scholarly journals Adaptive strategies of Rice Leaf Roller, Cnaphalocrocis medinalis in Response to Different Rearing Temperatures

2021 ◽  
Author(s):  
Weixiang Lv ◽  
Xingfu Jiang ◽  
Xiujie Chen ◽  
Yunxia Cheng ◽  
Jixing Xia ◽  
...  
Keyword(s):  
Immature Stage ◽  
Life History Strategies ◽  
Mating Frequency ◽  
Cnaphalocrocis Medinalis ◽  
Agricultural Pests ◽  
Flight Duration ◽  
Leaf Roller ◽  
Reproductive Ability ◽  
Immature Development ◽  
Pupal Mortality

Understanding how species that follow different life-history strategies respond to stressful temperature can be essential to efficient treatments against agricultural pests. Here we focus on how the development and reproduction of C. medinalis is influenced by exposure to different rearing temperatures in the immature stage. We found that low (18 or 22 °C) or high (30 and 34 °C) rearing temperatures negatively affected the immature development and flight performance compared to the normal temperature 26 °C, with higher larval and pupal mortality, lower pupation and eclosion rates and shorter flight duration and distance. Low rearing temperatures significantly slowed down the immature process, but accelerated adult reproduction. However, high rearing temperatures had the opposite impacts. Interestingly, the flight of adults with un-mature rearing low temperatures (18 and 22 °C) significantly decreased their lifetime fecundity and mating frequency, but increased pre-oviposition period of females compared to the control; On contrast, high rearing temperatures (30 and 34 °C) significantly accelerated onset of oviposition and enhanced synchrony of spawning. These results indicate high rearing temperatures in the immature stage are more likely to trigger the onset of migration, but low rearing temperatures induces adults to have a greater resident propensity with stronger reproductive ability.

scholarly journals Flight and Reproduction Variations of Rice Leaf Roller, Cnaphalocrocis medinalis in Response to Different Rearing Temperatures

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1083
Author(s):  
Weixiang Lv ◽  
Xingfu Jiang ◽  
Xiujie Chen ◽  
Yunxia Cheng ◽  
Jixing Xia ◽  
...  
Keyword(s):  
High Temperatures ◽  
Immature Stage ◽  
Life History Strategies ◽  
Cnaphalocrocis Medinalis ◽  
Lifetime Fecundity ◽  
Leaf Roller ◽  
Rice Leaf ◽  
Reproductive Ability ◽  
Tethered Flight ◽  
Reproductive Consequences

Understanding how species that follow different life-history strategies respond to stressful temperature can be essential for efficient treatments of agricultural pests. Here, we focused on how the development, reproduction, flight, and reproductive consequences of migration of Cnaphalocrocis medinalis were influenced by exposure to different rearing temperatures in the immature stage. We found that the immature rice leaf roller that were reared at low temperatures (18 and 22 °C) developed more slowly than the normal temperature 26 °C, while those reared at high temperatures (34 °C) grew faster. Female adults from low immature stage rearing temperatures showed stronger reproductive ability than those at 26 and 34 °C, such as the preoviposition period (POP) significantly decreased, while the total lifetime fecundity obviously increased. However, 34 °C did not significantly reduce the reproductive performances of females compared to 26 °C. On the contrary, one relative decreased tendency of flight capacity was found in the lower immature temperature treatments. Furthermore, flight is a costly strategy for reproduction output to compete for limited internal resources. In the lower temperature treatments, after d1-tethered flight treatment, negative reproductive consequences were found that flight significantly decreased the lifetime fecundity and mating frequency of females from low rearing temperatures in the immature stage compared to the controls (no tethered-flight). However, in the 26 and 34 °C treatments, the same flight treatment induced a positive influence on reproduction, which significantly reduced the POP and period of first oviposition (PFO). The results suggest that the experience of relative high temperatures in the immature stage is more likely to trigger the onset of migration, but lower temperatures in the immature stage may induce adults to have a greater resident propensity with stronger reproductive ability.

scholarly journals Characterization, Knockdown and Parental Effect of Hexokinase Gene of Cnaphalocrocis medinalis (Lepidoptera: Pyralidae) Revealed by RNA Interference

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1258
Author(s):  
Muhammad Shakeel ◽  
Juan Du ◽  
Shang-Wei Li ◽  
Yuan-Jin Zhou ◽  
Naeem Sarwar ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Expression Patterns ◽  
Control Group ◽  
Cnaphalocrocis Medinalis ◽  
Average Weight ◽  
Hatching Rate ◽  
Energy Regulation ◽  
Rnai Technology ◽  
Pupal Mortality ◽  
Dsrna Injection

Hexokinase (HK) is a key enzyme in chitin biosynthesis in insects and plays an important role in development and energy regulation. It also performs a crucial role in the synthesis of Glucose-6-phosphate and its putative functions are studied via injection of dsRNA corresponding to the hexokinase gene from Cnaphalocrocis medinalis (CmHK). This study was designed to analyze the characteristics and expression patterns of HK-related genes in various tissues of C. medinalis at different developmental stages. The CmHK ORF is a 1359 bp in length, encoding a protein of 452 amino acids, with homology and cluster analysis showing that CmHK shares an 85.11% sequence similarity with hexokinase from Ostrinia furnacalis.CmHK was highly expressed in the ovary and in the fifth instar larvae. Injection of dsCmHK significantly suppressed mRNA expression (73.6%) 120 h post-dsRNA injection as compared to a control group. The results demonstrated an increased incidence of larval and pupal mortality of 80% and 78%, respectively, with significant variation in the sex ratio between males (68.33%) and females (35%), overt larval deformities, and a reduction in average weight gain observed 120 h post-dsRNA injection. In addition, dsCmHK-injected C. medinalis showed a significant reduction in ovulation per female and larval hatching rate, along with increased larval and pupal mortality and variation in male and female emergence over three generations (G1, G2, and G3). Taken together, the outcomes of the study provide a foundation to study gene function and a new dimension to control C. medinalis by transgenic RNAi technology.

scholarly journals Seasonal migration ofCnaphalocrocis medinalis(Lepidoptera: Crambidae) over the Bohai Sea in northern China

2014 ◽  
Vol 104 (5) ◽  
pp. 601-609 ◽  
Author(s):  
X.-W. Fu ◽  
C. Li ◽  
H.-Q. Feng ◽  
Z.-F. Liu ◽  
J.W. Chapman ◽  
...  
Keyword(s):  
Bohai Sea ◽  
Ovarian Development ◽  
Direct Evidence ◽  
Insect Pest ◽  
Management Strategies ◽  
Northern China ◽  
Seasonal Migration ◽  
Cnaphalocrocis Medinalis ◽  
Effective Management ◽  
Leaf Roller

AbstractThe rice leaf roller,Cnaphalocrocis medinalis(Guenée), is a serious insect pest of rice with a strong migratory ability. Previous studies on the migration ofC. medinaliswere mostly carried out in tropical or subtropical regions, however, and what the pattern of seasonal movements this species exhibits in temperate regions (i.e. Northern China, where they cannot overwinter) remains unknown. Here we present data from an 11-year study of this species made by searchlight trapping on Beihuang Island (BH, 38°24′N; 120°55′E) in the centre of the Bohai Strait, which provides direct evidence thatC. medinalisregularly migrates across this sea into northeastern agricultural region of China, and to take advantage of the abundant food resources there during the summer season. There was considerable seasonal variation in number ofC. medinalistrapped on BH, and the migration period during 2003–2013 ranged from 72 to 122 days. Some females trapped in June and July showed a relatively higher proportion of mated and a degree of ovarian development suggesting that the migration of this species is not completely bound by the ‘oogenesis-flight syndrome’. These findings revealed a new route forC. medinalismovements to and from Northeastern China, which will help us develop more effective management strategies against this pest.

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