scholarly journals THE DISTRIBUTION, IMPORTANCE, BIOLOGY AND CONTROL, OF CHROMOLAENA ODORATA (L.) K.& R.A MAJOR WEED SPECIES OF COCONUT PLANTATION IN SRI LANKA

CORD ◽  
1995 ◽  
Vol 11 (02) ◽  
pp. 34
Author(s):  
T.G.L.G. Gunasekara

Chromolaena odorata (1.) K. & R. is a tropical peren­nial weed species qf the Asteraceae family that has be­come a serious problem in coconut plantations in Sri Lanka and in the tropics of Asia and Africa. The history of distribution, habitat and economic importance is summarized The botanical features and seed biology of this species are presented in this review Finally in­formation on the control measures such as mechanical, cultural, chemical and biological methods is discussed.

2012 ◽  
Vol 54 (4) ◽  
pp. 179-191 ◽  
Author(s):  
Jordi Sanchez-Ribas ◽  
Gabriel Parra-Henao ◽  
Anthony Érico Guimarães

Irrigation schemes and dams have posed a great concern on public health systems of several countries, mainly in the tropics. The focus of the present review is to elucidate the different ways how these human interventions may have an effect on population dynamics of anopheline mosquitoes and hence, how local malaria transmission patterns may be changed. We discuss different studies within the three main tropical and sub-tropical regions (namely Africa, Asia and the Pacific and the Americas). Factors such as pre-human impact malaria epidemiological patterns, control measures, demographic movements, human behaviour and local Anopheles bionomics would determine if the implementation of an irrigation scheme or a dam will have negative effects on human health. Some examples of successful implementation of control measures in such settings are presented. The use of Geographic Information System as a powerful tool to assist on the study and control of malaria in these scenarios is also highlighted.


2016 ◽  
Author(s):  
Justin Lessler ◽  
Cassandra T. Ott ◽  
Andrea C. Carcelen ◽  
Jacob M. Konikoff ◽  
Joe Williamson ◽  
...  

Background Evidence suggests that Zika virus has driven a 10-fold increase in babies born with microcephaly in Brazil, prompting the WHO to declare a Public Health Emergency of International Concern. However, little is known about the natural history of infection. These data are critical for implementation of surveillance and control measures such as protecting the blood supply. Methods We conducted a systematic review and pooled analysis to estimate the distribution of times from Zika infection to symptom onset, seroconversion, and viral clearance, and analyzed their implications for surveillance and blood supply safety. Results Based on 25 case reports, we estimate the median incubation period of Zika virus infection is 5.9 days (95% CI: 4.4-7.6), and that 95% of cases will develop symptoms by 11.1 days post-infection (95% CI: 7.6-18.0). On average seroconversion occurs 9.0 days (95% CI, 7.0-11.6) after infection, and virus is detectable in blood for 9.9 days (95% CI: 6.8-21.4). In 5% of cases detectable virus persists for over 18.9 days (95% CI: 12.6-79.5). The baseline (no screening) risk of a blood donation being infected with Zika increases by approximately 1 in 10,000 for every 1 per 100,000 person-days increase in Zika incidence. Symptom based screening reduces this by 7% (RR 0.93, 93% CI 0.86-0.99), and antibody screening by 29% (RR 0.71, 95% CI: 0.28-0.88). Conclusions Symptom or antibody-based surveillance can do little to reduce the risk of Zika contaminated blood donations. High incidence areas may consider PCR testing to identify lots safe for use in pregnant women.


2008 ◽  
Vol 77 (1) ◽  
pp. 117-121 ◽  
Author(s):  
S. Otlu ◽  
M. Sahin ◽  
H. I. Atabay ◽  
A. Unver

The prevalence of brucellosis was investigated in cattle, farmers and veterinarians in the Kars district of Turkey between 2004 - 2006. In order to achieve this, a total of 407 serum samples of cattle from 27 herds having history of abortions were examined for Brucella antibodies by RBPT and SAT. In addition, the sera collected from 246 farmers (130 males and 116 females) and 28 veterinarians in the same district were analysed serologically by RBPT, SAT and ELISA. Of the cattle sera analysed, 134 (32.92%) and 141 (34.64%) were determined as positive by RBPT and SAT, respectively. Thirty-two (13%), 35 (14.22%) and 44 (17.88%) of the farmers' sera were found positive for brucellosis by RBPT, SAT and ELISA, respectively. There was no significant difference between sexes for Brucella seropositivity. Of the 28 sera from veterinarians, 13 (46.42%) were positive by the three serological tests. The high prevalence of brucellosis both in cattle and humans suggests that brucellosis is common in this area. Preventive and control measures should be implemented and pursued more strictly to reduce and/or eradicate brucellosis from the area.


1982 ◽  
Vol 72 (2) ◽  
pp. 193-205 ◽  
Author(s):  
M. J. W. Cock ◽  
J. D. Holloway

AbstractChromolaena odorata is a tropical American species of the Compositae that has become a serious problem in plantations in the tropics of Asia and Africa. The history of attempts to control it using the arctiid moth Pareuchaetes pseudoinsulata Rego Barros (misidentified in previous literature as Ammalo insulata (Wlk.)) is summarised. The taxonomy and distributions of the five species in Pareuchaetes are presented, together with keys based on genitalic characters, three new synonyms and one new combination. Information on the biogeography and ecology of the Pareuchaetes species is used to assess their potential as biological control agents.


2021 ◽  
Vol 10 (14) ◽  
pp. e596101422480
Author(s):  
Paula Fassicolo Variza ◽  
Thiago Nunes Pereira ◽  
Joice Guilherme de Oliveira ◽  
Millena Fernandes ◽  
Daniel Moreira de Avelar ◽  
...  

The family Psychodidae has a cosmopolitan distribution with members that occur in many habitats, mainly in humid environments, and is most diverse in the tropics. Subfamilies Sycoracinae and Phlebotominae have females with hematophagous habits and the latter studied more due to medical and veterinary interest, since it includes species that can transmit diseases to animals and humans. The knowledge about the sand fly fauna in a region is extremely important for adequate monitoring and control measures for leishmaniasis. Thus, the objective of this study was to characterize Psychodidae fauna in relation to richness, abundance and molecular identification of Leishmania spp. in sand flies in southern Santa Catarina, Brazil. The ollections were carried out between 2015 and 2016 in three cities in Santa Catarina, Brazil. Samples were taken near feeding places for domestic animals, urban forest and peridomicile areas. The insects were identified and female sand flies were submitted to molecular analysis to detect the presence of Leishmania spp.. A total of 4,200 insects were collected, 4,193 from the Sycoracinae subfamily and 7 Phlebotominae from the Nyssomyia neivai and Pintomyia fisheri species. Of the studied municipalities, sandflies were registered in Tubarão and Imaruí and the most frequent habitat was the peridomicile areas. No samples were positive for Leishmania spp. In conclusion, the work highlights the presence of two species of sandflies, which were recorded for the first time in southern Santa Catarina.


1991 ◽  
Vol 42 (5) ◽  
pp. 827 ◽  
Author(s):  
PA Horne ◽  
JA Horne

The incidence and life-history of potato wireworm, Hapatesus hirtus Candeze, in Victorian potato crops were studied, and insecticidal control measures assessed. Larval stages were present and active throughout the year. Ten larval instars were identified, probably requiring several years to complete development. Egg development occurred in October-November and the most likely timing of oviposition was December. The relative numbers of larval H. hirtus detected in soil samples, pre-planting baits and harvested tubers are presented. Baiting with halves of potatoes provided an efficient means of detecting areas likely to suffer wireworm damage. One formulation of chlorpyrifos ('Lorsban') was effective in reducing damage to, and larval numbers in, potatoes in field trials. The granular formulation of tefluthrin and the controlled release chlorpyrifos were not effective in protecting potato tubers.


2017 ◽  
Vol 2 (3) ◽  
pp. 27 ◽  
Author(s):  
Janine Seetahal ◽  
Alexandra Vokaty ◽  
Christine Carrington ◽  
Abiodun Adesiyun ◽  
Ron Mahabir ◽  
...  

Plant Disease ◽  
2006 ◽  
Vol 90 (7) ◽  
pp. 869-876 ◽  
Author(s):  
G. T. Browne ◽  
J. H. Connell ◽  
S. M. Schneider

Trials were conducted in orchards near Chico, CA and microplots near Parlier, CA to examine symptoms and control measures for a replant disease (RD) on almond (Prunus dulcis). In the orchard trials, areas with a recent history of severe RD were cleared, given soil fumigation treatments in the fall, and replanted with almond trees on various rootstocks the following winter. The replants in nonfumigated soil developed severe RD (stunting, wilting, chlorosis, defoliation) by the following summer, while those in most fumigated treatments remained healthy. Trees in nonfumigated soil developed smaller trunk diameters and fewer healthy roots ≤1 mm diameter, compared with the healthy trees. Almond developed RD on all rootstocks evaluated (Marianna 2624, Lovell, and Nemaguard), but the trees on Marianna 2624 were the most severely affected. Pre-plant tree-site (spot) fumigation treatments with methyl bromide (MB), chloropicrin (CP), 1,3-dichloropropene (1,3-D), 1,3-D + CP, iodomethane, and iodomethane + CP all prevented severe RD. Broadcast soil fumigation with CP also was effective, but broadcast MB and 1,3-D were ineffective. In microplots filled with RD-conducive soil, CP was more potent than MB for prevention of RD on Nemaguard peach. There was no association between nematodes and RD in orchard or microplot trials. The RD apparently was mediated by a biological agent(s) other than nematodes and can be prevented by appropriate fumigation with CP or other MB alternatives.


2020 ◽  
Vol 50 (7) ◽  
Author(s):  
Deise Keli Farias ◽  
Gabriela Dick ◽  
Silvério Bunn ◽  
André Thaler Neto ◽  
Carolina Rech ◽  
...  

ABSTRACT: Leptospirosis is a zoonotic infectious disease caused by the bacterium Leptospira spp. The consequences of infection in horses are unclear, and the serogroups involved vary depending on the region. This study aimed to evaluate the seropositivity of unvaccinated horses in the Serra Catarinense region and the possible risk factors associated with the infection. We used 207 horses from 26 properties, with no clinical history of infection and unvaccinated for leptospirosis. We submitted serum samples to the microscopic agglutination serum (SAM) to obtain the main reference serogroups. We considered animals with titre ≥100 as infected. The results of the serology revealed seropositivity in 45.4% (94/207) of the animals studied. The most frequent antibodies reportedwere those against the serogroups Australis 16.9% (35/207), Ichterhaemorrhagiae 14.4% (30/207), and Grippotyphosa 5.31% (11/207). Among the primary risk factors associated with the infection we reported extensive rearing system (OR = 1.27; P<0.05) and the presence of other animal species such as cattle (OR = 3.85; P<0.01) and capybaras (OR = 2.07; P=0.06). The findings presented in this study showed that leptospirosis is endemic in horses in the Serra Catarinense region, and revealed the need for emergency surveillance and control measures specific to this important zoonosis.


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