Zealand Border Research Articles

DNA barcodes for biosecurity: invasive species identification.

Biosecurity encompasses protecting against any risk through 'biological harm', not least being the economic impact from the spread of pest insects. Molecular diagnostic tools provide valuable support for the rapid and accurate identification of morphologically indistinct alien species. However, these tools currently lack standardization. They are not conducive to adaptation by multiple sectors or countries, or to coping with changing pest priorities. The data presented here identifies DNA barcodes as a very promising opportunity to address this. DNA of tussock moth and fruit fly specimens intercepted at the New Zealand border over the last decade were reanalysed using the cox1 sequence barcode approach. Species identifications were compared with the historical dataset obtained by PCR-RFLP of nuclear rDNA. There was 90 and 96% agreement between the methods for these species, respectively. Improvements included previous tussock moth 'unknowns' being placed to family, genera or species and further resolution within fruit fly species complexes. The analyses highlight several advantages of DNA barcodes, especially their adaptability and predictive value. This approach is a realistic platform on which to build a much more flexible system, with the potential to be adopted globally for the rapid and accurate identification of invasive alien species.

Changes in plasma cortisol concentrations before, during and after analgesia, anaesthesia and anaesthesia plus ovariohysterectomy in bitches

Plasma cortisol concentrations were determined before, during and after analgesia, anaesthesia and anaesthesia plus ovariohysterectomy in six New Zealand border collie cross bitches. The treatments were: control, analgesia with butorphanol, anaesthesia with thiopentone sodium, halothane and oxygen and anaesthesia plus surgery. In addition, each bitch was given an ACTH challenge. All the bitches showed transient increases in plasma cortisol concentrations and the integrated cortisol responses (calculated as the area under the cortisol curve above the pre-treatment concentration) for 6·25 hours after treatment increased in the order: control, anaesthesia, analgesia, surgery. The control group had increased cortisol concentrations attributable to the excitement from handling. The plasma cortisol concentrations of the group subjected to surgery were greater than the other groups for at least 6·25 hours, with an approximately four-fold increase above pre-treatment values, but they had returned to pre-treatment levels after 24 hours.

Automation of New Zealand Border Strip Irrigation

ABSTRACT OF the 150 000 ha irrigated in New Zealand, half are irrigated by the border strip method. Labor and water efficiency have been improved by the use of automatic farm water control, new design practices, cor-rect management and better machine utilization. The discharge of water into the strips, which are grouped for optimum water use, has been designed for automatic control by using a pre-set drop gate system activated by mechanical, electrical, or pneumatic devices. Irrigation has changed from a downstream to an upstream method. Design effort has been directed towards a steepest grade, minimum earth-moving during grading, approach. The combination of automatic farm water control, system design and management, has resulted in a decrease in labor use from 90 min/ha to 3 min/ha and an increase in the rate of irrigation from 8 ha in a 12-h/day to 25 ha in a 24-h/day.