Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 

Help At Hand For Starving Monarchs


A caterpillar in the hanging "J" shape it assumes just before it changes to a pupa, or chrysalis.

Landcare Research has helpful advice for monarch butterfly enthusiasts, who are concerned that their ravenous caterpillars have stripped swan plants, and may not survive to chrysalis stage.

Scientists believe that monarch butterflies (Danaus plexippus) are self introduced into New Zealand. Earliest records of them date back to the 1880s, though their favourite food, the swan plant (Gomphocarpus fruticosus) was introduced some time later. Because monarch caterpillars eat only introduced plants, they have no harmful effects on the New Zealand ecosystem.

Landcare Research entomologist Leonie Clunie says she receives many calls at this time of year from people wanting to know how to save their starving caterpillars. Mrs Clunie says there are alternative sources of food, though none are ideal.

"One option is simply to transfer the caterpillars onto a slice of pumpkin. However, this is not the best food for them, and though it may tide the bigger ones over, the younger ones won't survive.

"The same applies to tweedia (Oxypetalum caeruleum), a popular garden plant with a small blue flower, and to moth plant (Araujia sericifera), which is a weed".

Chris Winks, a Landcare Research entomologist, says though monarch butterfly caterpillars will develop successfully on moth plant, eggs are generally not laid on it. Moth plant is also known as 'cruel plant', bringing both life and death to the monarch. Though it provides nutrients to caterpillars, the flowers trap the mouthparts of feeding butterflies, inflicting a slow death from exhaustion and dehydration.

Despite such casualties of both adults and starving caterpillars, monarchs will remain a colourful presence in New Zealand. "It is part of the monarchs' survival strategy to produce large numbers of caterpillars, many of which will die" says Leonie Clunie. "Therefore, monarch lovers need not be too distressed".

Also, some of the strugglers may end up to be the longest-lived. "Most of the monarch butterflies around at the height of summer live for about two weeks. But the caterpillars that reach chrysalis stage late in the season could emerge as the butterflies that hibernate through the winter, and produce more caterpillars the next summer".

ENDS/

For more information, contact: Mrs Leonie Clunie Mr Chris Winks Landcare Research Mount Albert Research Centre Auckland ph. (09) 815 4200 e-mail: ClunieL@landcare.cri.nz WinksC@landcare.cri.nz


© Scoop Media

 
 
 
Business Headlines | Sci-Tech Headlines

 

Voluntary Administration: Renaissance Brewing Up For Sale

Renaissance Brewing, the first local company to raise capital through equity crowdfunding, is up for sale after cash flow woes and product management issues led to the appointment of voluntary administrators. More>>

Elsewhere:

Approval: Northern Corridor Decision Released

The approval gives the green light to construction of the last link of Auckland’s Western Ring Route, providing an alternative route from South Auckland to the North Shore. More>>

ALSO:

Media Mega Merger: Full Steam Ahead For Appeal

New Zealand's two largest news publishers have confirmed they are committed to pursuing their appeal against the Commerce Commission's rejection of the proposal to merge their operations. More>>

Crown Accounts: $4.1 Billion Surplus

The New Zealand Government has achieved its third fiscal surplus in a row with the Crown accounts for the year ended 30 June 2017 showing an OBEGAL surplus of $4.1 billion, $2.2 billion stronger than last year, Finance Minister Steven Joyce says. More>>

ALSO:

Mycoplasma Bovis: One New Property Tests Positive

The newly identified property... was already under a Restricted Place notice under the Biosecurity Act. More>>

Accounting Scandal: Suspension Of Fuji Xerox From All-Of-Government Contract

General Manager of New Zealand Government Procurement John Ivil says, “FXNZ has been formally suspended from the Print Technology and Associated Services (PTAS) contract and terminated from the Office Supplies contract.” More>>