Simultaneously immobilized glucose oxidase and catalase in controlled-pore titania

The immobilization of glucose oxidase and catalase by adsorption within the pores of controlled-pore titania has yielded a remarkably stable enzyme system. Catalase apparently acts as both a stabilizer and an activator for glucose oxidase within the pores of this material. Hydrogen peroxide concentrations and flow rates have a marked effect upon the apparent activity of the immobilized enzyme system. The carrier parameters were varied to obtain optimum loading and stability information.     

Biosystematics ofAmblyseius andersoni andA. potentillae (Acarina: Phytoseiidae): Implications for biological control

Populations ofAmblyseius andersoni Chant from Verona, Italy and Oregon, U.S.A. and ofA. potentillae (Garman) from The Netherlands were hybridized in reciprocal crosses and examined for evidence of genetic isolation and morphological or isozyme discrimination. Hybridization studies showed that all crosses between the three populations produced viable and fertile female offspring. Backcrosses of F₁ hybrid females to males of the maternal strain likewise showed no evidence of genetic isolation. It is concluded that the populations are conspecific, and thatA. potentillae should be recognized as a junior synonym ofA. andersoni.Morphological examination showed that the Oregon and Netherlands biotypes were more similar to one another than either was to the Italian biotype. A linear discriminate-function analysis correctly classified the mites 78.3% of the time, with only 5% of the misclassifications involving the Italian biotype. Polyacrylamide gel electrophoresis of esterase isozymes showed distinct bands of enzyme activity with significantly differentR _f values for each of the three populations. The genetic continuity between the biotypes should allow us to incorporate specific biological traits of value for biological control in Oregon by hybridization with the other populations, while the morphological and electrophoretic markers may allow us to track the degree of establishment and dispersal which occurs under field conditions when foreign biotypes are introduced.     

Tissue taurine content and conjugated bile acid composition of rhesus monkey infants fed a human infant soy-protein formula with or without taurine supplementation for 3 months

The concentrations of taurine in a number of brain regions and in other tissues of rhesus morkeys fed a taurine-free human infant formula for 3 months are substantially lower than in similar monkeys fed the same formula supplemented with taurine. Activities of enzymes involved in taurine biosynthesis were not different in the two groups except for liver cysteinesulfinic acid decarboxylase, which was greater in the monkeys fed formula alone. There was no difference in the biliary bile acid composition, but the proportion of bile acids conjugated with taurine was significantly greater in the monkeys fed formula supplemented with taurine. These results indicate that the effects of a taurine-deficient diet on infant primates are widespread.     

Introduction and establishment ofTrioxys pallidus [Hym.: Aphidiidae] in Oregon,U.S.A. for control of filbert aphidMyzocallis coryli [Hom.: Aphididae]

Hazelnut orchards in Spain, France, and Italy were searched for parasitoids of the filbert aphid,Myzocallis coryli (Goetze). A biotype ofTrioxys pallidus Haliday was found to parasitize the aphid throughout western Europe. Wasps were imported, quarantined, mass-reared, and released in Oregon orchards. The wasp successfully attacked and completed its development on Oregon populations of the filbert aphid. A greenhouse culture of the parasitoid was maintained continuously for over 50 generations, and approximately 30,000 adult wasps were released in western Oregon. Overwintering survival has been documented in at least 12 different locations. In 3 commercial hazelnut orchards, the parasitoids proved capable of reducing aphid population peaks by 33–48%.      

Effects of origin and experience on patterns of host acceptance by the opiine parasitoid Diachasmimorpha tryoni

1. Patterns of host acceptance by Diachasmimorpha tryoni (Ashmead), a parasitoid of tephritid flies, were evaluated in relation to host–substrate complex, wasp origin, and wasp experience. 2. Naive female D. tryoni originating both from the Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann) and the lantana gall fly Eutreta xanthochaeta Aldrich probed medfly-infested coffee fruit two to six times more often than E. xanthochaeta-inhabited lantana galls. No significant differences were detected between the two groups of parasitoids in patterns of probing response to medfly-infested coffee fruit or to E. xanthochaeta galls. 3. An 18-h pretest exposure to medfly-infested coffee fruit or E. xanthochaeta-inhabited galls affected the probing response of D. tryoni to E. xanthochaeta galls significantly, but did not affect the probing response to medfly-infested coffee fruit. Diachasmimorpha tryoni exposed to E. xanthochaeta galls probed E. xanthochaeta galls two to three times more often than naive wasps, and seven to 11 times more than wasps exposed to medfly-infested coffee fruit. Regardless of the prior exposure treatments, a high proportion (75–100%) of the test parasitoids probed medfly-infested coffee fruit. 4. Parasitoid acceptance of less-preferred hosts or host–substrate complexes may be more amenable to conditioning through prior experience (i.e. learning) than preferred host–substrate complexes. The relevance of these findings to host range expansion of parasitoids used in fruit fly biological control is discussed.     

Current challenges to the implementation of classical biological control

Biological control is considered by many applied ecologists and pest management specialists to be among the safest, most environmentally benign, and most cost-effective methods of pest control available. Yet the practical implementation of projects, especially for classical biocontrol, is replete with challenges large and small; some long standing, and others relatively new. Here we review some of the most pressing current challenges, and provide some background about their foundation and derivation. A common thread that runs throughout this summary is that public education and public support for biological control technology is critical for maintaining the economic, regulatory, and logistical feasibility of this most effective tool for pest management.     

Regional analysis of brain opiate receptors in rats with hereditary hypothalamic diabetes insipidus.

The regional distribution of stereospecific ³H-dihydromorphine binding sites in Brattleboro rats with hereditary hypothalamic diabetes insipidus was studied. Control animals were homozygous normal Brattleboro rats and rats heterozygous for the vasopressin deficiency. Scatchard plots of ³H-dihydromorphine binding in a washed membrane preparation showed that rats with diabetes insipidus exhibited higher receptor concentrations in all assayed areas of the cerebral hemispheres. In the diencephalon, receptor concentrations were lower in diabetes insipidus rats. The results point to the existence of interactions between brain opioid systems and neurohypophyseal peptides.