The role of insect cell lines in an artificial diet for the parasitold wasp, Trichogramma pretiosum

Trichogramma species are mass-produced for biological control using host eggs. Artificial diets have been developed to reduce production costs, however, most include insect haemolymph as a major component, which still results in a significant expense. Medium conditioned with insect cell lines has produced some success as a haemolymph replacement in artificial diets for several parasitoid wasp species. Trichogramma australicum Girault (Hymenoptera: Trichogrammatidae) was the first species to develop successfully to the adult stage on diets containing concentrated HeliothiS zea (Boddie) (Lepidoptera: Noctuidae) cells. Tricho-gramma pretiosum Riley (Hymenoptera: Trichogrammatidae) was subsequently grown to the adult stage on a similar cell line diet. This success encouraged a systematic investigation into the use of insect cell lines in Trichogramma artificial diets. We compared the effect of diets containing insect cells with diets containing conditioned cell line media. Diets containing insect cells produced significantly more pupae than diets containing conditioned medium and, although not significant, produced a higher number of adults. Second, we compared the effect of diets containing cell lines established from ovary-associated tissue of H. zea and embryo tissue of Aedes albopictus (Skuse) (Diptera: Culicidae) on T pretiosum development. Trichogramma pretiosum development was not significantly different on diets containing cells from the two origins and tissue types. Third, the effect of cell storage on T pretiosum development was observed. HeliothiS zea cells in medium were stored at 4 degrees C and room temperature (22 degrees C for one, two, four and seven days before addition to artificial diets. Cell viability was calculated for these storage treatments. HeliothiS zea cells could be stored at 4 degrees C for up to seven days with no detrimental effect on T pretiosum development. Tricho-gramma pretiosum development did not depend on cell viability. The use of insect cell lines as a haemolymph replacement has the potential to significantly reduce production costs and simplify Trichogramma artificial diets with the eventual aim of replacing host production in mass rearing facilities. (c) 2005 Elsevier Inc. All rights reserved.

The relationship between media reporting of suicide and actual suicide in Australia

This study aimed to determine whether media items about suicide were associated with differential increases in actual suicides. Data were available on 4635 suicide-related items appearing in Australian newspapers and on radio and television news and current affairs shows between March 2000 and February 2001. These data were combined with national data on completed suicides occurring during the same period, by a process that involved identifying the date and geographical reach of the media items and determining the number of suicides occurring in the same location in selected weeks pre- and post-item. Regression analyses were conducted to determine whether the likelihood of an increase in post-item suicides could be explained by particular item characteristics. We found that 39% of media items were followed by an increase in mate suicides, and 31% by an increase in female suicides. Media items were more likely to be associated with increases in both male and female suicides if they occurred in the context of multiple other reports on suicide (versus occurring in isolation), if they were broadcast on television (versus other media), and if they were about completed suicide (versus attempted suicide or suicidal ideation). Different item content appeared to be influential for males and females, with an increase in male suicides being associated with items about an individual's experience of suicide and opinion pieces, and an increase in female suicides being associated with items about mass- or murder-suicide. Item prominence and quality were not differentially associated with increases in male or female suicides. Further research on this topic is required, but in the meantime there is a need to remain vigilant about how suicide news is reported. Mental health professionals and suicide experts should collaborate with media professionals to try to balance 'public interest' against the risk of harm. (c) 2005 Published by Elsevier Ltd.