Farmers control practices against the invasive red spider mite, Tetranychus evansi Baker & Pritchard in Benin

n 2008, the invasive tomato red spider mite Tetranychus evansi (Acari: Tetranychidae), a pest of sola- naceous crops, was identi fi ed for the fi rst time as the cause of serious damage on tomato ( Solanum lycopersicum L.; Solanaceae) crops in Benin. Since then, frequent outbreaks have been observed on Solanaceae and other leafy vegetables such as purple amaranth ( Amaranthus cruentus L.; Amaranthaceae) and bitter leaf ( Vernonia amygdalina D.; Asteraceae) in all growing areas in southern Benin. The objective of this study was to evaluate the intensity of damage by this invasive pest and the impact of farmers' control practices on purple amaranth, African eggplant (Solanum macrocarpon L. ; Solanaceae) and tomato crops. A survey was carried out in January 2013 among 150 farmers in the three major growing areas in southern Benin: S em e-Kpodji, Grand-Popo and Pahou. Tetranychus evansi was the only mite observed, causing production losses estimated at 65% for African eggplant, 56% for tomato and 25% for purple amaranth. Previously encountered species such as Tetranychus urticae Koch, Tetranychus ludeni Zacher (Acari: Tetranychidae) and Polyphagotarsonemus latus Banks (Acari: Tarsonemidae) were not observed in any of the 45 samples. To protect the infested crops, growers sprayed various synthetic pesticides at high frequencies according to crop phenology 3, 6 and 12 times per month, respectively, on purple amaranth, African eggplant and on tomato, on average. The most frequently used pesticides were pyrethroids and organophosphate compounds. Farmers reported that these compounds were largely ineffective against T. evansi . The risks posed to human and environmental health, as well as existing alternatives to chemical pesticide use, are discussedn 2008, the invasive tomato red spider mite Tetranychus evansi (Acari: Tetranychidae), a pest of sola- naceous crops, was identi fi ed for the fi rst time as the cause of serious damage on tomato ( Solanum lycopersicum L.; Solanaceae) crops in Benin. Since then, frequent outbreaks have been observed on Solanaceae and other leafy vegetables such as purple amaranth ( Amaranthus cruentus L.; Amaranthaceae) and bitter leaf ( Vernonia amygdalina D.; Asteraceae) in all growing areas in southern Benin. The objective of this study was to evaluate the intensity of damage by this invasive pest and the impact of farmers' control practices on purple amaranth, African eggplant (Solanum macrocarpon L. ; Solanaceae) and tomato crops. A survey was carried out in January 2013 among 150 farmers in the three major growing areas in southern Benin: S em e-Kpodji, Grand-Popo and Pahou. Tetranychus evansi was the only mite observed, causing production losses estimated at 65% for African eggplant, 56% for tomato and 25% for purple amaranth. Previously encountered species such as Tetranychus urticae Koch, Tetranychus ludeni Zacher (Acari: Tetranychidae) and Polyphagotarsonemus latus Banks (Acari: Tarsonemidae) were not observed in any of the 45 samples. To protect the infested crops, growers sprayed various synthetic pesticides at high frequencies according to crop phenology 3, 6 and 12 times per month, respectively, on purple amaranth, African eggplant and on tomato, on average. The most frequently used pesticides were pyrethroids and organophosphate compounds. Farmers reported that these compounds were largely ineffective against T. evansi . The risks posed to human and environmental health, as well as existing alternatives to chemical pesticide use, are discusse

Work system design with the ergonomic harmony framework for aging workforce

The general workforce is aging, especially in the Asian countries where most of the world's production operation is taking place, and it has indeed become one of the dominant issues in various sectors of industry all around the world. This paper develops a theoretical ergonomic evaluation and design model named 'Ergonomic Harmony Framework' for the aging workforce based on four existing approaches which are separately used to evaluate and solve the physiological, psychological, psychosocial and behavioral problems of human factors in a work system. A descriptive work system model and a mathematical framework specifically assessing this model are integrated for obtaining the harmony of the entire work system

Insecticidal activity of the medicinal plant, Alstonia boonei De Wild, against Sesamia calamistis Hampson*

The bioactivity of the aqueous extracts of the leaf and stem bark of the medicinal plant, Alstonia boonei De Wild (Apocyanaceae), against the pink stalk borer, Sesamia calamistis Hampson (Lepidoptera: Noctuidae) was studied in a laboratory bioassay. The extracts were incorporated into artificial diet at a rate of 0.0% (control), 1.0%, 2.5%, 5.0%, and 10.0% (w/w). Both extracts significantly (P<0.01) reduced larval survival and weight in a dose dependent manner. The concentrations that killed 50% of the larvae (LC50) for the stem bark extract were 2.8% and 2.1% at 10 and 20 DAI (days after introduction), respectively, while those for the leaves extract were 5.6% and 3.5%. The weights of the larvae also varied significantly (P<0.05) between the treatments in a dose dependent manner. We conclude that both leaf and stem bark extracts of A. boonei are toxic, used as growth inhibitors to S. calamistis larvae, and hold good promise for use as alternative crop protectants against S. calamistis