By COMFORT NJIONYE
Tuta Absoluta locally called ‘Tomato Ebola’, but more commonly known as Tomato leaf miner or tomato moth, is a major pest of tomato.
It lays eggs on tomato plants and develops into a hungry caterpillar that feeds on the leaves, stems and fruit. When not controlled, damage can reach 60 to 100% as feeding on other plant parts can drastically reduce the yield.
Tuta Absoluta had last year affected more than 90% of 17,000 hectares (42,000 acres) of tomato fields outside the northern city of Kano as the farms were ravaged by the insect, which lead to high cost of tomato in Nigeria.
Tomato Experts where sent to Kenya to develop a strategy to combat the moth.
A $200m local tomato paste manufacturing company in Nigeria was forced to shut down because of the insufficient supply, which added to the existing hardship as a result of about 67% rise in the price of petrol and soaring inflation in the Africa’s largest economy.
These “tomato ebola” invaded six states in Nigeria, including Jigawa, Kano, Kastina, Lagos, Plateau and Bauchi.
Nigeria spend about N80 billion ($400m) annually importing tomato paste.
In Latin America, tuta absoluta is a key pest of tomato.
The pest also damages potatoes, but to a lesser extent because it does not attack tubers in the field or in storage.
Both crops can also be affected by rot pathogens that may invade via wounds made by the pest.
The larva feeds voraciously upon tomato plants, producing large galleries in leaves, burrowing in stalks, and consuming apical buds and green and ripe fruits. It is capable of causing a yield loss of 100%.
The adult moth has a wingspan around one centimeter. In favorable weather conditions eight to ten generations can occur in a single year.
The leaf miner currently continues to spread in Afro-Eurasia and beyond. It is considered a threat to tomato world production in the field and in protected environments, especially in warmer parts of the world.
In 2004 the pest was added to the EPPO A1 action list of pests recommended for regulation as quarantine pests.
The Life of Tuta Absoluta
Classification: Insectan, Holometabola, Lepidoptera,Gelechiidae
Common name: Tomato leaf miner or tomato moth.
Geographical distribution: World-wide.
Morphology: Larva about 7-9 mm long, green to pink with a brown head, adult 9-10 mm long, brown with black spots on the forewings.
Host plants: Various solanaceous species, Tomato is the main host plant, but T. absoluta also attacks other crop plants of the nightshade family, including potato, eggplant, pepper and tobacco. It is known from many solanaceous weeds, including Datura stramonium, Lycium chilense and solanum nigrum.
Life cycle: Female species lay about 250-300 eggs on the solanaceous host plants. At hatching the larvae feed and burrow tunnels in the leaves, flowers stems especially in fruits.
They pupate within their mines, in the soil, or on the leaf surface. The pest, which can raise a generation in 4-5 weeks, may complete 10–12 annual generation in different regions. The moths are nocturnal and usually remain between leaves during the day.
Chemical control: Many pesticides have been used against tuta absoluta but the pest has developed much resistance to most.
Biological control: Many natural enemies of T. absoluta occur in different regions, especially in South America. These include parasitoids such as Eulophidae, Braconidae and Trichogrammatidae, as well as predatory Anthocoridae and Miridae. In Israel the natural enemies, especially the indigenous mirid Nesidiocoris tenuis, successfully control the pest in open-field tomatoes. In addition, entomopathogenic nematodes, and entomopathogenic fungi were assayed. Several of these natural enemies were used in integrated, international leaf miner control programs.
Global spread: This moth was first known as a tomato pest in many South American countries. In 2006, it was identified in Spain, the following year it was detected in France, Italy Greece, Malta, Morocco, Algeria and Libya. In 2009 it was first reported from Turkey. The advance of T.absoluta continued to the east to reach Syria, Lebanon, Jordan, Iraq and Iran. Further advances southward reached Saudi Arabia, Yemen, Oman and the rest of the Gulf States. In Africa, T.absoluta, moved from Egypt to Sudan, South Sudan and Ethiopia from the east and to the Senegal from the west. It was reported in Nigeria and Zambia in 2016. An up-to-date global distribution map is available on the tuta absoluta information network. In India, Maharashtra state tomato cultivation more affect in Nov.2016
Management: Some populations of T. absoluta have developed resistance to organophosphate and pyrethroid pesticides. Newer compounds such as spinosad, imidacloprid and bacillus thuringiensis, have demonstrated some efficacy in controlling European outbreaks of this moths.
An experiment has revealed some promising agents of biological pest control for this moth, including Nabis pseudoferus, specie of damsel bug.
The sex pheromone for T. absoluta has been identified by researchers at Cornell University and has been found to be highly attractive to male moths. Pheromone lures are used extensively throughout Europe, South America, North Africa and the Middle East for the monitoring and mass-trapping of T. absoluta.
The combined use of pheromones as well as specific light frequency proved to be effective in suppressing the T. absoluta population and keeping it within the economic threshold as was disclosed by Russell IPM in a United Kingdom patent. In India Pest control of India provide lure of Tuta absoluta.To population control to the Farmer
This pest is crossing boarders and devastating tomato production both protected and open fields. The infestation of Tuta absoluta also reported on potato, Aubergine and common beans.
Tuta absoluta is a very challenging pest to control. Effectiveness of chemical control is limited due to insect’s nature of damage as well as its rapid capability of development of insecticide resistant strains. The use of biological factors are still largely under development and not ready to combat this pest effectively and in a cost effective way. Sex pheromone trap is using as an early detection tool. Mass trapping and lure and Kill application of pheromone has been found to be effective to control Tuta absoluta. IPM strategies are being developed to control Tuta absoluta. Various active substances can be applied in combination with bio-rational control tactics.
The larvae of Tuta absoluta mine the leaves producing large galleries and burrow into the fruit, the larvae feed on mesophyll tissues and make irregular mine on leaf surface. This pest damage occurs throughout the entire growing cycle of tomatoes. The larvae are very unlikely to enter diapause as long as food source is available.
Tuta absoluta can overwinter as eggs, pupae and adults. Adult female could lay hundreds of eggs during her life time. Tomato plants can be attacked from seedlings to mature plants. In tomato infestation are found on apical buds, leaves, and stems, flowers and fruits, on which the black frass is visible. On potato, mainly aerial parts are attacked. However damage on tuber also recently reported.
Tuta absoluta reduced yield and fruit quality of Tomato grown in green house and open field. Severely attacked tomato fruits lose their commercial value. 50–100% losses have been reported on tomato (EPPO, 2005).
As larvae are internal feeders it is difficult to achieve an effective control through application of chemical insecticides. Moreover, Tuta absoluta can rapidly evolve strains with reduced susceptibility to insecticides that have been previously effective. Failure of synthetic insecticides has also been reported in many countries.