The Ministry for Primary Industries has rejected claims by a Far North man that a colony of the Asian tiger mosquito, one of two species implicated in the spread of the Zika virus, has established in Northland.
Eric Albert said he had seen tiger mosquitoes in his farmer son's home in Whangarei, his son blaming them for the loss of about 30 calves, born dead or deformed, in the last three years.
Mr Albert believed the insects had arrived in the ballast of log ships, and had found Northland warm enough to survive and breed.
However, a senior communications adviser for the MPI said entomologists had confirmed that neither the Asian tiger (Aedes albopictus) nor the yellow fever (Aedes aegypti) mosquito, regarded as the major threats in spreading the Zika virus, were established anywhere in New Zealand.
The ministry's manager of surveillance and incursion investigation for animals was not aware of calf deaths associated with mosquitoes.
The ministry's advice to anyone who believed they had seen an exotic organism or unusual signs of disease was to phone its hotline, 0800 809-966. There was another, specific number (0800 MOSSIE, 0800 669-943) for reporting suspected exotic mosquito sightings.
Meanwhile Public Health England has warned those who travel to any of the 23 affected countries against trying for a baby for six months after leaving as a precaution against passing the Zika virus on to a foetus.
The New Zealand Olympic Committee has reiterated government advice that expectant mothers, or those planning pregnancy, do not travel to areas where the Zika virus is present. That includes women who are pregnant, or planning pregnancies, in a period of weeks after being in Olympic host country Brazil.
The Zika virus can lead to Guillain-Barre syndrome, a serious immune system disorder. A major concern is that pregnant women who get infected can transmit the disease to their unborn children, with reports there have been an increase in severe birth defects where mothers were in affected areas.