Archive for the ‘Emerging/invasive pests’ Category


Thursday, August 3, 2017 Notification

First report of tomato leaf miner, Tuta absoluta (Lepidoptera: Gelechiidae), in Ghana  
Source: International Plant Protection Convention
Event:  New Location

Recently, tomato leaf miner, Tuta absoluta (Lepidoptera: Gelechiidae), was found infesting cultivated Solanum lycopersicum (tomato) plants in Ghana. This is the first report of T. absoluta in Ghana.

Tuta absoluta is an economically important pest of tomato and other solanaceous plants. Native to South America, T. absoluta has been reported from parts of Central America, Africa, Europe, the Middle East, India, Nepal, and Bangladesh. It is not known to occur in the United States. Tuta absoluta is listed as reportable in the PEST ID database (queried 8/2/17) and is listed as a pest of concern on the 2015 PPQ Prioritized Offshore Pest List.


  1. IPPC. 2017. Report on tomato leafminer (Tuta absoluta). International Plant Protection Convention (IPPC) pest report. July 27, 2017. Last accessed August 3, 2017, from https://www.ippc.int/en/countries/ghana/pestreports/2017/07/report-on-tomato-leaf-miner-tuta-absoluta/.

Other PestLens articles about this pest:
First report of tomato leaf miner, Tuta absoluta (Lepidoptera: Gelechiidae), in Kyrgyzstan
First reports of tomato leaf miner, Tuta absoluta (Lepidoptera: Gelechiidae), in Mozambique and Botswana
First report of tomato leaf miner, Tuta absoluta (Lepidoptera: Gelechiidae), in Bangladesh
New host records for tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae)
First report of the tomato leaf miner, Tuta absoluta (Lepidoptera: Gelechiidae), in Zambia and T. absoluta detected in South Africa

If you have any questions or comments for us about this article, please e-mail us at PestLens@aphis.usda.gov or log into the PestLens web system and click on “Contact Us” to submit your feedback.

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Science News
from research organizations

‘Invasive’ species have been around much longer than believed

July 31, 2017
University of the Witwatersrand
The pollen record of a plant that is currently being eradicated extends much further back than the 100 years it is believed to be growing in the Lesotho Highlands, a new study concludes. The research confirms that a shrub believed to be an invasive in the eastern Lesotho Highlands has been growing in the region for over 4,000 years.

The DST-NRF Centre of Excellence for Palaeoscience funded researchers based in the School of Geography, Archaeology and Environmental Studies and in the Evolutionary Studies Institute of the University of the Witwatersrand have used fossil pollen records to solve an on-going debate regarding invasive plant species in eastern Lesotho.

Their study, Chrysocoma ciliata L. (Asteraceae) in the Lesotho Highlands: an anthropogenically introduced invasive or a niche coloniser?, published in Biological Invasions, confirms that a shrub believed to be an invasive in the eastern Lesotho Highlands has been growing in the region for over 4,000 years.

Dr Jennifer Fitchett of the School of Geography, Archaeology and Environmental Studies, and her co-authors Professors Marion Bamford (ESI, Wits), Stefan Grab (GAES, Wits) and Anson Mackay (University College London Environmental Change Research Centre and Geography Department) have been investigating the palaeoenvironments of eastern Lesotho through the use of pollen, diatom and sedimentary records.

In a case of ‘accidental science’, the group discovered the pollen of Chrysocoma cilliata at intermittent locations throughout the depth of the sediment profile they were studying. This was unexpected, as Chrysocoma ciliata is believed to be an invasive species introduced to the eastern Lesotho Highlands by cattle herders at the turn of the 20th century. The species was found to extend much further back in the pollen record than the 100 years that it is believed to have been growing in the region.

Chrysocoma cilliata came to the attention of environmental managers as it proliferates under drought conditions, and rapidly colonises degraded landscapes. In particular, the plant grows easily in abandoned cattle stations, where over-grazing has resulted in the loss of both top soil and vegetation. As the shrub was believed to be an invasive species, introduced to the region from the South African Karoo to the west, the primary management response was to attempt to eliminate the crop.

In recent years, Dr Clinton Carbutt of Ezemvelo KwaZulu-Natal Wildlife suggested on the basis of vegetation surveys that the species may in fact not be an invasive, but rather a species that thrives under conditions that the more typical alpine wetland groups struggle to survive. The pollen evidence for Chrysocoma cilliata dating back to 4,000 years before present supports this hypothesis.

Although this study proves that the species was not introduced to the region 100 years ago with the introduction of cattle grazing, as has previously been suggested, it is not possible at this stage to prove that it was not accidentally introduced by early inhabitants of the eastern Lesotho highlands. Archaeological records provide evidence for settlement in the eastern Lesotho highlands by Stone Age groups as far back as 80,000 years ago.

There is strong archaeological evidence to suggest that these groups migrated both seasonally and inter-annually to warmer regions, with water providing the primary attraction of the otherwise uninhabitable cold highlands. It is thus possible that they may have accidentally transported seeds of this plant into the region. If this were the case, the plant would be more accurately classified as an archetype invasive. However, until the presence or absence of this species prior to 80,000 years ago can be confirmed, Chrysocoma ciliata can most accurately be termed a niche coloniser, most probably native to the eastern Lesotho highlands.

This study highlights the importance of palaeoscience research in addressing global change challenges. In addition to determining the provenance of plant species, and hence resolving debates regarding their status as invasives, the analysis of plant and animal fossils can provide valuable information relating to climate change, and critical biological thresholds under changing conditions.

Story Source:

Materials provided by University of the Witwatersrand. Note: Content may be edited for style and length.

Journal Reference:

  1. Jennifer M. Fitchett, Marion K. Bamford, Anson W. Mackay, Stefan W. Grab. Chrysocoma ciliata L. (Asteraceae) in the Lesotho Highlands: an anthropogenically introduced invasive or a niche coloniser? Biological Invasions, 2017; DOI: 10.1007/s10530-017-1478-1

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Plantwise Blog

Five invasive pests cost African economy $1 billion every year

New research by CABI reveals that just five invasive alien species are causing US$0.9 – 1.1 billion in economic losses to smallholder farmers across six eastern African countries each year, equating to 1.8% – 2.2% of total agricultural GDP for the region. These losses are expected to grow to $1.0 – 1.2 billion per year over the next 5-10 years, highlighting the urgent need for coordinated responses at regional, national and international levels.

New research published in the open-access journal Global Food Security estimates the alarming level of economic losses suffered by smallholder farmers each year in eastern Africa, to a handful of species that have become damaging crop pests since their introduction to the region. These few invasive species can have devastating impacts on important staples such as maize, but also high-value crops including tomatoes, peas and green beans.

CABI researchers carried out the study to quantify the impacts of five important invasive alien species on mixed maize farming in economic terms. The countries included in the study were Ethiopia, Kenya, Malawi, Rwanda, Tanzania and Uganda, all of which have large rural communities dependent on small-scale farming for food security and income.

Invasive alien species can have a variety of effects on farming, livestock, pastures and forests, as well as human and animal health. Accelerating global trade is increasing the rate of invasive species introduction and establishment, with developing regions some of the worst affected.

CABI invasive species expert, Dr Sean Murphy, said, “Invasive species can have a devastating impact on smallholder livelihoods, and poorly regulated trade and movement of produce can contribute to the spread and establishment of pest species. Invasive species are a growing threat to food security in Africa and the results of this study highlight the need to take action. We urgently require a coordinated response at regional, national and international levels.”

Five important invasive species

The study reports that maize, the most important staple crop in eastern Africa, is affected by several invasive species:

1.As much as $450 million is lost to smallholders each year to the spotted stem borer, Chilo partellus, a caterpillar which feeds inside the growing maize plant, reducing its yield. This pest also attacks other important crops such as sorghum. A biological control agent (Cotesia flavipes) released against this pest is playing an important role in reducing the crop losses suffered by smallholder farmers.

2. Maize Lethal Necrosis Disease (MLND) is caused by a dual viral infection and leads to the production of deformed maize ears which can result in total crop loss. Current smallholder losses to this disease are estimated to be up to $339.3 million each year, but are likely to increase significantly with the ongoing spread of the disease.

3.The invasive ‘famine weed’, Parthenium hysterophorus, affects farmland and pasture, reducing production levels in a variety of crops and having human and animal health impacts. The weed is most widespread in Ethiopia, but is increasing its range in Kenya, Tanzania and Uganda. Current smallholder losses in maize for the region are estimated to be as high as $81.9 million annually, but can be expected to rise with the ongoing march of this damaging weed.

4. Horticultural crops, often grown along with staples such as maize are valuable nutritionally, but also as cash crops that can be an important route out of poverty for smallholder growers. A number of invasive species affect horticultural crops and this study included three species of Liriomyza leaf-mining flies, which attack a variety of important crop families including ornamental plant species and vegetables. In this study, impacts on beans and peas were considered, with total annual losses up to $149.1 million. Climate change is likely to result in a range increase for damaging Liriomyza species.

5. The South American tomato leaf miner, Tuta absoluta, has had a devastating impact since its recent introduction to Africa, frequently causing total crop loss and leading to three-fold increases in tomato prices. Losses to eastern African smallholders are estimated at up to $79.4 million per year at present, but this figure is expected to grow substantially with the rapid spread of this pest.

Taking action

The CABI study clearly highlights the need to improve the outlook for smallholders in developing countries, who are resource-poor and susceptible to invasive species impacts.

Collaboration at national, regional and international levels, analysis of invasion pathways, and implementation of effective monitoring and rapid management responses to new invasive species arrivals are priority areas for follow-up to the study. Where invasive species are widespread, integrated approaches, including biological control, should be considered.

Dr Sean Murphy said, “In carrying out this research, CABI has taken the first step in highlighting the vast scale of losses being suffered by resource-poor smallholders to invasive alien species. This data illustrates that the issue is both critical and pressing. With such a large scale of economic losses to just five invasive species across six countries alone, we need to consider the big picture: a long-term invasive species management policy in Africa with full policy support is needed urgently.”

The recent invasion of Fall armyworm (Spodoptera frugiperda) will add significantly to these losses as it is known to cause great damage to maize and other crops in its native range.

CABI’s global invasive species programme aims to improve the livelihoods of the 50 million poor rural households that are impacted by damaging invasive species. The programme will contribute to improved food security and trade, and will aid the protection of agricultural and natural ecosystems. See the website http://www.invasive-species.org/.


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General News of Thursday, 27 July 2017

Source: http://www.ghanaweb.com


Army worms completely eradicated – Agric Minister

Agric Minister Parliament play videoAgriculture Minister, Dr Afriyie Akoto responding to questions in Parliament

Contrary to widespread speculation about the impact of the fall army invasion, the Agric Minister, Dr Afriyie Akoto has reassured Ghanaians that the phenomenon has been dealt with.

He disclosed that the impact of the invasion is not as dire as it has been reported.

He noted that out of the total hectares of farmlands that were affected, a minute percentage had been completely destroyed by the invasion.

“The total hectares affected by the army worm came to 112,812 hectares. That is what was affected. There is a difference between affected and destroyed and this is where a lot of people were confused. The total number destroyed was only 14,430 hectares. It is not even up to 2% of the total area under maize alone never mind the total area under all crops in Ghana, so there is a huge exaggeration of the total impact of the army worm invasion” he observed

The Minister was speaking on the floor of Parliament when he was called to answer urgent question filed by Asunafo South, Eric Opoku on the status of the Planting for Food and Jobs.

He explained that the invasion this year was as a result of poor handling of the situation when it happened last year.

The fall army worm is of American origin and was first recorded in the country in 2016. The Minister asserted that the effort put in by this government has ensured a timely containment of the situation

He further said that the country, based on the measures put in place will never witness such an invasion again.

“I would like to use this opportunity to assure that nation that the fall army worm has been defeated by the government, totally defeated. The impression being created by some people that the armyworm is consuming planting for food and jobs is not correct, it’s wrong”

“This is why in anticipation of the surpluses we are expecting, we are making frantic efforts to ensure that not one single grain or bean is affected because of lack of markets” he detailed

The fall armyworm invasion was one of five challenges the Minister enumerated as hindering the progress of the planting for food and jobs initiated.


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FAW wksp Addis 2017

       logo-feed-the-future 1

The fall armyworm (FAW), Spodoptera frugiperda, a native to the Americas, arrived in Africa in early 2016. Since its arrival, it has moved quickly and is now in over 25 African countries including Ethiopia, Kenya, Niger, and Tanzania. The pest has the potential to cause significant damage and yield loss to over 80 plant species, including maize, rice, and sorghum. Already, it is estimated that it will cause over $3 billion in damage to maize throughout Africa in regions that are already food insecure.

In order to help farmers and policy makers manage this pest, the USAID-funded Feed the Future Integrated Pest Management Innovation Lab held an awareness and management workshop in Addis Ababa, Ethiopia on July 14-15. The workshop, co-organized by USAID Mission in Ethiopia and the International Centre for Insect Physiology and Ecology, had over 75 participants, including representatives from FAO, CIMMYT, ICRISAT, WorldVeg, DFID, Netherlands Development Agency, EIAR, EARC, KALRO, Desert Locust Research Organization, Fintrac, CropLife, and others. Presentations covered topics including biological control, host plant resistance, and economic impacts among many others. His Excellency Eyassu Abrha, Ethiopian Minister of Agriculture, addressed the participants with the message that IPM is a strategic issue for the Ministry, and encouraged a holistic approach to management of the FAW pest, with pesticides being only one component of an integrated strategy that considers alternative control methods.

Summary of High Priority Recommendations from USAID IPM Innovation Lab Workshop in Addis Ababa

The IPM Innovation Lab, in association with the USAID mission in Ethiopia, organized a two-day workshop on Fall Armyworm in Addis Ababa, Ethiopia, July 14-15, 2017. The purpose of the workshop was to assess the magnitude of the problem in Ethiopia, Kenya, and Tanzania; develop research strategies; identify high priority areas of research; create awareness; enhance collaboration among national, regional, and international agencies; provide collective insights on training, capacity building, and information dissemination on management options.

The workshop was attended by about 75 participants from national, regional, and international organizations, including members from the governments of Ethiopia, Kenya, and Tanzania. The workshop also included members from plant protection departments, extension, universities, NGOs, the private sector, and international research organizations.

Breakout sessions organized by the workshop resulted in a list of high priority recommendations for combating the Fall Armyworm. They are:

  • Integrate cultural, physical, chemical, and biological controls with host plant resistance in management of FAW.
  • Survey and document natural enemies of the FAW in East Africa.
  • Evaluate the efficacy of the local larval parasitoid Habrobracon hebetor on FAW.
  • Evaluate the efficacy of the local egg parasitoid, Trichogrammatoidea armigera on FAW.
  • Evaluate the efficacy of other local FAW natural enemies.
  • Screen and identify the correct pheromone lure combination for attraction of FAW strains in East Africa.
  • Screen insecticides included in the USAID PERSUAP for efficacy and safety under local conditions in East Africa.
  • Governments should consider fast track registration of pesticides for control of FAW.
  • Conduct FAW host preference and host range studies in East Africa.
  • Collaboration within local governments, private companies, and international agencies.
  • Integrate management technologies developed for FAW in the IPM package that will be developed by the IPM Innovation Lab for maize and other crops (chickpea, rice, horticulture) in East Africa.


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The Life Cycle of Fall Armyworm

1d ago

Fall armyworm life cycleThe Fall armyworm, Spodoptera frugiperda, is a major invasive pest in Africa. It has a voracious appetite and feeds on more than 80 plant species, including maize, rice, sorghum and sugarcane. Another feature which makes it an incredibly successful invasive species is its ability to spread and reproduce quickly. CABI have developed a poster to show the life cycle of the Fall armyworm, which includes egg, 6 growth stages of caterpillar development (instars), pupa and adult moth. Click here to view the full poster, or read about the life cycle below.

Day 1-3
100-200 eggs are generally laid on the underside of the leaves typically near the base of the plant, close to the junction of the leaf and the stem. These are covered in protective scales rubbed off from the moths abdomen after laying. When populations are high, the eggs may be laid higher up the plants or on nearby vegetation.

Day 3-6
Growth stages 1-3: After hatching, the young caterpillars feed superficially, usually on the undersides of leaves. Feeding results in semitransparent patches, or “windows”, on the leaves. Young caterpillars can spin silken threads which catch the wind and transport the caterpillars to a new plant. The leaf whorl is preferred in young plants, whereas the leaves around the cob silks are attractive in older plants. If the plant has already developed cobs then the caterpillar will eat its way through the protective leaf bracts into the side of the cob where it begins to feed on the developing kernels. Feeding is more active during the night.

Day 6-14
Growth stages 4-6: By stages 4-6, the fall armyworm will have reached the protective region of the whorl, where it does the most damage, resulting in ragged holes in the leaves. Feeding on young plants can kill the growing point, resulting in no new leaves or cobs. Often only 1 or 2 caterpillars found in each whorl, as they become cannibalistic when larger and will eat each other to reduce competition for food. Large quantities of frass (caterpillar poo) , which resembles sawdust, will be present.

Day 14-23
After approximately 14 days the fully grown caterpillar will drop to the ground. The caterpillar will then burrow 2-8 cm into the soil before pupating. The loose silk oval shape cocoon is 20-30 mm in length. If the soil is too hard then the caterpillar will cover itself in leaf debris before pupating. After approximately 8-9 days the adult moth emerges to restart the cycle.

This information has been adapted from ‘Fall Armyworm: Life cycle and damage to Maize’
To read more about what CABI is doing to help control Fall Armyworm in sub-Saharan Africa, please visit www.cabi.org/fallarmyworm

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  1. Reblogged this on The Invasives Blog.


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