Oviposição do curuquerê e alimentação de suas lagartas neonatas em algodoeiros tratados com caulim

Abstract

Resumo -O objetivo deste trabalho foi avaliar a capacidade do caulim de afetar a oviposição e a alimentação de Alabama argillacea (Lepidoptera: Noctuidae) em algodoeiro. Determinou-se a preferência de oviposição, a viabilidade de ovos e o consumo das lagartas de primeiro instar de A. argillacea, em folhas de algodão tratadas ou não com caulim. A preferência de oviposição foi determinada por teste de escolha e confinamento, em delineamento experimental de blocos ao acaso, em arranjo fatorial 2x7, representado pelos tratamentos com caulim em água destilada (60 g L -1 ) ou somente água destilada (testemunha), e pela avaliação de sete estruturas vegetais da planta. O consumo pelas lagartas de primeiro instar foi determinado em delineamento experimental inteiramente casualizado, em arranjo fatorial 2x4, representado pelo tratamento com caulim em água destilada, pela testemunha e pelos quatro períodos de observação (6, 12, 24 e 48 horas). A oviposição das mariposas do curuquerê-do-algodoeiro foi reduzida nas plantas de algodão tratadas com caulim; no entanto, a viabilidade dos ovos não foi afetada. A folha da haste foi a estrutura preferida para oviposição. A sobrevivência e o consumo de lagartas de primeiro instar do curuquerê são menores nas plantas de algodão tratadas com caulim.Termos para indexação: Alabama argillacea, Gossypium hirsutum, filme de partículas, herbivoria. Oviposition of leafworm and feeding of its neonate larvae on cotton treated with kaolinAbstract -The objective of this work was to evaluate the ability of kaolin to affect oviposition and feeding of Alabama argillacea (Lepidoptera: Noctuidae) on cotton. The oviposition preference, the egg viability, and the feed consumption of the first instar larvae of A. argillacea were determined on cotton leaves treated or not with kaolin. The oviposition preference was determined under choice test and confinement, in a randomized complete block design, in a 2x7 factorial arrangement, represented by the treatments with kaolin in distilled water (60 g L -1 ) or distilled water only (control), and by the evaluation of seven plant structures. The feed consumption by the first instar larvae was determined in a completely randomized design, in a 2x4 factorial arrangement, represented by the treatment with kaolin in distilled water, by the control, and by the four observation periods (6, 12, 24, and 48 hours). The oviposition of cotton leafworm moths was reduced in cotton plants treated with kaolin; however, the viability of eggs was not affected. Leaf stem was the preferred structure for oviposition. Survival and feed consumption of first instar larvae of cotton leafworm are lower on cotton plants treated with kaolin.

Susceptibility of Alabama argillacea and Chrysodeixis includens (Lepidoptera: Noctuidae) larvae to Beauveria bassiana associated with kaolin

“…The similar mortality of A. argillacea larvae with B. bassiana (CG 138) and kaolin + B. bassiana (CG 138) indicate no additive or synergistic activity between this mineral and the fungus against this insect. The high mortality rates of kaolin-treated A. argillacea larvae corroborate results of lower survival and leaf consumption by first-instars of this pest on cotton plants treated with kaolin compared to non-treated ones (Gonçalves et al, 2015). The mortality of A. argillacea larvae was lower in the control.…”

“…The B. bassiana conidia suspension was composed by the isolate selected in the experiment of this fungus against A. argillacea or C. includens first-instar larvae. The kaolin dose was chosen based on previous studies against the cotton lepidopteran pests Spodoptera exigua (Lepidoptera: Noctuidae) (Showler, 2003) and A. argillacea (Lepidoptera: Noctuidae) (Gonçalves et al, 2015) and the apple leafworm Choristoneura rosacean (Harris) (Lepidoptera: Tortricidae) (Sackett et al, 2005).…”

“…This is probably due to the hygroscopic kaolin action, reducing the digestibility and the protective function of the cuticle that lines the digestive tract of these larvae, making feeding difficult. This fact may have facilitated the pathogen's action and increasing the infection process (Eigenbrode et al, 2006;Gonçalves et al, 2015).…”

“…The use of kaolin particle film technology can improve the efficiency of insecticides to controlling cotton pests (Silva and Ramalho, 2013), including aphids, boll weevils, cotton leafworms, pink larvae and white flies, as well as the cotton bollworm complex and those of the genus Spodoptera (Neves et al, 2014;Gonçalves et al, 2015). The film of kaolin particles, sprayed on the surface of the host plants, creates a physical or mechanical barrier that can alter plant tissue taste and digestibility, reducing the feeding and survival of chewing insects (Gonçalves et al, 2015;Guedes et al, 2020). Kaolin may affect the insect cuticle permeability to water, a limiting factor for these organisms (Cook et al, 2008).…”

Survival, development and reproduction of Phenacoccus solenopsis (Hemiptera: Pseudococcidae) on kaolin-treated cotton

“…Kaolin, a white clayey mineral that dissolves to form a white syrup in water, has been successfully used to protect cotton plants against pests, including the boll weevil, Anthonomus grandis (Boheman, 1843) (Coleoptera: Curculionidae) (Silva and Ramalho, 2013); cotton leafworm, Alabama argillacea (Hübner, 1818) (Lepidoptera: Noctuidae) (Gonçalves et al, 2015); cotton bollworm, Helicoverpa armigera (Hübner, 1809) (Lepidoptera: Noctuidae) (Alavo et al, 2011); beet armyworm, Spodoptera exigua (Hübner, 1808) (Lepidoptera: Noctuidae) (Showler, 2003); pink bollworm, Pectinophora gossypiella (Saunders, 1844) (Lepidoptera: Gelechiidae) (Sisterson et al, 2003) and aphid, Aphis gossypii (Glover, 1877) (Homoptera: Aphididae) (Alavo et al, 2011), although adverse effects of its application were reported (Showler and Armstrong, 2007).…”