Lethal Effects of a Commercial Diatomaceous Earth Dust Product on Amblyomma americanum (Ixodida: Ixodidae) Larvae and Nymphs

Abstract

With increasing development of resistance to conventional synthetic acaricides in economically and medically important ixodid species, interest in finding alternative control tactics has intensified. Laboratory bioassays were conducted, using the lone star tick, Amblyomma americanum (L.), as a model species, to assess the efficacy of a diatomaceous earth-based product, Deadzone, in comparison with a silica gel-based product, CimeXa. CimeXa is already known to be highly lethal against A. americanum larvae and nymphs. The two dust treatments were 100% effective against larvae and nymphs within 24 h after contact occurred by immersion in dry dusts and after crawling across a surface treated with the dry dusts. Contact by crawling on a dried aqueous film of the dusts, even at a concentration of 10%, was not as effective as exposure to the dusts in dry powder form. As has been demonstrated with CimeXa, it is likely that Deadzone will be capable of providing prophylactic protection of cattle from economically important one-host ixodids, such as the southern cattle fever tick, Rhipicephalus microplus (Canestrini), which vectors the causal agents of babesiosis. Diatomaceous earth can be stored indefinitely, will remain efficacious for as long as sufficient quantities remain on the substrate, it is a natural (organic) substance, and it might be amenable for limited use in environmentally protected habitats.

Bio-Efficacy of Diatomaceous Earth, Household Soaps, and Neem Oil against Spodoptera frugiperda (Lepidoptera: Noctuidae) Larvae in Benin

“…It is an EPA (U.S. Environmental Protection Agency) registered and OMRI (Organic Materials Review Institute)-approved mechanical insecticide/miticide [35]. Dezone is a high efficacy, natural DE-containing product designed to provide a physical mode of action against a broad range of insect pests to mitigate chemical insecticide resistance [35,60]. In fact, DE kills insects by removing the protective lipid layer of the insect's cuticle, thus leading to death by desiccation.…”

“…In fact, DE kills insects by removing the protective lipid layer of the insect's cuticle, thus leading to death by desiccation. Due to their mode of action, inert powders, such as DE, are expected to prevent the development of resistance in insects [21,[60][61][62]. DE is generally regarded as safe and is one of the most used grain protectants [20,[63][64][65][66][67][68].…”

“…In fact, it has been shown that spraying agricultural crops with mineral crop protectants reduces herbivory and oviposition, as well as water stress [70,71]. Furthermore, Dezone is rich in amorphous silicon dioxide (85% SiO 2 , Showler et al [60]), and silicon has been characterized as a "quasi essential" mineral which promotes growth and increases yield in many plant species through various mechanisms, such as protection against biotic (diseases) and abiotic (metal ion toxicity and salinity) stresses [72,73]. However, doubling the application rate of Dezone (7.5 vs. 15 kg/ha) did not significantly improve the efficacy of the product.…”

Métodos alternativos para o controle de carrapatos: uma análise bibliométrica / Alternative methods for the control of ticks: bibliometric analysis

“…Além disso, as doenças infecciosas e parasitárias imprimem forte impacto negativo na bovinocultura mundial (STOTZER et al, 2014). A tristeza parasitária bovina (TPB) é a doença que mais gera prejuízos ao rebanho, sendo transmitida pelo carrapato Rhipicephalus (Boophilus) microplus que tem como agentes etiológicos a Babesia spp.…”

“…O carrapato tem sido considerado um dos principais empecilhos da atividade pecuária de corte e leite, sendo considerado endêmico em regiões tropicais e subtropicais (EMBRAPA, 2019). Assim, além dos fatores estressantes provocados diretamente pelo parasita, há diminuição no desempenho produtivo e reprodutivo do rebanho, altos índices de morte e de descartes involuntários dos animais (STOTZER et al, 2014).…”