Relationship between Population Fluctuation of Oriental Fruit Fly Bactrocera dorsalis Hendel and Abiotic Factors in Yezin, Myanmar

Population fluctuation of oriental fruit fly, Bactrocera dorsalis （Hendel） （Diptera： Tephritidae）, was monitored by using methyl eugenol traps during May, 2011 to December, 2011 and May, 2016 to December, 2016 in mango orchard farms of Department of Agricultural Research in Yezin, Myanmar. In 2011, the highest mean number of male oriental fruit flies/trap/day （241.42 ± 11.79） was recorded in June and the lowest （2.21 ± 0.40） in December. The highest mean number of male oriental frui t flies/trap/day （388.95 ± 8.56） was recorded in the month of June and the lowest （2.33 ± 0.20） in December, 2016. Population data were correlated with meteorological data including temperature, duration of sunshine, and rainfall. Population fluctuation of male fruit flies was positively correlated with temperature and rainfall, and negatively correlated with the duration of sunshine.

Habitat fragmentation, vole population fluctuations, and the ROMPA hypothesis: An experimental test using model landscapes

Increased habitat fragmentation leads to smaller size of habitat patches and to greater distance between patch­es.The ROMPA hypothesis(ratio of optimal to marginal patch area)uniquely links vole population fluctuations to the composition of the landscape.It states that as ROMPA decreases(fragmentation increases),vole popu­lation fluctuations will increase(including the tendency to display multi-annual cycles in abundance)because decreased proportions of optimal habitat result in greater population declines and longer recovery time after a harsh season.To date,only comparative observations in the field have supported the hypothesis.This paper re­ports the results of the first experimental test.I used prairie voles,Microtus ochrogaster,and mowed grassland to create model landscapes with 3 levels of ROMPA(high with 25%mowed,medium with 50%mowed and low with 75%mowed).As ROMPA decreased,distances between patches of favorable habitat(high cover)in­creased owing to a greater proportion of unfavorable(mowed)habitat.Results from the first year with intensive live trapping indicated that the preconditions for operation of the hypothesis existed(inversely density depen­dent emigration and,as ROMPA decreased,increased per capita mortality and decreased per capita movement between optimal patches).Nevertheless,contrary to the prediction of the hypothesis that populations in land­scapes with high ROMPA should have the lowest variability,5 years of trapping indicated that variability was lowest with medium ROMPA.The design of field experiments may never be perfect,but these results indicate that the ROMPA hypothesis needs further rigorous testing.

Effect of Mixed Orchards on Population Dynamics and Dominant on Tephritid Flies in the New Valley Governorate, Egypt

Peach Fruit Fly （PFF） Bactrocera zonata （Saunders） and of the Mediterranean fruit fly （MFF） Ceratitis capitata （Wiedemann） are the most of dominant and destructive key pests in fruit orchards in different agro-ecosystem in Egypt. Population fluctuations of the Mediterranean fruit fly Ceratitis capitata （Wiedemann） and the peach fly Bactrocera zonata （Saunders） was monitored with lure traps collections in three provinces in the New Valley oases, Western Desert, Egypt. Results showed marked temporal differences in peak trap catches of the two flies in the selected sites all over the entire studied areas. One annual peak of C. capitata was recorded during both October and February and coincided with the ripening period of citrus trees in Kharga oases. However, two annual peaks were recorded during June and September in Bodkholow province and coincided with the ripening period of apple and mango. On the other hand, two annual peaks of B. zonata were recorded in Kharga oases throughout May and September and coincided with the ripening periods of apricot, mango and guava. One annual peak only was recorded round up of September and/or October in both of Moot and Bodkholow in Dakhla oases and coincided with the ripening period of mango, guava and citrus. Occurrence of C. capitata was very limited in comparison with B. zonata. Population fluctuations of the two pests in the studied sites were significantly different. The ability of the used traps in capturing both of C. capitata and B. zonata indicated that the yellow sticky trap was more effective in capturing C. capitata. However, Abdel-Kawi trap was significantly efficient in trapping B. zonata. Occurrence of B. zontata in high numbers all over the study period than C. capitata is considered as a good proof that this invading fly may be consider a vigor competitive tephritid fly to the native fly C. capitata.

Population genomic analysis reveals distinct demographics and recent adaptation in the black flying fox(Pteropus alecto)

As the only mammalian group capable of powered flight,bats have many unique biological traits.Previous comparative genomic studies in bats have focused on long-term evolution.However,the microevolutionary processes driving recent evolution are largely under-explored.Using resequencing data from 50 black flying foxes(Pteropus alecto),one of the model species for bats,we find that black flying fox has much higher genetic diversity and lower levels of linkage disequilibrium than most of the mammalian species.Demographic inference reveals strong population fluctuations(>100 fold)coinciding with multiple historical events including the last glacial change and Toba super eruption,suggesting that the black flying fox is a very resilient species with strong recovery abilities.While long-term adaptation in the black flying fox is enriched in metabolic genes,recent adaptation in the black flying fox has a unique landscape where recently selected genes are not strongly enriched in any functional category.The demographic history and mode of adaptation suggest that black flying fox might be a well-adapted species with strong evolutionary resilience.Taken together,this study unravels a vibrant landscape of recent evolution for the black flying fox and sheds light on several unique evolutionary processes for bats comparing to other mammalian groups.

Response of Japanese anchovy(Engraulis japonicus)to the Pacific Decadal Oscillation in the Yellow Sea over the past 400 a

Quantitative identification of long-term changes in the abundance of Japanese anchovy(Engraulis japonicus)in the Yellow Sea is particularly important for understanding evolutionary processes of the Yellow Sea ecosystem.Unfortunately,the driving mechanisms of climate variability on the anchovy are still unclear due to the lack of long-term observational data.In this study,we used the fish scale deposition rate in the central Yellow Sea to reconstruct the time series of the anchovy stock over the past 400 a.On this basis,we further explored the impacts of the Pacific Decadal Oscillation(PDO)on the anchovy.Our results show that the anchovy stock is positively correlated with the PDO on a decadal time scale.In addition,anchovy abundance was relatively high during1620–1860 AD(the Little Ice Age,LIA),though in a state of constant fluctuation;anchovy abundance maintained at a relatively low level after~1860 AD.In particular,followed by overfishing since the 1980 s,the anchovy stock has declined sharply.Based on these findings,we infer that fluctuations of the anchovy stock may be regulated by basin-scale“atmosphere–ocean”interactions.Nevertheless,the role of overfishing should not be ignored.

Discussion on the paper “Analyzing short time series data from periodically fluctuating rodent populations by threshold models: A nearestblock bootstrap approach”

The authors are to be congratulated for an innovative paper in terms of both modelling methodology and subject matter significance. The analysis of short time series is known to be

Discussion on the paper “Analyzing short time series data from periodically fluctuating rodent populations by threshold models: A nearestblock bootstrap approach”

This is a very attractive article. It combines fascinating new methodology with a most interesting dataset, and a highly motivating presentation. However, despite the many

Sustainability of urban drainage management： a perspective on infrastructure resilience and thresholds

Urban wastewater infrastructures have been threatened by natural and socioeconomic disturbances. This study investigates infrastructure resilience against the risks of long-term changes rather than natural disasters. Urban expansion that leads to an increased urban runoff and massive population movements that cause fluctuations in domestic emissions are considered in this study. Pollution permits for water bodies are ＇adopted as constraints on wastewater infrastructures. A land use- based accounting method, combined with a grid-based database, is developed to map domestic discharge and urban runoff to service areas of wastewater treatment plants. The results of a case study on downtown Sanya, the most famous seashore tourist attraction in China, show that the average resilient values of three sub-catchment areas in 2010 were -0.57, 0.10 and 0.27, respectively, a significant spatial variation. The infrastructure in the Sanya River sub- region is the least flexible, and is more likely to fail due to unstable inflows. The resiliencies will increase to 0.59, 1.01 and 0.54, respectively, in 2020, a considerable improvement in robustness. The study suggests that infrastructure resilience needs to be taken into further consideration for urban planning and the related realm of urban governance to foster more robust wastewater management under various risks.