scholarly journals Toxicity and application of neem in fall armyworm

2015 ◽  
Vol 6 (3) ◽  
pp. 359 ◽  
Author(s):  
Marcílio Souza Silva ◽  
Sônia Maria Forti Broglio ◽  
Roseane Cristina Prédes Trindade ◽  
Emerson Santos Ferrreira ◽  
Ismael Barros Gomes ◽  
...  

Aqueous extracts of neem, Azadirachta indica A. Juss., leaf and seed cake were tested for toxicity in Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) utilizing different methods of application (foliar and systemic). Probit analysis was used to determine the LC50 and regression analysis for mortality at different concentrations of the extracts (0.5%, 1.0%, 1.5%, 2.0% and control treatment). Two caterpillar morphometric variables (larval length and cephalic capsule width) and the scale of damage of attacked plants were measured and, analyzed using the Kruskal-Wallis test (P<0.05). The LC50 values for neem seed cake and leaves were 0.13% and 0.25%, respectively. For larval length and cephalic capsule width, the larvae were more affected to the seed cake extract than leaf extract, however there was no significant difference between the methods of application for these variables. There was no difference in the scale of damage by the extracts and the methods of application analyzed. Both methods of application provided similar results and, the main differences were associated with more efficient of the seed cake extract.  

2019 ◽  
Vol 11 (4) ◽  
pp. 126
Author(s):  
Lauren M. Barcelos ◽  
Fabrício O. Fernandes ◽  
Caroline Lopes ◽  
Beatriz M. Emygdio ◽  
Ricardo Valgas ◽  
...  

Saccharine sorghum has been analyzed as a supplementary prime matter for ethanol production, especially during the sugarcane off-season period. However, it has proven to be highly susceptible to insect attacks during the cultivation cycle. The fall armyworm should be emphasized due to its voracity and high damage capacity enhanced by feeding-caused decrease in photosynthetic area. Current analysis studies the biology and determines the nutritional indexes of Spodoptera frugiperda in saccharine sorghum. Cultivars of saccharine sorghum BRS 506, BRS 509 and BRS 511were evaluated. Duration and survival of the egg, caterpillar, pre-pupal and pupal phases were determined, coupled to weight of pupae and caterpillar, life span, fecundity and pre-egg laying period. Although S. frugiperda completed its life cycle on cultivars BRS 506 and BRS 511, egg-laying and egg feasibility rates were low, whereas insects did not lay eggs on cultivar BRS 509. There was no significant difference in feeding intake by S. frugiperda among these three sorghum cultivars. Results suggest that saccharine sorghum is not a suitable host for S. frugiperda. Biological data reveal that the three saccharine sorghum cultivars are recommended for the grain production system since the number of specimens of the next generation is low or null.


Author(s):  
Yago Barros Triboni ◽  
Luciano Del Bem Junior ◽  
Carlos Gilberto Raetano ◽  
Matheus Mereb Negrisoli

ABSTRACT Fall armyworm is one of the main insect pests in Brazil. Thus, the present work aimed to evaluate the seed treatment effect on the control of Spodoptera frugiperda in initial infestations of soybean crops. The experimental design was completely randomized with four replicates of six insecticide treatments applied through seed treatment: imidacloprid plus thiodicarb at the dose of 52.5 plus 105 g a.i. (active ingredient) 100 kg-1 of seed (Cropstar® 0.350 L 100 kg-1 of seed); thiamethoxam at 105 g a.i. 100 kg-1 of seed (Cruiser 350 FS® 0.3 L 100 kg-1 of seed); chlorantraniliprole at 62.5 g a.i. 100 kg-1 of seed (Dermacor® 0.1 L 100 kg-1 of seed); cyantraniliprole at 120 g a.i. 100 kg-1 of seed (Fortenza 600 FS® 0.2 L 100 kg-1 of seed); fipronil plus pyraclostrobin and thiophanate-methyl 50 + 5 + 45 g a.i. 100 kg-1 of seed (Standak Top® 0.2 L 100 kg-1 of seed), and a control treatment. The experiment was carried out in a greenhouse. Diamide insecticides (chlorantraniliprole and cyantraniliprole) presented the best results among all treatments, with lower consumption of the treated leaves by the caterpillars and greater control efficacy of this insect. We verified that seed treatment is a viable alternative for controlling S. frugiperda at the beginning of crop development, when the caterpillar presents the behavior of cutting the seedlings and/or the consumption of leaf area, causing a reduction in the plant population and a consequent yield loss.


2022 ◽  
Vol 52 (7) ◽  
Author(s):  
Orcial Ceolin Bortolotto ◽  
Aline Pomari-Fernandes ◽  
Gilberto Rostirolla Batista de Souza

ABSTRACT: The fall armyworm, Spodoptera frugiperda Smith, 1797 (Lepidoptera: Noctuidae), is a polyphagous pest that causes losses in several crops. The knowledge of host plants is essential for establishing management and control strategies. The present study reported the first occurrence of S. frugiperda in Brazilian grapevines. It is recommended that further studies should be carried out in the laboratory to understand the biological aspects of the damage to different structures (leaves and grapes). This information will be essential to assess the potential of S. frugiperda damage to vines.


2017 ◽  
Vol 66 (2) ◽  
Author(s):  
Gloria Patricia Barrera Cubillos ◽  
Juliana Andrea Gómez-Valderrama ◽  
Laura Fernanda Villamizar Rivero

Wettable powder formulations by microencapsulation of viral occlusion bodies (OBs) of both Spodoptera frugiperda multiple nucleopolyhedrovirus from Colombia (SfCOL) and a genotypic variant (SfCOL-A) were evaluated for controlling the fall armyworm S. frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in maize crops. Microencapsulation preserved OBs activity after three months of storage at 35ºC, where insecticidal activity loss was not greater than 12%. Additionally, the formulation protected the OBs against inactivation caused by UV-B radiation, retaining its insecticidal activity after 6 hours of UV laboratory exposure, in contrast to unformulated viral suspensions, which presented an Original Activity Remaining (OAR) between 12.1 and 50%. Under greenhouse conditions, the insect mortality was greater than 80% with microencapsulated viruses. In field trials, treatments reduced the percentage of damaged plants to levels below the economic injury level (35%) when the formulated and unformulated virus were applied at 8x1011 OBs/ha (800g/ha) dose, while the damage in the control treatment was close to 60%. Microencapsulation of SfCOL and SfCOL-A OBs provides useful advantages related to half-life and photostability.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1074
Author(s):  
Bonoukpoè Mawuko Sokame ◽  
Boaz Musyoka ◽  
Julius Obonyo ◽  
François Rebaudo ◽  
Elfatih M. Abdel-Rahman ◽  
...  

The interactions among insect communities influence the composition of pest complexes that attack crops and, in parallel, their natural enemies, which regulate their abundance. The lepidopteran stemborers have been the major maize pests in Kenya. Their population has been regulated by natural enemies, mostly parasitoids, some of which have been used for biological control. It is not known how a new exotic invasive species, such as the fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera, Noctuidae), may affect the abundance and parasitism of the resident stemborers. For this reason, pest and parasitism surveys have been conducted, before and after the FAW invaded Kenya, in maize fields in 40 localities across 6 agroecological zones (AEZs) during the maize-growing season, as well as at 3 different plant growth stages (pre-tasseling, reproductive, and senescence stages) in 2 elevations at mid-altitude, where all maize stemborer species used to occur together. Results indicated that the introduction of the FAW significantly correlated with the reduction of the abundance of the resident communities of maize stemborers and parasitoids in maize fields; moreover, the decrease of stemborer density after the arrival of FAW occurred mostly at both reproductive and senescent maize stages. It also suggests a possible displacement of stemborers by FAW elsewhere; for example, to other cereals. However, since this study was conducted only three years after the introduction of the FAW, further studies will need to be conducted to confirm such displacements.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Sharanabasappa S. Deshmukh ◽  
S. Kiran ◽  
Atanu Naskar ◽  
Palam Pradeep ◽  
C. M. Kalleshwaraswamy ◽  
...  

AbstractThe fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), has become a major threat in maize cultivation since its invasion to India in 2018. The humpbacked fly, Megaselia scalaris (Loew) (Diptera: Phoridae), was recorded as a laboratory parasitoid of FAW, for the first time in India. Initially, 30–40 maggots of M. (M) scalaris emerged out from the dead pre-pupa and pupa of laboratory-reared FAW. The fly laid up to 15 eggs on the outer surface of 6th instar larva or pre-pupa of the FAW. The incubation period was 1–2 days. The fly had 3 larval instars which lasted 3–4 days and a pupal period of 10–11 days. The adults survived for 6–7 days.


2013 ◽  
Vol 63 (2) ◽  
pp. 185-197 ◽  
Author(s):  
Franklin M. Cunha ◽  
Valéria Wanderley-Teixeira ◽  
Jorge B. Torres ◽  
Álvaro A.C. Teixeira ◽  
Thiago J.S. Alves ◽  
...  

Despite the efficiency of transgenic plants expressing Bacillus thuringiensis (Bt) toxins as insecticides against several lepidopterans, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is one species that presents low susceptibility to most Bt crops. This study investigated the effects of the Cry1Ac toxin expressed by Bt cotton in the midgut of S. frugiperda and its effects on the humoral and cellular immune responses. Three hypotheses were proposed and tested with contributing factors for the natural tolerance of S. frugiperda: (i) midgut regenerative cells are activated by the Cry1Ac toxin, and thus renew the epithelial cells damaged by the protein, (ii) Cry1Ac increased production of nitric oxide or phenoloxidase in the hemolymph, and (iii) there are qualitative and quantitative variations in the hemocyte levels of S. frugiperda. Caterpillars were reared using Bt cotton (Acala 90B) and non-Bt isolines (Acala 90), from the first to the fourth instar. The Bt cotton promoted elongation of the epithelial cells in the midgut of S. frugiperda caterpillars. Hence, evidence only supported the hypothesised increase of phenoloxidase (ii) and qualitative and quantitative differences in hemocyte levels (iii) in insects that were fed with Bt and non-Bt cotton. These parameters seem to explain the low susceptibility of S. frugiperda to Cry1Ac toxin and they are a viable set of responses for the evaluation of other xenobiotic factors.


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