RNAi technology: a new platform for crop pest control

Potential of frogs as important natural pest control agents has been highlighted earlier. But the effectiveness of frogs in regulating the pest load in intensive agricultural landscape in a multi-trophic system is not clear. We performed controlled field experiment in paddy field with a varying density (observed in high and low agricultural intensity (AI) areas) of a commonly found frog species and compared the pest and pest predator build-up. The consumption rate of the model amphibian was studied using enclosure experiment. The consequent trophic cascade effect of frogs on both crop pest and other arthropod pest predator was analyzed using mathematical population growth models. Although frogs consumed pests, they could not reduce crop pest abundance. Although a lesser frog density found in high AI areas significantly affected the pest predator abundance. Based on the functional response result, mathematical growth models demonstrated that with a constant harvesting factor (Holling Type II) frogs will always have a negative impact on the beneficial natural enemy population due to intraguild predation thereby limiting its potential as a pest regulator. Our study challenges the notion of frogs as an effective pest control agent and argues that increasing habitat diversity might improve overall biological pest suppression.

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GFAT and PFK genes show contrasting regulation of chitin metabolism in Nilaparvata lugens

Scientific Reports ◽

10.1038/s41598-021-84760-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Cai-Di Xu ◽

Yong-Kang Liu ◽

Ling-Yu Qiu ◽

Sha-Sha Wang ◽

Bi-Ying Pan ◽

...

Keyword(s):

Rna Interference ◽

Pest Control ◽

Mortality Rates ◽

Nilaparvata Lugens ◽

Chitin Synthesis ◽

Chitin Synthesis Inhibitors ◽

Expression Of Genes ◽

Rnai Technology ◽

Wing Bud

AbstractGlutamine:fructose-6-phosphate aminotransferase (GFAT) and phosphofructokinase (PFK) are enzymes related to chitin metabolism. RNA interference (RNAi) technology was used to explore the role of these two enzyme genes in chitin metabolism. In this study, we found that GFAT and PFK were highly expressed in the wing bud of Nilaparvata lugens and were increased significantly during molting. RNAi of GFAT and PFK both caused severe malformation rates and mortality rates in N. lugens. GFAT inhibition also downregulated GFAT, GNPNA, PGM1, PGM2, UAP, CHS1, CHS1a, CHS1b, Cht1-10, and ENGase. PFK inhibition significantly downregulated GFAT; upregulated GNPNA, PGM2, UAP, Cht2-4, Cht6-7 at 48 h and then downregulated them at 72 h; upregulated Cht5, Cht8, Cht10, and ENGase; downregulated Cht9 at 48 h and then upregulated it at 72 h; and upregulated CHS1, CHS1a, and CHS1b. In conclusion, GFAT and PFK regulated chitin degradation and remodeling by regulating the expression of genes related to the chitin metabolism and exert opposite effects on these genes. These results may be beneficial to develop new chitin synthesis inhibitors for pest control.

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Biological control of the Asian chestnut gall wasp in Portugal: Insights from a mathematical model

PLoS ONE ◽

10.1371/journal.pone.0254193 ◽

2021 ◽

Vol 16 (7) ◽

pp. e0254193

Author(s):

Carlos Balsa ◽

Albino Bento ◽

Francesco Paparella

Keyword(s):

Mathematical Model ◽

Biological Control ◽

Pest Management ◽

Pest Control ◽

Gall Wasp ◽

Production Studies ◽

Crop Pest ◽

Torymus Sinensis ◽

Collective Strategy ◽

Made In

In recent years, the Asian gall wasp Dryocosmus kuriphilus has invaded chestnut trees and significantly affected the Portuguese chestnut production. Studies in other countries, such as Japan or Italy, have shown that the parasitoid Torymus sinensis can successfully achieve biological control of D. kuriphilus. Mathematical models help us to understand the dynamics of the interaction between the pest D. kuriphilus and its parasitoid T. sinensis and, consequently, they can help to implement measures that enhance crop pest management. In this work, the evolution of the density of D. kuriphilus and T. sinensis across time and space is studied through the numerical solution of models that include parameters based on observations made in Portugal. Simultaneous releases of the parasitoid are simulated at various locations and at different times. The results indicate that, in the case of a small and homogeneous orchard, biological control can be effective, but, in the case of extensive domains, the pest control is much more difficult to achieve. In order for biological control to be efficient, it is necessary to implement, in each chestnut-producing region, a collective strategy based on the annual monitoring of infestation levels.

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