Potential of Bacillus thuringiensis in the Management of Pernicious Lepidopteran Pests

Abstract

Microbial products have a long history of safe use and most of the microbial agents are compatible with other methods of pest control. A number of microbial biopesticides have been registered for fi eld application on various vegetables, fruits, and other crops of agricultural, horticultural, and forest importance. During sporulation phase, Bacillus thuringiensis accumulates certain insecticidal crystal proteins which are pathogenic to a number of insect orders. Thousands of toxicogenic strains of B. thuringiensis exist and each strain produces its own unique well-known insecticidal crystal protein. B. thuringiensis is biodegradable and safe to nontarget organisms as the conditions required for complex steps in the mode of action do not exist in mammals or most of invertebrates. Development of agricultural crop varieties that contain B. thuringiensis proteins provides a safe alternative to the use of chemical insecticides. Tobacco and tomato were the fi rst transgenic plants encoding for B. thuringiensis insecticidal crystal protein. The development of resistance to B. thuringiensis toxins is, however, particularly unfortunate. Thousands of B. thuringiensis isolates are available around the world, and fortunately almost all the major insect pests are susceptible to these strains. Moreover synthetic insecticides in combination with biopesticides are economic, 278 effective, and eco-friendly. The aim of this chapter is to focus on the potentiality of B. thuringiensis in the management of pernicious lepidopteran pests and their mode of their interactions to develop the cost-effective medium for the formulation of biopesticides.

Morphology, life cycle and management of two invasive subspecies of Papilio demoleus (Lepidoptera: Papilionidae): A review

“…Microbial pesticides have been used for over a century, although their use has increased markedly in recent years (Arthurs & Dara, 2019). One of the most commonly used microorganisms is Bacillus thuringiensis , which has a complex mode of action preventing it from affecting mammals or most invertebrates (Khan et al., 2016). However, it is highly efficacious against most Lepidopteran larvae.…”

Technological Microbiology: Development and Applications

“…These endotoxins are synthesized by the soil bacterium B. thuringiensis (Bt) and have an entomopathogenic action, controlling the pests present in cabbage, potato, and grains ( Sarwar, 2015a ). Several transgenic species expressing Bt protein crystals, such as tomato, tobacco, and corn, have been cultivated worldwide because they have been successful in preventing the spread of caterpillars, especially Lepidoptera ( Khan et al, 2016 ). Caterpillars and eggs of pests such as Spodoptera frugiperda can also be infected by baculovirus, thus reducing the agricultural losses caused by this caterpillar, especially in corn.…”

Methodological Approaches to the Assessment of the Entomopathogenic Activity of Microorganisms Against Insect Pests in Vitro (Review)

“…В некоторых работах отмечена гибель гусениц на вторые-четвертые сутки. Различия в восприимчивости к B. thuringiensis зависели не только от взаимодействия «токсин-рецептор», но и от защитных иммунных механизмов хозяина [33,37]. Кристаллы проникали в кишечные стенки при высоком рН в средней кишке, высвобождая δ-эндотоксины (прототоксины).…”

“…Кристаллы проникали в кишечные стенки при высоком рН в средней кишке, высвобождая δ-эндотоксины (прототоксины). Токсины активировались резидентной протеазой и связывались с рецепторными протеинами и образовывали поры на мембране, что приводило к гибели насекомых [33,37]. В 2011 г. ученые установили, что бактериальные токсины взаимодействуют с кишечными белками чешуекрылых [23].…”

“…Из качественных методов оценки энтомопатогенного действия можно выделить исследование кишечника и кишечного эпителия на предмет патологий и деформаций, а также измерения уровня гловерина в организме инфицированных насекомых. В этих случаях авторы вводят в тело насекомого инъекции на основе штаммов [23,33,37,40].…”