Tomato Leaf miner (Tuta absoluta) (Meyrick 1917) (Lepidoptera: Gelechiidae) prevalence and farmer management practices in Kirinyanga County, Kenya

Abstract

Pest invasion is one of the limiting factors affecting food production. Tomato leaf miner (Tuta absoluta) (Meyrick 1917) (Lepidoptera: Gelechiidae), is an invasive insect pest of tomato. However, In Kenya, there is limited information on the level of invasion of the pest in tomato producing areas in the country. We assessed the level of invasion of T. absoluta and farmer management practices in Kirinyaga County. Tomato farmers were interviewed using questionnaires aimed at identifying the management practices used by farmers to control T. absoluta and their awareness on the insect pest. Two hundred and eight tomato farmers were interviewed, 90% of the respondents rated T. absoluta as a major pest of tomato. Results show that 94% of the respondents use synthetic chemicals in the control of T. absoluta with an average frequency of 12 times per growing season of three months with the highest frequency being 16 times. Increased use of synthetic insecticides was associated with a negative impact on the natural enemies. Among the interviewed farmers, 52 and 46% of respondents stated that after chemical spraying natural enemies disappear and are killed respectively, while 2% did not know what happened to them. It is therefore imperative to design an integrated pest management program that integrates biological control and environmentally friendly chemicals for sustainable control of T. absoluta populations.

Combining Host Plant Resistance, Selective Insecticides, and Biological Control Agents for Integrated Management of Tuta absoluta

“…is was linked to the product usage abuse, when on-farm interviews were taken where farmers used the insecticide more often than the prescribed manucturer's application rate of a maximum of two applications per crop per year. ese findings are similar to previous study findings where farmers in Kirinyaga consistently use coragen ® chlorantraniliprole to control T. absoluta, and this may accelerate resistance development of the insect pest [28].…”

“…e experimental unit was made up of 16 buckets with a total of 288 buckets for the whole experiment. e treatments included Advances in Agriculture absoluta in Kirinyaga County [28]. Tuta absoluta introduction was performed two weeks after transplanting, and the populations were allowed to establish for two weeks before insecticide application.…”

Distribution, abundance and natural enemies of the invasive tomato leafminer, Tuta absoluta (Meyrick) in Kenya

“…Low abundance of natural enemies could also be due to adverse farming practices adopted by growers such as calendar-scheduled applications of pesticides to control T. absoluta and other tomato pests. Indeed, Nderitu et al (2018) observed that farmers in Kirinyaga County sprayed up to 16 times per growing season, which had adverse effects on natural enemies. Awareness campaigns, therefore, on the need to conserve native natural enemies should be considered, because in addition to reducing environmental damage and human health risks, fortuitous biological control could provide some huge economic benefits to growers.…”

“…The current control practices for T. absoluta in tomato production systems in Kenya are limited to routine application of synthetic insecticides just like in the native and other invaded regions (Zappalà et al, 2013;Mansour et al, 2018;Nderitu et al, 2018). The larvae, however, escape this approach due to their leaf-mining behaviour (Luna et al, 2012).…”

“…Therefore, generalist natural enemies in tomato production systems in Kenya could apparently suppress the populations of T. absoluta. However, their field performance is majorly limited by extensive use of pesticides (Nderitu et al, 2018). More effort is thus needed to identify and conserve the indigenous natural enemies adapting to T. absoluta to guide on suitable biological control programs and increase their impact in pest management.…”