Archive for the ‘Pest control’ Category

Queensland lambing rates burgeon after state-funded building of 5000km of fences

A fence-building spree to keep out wild dogs has created a booming lambing rate in western Queensland.

An extra 213,000 sheep have been recorded in the state flock in the past two years, following the state government’s funding of the construction of 5000km of fencing to keep out wild dogs and other feral invaders.

The region’s lambing rate – the number born per 100 “matings” – has soared from less than 20% to 90%, says the premier, Annastacia Palaszczuk.

She said this would deliver an extra “45 full-time jobs worth $2.5m per year”.

The fencing, funded by $13.2m in state grants, now protects almost 300 western Queensland properties from wild dogs and other feral invaders and stretches along a distance which Palaszcuk said was “the same as a return highway journey from Cairns to Sydney”.

The state government has also loaned Longreach regional council $18m to build another 2500km.

Palaszczuk said the government had gone “way beyond” a 2015 election promise to give $5m in funding over three years to tackle feral animals that threaten farmers, and “as a result we are now seeing renewed confidence in the sheep and wool sector”.

In its report on this project (HERE), The Guardian describes Queensland as a relative minnow in Australia’s $4.8b sheep meat export industry, the world’s largest.

It had only 2.2m of the nation’s 70m flock in 2015 and only 1.4% of its lamb production, according to Meat and Livestock Australia.


UCSB scientists report on the effects of landscape characteristics on insecticide use

The effects of certain landscape characteristics on insecticide use depend on context and crop type, an American study has found.

The research has been reported (HERE) by the University of California – Santa Barbara.

Over the past half century, food production has intensified to meet the growing demand, the UCSB report says. And as agricultural fields have become ever larger, more pesticides are required to enhance yield.

Among increasingly huge spreads of single crops, insects tend to thrive as the landscape leaves little habitat for natural enemies such as birds or other predators. whether this plays out in reality has been difficult to determine scientifically.

Empirical landscape-scale studies of the drivers of agricultural insecticide use have produced ambiguous results and aggregated statistics make it difficult to tease apart the effects of underlying components.

A new study by UC Santa Barbara scientists has overcome that obstacle. Using detailed data from roughly 13,000 fields observed from 2005 to 2013 in Kern County, California, Ashley Larsen and Frederik Noack parsed the different effects of landscape characteristics such as crop diversity, field size and cropland extent on insecticide use. Their findings appear in the Proceedings of the National Academy of Sciences.

“If we are to minimize the negative effects of insecticides on human and environmental health, it is critical to understand if and how we can leverage landscape features to reduce insecticide use,” said lead author Larsen, an assistant professor in UCSB’s Bren School of Environmental Science & Management.

“Unlocking the different landscape components across multiple crops and spatial scales provides a novel understanding of which characteristics are likely to increase or decrease insecticide use for specific crops.”

The analysis by Larsen and Noack, a post-doctoral researcher at the Bren School, demonstrated potentially valuable benefits to crop diversity and to smaller fields. However, these benefits were highly dependent on crop type.

The research showed that while crop diversity reduced insecticide use, its impact was small in comparison to the differences in insecticide use between different crops.

“The choice of crops we produce or the type of crops we eat has a much larger impact on overall insecticide use than do landscape characteristics such as crop diversity or cropland extent,” Noack said.

As surrounding grape crop diversity increased, for example, insecticide use fell by nearly 8 kilograms per hectare.

“Grapes use about 49 kilograms of insecticide per hectare, so an 8 kg reduction is a fairly substantial fraction,” Larsen explained. “For oranges, the reduction is less than 2 kilograms per hectare, which is not significant, and for carrots there is no effect at all.”

Moreover, the investigators consistently found that larger fields use more insecticide.

A huge swath of single crop may serve to meet growing demand, but it also provides an uninterrupted breeding ground for insects, which in turn may promote increased chemical treatment to control the pests.

While many factors are at play, on the ecological side the paper was a big advance because scientists haven’t had this type of fine-scale understanding before, Larsen said. The researchers had been able to show that landscape drivers of agricultural insecticide use are very crop specific.

Landcare team looks into fighting wasps with wasps

Landcare Research scientists are exploring possible biocontrol agents, including a mite, to help control German and common wasps which cost the country’s primary industries around $130 million each year.

The most recent addition to the line-up is Sphecophaga, a species of parasitic wasp whose larvae feed off their host, eventually killing it.

The species was tried as a biocontrol agent against wasps in New Zealand starting in the 1980s, but so far has been established only in a few locations.

Recent research suggests this could have happened because the parasitic wasps were from the wrong region – sourced from Switzerland, Israel and the United States. Victoria University recently discovered New Zealand’s dominate wasp species originate from the UK.

Landcare Research biocontrol scientist Dr Ronny Groenteman said this information was “a key piece of the puzzle”.

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Combined seed treatment to help protect NZ crops is given approval

A new version of an insecticide used to help protect corn, wheat grass and brassica crops has been approved by the Environmental Protection Authority (EPA).

Bayer New Zealand’s Poncho Votivo is a seed treatment that will help control pests that can attack these crops.such as Argentine stem weevil, black beetle, greasy cutworm and parasitic nematodes.

It’s a reformulation of an already approved insecticide called Poncho and is applied to seeds at a treatment plant before they’re sown.

“What’s different about Poncho Votivo is that it contains a lower concentration of the neonicotinoid clothianidin, alongside a soil-dwelling micro-organism called Bacillus firmus. This is found naturally in New Zealand soil but has not been used before as an active ingredient in an insecticide,” says Ray McMillan, EPA’s Acting General Manager of Hazardous Substances and New Organisms.

After weighing the risks and benefits of Poncho Votivo following a public hearing in December 2015, the EPA’s decision-making committee approved its use and set specific controls to manage risks to people and our environment. It means those applying the insecticide must wear protective clothing and adhere to specific restrictions related to the rate, method and timing of application.

Mr McMillan said the combined insecticide had benefits for the New Zealand environment because it treats two types of pest at once and farmers are less likely to need a separate soil treatment.

View decision details and information



Wasp approved to lead fight against tomato and potato pest

The Environmental Protection Authority has approved a type of parasitic wasp as a biological control agent to combat the tomato potato psyllid (a plant louse), which attacks tomatoes, potatoes, capsicums and tamarillos in New Zealand. Biological control agents are natural enemies of a plant or insect pests, and are released to reduce, control or supress those pests.

The wasp (Tamarixia triozae) will be introduced and released to kill the tomato potato psyllid (Bactericera cockerelli).

The psyllid was first found in New Zealand in 2006 and is known as a pest in several countries, creating a significant impact on plants and crops. The psyllid has three life stages – egg, nymph and adult. Adult females lay eggs on the upper and lower surface of potato, tomato, capsicum and tamarillo plant leaves.

The psyllid nymphs and adults feed on the underside of leaves, leaving the plant stunted and discoloured, with poor or little fruit growth. The psyllid also spreads a bacteria that causes Zebra Chip disease in some crops, like potatoes, which affects crop yields.

The wasp is a psyllid parasitoid which means it attaches to or within a single host, eventually killing it. It is a black, winged red-eyed wasp normally found in North America and Mexico. The wasp lays its eggs on the surface of the psyllid nymphs. The eggs develop into larvae that feed on the nymphs, killing them.

The parasitic wasp will be introduced as part of a pest management programme, in combination with other beneficial insects and chemical control strategies.

The application to introduce the wasp was made by Horticulture New Zealand Inc on behalf of a number of growers’ industry groups under the Hazardous Substances and New Organisms Act 1996.

The EPA received 36 submissions on the application, 32 of them in support, two neither supporting nor opposing, and two opposed.

Chemicals that make plants defend themselves could replace pesticides

New research published in Bioorganic & Medicinal Chemistry Letters identifies five chemicals that trigger rice plants to fend off a common pest – the white-backed planthopper, Sogatella furcifera.

This paves the way for  pesticides being replaced by chemical triggers that make plants defend themselves against insects.

The widespread use of pesticides to control insects that destroy crops has raised environmental concerns because of the detrimental effect on ecosystems. One problem is that many pesticides kill indiscriminately.

Plants have natural self-defence mechanisms that kick in when they are infested with pests like the white-backed planthopper, Sogatella furcifera, that is a pest for rice crops. This mechanism can be switched on using chemicals that do not harm the environment and are not toxic to the insects or their natural enemies.

In the new study, researchers from Zhejiang University 
in China developed a new way of identifying these chemicals. Using a specially designed screening system, they determined to what extent different chemicals switched on the plants’ defence mechanism.

The team designed and synthesized 29 phenoxyalkanoic acid derivatives. Of these, they identified five that could be effective at triggering the rice plants to defend themselves.

The researchers used bioassays to show that these chemicals could trigger the plant defense mechanism and repel the white-backed planthopper. This suggests that these chemicals have the potential to be used in insect pest management.

“We demonstrate for the first time that some phenoxyalkanoic acid derivatives have the potential to become such plant protection agents against the rice white-backed planthopper,” said Dr. Yonggen Lou, one of the authors of the study and professor at Zhejiang University 
in China.

“This new approach to pest management could help protect the ecosystem while defending important crops against attack.”

The next step for the research will be to explore how effective the chemicals are at boosting the plants’ defenses and controlling planthoppers in the field.

Submissions sought on fungicide for onion mildew

The Environmental Protection Authority is calling for submissions on an application for release of DuPont Zorvec Enicade Fungicide. This fungicide contains the active ingredient oxathiapiprolin and is intended to be used for the control of downy mildew in onions. This active ingredient has not previously been approved under the Hazardous Substances and New Organisms Act and is not a component in any approved formulation.

DuPont Zorvec Enicade Fungicide is an oil dispersion formulation to be applied to onion foliage by boom spray methods. It is intended to be applied up to two times per crop cycle, with a minimum of 10 days between applications. The intended maximum application rate is equivalent to 35 g of oxathiapiprolin per hectare.

Application details and decision documents can be viewed here.

The public are invited to make submissions on the application to the EPA. The submissions period for this application opened on 23 July and closes at 5pm on 3 September.

Submissions are an opportunity to provide further information and raise issues about an application. They will inform a decision-making committee that will decide whether to approve or decline the application.

A public hearing may be held before a decision is made. The EPA will provide at least 10 working days’ notice of the hearing date, time and place. We’ll provide this information to all submitters and the applicant.

Find more information on submissions and the hearing process here.