the low oviposition rate and vurvivorship of the predator when fed T. evansi was the low amount of food ingested. P. persimilis detected and initiated feeding on T. evansi equaly as well as on T. urticae. However, a feeding depressant was apparently responsible for a longer time spent by P. persimilis feeding on eggs of T. evansi than on eggs of T. urticae. Eggs of the former prey were totally consumed only occasionally. The depressant effect influenced subsequent feeding on T. urticae, increasing the time requered for consomption and the number of partially consumed eggs for at least 3 days

Behavior of three cowpea varieties in relation to leafhopper attack in Northeastern Brazil.

The cowpea varieties "Pitiuba", "Sempre Verde" and "VITA-3" have been tested in Petrolina, PE, northeastern Brasil, to observe their behavior in relation to the attack of leafhopper, Empoasca Kraemeri Ross and More. The first two are common, local varieties, whereas the third was recently introduced from Nigeria, where, reportedly, it is tolerant to Empoasca dolichi (Paoli)

Nematic liquid crystal dynamics under applied electric fields

In this paper we investigate the dynamics of liquid crystal textures in a two-dimensional nematic under applied electric fields, using numerical simulations performed using a publicly available LIquid CRystal Algorithm (LICRA) developed by the authors. We consider both positive and negative dielectric anisotropies and two different possibilities for the orientation of the electric field (parallel and perpendicular to the two-dimensional lattice). We determine the effect of an applied electric field pulse on the evolution of the characteristic length scale and other properties of the liquid crystal texture network. In particular, we show that different types of defects are produced after the electric field is switched on, depending on the orientation of the electric field and the sign of the dielectric anisotropy.Comment: 7 pages, 12 figure

Phytoseiid mites of Colombia (Acarina: Phytoseiidae).

This is the second report of the phytoseiids of Colombia. A new genus and species, Quadromalus colombiensis and Euseius ricinus n.sp. are described, bringing the total to 17 species of phytoseiids for Colombia

Expected selection gain for resin-yielding in progenies test of Pinus caribaea var. bahamensis.

Abstract. IUFRO Working Group 2.02.20