Fatores de mortalidade na fase de ovo de Tuta absoluta em sistemas de produção orgânica e convencional de tomate

Abstract

A traça-do-tomateiro Tuta absoluta (Meyrick) (Lep.: Gelechiidae) está sujeita a fatores de mortalidade bióticos como predadores e parasitoides e fatores abióticos como água da irrigação e da chuva que influenciam sua dinâmica populacional. O objetivo deste trabalho foi quantificar a importância desses fatores na sobrevivência de ovos da traça-do-tomateiro. Os experimentos foram desenvolvidos na Embrapa Hortaliças, de 1/8/2004 a 7/11/2005, em plantio de tomate e tomate consorciado em sistema orgânico e tomate em sistema convencional. As avaliações consistiram em: 1) coleta de ovos no campo em diferentes épocas do ciclo da cultura e sua incubação em laboratório até a emergência do parasitoide ou eclosão da lagarta; 2) exposição de ovos sentinelas no campo por 72 horas; 3) ovos marcados e acompanhados a cada 24 horas até eclosão das lagartas em campo. Ovos coletados no campo e incubados em laboratório mostraram que a mortalidade por Trichogramma sp. foi de 32%. A mortalidade dos ovos que permaneceram no campo (metodologia 2 e 3), evidenciaram que o parasitismo por Trichogramma sp. foi de 12% e que os predadores e o efeito mecânico da água produziram 36% de mortalidade dos ovos. Essa diferença revela que a permanência dos ovos no campo os expõe à competição com predadores e a mortalidade causada pelo efeito mecânico da água reduzindo o recrutamento de Trichogramma sp. Parasitoides de ovos, predadores generalistas associados à ação da água acarretaram maior mortalidade de T. absoluta em sistemas de produção orgânica de tomate.Palavras-chave: Agroecologia, controle biológico conservativo, controle cultural, irrigação, inimigo natural.Mortality factors at egg stage of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) on organic tomato system and on conventional tomato system Abstract The population dynamics of South American tomato pinworm Tuta absoluta (Meyrick) (Lep.: Gelechiidae) affected by several mortality biotic factors such as predators, parasitoids and water (irrigation and raining). The objective of the present work was to quantify the role of each factor in the survivorship of tomato pinworm eggs. The experiments were conducted at Embrapa Hortaliças from 01/08/2004 to 07/11/2005 in tomato and tomato-coriander organic system and traditional tomato crop system. The following methodology were conducted: 1) tomato pinworm eggs were collected in the field at different stages of the crop cycle and incubated in laboratory until the caterpillar/parasitoid emergency; 2) tomato pinworm eggs were marked and recollected after 72 hours, as sentinel prey; 3) cohorts of tomato pinworm eggs were marked and monitored each 24h until caterpillar eclosion. The eggs collected in the field and kept in the lab showed greater mortality by Trichogramma sp. (32%) than those kept in the field (methodology 2 and 3). However, under field conditions (method 2 and 3) by Trichogramma sp. was as lower as 12%, and mortality caused by predator and water effects reach 36%. This difference suggests that egg permanence in the field expose it to...

Sprinkler and drip irrigation in the organic tomato for single crops and when intercropped with coriander

“…The lowest levels of boring by the pinworm happened in those tomato plants which were intercropped with coriander and irrigated by sprinkler (4.2% of damaged fruits). According to Lopes and Café Filho (2006) and Medeiros, Sujii and Morais (2011), a reduction in the infestation of tomato pinworm under sprinkler irrigation happens mainly due to the removal of eggs and small larvae by the impact of water droplets, especially on the upper third of staked tomato plants. Medeiros, Sujii and Morais (2009) and Togni et al (2009) however, report that the coriander allows natural enemies of the tomato pinworm to become established.…”

“…Unlike most conventional producers of fresh tomatoes, who basically use furrow and drip irrigation systems, sprinklers have been used by organic farmers (TOGNI et al, 2009), especially as a way to control powdery mildew and some insect pests (LOPES; MAROUELLI; CAFÉ FILHO, 2006;MORAIS, 2011).…”

Brazilian Legislation Leaning Towards Fast Registration of Biological Control Agents to Benefit Organic Agriculture

“…The species was successfully used in Brazil to control Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in tomato fields (Haji et al 2002) and has stimulated research in several crops to control other lepidopteran species (Parra & Zucchi 2004). In fact, T. pretiosum was considered an important mortality factor of T. absoluta eggs in conventional (Bacci et al 2018) and organic tomato fields (Medeiros et al 2011). Moreover, Figueiredo et al (2015) demonstrated that the release of T. pretiosum to control S. frugiperda eggs in organic maize increased maize productivity by 19.4% in Brazil. Among the predators, the number of products per species is more balanced than the other BCAs, with five species of predators being associated with 10 different products (Table 1).…”

“…Coriander plants attract many predators of aphids (Lixa et al 2010, Resende et al 2017 and predators and parasitoids of whiteflies (Togni et al 2009), increase the parasitism of the tomato pinworm by Trichogramma spp. (Medeiros et al 2011), and provide pollen as a food source for lacewings (Resende et al 2017) and coccinellids (Togni et al 2016). Another promising intercrop for horticultural crops is basil (Ocimum basilicum).…”

Monitoring and population changes of Tuta absoluta (Meyrick, 1917) on tomato under greenhouse conditions in an arid expanse of south-eastern Algeria

“…In South America, the pest is faced with several insects parasitoids and predators including, the egg parasitoid Trichogramma spp. (Medeiros et al, 2011); and many others antagonist of different stages (Sanchez & Redolfi de Huiza, 1985;Desneux et al, 2010). Some have been tested and used in biological control against T. absoluta with promising results.…”