No abstract

Synthetic attractant lures enriched in the (+) enantiomer of cis-7,8-epoxy-2-methyloctadecane were many times more effective in eliciting trap catch of male gypsy moth, Lymantria dispar (L.), than racemic cis-7,s-epoxy-2-methyloctadecane. The lowered trap catch at the racemate was due to the antagonistic effects of the (-) enantiomer on the male behaviors of long-range upwind flight, the likelihood of landing on the baited trap and duration of the persistent "searching" behavior of wing fanning concurrent with walking on the trap. The admixture of 2-methyl-(Z)-7-octadecene with the (-I-) enantiomer also effected a reduction in trap catch.

No abstract

Biological activities in chickens of crude polysaccharide extracted from two different immunotype strains of Hemophilus gallinarum (HG), strain 221 and S1, were studied to clarify a type-specific protecting antigen and a toxin. Crude polysaccharide materials extracted from strains 221 and S1 were not only protective but toxic to chickens. They also contained at least two heat-labile antigens. When the polysaccharide materials were subjected to gel filtration on Sepharose 6B by tracing at 280 and 490 nm, the protective and toxic activities could be fractionated as peak-1 and -2 polysaccharides, respectively. The fraction of peak-1 polysaccharides from strains 221 and S1 was eluted at void volume. Cross-protection was not found between strains 221 and S1 in the fraction of peak-1 polysaccharide. Hemagglutination-inhibition (HI) antibody to type 1 hemagglutinin of HG (trypsin-sensitive hemagglutinin) was detected in chickens immunized with this fraction from strain 221 but not with that from strain S1. Type specificity between both strains was also found in this fraction by agar-gel precipitation (AGP) test. On the other hand, the toxic fraction of peak-2 polysaccharide, which caused hydropericardium in chickens, had a lower molecular weight than did that of peak-1 polysaccharide. It did not give HI antibody in chickens. Common antigenicity between strains 221 and S1 was found in the peak-2 polysaccharide by AGP test.

Subunit vaccines containing haemagglutinin-neuraminidase (HN) glycoprotein of