Toxicity of several botanical essential oils and their combinations against females of Aedes albopictus(Skuse) and Anopheles minimus(Theobald): Oviposition deterrent, ovicidal and adulticidal efficacies

Objective: To investigate the efficacies of 12 essential oil(EO) formulations from three Zingiberaceae plants(Alpinia galanga, Curcuma zedoaria, and Zingiber cassumunar) individually and in combination with an augmenting Eucalyptus globulus(E. globulus) EO against females of Aedes albopictus(Ae. albopictus) and Anopheles minimus(An. minimus). Methods: These formulations were evaluated for their ovicidal, oviposition deterrent and adulticidal activities against Ae. albopictus and An. minimus by a topical method, a double-choice method and a WHO susceptibility test, respectively. Results: It was found that all formulations of Zingiberaceae plants EOs augmented with E. globulus EO were more effective in oviposition deterrent, ovicidal, and adulticidal activities against the two mosquito species than all of the formulations used without E. globulus EO. Their oviposition deterrent, ovicidal and adulticidal activities were equivalent to those of 10% w/v cypermethrin. In contrast, 70% v/v ethyl alcohol as a control alone was not effective at all. The highest synergistic effect in effective repellency against Ae. albopictus was achieved by 5% Alpinia galanga EO + 5% E. globulus EO and against An. minimus was 5% Zingiber cassumunar EO + 5% E. globulus EO. Moreover, the highest synergistic effects in ovicidal activities against Ae. albopictus and An. minimus were achieved by 10% Zingiber cassumunar EO + 10% E. globulus EO and 5% Curcuma zedoaria EO + 5% E. globulus EO, respectively. For the adulticidal activities, the highest synergistic effect against two mosquitoes was achieved by 5% Curcuma zedoaria EO + 5% E. globulus EO. Conclusions: These results suggest that Zingiberaceae plant EOs augmented with E. globulus EO have a high potential to be developed into oviposition deterrent, ovicidal, and adulticidal agents for controlling populations of Ae. albopictus and An. minimus.

Larvicidal efficacy of crude and fractionated extracts of Dracaena loureiri Gagnep against Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and Anopheles minimus mosquito vectors

Objective:To evaluate the larvicidal efficacy of crude and fractionated extracts of Dracaena loureiri endocarp against Aedes aegypti,Aedes albopictus,Culex quinquefasciatus,and Anopheles minimus mosquitos.Methods:Larvicidal activity was tested according to World Health Organization standard protocol.The third-stage larvae of each mosquito species were exposed to various concentrations of Dracaena loureiri crude extract and six groups of Dracaena loureiri fractionated extracts(RC-DT 009-014).Larval mortality rates were observed after 24 h and48 h of exposure.Then,a computerized probit analysis of the mortality data was performed to determine lethal concentration 50(LC_(50))and lethal concentration 90 values.Results:Anopheles minimus larvae(24-h LC_(50)77.88 mg/L)had the highest susceptibility to crude extract,whereas others(Aedes aegypti,24-h LC_(50)224.73 mg/L;Aedes albopictus,24-h LC_(50)261.75 mg/L;and Culex quinquefasciatus,24-h LC_(50)282.86 mg/L)were significantly less susceptible.The most effective groups of fractionated extracts were RC-DT 012 and RC-DT 013.The mosquito species most susceptible to fractionated extracts was Culex quinquefasciatus,with 24-h LC_(50)values of 0.66 and 0.94 mg/L for RC-DT 012 and RC-DT 013,respectively.Conclusions:The larvicidal activity of fractionated extracts is more effective than that of crude extract against all tested mosquito species.For the most effective alternative larvicide,purification and a phytochemical constituent analysis must be performed.

Genetic diversity and gene structure of mitochondrial region of Anopheles minimus(Diptcra:Culicidae)-major malaria vector of North east India

Objective:To depict mitochondrial genetic variation for the first time among Anopheles minimus(An.minimus)(Diptera:Culicidae) species from two malaria endemic states of NE India.Methods:Phylogeographic analysis was carried at 9 out of 12 sites oi An.minimus confirmed malaria endemic places.Results:All sequences were Adenine-Thymine rich regions.Transitions were observed in 6 sequences where 5 mutations were synonymous substitutions and in 1 ease non synonymous mutation was observed.Three distinct clusters of haplolypes were generated.Haplotvpe diversity and low nucleotide diversity were studied.Overall negative values obtained from Tajima's D test and Fu'sF_S test indicate a recent genetic population expansion.Network analysis has explained sequence diversity that was also shown by mutations in 6 sequences.Conclusions:High genetic diversity observed within the populations of An.minimus species has several possible implications for vector control in the region.

脱缰奔跑——NEW BALANCE MINIMUS系列跑鞋

不想再被双脚束缚，解脱从双脚开始。新百伦（NEW BALANCE）再次突破传统，领先上市MNMUS跑鞋系列。

The complete mitochondrial genome of Anopheles minimus （Diptera： Culicidae） and the phylogenetics of known Anopheles mitogenomes

Anopheles minimus is an important vector of human malaria in southern China and Southeast Asia. The phylogenetics of mosquitoes has not been well resolved, and the mitochondrial genome （mtgenome） has proven to be an important marker in the study of evolutionary biology. In this study, the complete mtgenome of An. minimus was sequenced for the first time. It is 15 395 bp long and encodes 37 genes, including 13 protein-coding genes （PCGs）, 22 transfer RNAs （tRNAs）, two ribosomal RNAs （rRNAs） and a non-coding region. The gene organization is consistent with those of known Anopheles mtgenomes. The mtgenome performs a clear bias in nucleotide composition with a positive AT-skew and a negative GC-skew. All 13 PCGs prefer to use the codon UUA （Leu）, ATN as initiation codon but cytochrome-oxidase subunit 1 （COI） and ND5, with TCG and GTG, and TAA as termination codon, but COI, COII, COIII and ND4, all with the incomplete T. tRNAs have the typical clover-leaf structure, but tRNAser^a~N） is consistent with known Anopheles mtgenomes. The control region includes a conserved T-stretch and a （TA）n stretch, and has the highest A＋T content at 93.1%. The phylogenetics of An. minimus with 18 other Anopheles species was constructed by maximum likelihood and Bayesian inference, based on concatenated PCG sequences. The subgenera, Cellia and Anopheles, and Nyssorhynchus and Kerteszia have mutually close relationships, respectively. The Punctulatus group and Leueosphyrus group of Neomyzomyia Series, and the Albitarsis group of Albitarsis Series were suggested to be monophyletic. The monophyletic status of the subgenera, Cellia, Anopheles, Nyssorhynchus and Kerteszia need to be further elucidated.

Changing Trend and Sustainable Development of Farmland Resources in Pingdingshan City,China

The grey forecast and the sustainable use evaluation are conducted on the data of farmland resources from 2010 to 2020 in Pingingshan City by using the area of farmland land from 1999 to 2010 and by applying the grey forecast and land pressure system.The results show that from 2010 to 2020 the quantity of farmland resources maintains balance;the minimum per capita farmland in Pingdinshan stays around the lower limit of per capita amount of farmland in China;the pressure of farmland is rather huge and the farmland protection is not so optimistic.Therefore,in order to realize the sustainable use of land resources in Pingdinshan City,the government should try to improve the efficiency of farmland use and implement stricter land protection system.as well as the requisition-compensation balance of farmland resources,land consolidation and land reclaimation and so on.