Evaluation of the effectiveness of Neoseiulus cucumeris (Oudemans) as a predator of Tuta absoluta (Meyrick)

The leaf miner, Tuta absoluta is continue to be a serious threat to solanaceous plants, especially tomato plant worldwide. Tomato crop in Saudi Arabia has been recently affected by T. absoluta, which is difficult to control due to its unique biological features, such as high fecundity and its potential to develop resistance to chemical pesticides. In this article, the suitability and effectiveness of the predatory mite, Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae), an indigenous species usually found in tomato greenhouses of northcentral Saudi Arabia, has been evaluated on eggs and 1st instar larvae of T. absoluta in the laboratory. All experiments were conducted in an incubator at three constant temperatures of 22, 27 and 32°C ± 1°C, 50 ± 4% R.H. and L12:D12 h photoperiod. Adult females and males of N. cucumeris were able to feed and sustain oviposition on eggs and 1st instar larvae of T. absoluta, and could be an effective biocontrol agent against T. absoluta. The N. cucumeris had a clear preference for eggs compared to 1st instar larvae of T. absoluta. The results showed the obvious effect of the temperature on the consumption rate of the predatory mite. The maximum daily consumption rate occurred during the oviposition period, when the females of the predatory mite consumed an average of 4.26 eggs and 2.44 1st instar larvae of T. absoluta. In general, total fecundity was high with T. absoluta eggs as a food source when temperature increased from 22 to 32°C. The highest fecundity rate (42.92 and 20.97 eggs /female) was recorded at 32°C, while the lowest one (26.77 and 10.12 eggs / female) was recorded at 22°C, when N. cucumeris female fed on eggs and 1st instar larvae of T. absoluta, respectively. The results of this study indicated that the predatory mite, N. cucumeris can be considered a promising potential candidate for controlling the leaf miner T. absoluta, and further research is required to assess its effectiveness under greenhouse conditions.

Déterminants Socio-Économiques De L’adoption Des Technologies Agro Écologiques De Productions Agricoles Dans Le Département De Mayahi Au Niger

Cette étude conduite dans le département de Mayahi, au Niger oriental, a pour objectif, d’identifier les facteurs influençant l’adoption des pratiques culturales de production du mil et du niébé et aussi celle de l’utilisation du bloc multi-nutritionnel. Ainsi, cent-vingt (120) chefs d’exploitation choisis aléatoirement ont été enquêtés sur l’utilisation des technologies de production diffusées au cours des trois dernières années. La régression logistique a permis de déterminer les corrélations entre les contextes et l’adoption des technologies. Ainsi, l’implication des producteurs dans les démonstrations a influencé positivement sur l’adoption des techniques d’application du compost (P<0,001), l’utilisation des variétés améliorées de mil et de niébé (P<0,05), des extraits aqueux des graines de Neem (P<0,001) et de la technologie de stockage hermétique des récoltes (P<0,001). Cependant, la proximité des villages du marché hebdomadaire a eu une corrélation négative avec l’utilisation du compost (P<0,05) ; alors que la proximité du village aux zones urbaines a influencé positivement l’achat des blocs multi nutritionnels densifiés et la pratique du défrichement amélioré (P<0,001). Par ailleurs, l’accès au crédit a influencé positivement sur l’achat des blocs multi nutritionnels densifiés (P<0,05) ; le contact avec les services de vulgarisation agricole public a été corrélé par l’utilisation de la technologie de lutte contre la chenille mineuse de l’épi du mil (P<0,05). Ces résultats peuvent contribuer à orienter les acteurs de développement rural à mieux planifier les activités de diffusion et de promotion des nouvelles pratiques agronomiques. The objective of this study is to identify the determinants of production technology’s adoption of millet and cowpea as well as the densified multi-nutritional block in the department of Mayahi. One hundred and twenty (120) randomly selected farm managers were surveyed on the use of production technologies released over the past three years. Logistic regression was used to determine that were between contexts and technology adoption. Results showed that producers’ participation in the demonstration, the adoption of compost application techniques, the use of improved varieties of millet and cowpea, aqueous extracts and neem seeds, and hermetic crop storage technology positively influenced. Similarly, results reveal that the proximity of villages to the weekly market had a negative correlation with the use of compost and the location of the village next to urban areas positively influenced the purchase of densified multi-nutritional blocks. R ults also indicate that the practice of improved land clearing and access to credit positively influenced the purchase of densifieal blocks; while contact with public agricultural extension services was correlated with the use of millet ear leaf miner control technology. These findings could help to guide rural development agents to better plan activities for the dissemination and promotion of new agronomic practices

A Comprehensive Review of the Coffee Leaf Miner Leucoptera coffeella (Lepidoptera: Lyonetiidae)—A Major Pest for the Coffee Crop in Brazil and Others Neotropical Countries

The coffee leaf miner (CLM) Leucoptera coffeella moth is a major threat to coffee production. Insect damage is related to the feeding behavior of the larvae on the leaf. During the immature life stages, the insect feeds in the mesophyll triggering necrosis and causing loss of photosynthetic capacity, defoliation and significant yield loss to coffee crops. Chemical control is used to support the coffee production chain, though market requirements move toward conscious consumption claiming for more sustainable methods. In this overview, we discuss aspects about the CLM concerning biology, history, geographical distribution, economic impacts, and the most relevant control strategies in progress. Insights to develop an integrated approach for a safer and eco-friendly control of the CLM are discussed here, including bio-extracts, nanotechnology, pheromones, and tolerant cultivars.

Insect Herbivore Populations and Plant Damage Increase at Higher Elevations

Elevation gradients are used as a proxy to simulate climate change effects. A field study was conducted along an elevational gradient in Nepal to understand the effects of abiotic conditions on agriculturally important insect herbivore populations (tobacco caterpillar: Spodoptera litura, tomato fruit worm: Helicoverpa armigera, and South American leaf miner, Tuta absoluta) and herbivory damage on tomatoes. Elevation ranged from 100 m to 1400 m above sea level, representing different climatic zones where tomatoes are grown. Contrary to our hypothesis, natural herbivore populations and herbivory damage significantly increased at higher elevations. Individual insect species responses were variable. Populations of S. litura and T. absoluta increased at higher elevations, whereas the H. armigera population was highest at the mid-elevational range. Temperature variations with elevation also affected insect catch numbers and the level of plant damage from herbivory. In the context of climate warming, our results demonstrate that the interactive effects of elevation and climatic factors (e.g., temperature) will play an important role in determining the changes in insect pest populations and the extent of crop losses.

Evaluation of different traps for the invasive leaf miner, Liriomyza huidobrensis in potato (Solanum tuberosum) fields of the Nilgiris district, Tamil Nadu, India

Potatoes are currently threatened by the pea leaf miner (Liriomyza huidobrensis Blanchard), an exotic, exceedingly polyphagous, and chemically resistant pest that attacks a wide range of crops, ornamental plants, and weeds. The present work was conducted to study the attractiveness of various traps to Liriomyza leaf miner, one of the invasive pests recently observed in potato fields of Kotagiri and Ooty in Nilgiris district of Tamil Nadu. A trial was conducted at these two different locations, the Nilgiris district, in 2021. The results revealed that among different traps tested for their efficacy in attracting the leaf miner, L. huidobrensis, yellow sticky trap was found to be more efficient in attracting adult leaf miner flies with the mean trap catches of 40.49 and 36.64 adult flies/ 10 cm2 areas at Kotagiri and Ooty respectively. The peak population of leaf miners was recorded in the last week of April (45.67 adult flies/ 10 cm2 areas) at Ooty and during the 3rd week of June (52.33 adult flies/ 10 cm2 areas) at Kotagiri. The correlation study revealed a significant positive correlation of the trap catches with maximum temperature, diurnal variation (DV) and growing day degrees (GDD). Multiple regression equation was also developed, where the abiotic factors contributed 46.1% and 65.5% to the Liriomyza leaf miner population fluctuation in the potato ecosystem. The trappers may be used to determine the initial presence of a leaf miners’ population and in projecting their future population through pest management models and management decisions.

Morphological and Biochemical Bases of Resistance of Some Groundnut Germplasms against Tobacco Caterpillar, Spodoptera litura (Fabricius) and Leaf Miner, Aproaerema modicella (Deventer)

A screening experiment of forty germplasm lines was conducted at College Farm, College of Agriculture, Rajendranagar, Hyderabad in rabi, 2019-20 and was laid in Randomized block design (RBD) having two replicates. Three germplasm lines viz., ICGV 16679 (13.71% leaf damage), ICGV 07222 (14.00% leaf damage) and ICGV 93468 (14.25% leaf damage) showed greater resistance than the resistant check, ICGV 86031 (15.04% leaf damage) against tobacco caterpillar and with respect to resistance against leaf miner, no germplasm line was found to be superior than the resistant check, ICGV 86031 (7.82% leaf damage). However, the germplasm line, ICGV 02266 (8.35% leaf damage) was next best to the resistant check. The various morphological and biochemical characters were recorded and correlated with insect pest damage and incidence to know their role in imparting resistance/susceptibility. Resistance to various insect pests in germplasm lines was due to significantly higher trichome density on leaf lamina, higher phenol and tannin content.

The role of meteorological parameters on the infestation of rust and leaf miner of groundnut at Akola

ABSTRACT- Effect of meteorological parameters on the incidence of rust and leaf miner of groundnut at Akola, Maharashtra is studied. Both graphical and statistical methods are used as tools for evaluating correlation of meteorological parameters with rust and leaf miner. It is found that rust infestation occurs in the pod ripening stage whereas leaf miner attack extends from pod formation to pod ripening stage of groundnut. Decrease of minimum temperature, relative humidity and increases of sunshine hours a few days back increases rust infestation. Increase in maximum temperature in humid and bright sunshine condition helps to raise leafminer population.

Knowledge, Attitude, and Practices on Tomato Leaf Miner, Tuta absoluta on Tomato and Potential Demand for Integrated Pest Management among Smallholder Farmers in Kenya and Uganda

Agricultural growth and food security are a priority in many developing countries. This has led to increased attention to effective pest management. Integrated Pest Management (IPM) strategy is a sustainable and recommended alternative to the use of synthetic pesticides in the management of tomato pests, with Tuta absoluta being the major one. This study seeks to assess the awareness, attitude, and control practices on T. absoluta and examine the potential adoption of a proposed IPM strategy for the management of a pest using a randomly selected sample of 316 and 345 tomato growing households in Kenya and Uganda, respectively. The study findings indicate that T. absoluta is the major pest affecting tomato production, with most farmers using synthetic pesticides to manage it. Furthermore, we find a significant proportion of the survey respondents willing to adopt the IPM strategy. The probability of adopting the strategy was positively related to a farmer being male, residing near a source of inputs, accessing training, and possessing good knowledge, attitude, and practices towards the use of non-pesticides strategies. Thus, training, promotion, and awareness creation of the T. absoluta IPM are recommended for the sustainable management of the pest in tomato production.