Visual Ability and Searching Behavior of Adult Laricobius nigrinus, a Hemlock Woolly Adelgid Predator

Very little is known about the searching behavior and sensory cues that Laricobius spp. (Coleoptera: Derodontidae) predators use to locate suitable habitats and prey, which limits our ability to collect and monitor them for classical biological control of adelgids (Hemiptera: Adelgidae). The aim of this study was to examine the visual ability and the searching behavior of newly emerged L. nigrinus Fender, a host-specific predator of the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Phylloxeroidea: Adelgidae). In a laboratory bioassay, individual adults attempting to locate an uninfested eastern hemlock seedling under either light or dark conditions were observed in an arena. In another bioassay, individual adults searching for prey on hemlock seedlings (infested or uninfested) were continuously video-recorded. Beetles located and began climbing the seedling stem in light significantly more than in dark, indicating that vision is an important sensory modality. Our primary finding was that searching behavior of L. nigrinus, as in most species, was related to food abundance. Beetles did not fly in the presence of high A. tsugae densities and flew when A. tsugae was absent, which agrees with observed aggregations of beetles on heavily infested trees in the field. At close range of prey, slow crawling and frequent turning suggest the use of non-visual cues such as olfaction and contact chemoreception. Based on the beetles' visual ability to locate tree stems and their climbing behavior, a bole trap may be an effective collection and monitoring tool

Disulfide exchange in domain 2 of CD4 is required for entry of HIV-I

Lisa J. Matthias, Patricia T.W. Yam, Xing-Mai Jiang, Nick Vandegraaff, Peng Li, Pantelis Poumbourios, Neil Donoghue & Philip J. Hog

Design and engineering of O₂ transport protein

The principles of natural protein engineering are obscured by overlapping functions and complexity accumulated through natural selection and evolution. Completely artificial proteins offer a clean slate on which to define and test these protein engineering principles, while recreating and extending natural functions. We introduce this method here with the first design of an oxygen transport protein, akin to human neuroglobin. Beginning with a simple and unnatural helix-forming sequence with just three different amino acids, we assemble a four helix bundle, position histidines to bis-his ligate hemes, and exploit helical rotation and glutamate burial on heme binding to introduce distal histidine strain and facilitate O(2) binding. For stable oxygen binding without heme oxidation, water is excluded by simple packing of the protein interior and loops that reduce helical-interface mobility. O(2) affinities and exchange timescales match natural globins with distal histidines with the remarkable exception that O(2) binds tighter than CO