Phagostimulants enhancing the efficacy ofBacillus Thuringiensis formulations against the Giant Looper,Boarmia (Ascotis) Selenaria,in avocado

In both laboratory and field trials, as well as in semicommercial scale applications, the minimum concentration ofBacillus thuringiensis (B.t.) required to secure satisfactory larval mortality ofBoarmia selenaria could be halved, from 0.5% to 0.25%, by addition of 1% of the commercial phagostimulant Coax. Another phagostimulant product, Gustol, was inactive. Coax did not attract caterpillars from a distance. However, individual, Coax-treated spots on the avocado leaf surface were consumed by the larvae to a significantly greater extent than control. The same difference in palatability was recorded when the spots were treated with a mixture of Coax and aB.t. formulation. This explains, at least partially, the aforementioned advantageous effect of Coax in practical control of the looper byB.t.     

The site of attachment in human rhinovirus 14 for antiviral agents that inhibit uncoating

WIN 51711 and WIN 52084 are structurally related, antiviral compounds that inhibit the replication of rhino (common cold) viruses and related picornaviruses. They prevent the pH-mediated uncoating of the viral RNA. The compounds consist of a 3-methylisoxazole group that inserts itself into the hydrophobic interior of the VP1 beta-barrel, a connecting seven-membered aliphatic chain, and a 4-oxazolinylphenoxy group (OP) that covers the entrance to an ion channel in the floor of the "canyon." Viral disassembly may be inhibited by preventing the collapse of the VP1 hydrophobic pocket or by blocking the flow of ions into the virus interior.     

The atomic structure of Mengo virus at 3.0 A resolution

The structure of Mengo virus, a representative member of the cardio picornaviruses, is substantially different from the structures of rhino- and polioviruses. The structure of Mengo virus was solved with the use of human rhinovirus 14 as an 8 A resolution structural approximation. Phase information was then extended to 3 A resolution by use of the icosahedral symmetry. This procedure gives promise that many other virus structures also can be determined without the use of the isomorphous replacement technique. Although the organization of the major capsid proteins VP1, VP2, and VP3 of Mengo virus is essentially the same as in rhino- and polioviruses, large insertions and deletions, mostly in VP1, radically alter the surface features. In particular, the putative receptor binding "canyon" of human rhinovirus 14 becomes a deep "pit" in Mengo virus because of polypeptide insertions in VP1 that fill part of the canyon. The minor capsid peptide, VP4, is completely internal in Mengo virus, but its association with the other capsid proteins is substantially different from that in rhino- or poliovirus. However, its carboxyl terminus is located at a position similar to that in human rhinovirus 14 and poliovirus, suggesting the same autocatalytic cleavage of VP0 to VP4 and VP2 takes place during assembly in all these picornaviruses.     

Use of a self-expanding metallic stent for the treatment of a urethral stricture in a young cat

A 4-month-old intact male domestic shorthair cat was evaluated for urinary outflow obstruction after several weeks of medical management for traumatic urethral rupture. Positive-contrast retrograde urethrography and anterograde cystoscopy performed 4 weeks after the initial urethral injury confirmed a stricture approximately 1cm distal to the bladder trigone at the site of the initial urethral tear. A self-expanding metallic urethral stent (SEMS) was placed under fluoroscopic guidance to relieve the urethral stricture and re-establish luminal patency. After stent placement, the cat was able to void urine normally with minimal urinary incontinence noted. This resolved several months post-stent placement. No known clinical complications persisted other than mild intermittent hematuria.     

Methods for Determining Pythium Suppression In Container Media

Pythium damping-off and root-rot are among the most important soilborne diseases of greenhouse plants and seedlings grown in container media. It has been shown previously that composts may be conducive, suppressive or partially suppressive to Pythium diseases. The major goal of this work was to investigate rapid, practical and reliable methods for determining of the degree of suppressiveness of container media to Pythium damping-off. Several inoculation methods were tested in greenhouse bioassays, survival of propagules in suppressive versus conducive media was studied under laboratory conditions. Although both greenhouse and laboratory tests could indicate disease suppression, a bioassay with cucumber seedlings is suggested to be the most simple, effective and comprehensive method for testing suppression of Pythium diseases in compost amended container media.     

Postdiapause development and spring emergence of the european corn borer,Ostrinia nubilalis,in Israel

The European corn borer (ECB),Ostrinia nubilalis (Hübner) (Lepidoptera: Pyralidae), is the major pest of corn (Zea mays L.) in Israel. We investigated the temporal patterns of pupation and emergence of various overwintering ECB populations in Israel during 1992-94. The association between Julian date (JD) or cumulative degree-days (DD) and the rates of either pupation or emergence was studied using simple linear regression models. Differences between populations in JDs required to reach 50% pupation amounted to 5%, whereas for DD differences amounted to 26%. Similarly, at 50% emergence, differences between populations were up to 3% for JD and to 12% for DD. Two different forecasting models are proposed for either pupation or emergence. Based on these models, both pupation and emergence develop over a period of 4 to 5 weeks, and they are expected to occur between the following JDs: onset of pupation, 66–70 (March 7–11); 50% pupation, 96–102 (April 6–12); onset of emergence, 85–94 (March 26-April 4); and 50% emergence, 115–121 (April 25-May 1). Pupal development required 160 DD (confidence interval [C.I.] 141–179 DD) and it is expected to takeca 16 days (C.I. 14–18 days). The simple linear regression models obtained in this study are suggested as preliminary phenological models for the temporal prediction of postdiapause pupation and emergence of ECB.     

Indexing system for<Emphasis Type="Italic">Tomato mosaic virus</Emphasis> (ToMV) in commercial tomato seed lots

An indexing system for detectingTomato mosaic virus (ToMV) in commercial tomato seed lots is described. Factors associated with the procedure were analyzed and the following standard two-step working scheme is proposed: (i) mass screening by ELISA for the presence of the virus; (ii) evaluation of virus infectivity within the infested seed lots. A threshold of 10 ng ml⁻¹ was determined for detection of purified ToMV by either ELISA or plant inoculation.Nicotiana tabacum cv. Xanthi NN was found to be a highly sensitive local lesion assay plant for the detection of ToMV. A positive ELISA threshold (1.3 times above the non-specific background) was set for seed samples taken from commercial seed lots by testing the same samples by both ELISA and a bioassay. http://www.phytoparasitica.org posting July 14, 2004.