Characterizing Flight Aggregation of the Southern Pine Beetle

Spatial aggregation patterns of flying southern pine beetles, Dendroctonus frontalis Zimm., were studied using a systematic grid of sticky flight traps placed in 3 beetle infestations. Five methods of characterizing dispersion were compared: Lloyd\u27s index of patchiness (IP), Morisita\u27s index of dispersion (15), the coefficient of dispersion (CD), the slope of Taylor\u27s power function (b) and the slope of Iwao\u27s regression of mean crowding on mean density (m). All indices indicated a high degree of aggregation of flying southern pine beetles within the infestations. The indices varied, however, in their ranking of aggregation for the 3 study sites. IP and 15 gave the same relative results while CD showed a different pattern. The two regression techniques showed no significant differences between slopes for the various study sites. The m-m regression provided more information for interpretation and more potential for evaluating influences of system manipulations. It is recommended, therefore, for characterization of southern pine beetle aggregation within infestations. IP (which serves as the theoretical basis of the regression), is suggested for comparisons between daily aggregation patterns. The m-m regression may be useful for evaluating behavioral chemical effects on aggregation through comparison of daily m-m pairs to the 95% prediction limits about the regression line; pairs falling outside these limits represent aggregation patterns significantly different from the norm

Probability of Attack by Southern Pine Beetle in Relation to Distance from an Attractive Host Tree

The pattern of southern pine beetle (SPB) attack was examined in two infestations in East Texas to determine the probability of host tree attack (PA) as a function of distance (X) from a recently attacked tree (pheromone source). In an infestation having a low rate of newly attacked trees per day and only a few pheromone sources occurring simultaneously, distance was a critical factor in determining PA. The probability decreased as In X, and was described by the regression model, PA=0.06757- 0.2583 In X. Distance, however, was less critical in a larger infestation which had multiple pheromone sources occurring simultaneously and a high rate of new trees attacked each day. Implications for pheromone control strategies utilizing SPB attractants are discussed. FOREST SCL 24:574-580

Behavioral and Genetic Diversity during Dispersal: Analysis of a Polymorphic Esterase Locus in Southern Pine Beetle, Dendroctonus frontalis

Dispersal behavior of the southern pine beetle, Dendroctonus frontalis Zimmermann (Coleoptera: Scolytidae), in response to synthetic aggregating pheromone (frontalin) indicates an exponential decrease in response with distance from the site of emergence. Differential response during dispersal among genotypes at a polymorphic esterase locus was found by using starch gel electrophoresis. These differences produced allelic distributions that predict increased genetic diversity concurrent with increasing dispersal distance from the source population

Spatial Distribution of Flying Southern Pine Beetle (Coleoptera:Scolytidae) and the Predator ThanasUnus dubius (Coleoptera:Cleridae)

Spatial dispersion patterns of flying southern pine beetles, Dendroctonus frontalis Zimm., and the clerid predator Thanasimus dubius (F.) were determined within 3 natural infestations of southern pine beetle (SPB) in eastern Texas using grids of sticky traps. There was significant positive association of the 2 insects throughout the trapping grids, although aerial population densities of the clerid were inversely related to aerial densities of SPB. Aggregation patterns were quantified using the index of patchiness (lP) and the regressions of mean crowding (m) on mean density (m). Both methods showed a highly clumped pattern for both beetle species. SPB density in the infestations was positively associated with the daily rate of tree attack by the beetles, but the degree of population aggregation in the infestations was inversely related to the daily rate of tree attack. Although densities of the two species did not follow the same trends among the 3 infestations, the degree of aggregation did (i.e., SPB was most highly aggregated in the location where T. dubius was most highly aggregated) and Lloyd\u27s index of interspecific patchiness indicated overlapping aggregate distributions. A kairomonal response mechanism for T. dubius, and SPB co-aggregation within infestations is hypothesized

Panel docking of small-molecule libraries - Prospects to improve efficiency of lead compound discovery

Computational docking as a means to prioritise small molecules in drug discovery projects remains a highly popular in silico screening approach. Contemporary docking approaches without experimental parametrisation can reliably differentiate active and inactive chemotypes in a protein binding site, but the absence of a correlation between the score of a predicted binding pose and the biological activity of the molecule presents a clear limitation. Several novel or improved computational approaches have been developed in the recent past to aid in screening and profiling of small-molecule ligands for drug discovery, but also more broadly in developing conceptual relationships between different protein targets by chemical probing. Among those new methodologies is a strategy known as inverse virtual screening, which involves the docking of a compound into different protein structures. In the present article, we review the different computational screening methodologies that employ docking of atomic models, and, by means of a case study, present an approach that expands the inverse virtual screening concept. By computationally screening a reasonably sized library of 1235 compounds against a panel of 48 mostly human kinases, we have been able to identify five groups of putative lead compounds with substantial diversity when compared to each other. One representative of each of the five groups was synthesised, and tested in kinase inhibition assays, yielding two compounds with micro-molar inhibition in five human kinases. This highly economic and cost-effective methodology holds great promise for drug discovery projects, especially in cases where a group of target proteins share high structural similarity in their binding sites

Little Pink Bush, Drive Through Movie

Little Pink Bush, Drive Through Movie is a collaboration between UK artists Lewis Paul, Sarah Taylor, and American artists Deen Modino and Nicholas J Coste

The first sawfly from the Oligocene of Céreste (Southern France) (Hymenoptera: Tenthredinidae)

Luberotenthredo cerestensis gen. et sp. nov. is the first record of the sawfly family Tenthredinidae from the Oligocene of Céreste (Southern France). This taxon is described and illustrated based on a well-preserved specimen. This genus resembles the extant genus Perineura (subfamily Tenthredininae, tribe Perineurini) with which it shares forewing venation similarities and numerous morphological characters. This new taxon is the first fossil representative of the tribe Perineurini and can be used as a calibration point for future investigation of the diversification of the family Tenthredinidae