Do aphids in Dutch sweet pepper greenhouses carry heritable elements that protect them against biocontrol parasitoids?

Biological control (biocontrol) of crop pests is a sustainable alternative to the use of biodiversity and organismal health-harming chemical pesticides. Aphids can be biologically controlled with parasitoid wasps; however, variable results of parasitoid-based aphid biocontrol in greenhouses are reported. Aphids may display genetically encoded (endogenous) defences that increase aphid resistance against parasitoids as under high parasitoid pressure there will be selection for parasitoid-resistant aphids, potentially affecting the success of parasitoid-based aphid biocontrol in greenhouses.

[A case of swollen head syndrome in a flock of guinea fowl].

A case of swollen head syndrome in guinea-fowl is reported. In addition to the isolation of E. coli and staphylococci during the course of the disease, antibodies to rhinotracheitis were shown to be present in the blood.

[Several cases of nitrite poisoning in broiler breeding hens].

Because of insufficient ventilation during winter, water condensation associated with a high concentration of ammonia (70-100 ppm) in the air, occurred on several breeding farms. The ammonia became bound to the condensation water and was converted into nitrites (6000-16000 mg/l) and nitrates (1630-1700 mg/l). Ingestion by the birds resulted in acute death, probably as a result of the high nitrite concentration.

Quantitative determination of diethylstilboestrol in bovine urine with isotope dilution mass spectrometry.

A method has been described for the quantification of diethylstilboestrol (DES) in bovine urine. The determining step is based on isotope dilution mass spectrometry (IDMS). The chemical work-up consisted of enzymatic deconjugation, Sep-Pak clean-up and high-performance liquid chromatography (HPLC).