Herbivore-Induced Volatiles from Maize Plants Attract Chelonus insularis, an Egg-Larval Parasitoid of the Fall Armyworm

2019 ◽  
Vol 45 (3) ◽  
pp. 326-337 ◽  
Author(s):  
Fabian R. Ortiz-Carreon ◽  
Julio C. Rojas ◽  
Juan Cisneros ◽  
Edi A. Malo
2021 ◽  
Author(s):  
jiyingzi Wu ◽  
xianjia Li ◽  
ruiquan Hou ◽  
kunyu Zhao ◽  
yongqin Wang ◽  
...  

Abstract BACKGROUND: Since the invasion of the fall armyworm moth (Spodoptera frugiperda) in China in January 2019, damage to maize crops has gradually intensified, and chemical control has become the main control measure. This study aimed to examine methods of effective pest control while monitoring the environmental impact of pesticide use. The effectiveness of S. frugiperda pest control by foliar spraying and root irrigation of maize plants with acephate was determined, and the absorption, distribution, and dissipation of acephate and methamidophos by maize were studied.RESULTS: Field trials showed that acephate treatment at 6000 g.a.i ha-1 was the most effective for controlling S. frugiperda. Acephate and methamidophos were absorbed from the roots, transported upward, and concentrated in the leaves, particularly new leaves. The terminal residues of acephate and methamidophos in maize grains were below detectable levels at 60 days after treatment.CONCLUSIONS: The results demonstrate that acephate treatment via root irrigation can more effectively control the infestation of S. frugiperda in maize than acephate treatment via foliar spraying. The translocation and distribution of acephate and methamidophos by root irrigation were more uniform, and the holding efficiency was higher than those in foliar spraying, suggesting an extended period of control efficacy. This pest control method could be utilized to reduce pesticide residues while safely and efficiently controlling S. frugiperda infestation.


2000 ◽  
Vol 41 (4) ◽  
pp. 391-398 ◽  
Author(s):  
R. Ozawa ◽  
G.-i. Arimura ◽  
J. Takabayashi ◽  
T. Shimoda ◽  
T. Nishioka

Chemoecology ◽  
2003 ◽  
Vol 13 (2) ◽  
pp. 63-74 ◽  
Author(s):  
Petru Scutareanu ◽  
Jan Bruin ◽  
Maarten A. Posthumus ◽  
Bas Drukker

2018 ◽  
Author(s):  
Laila Gasmi ◽  
María Martínez-Solís ◽  
Ada Frattini ◽  
Meng Ye ◽  
María Carmen Collado ◽  
...  

AbstractIn response to insect herbivory, plants mobilize various defenses. Defense responses include the release of herbivore-induced plant volatiles (HIPVs) that can serve as signals to alert undamaged tissues and to attract natural enemies of the herbivores. It has also been shown that some HIPVs can have a direct negative impact on herbivore survival, but it is not yet understood by what mechanism. Here we tested the hypothesis that exposure to HIPVs renders insects more susceptible to natural pathogens. Exposing caterpillars of the noctuid Spodoptera exigua to indole and linalool, but not exposure to (Z)-3-hexenyl acetate increased the susceptibility to its nucleopolyhedrovirus (SeMNPV). We also found that exposure to indole, but not exposure to linalool or (Z)-3-hexenyl acetate, increased the pathogenicity of Bacillus thuringiensis. Additional experiments revealed significant changes on gut microbiota composition after forty-eight hours of larval exposure to indole. Overall, these results provide evidences that certain HIPVs can strongly enhance the susceptibility of caterpillars to pathogens, possibly through effects on the insects’ gut microbiota. These findings suggest a novel mechanism by which HIPVs can protect plants from herbivorous insects.


2020 ◽  
Vol 49 (3) ◽  
pp. 645-650 ◽  
Author(s):  
Djima Koffi ◽  
Komi Agboka ◽  
Delanyo Kokouvi Adenka ◽  
Michael Osae ◽  
Agbeko Kodjo Tounou ◽  
...  

Abstract The fall armyworm Spodoptera frugiperda (J. E. Smith) invaded several West African countries in 2016 causing severe injury to maize plants and economic damage. This study assesses variations in the occurrence of this species in different Agro-Ecological Zones (AEZs) in Togo and Ghana during the 3 yr following its discovery. The surveys were conducted on 120 farms in Togo and 94 farms in Ghana by collecting larvae from 200 maize plants per hectare. Infestation levels were 68.46% in 2016, 55.82% in 2017, and 17.76% in 2018. The number of larvae recorded per hectare and infestation levels were higher in Togo than in Ghana. The lowest number of collected larvae and infestation levels of S. frugiperda were in 2018, compared to the other 2 yr. Larvae per hectare and the infestation level varied regionally inside the two countries. The southern part of Togo (AEZ five) contained higher numbers of larvae and higher infestation levels during the 2 yr following the invasion of the pest. We concluded that infestation levels of S. frugiperda are much lower in 2018 than the two previous years and it is therefore necessary to determine the factors that affect the population dynamics of S. frugiperda in the field, which is a perquisite for developing management interventions.


Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 195 ◽  
Author(s):  
Birhanu Sisay ◽  
Josephine Simiyu ◽  
Esayas Mendesil ◽  
Paddy Likhayo ◽  
Gashawbeza Ayalew ◽  
...  

The fall armyworm (FAW), Spodoptera frugiperda, threatens maize production in Africa. A survey was conducted to determine the distribution of FAW and its natural enemies and damage severity in Ethiopia, Kenya and Tanzania in 2017 and 2018. A total of 287 smallholder maize farms (holding smaller than 2 hectares of land) were randomly selected and surveyed. FAW is widely distributed in the three countries and the percent of infested maize fields ranged from 33% to 100% in Ethiopia, 93% to 100% in Tanzania and 100% in Kenya in 2017, whereas they ranged from 80% to 100% and 82.2% to 100% in Ethiopia and Kenya, respectively, in 2018. The percent of FAW infestation of plants in the surveyed fields ranged from 5% to 100%. In 2017, the leaf damage score of the average of the fields ranged from 1.8 to 7 (9 = highest level of damage), while 2018, it ranged from 1.9 to 6.8. In 2017, five different species of parasitoids were recovered from FAW eggs and larvae. Cotesia icipe (Hymenoptera: Braconidae) was the main parasitoid recorded in Ethiopia, with a percent parasitism rate of 37.6%. Chelonus curvimaculatus Cameron (Hymenoptera: Braconidae) was the only egg-larval parasitoid recorded in Kenya and had a 4.8% parasitism rate. In 2018, six species of egg and larval parasitoids were recovered with C. icipe being the dominant larval parasitoid, with percentage parasitism ranging from 16% to 42% in the three surveyed countries. In Kenya, Telenomus remus (Hymenoptera: Scelionidae) was the dominant egg parasitoid, causing up to 69.3% egg parasitism as compared to only 4% by C. curvimaculatus. Although FAW has rapidly spread throughout these three countries, we were encouraged to see a reasonable level of biological control in place. Augmentative biological control can be implemented to suppress FAW in East Africa.


2018 ◽  
Vol 48 (1) ◽  
pp. 202-210 ◽  
Author(s):  
Adam J Ingrao ◽  
Jenna Walters ◽  
Zsofia Szendrei

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