KEY POINTS:
Plagues of locusts have crossed the Tasman to make the most of New Zealand's hottest summer for a decade.
Forest and Bird Society president Dr Peter Maddison said there had been unusual insect activity in parts of the country affected by drought.
Swarms of crickets, an insect "associated with drought", had hit the Hauraki Plains and there had been larger numbers of locusts in the northern regions, many of which may have come from Australia.
"It's the remains of the swarms that get over here, but the weather conditions are right to bring them over," Maddison said.
Grass grub beetles, whose growth is encouraged by hot temperatures, had been causing problems in the Bay of Plenty.
"They haven't been a problem for several years, I think," said Maddison.
There have been strange goings-on at sea, too.
Fisherman and tackle salesman Scott Malcon, of Auckland's Fish City, said mahi mahi, typically a tropical water fish, had been caught off Auckland.
Other species, including the skipjack tuna and blue marlin were more plentiful than usual, and Malcon said there had been a highly rare spotting of a tropical sailfish near Great Barrier Island.
Last week a Pacific spotfin burrfish was caught in Northland and there had been catches of wahoo around the Three Kings Islands, east of Cape Reinga.
Average summer temperatures were almost 1C above normal in December, January and February at 17.3C The warm weather is set to continue into autumn.
Niwa principal climate scientist Jim Salinger said it had been warm and very dry in the North Island, although sunshine levels were near or below average.
Auckland was the warmest of the five main centres over the three summer months while Hamilton was the driest.
The highest temperature for the year, 34.8C, was recorded in Timaru last week, and several other towns had their hottest temperatures in March.
Increased temperatures were associated with the La Nina weather system, which brings more frequent northeasterly winds and warmer weather.
The rest of the Easter weekend is expected to stay mainly dry and settled. Metservice weather ambassador Bob McDavitt said temperatures were expected to stay warm in Auckland and the upper North Island.
