Another New Garden Pest
There is a new to New Zealand beetle which comes from the South Pacific commonly called the Hadda Beetle.
The first public notice of this beetle was in February 2010 when a entomologist with a close association with MAF Biosecurity New Zealand spotted a Hadda Beetle in Dove -Myer Robinson Park, along Tamaki Drive and the Auckland Domain in Auckland while walking his dog.
It was then reported ( From the Internet) :
David Yard, MAF Biosecurity New Zealand Response Manager, says the beetle causes distinctive damage to foliage.
“The species are found throughout Asia and the Pacific region and are foliage feeders that feed on solanaceous crops including potatoes, tomatoes, and aubergines plus beans and capsicums.
“The leaf surface is scraped away leaving irregular windows or parallel strips. This feeding damage gives leaves a distinctive “lace-like” appearance which is quite visible. Both adults and larvae feed on the host plants.”
Although similar to the common lady bird, Hadda beetles have some distinctive differences.
Hadda beetle larvae are about 7 mm long, and pale yellow in colour with black spiny hairs. The adults are 7 10 mm in size and yellow/ orange coloured with around 26 black spots on their backs.
Now as a matter of interest I am sure I had a couple of calls this summer from gardeners who said they had found some beetles in their gardens that looked a lot like ladybirds but with different colouring.
I cant remember which areas of New Zealand the gardeners were calling from but I would suspect that the distribution of the beetle is much greater than thought.
This was highlighted from another recent report which said; ‘In March this year MAF Biosecurity announced that eradication of the Hadda beetle would not be feasible. Investigations have found the beetle is widespread across central Auckland and the maturity of the beetles indicates that it may have been in New Zealand since 2006.’
A female Hadda beetle lays about 300 small cigar-shaped yellow eggs in clusters of 10 to 50 on the under surface of potato leaves or other host plants.
Eggs hatch in about 5 days into small, yellow grubs, covered with hairy spines.
The grubs feed on the lower epidermis of leaves and are full grown in 7 to 18 days.
The pupal stage lasts 5 to 14 days.
It was in the Dominion Newspaper this week that I read an article about the Hadda Beetle and thus alerted me to the pest.
If you goto http://www.nba.org.nz/docs/hadda-beetle-fact-sheet.pdf you will find some excellent pictures of the beetle, the grubs and the damage patterns on foliage from their feeding.
Also if you find a Hadda Beetle in your garden then call MAF Biosecurity on 0800 809966 to inform them.
This new threat follows on from the other recent problem which is the potato/tomato psyllid that attacks the same family of plants. During feeding the psyllid releases a toxin which affects the development of the potatoes or the fruit of tomatoes.
Thus instead of having a good crop of nice size tubers at harvest you find a number of marble sized potatoes that are already re-shooting. On tomatoes the fruit also are very small.
Now with the Hadda Beetle coming along to strip the foliage of potatoes, tomatoes and other plants then greater care will have to be taken of these crops.
Early season crops are likely to be less effected as the pest populations have not built up till later in the season. Late crops will therefore suffer the greatest damage.
I suggest the placement of Neem Tree Granules in the planting hole of all host plants and also sprinkling the same every 6 weeks on the soil surface in the plant’s root zone.
Back this up with a spray of Neem Tree Oil once or twice a month.
Spray for total coverage of the foliage and add Raingard to the spray.
This keeps the Neem Oil active longer and prevents washing off or been diluted with watering or rain.
It will not be long now before the new seasons certified seed potatoes become available so don’t forget to protect them.
Talking about protection it looks very much like our Indian Summer has reached its end and the cold times of winter are at hand.
Frost or cold sensitive plants should be protect with a spray of Vaporgard over the foliage which gives reasonable frost protection down to minus three for about 3 months within 3 days of application.
Great protection for the occasional frost but when two or more frosts are going to occur, nite after nite then additional protection must be applied such as frost cloth, sacks or newspaper.
A word of warning, do not prune roses or fruit trees when the weather is cool and moist.
The dreaded disease, ‘Silver Leaf’ is in the air when its cool and damp and if you open up your roses or fruit trees then they can be affected.
Moss and liverworts love moist conditions so at the first sign of them spray with Moss and Liverwort Control.
Problems ring me at 0800 466464 (Palmerston North 3570606)
