While Auckland battles the hornets, a highly invasive type of clam is poised to devastate waterways further south. Meanwhile the campaign against feral cats is officially gearing up, writes Catherine McGregor in today\u2019s extract from The Bulletin.<\/p>\n
To receive The Bulletin in full each weekday,\u00a0sign up here<\/a>.<\/p>\n Hornets: new tech for a fast-moving threat<\/p>\n As New Zealand heads into summer, the threat from the invasive Asian yellow-legged hornet is rising, and officials are turning to new tools to keep ahead of it.\u00a0RNZ\u2019s Victor Waters reports<\/a>\u00a0that Biosecurity New Zealand has begun using Dutch tracking devices that can be attached to male hornets and used to follow them back to their nests.<\/p>\n Scientists say the window for eradication is narrowing.\u00a0In The Conversation<\/a>, entomologist Phil Lester warns that \u201cwhat we\u2019ve seen is a potential nightmare\u201d, with the current finds likely only a fraction of what is out there. In Europe, invasion spread rates can get as high as 112km each year once populations become established. \u201cIf these European patterns apply even partially to New Zealand, the search radius must expand dramatically\u201d from its current North Shore location, Lester writes.<\/p>\n Once established, the hornet can produce hundreds of queens in a single season and wipe out vast numbers of honey bees, a species that tends to make up the majority of the hornet\u2019s diet. \u201cPeople are at risk, too,\u201d Lester writes. \u201cThose who approach nests too closely risk severe stings known to cause intense pain, rapid swelling and, in some cases, life-threatening allergic reactions. People have died after being stung by these hornets.\u201d The public is being asked to\u00a0 stay alert and report any suspected sightings, either\u00a0online<\/a>\u00a0or by phoning 0800 809 966<\/p>\n Gold clams: council braces for costly \u2018hard calls\u2019<\/p>\n In Taranaki, the discovery of gold clams in Lake Rotomanu has forced regional authorities into emergency planning,\u00a0writes Helen Harvey in the Taranaki Daily News<\/a>. A report to councillors warns that the next few weeks will involve \u201chard calls\u201d, with options ranging from banning motorised boats to draining and drying the entire lake. Because the gold clam is already established elsewhere \u2013 originally from east Asia, it was first discovered in New Zealand in Lake Karapiro, in Waikato, in 2023 \u2013 MPI is unlikely to provide any funding for the project. Instead, costs will need to be absorbed by existing council budgets.<\/p>\n Scientists say the risks go well beyond Taranaki. As Lincoln University geochemist Adam Hartland\u00a0explains in The Conversation<\/a>, the clams are already altering the Waikato River\u2019s chemistry \u201cin ways that could jeopardise drinking water for up to two million people\u201d. As the clam builds its shell, it strips calcium from the water; Hartland\u2019s team has documented a significant drop in calcium levels in the river, which in turn impairs arsenic removal during water treatment. There\u2019s also a risk that the clam population could reduce hydroelectric efficiency in a river that generates upwards of 13% of New Zealand\u2019s power. \u201cGlobally, the gold clam has cost billions in damages,\u201d Hartland writes. \u201cNew Zealand can\u2019t afford to wait.\u201d<\/p>\n Feral cats: new classification brings new ethical questions<\/p>\n Last month the government added feral cats to the Predator Free 2050 target list, its first expansion since the programme began in 2016.\u00a0RNZ\u2019s Farah Hancock noted<\/a> that the move appeared to be \u201ca sudden change of tack\u201d after RNZ pointed out Christopher Luxon had promised during a 2023 election debate to add feral cats to the list but failed to do so. It\u2019s estimated that NZ is home to at least 2.4 million feral cats, apex predators which have been linked to the extinction of several native bird species.<\/p>\n