Managing Insect and Mite Pests of Texas Corn.

20 p

Managing Insects and Mite Pests of Texas Sorghum

32 pp., 22 tables, 3 figures, 30 color photos, 20 drawingsThis is the complete guide for Texas sorghum growers. It covers an integrated approach to managing insect and mite pests to help growers prevent, diagnose and control damaging infestations. This publication offers suggestions for managing 26 insect and mite pests of sorghum

Managing Soybean Insects

36 pp., 3 tables, 18 illustrations, 28 photosThis publication details integrated pest management principles for managing soybean insects. Topics include variety selection, inspecting fields for insects and damage, soybean insect pests, and insecticide application methods. A table lists products registered for controlling soybean insects

A fossil winonaite-like meteorite in Ordovician limestone: A piece of the impactor that broke up the L-chondrite parent body?

AbstractAbout a quarter of all meteorites falling on Earth today originate from the breakup of the L-chondrite parent body ∼470 Ma ago, the largest documented breakup in the asteroid belt in the past ∼3 Ga. A window into the flux of meteorites to Earth shortly after this event comes from the recovery of about 100 fossil L chondrites (1–21 cm in diameter) in a quarry of mid-Ordovician limestone in southern Sweden. Here we report on the first non-L-chondritic meteorite from the quarry, an 8 cm large winonaite-related meteorite of a type not known among present-day meteorite falls and finds. The noble gas data for relict spinels recovered from the meteorite show that it may be a remnant of the body that hit and broke up the L-chondrite parent body, creating one of the major asteroid families in the asteroid belt. After two decades of systematic recovery of fossil meteorites and relict extraterrestrial spinel grains from marine limestone, it appears that the meteorite flux to Earth in the mid-Ordovician was very different from that of today

Rare meteorites common in the Ordovician period

© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. Most meteorites that fall today are H and L type ordinary chondrites, yet the main belt asteroids best positioned to deliver meteorites are LL chondrites 1,2. This suggests that the current meteorite flux is dominated by fragments from recent asteroid breakup events 3,4 and therefore is not representative over longer (100-Myr) timescales. Here we present the first reconstruction of the composition of the background meteorite flux to Earth on such timescales. From limestone that formed about one million years before the breakup of the L-chondrite parent body 466 Myr ago, we have recovered relict minerals from coarse micrometeorites. By elemental and oxygen-isotopic analyses, we show that before 466 Myr ago, achondrites from different asteroidal sources had similar or higher abundances than ordinary chondrites. The primitive achondrites, such as lodranites and acapulcoites, together with related ungrouped achondrites, made up ∼15-34% of the flux compared with only ∼0.45% today. Another group of abundant achondrites may be linked to a 500-km cratering event on (4) Vesta that filled the inner main belt with basaltic fragments a billion years ago 5. Our data show that the meteorite flux has varied over geological time as asteroid disruptions create new fragment populations that then slowly fade away from collisional and dynamical evolution. The current flux favours disruption events that are larger, younger and/or highly efficient at delivering material to Earth

Managing Insect and Mite Pests of Texas Corn.

16 p