22 research outputs found
Surveillance study of vector species on board passenger ships, Risk factors related to infestations
<p>Abstract</p> <p>Background</p> <p>Passenger ships provide conditions suitable for the survival and growth of pest populations. Arthropods and rodents can gain access directly from the ships' open spaces, can be carried in shiploads, or can be found on humans or animals as ectoparasites. Vectors on board ships may contaminate stored foods, transmit illness on board, or, introduce diseases in new areas. Pest species, ship areas facilitating infestations, and different risk factors related to infestations were identified in 21 ferries.</p> <p>Methods</p> <p>486 traps for insects and rodents were placed in 21 ferries. Archives of Public Health Authorities were reviewed to identify complaints regarding the presence of pest species on board ferries from 1994 to 2004. A detail questionnaire was used to collect data on ship characteristics and pest control practices.</p> <p>Results</p> <p>Eighteen ferries were infested with flies (85.7%), 11 with cockroaches (52.3%), three with bedbugs, and one with fleas. Other species had been found on board were ants, spiders, butterflies, beetles, and a lizard. A total of 431 <it>Blattella germanica </it>species were captured in 28 (9.96%) traps, and 84.2% of them were nymphs. One ship was highly infested. Cockroach infestation was negatively associated with ferries in which Hazard Analysis Critical Control Point system was applied to ensure food safety on board (Relative Risk, RR = 0.23, <it>p </it>= 0.03), and positively associated with ferries in which cockroaches were observed by crew (RR = 4.09, <it>p </it>= 0.007), no cockroach monitoring log was kept (RR = 5.00, <it>p </it>= 0.02), and pesticide sprays for domestic use were applied by crew (RR = 4.00, <it>p </it>= 0.05). Cockroach infested ships had higher age (<it>p </it>= 0.03). Neither rats nor mice were found on any ship, but three ferries had been infested with a rodent in the past.</p> <p>Conclusion</p> <p>Integrated pest control programs should include continuing monitoring for a variety of pest species in different ship locations; pest control measures should be more persistent in older ships. HACCP system aids in the prevention of cockroach infestations on board.</p
Biocontrol of larval mosquitoes by Acilius sulcatus (Coleoptera: Dytiscidae)
<p>Abstract</p> <p>Background</p> <p>Problems associated with resistant mosquitoes and the effects on non-target species by chemicals, evoke a reason to find alternative methods to control mosquitoes, like the use of natural predators. In this regard, aquatic coleopterans have been explored less compared to other insect predators. In the present study, an evaluation of the role of the larvae of <it>Acilius sulcatus </it>Linnaeus 1758 (Coleoptera: Dytiscidae) as predator of mosquito immatures was made in the laboratory. Its efficacy under field condition was also determined to emphasize its potential as bio-control agent of mosquitoes.</p> <p>Methods</p> <p>In the laboratory, the predation potential of the larvae of <it>A. sulcatus </it>was assessed using the larvae of <it>Culex quinquefasciatus </it>Say 1823 (Diptera: Culicidae) as prey at varying predator and prey densities and available space. Under field conditions, the effectiveness of the larvae of <it>A. sulcatus </it>was evaluated through augmentative release in ten cemented tanks hosting immatures of different mosquito species at varying density. The dip density changes in the mosquito immatures were used as indicator for the effectiveness of <it>A. sulcatus </it>larvae.</p> <p>Results</p> <p>A single larva of <it>A. sulcatus </it>consumed on an average 34 IV instar larvae of <it>Cx. quinquefasciatus </it>in a 24 h period. It was observed that feeding rate of <it>A. sulcatus </it>did not differ between the light-on (6 a.m. – 6 p.m.), and dark (6 p.m. – 6 a.m.) phases, but decreased with the volume of water i.e., space availability. The prey consumption of the larvae of <it>A. sulcatus </it>differed significantly (P < 0.05) with different prey, predator and volume combinations, revealed through univariate ANOVA. The field study revealed a significant decrease (p < 0.05) in larval density of different species of mosquitoes after 30 days from the introduction of <it>A. sulcatus </it>larvae, while with the withdrawal, a significant increase (p < 0.05) in larval density was noted indicating the efficacy of <it>A. sulcatus </it>in regulating mosquito immatures. In the control tanks, mean larval density did not differ (p > 0.05) throughout the study period.</p> <p>Conclusion</p> <p>the larvae of the dytiscid beetle <it>A. sulcatus </it>proved to be an efficient predator of mosquito immatures and may be useful in biocontrol of medically important mosquitoes.</p
Biological control of mosquito populations: An applied aspect of pest control by means of natural enemies
Biological control of mosquito populations: An applied aspect of pest control by means of natural enemies
Molecular and morphological characterization of Aedes albopictus in northwestern Greece and differentiation from Aedes cretinus and Aedes aegypti
The presence of Aedes albopictus (Skuse) was recently confirmed for the
first time in northwestern Greece. This location is within the
distribution range of a morphologically similar species, Aedes cretinus
Edwards, and is a potentially favorable region for the reintroduction of
Aedes aegypti (L.). It was thus compelling to use methods in addition to
morphology-based keys to correctly identify specimens badly damaged,
rubbed, or otherwise altered in their external characteristics. It was
decided to use molecular techniques as a novel and reliable method for
differentiating the three Stegomyia species. The nuclear internal
transcribed spacer 2 (ITS2) fragments from morphologically identified
Ae. albopictus and Ae. cretinus specimens were amplified, and their
sequences were compared with those in GenBank for Ae. albopictug, Ae.
cretinus, and Ae. aegypti. Also, mitochondrial cytochrome oxidase 1
(001) fragments were amplified for Ae. albopictus and Ae. cretinus (so
far not available in GenBank) and compared with Ae. aegypti fragments.
ITS2 and COI sequences generated in our study were deposited in GenBank
and could be useful in future studies of mosquitoes by other research
workers
Morphological and molecular characterization of Anopheles (Anopheles) maculipennis Meigen, type species of the genus and nominotypical member of the Maculipennis Complex
Adults and larvae of Anopheles maculipennis Meigen were collected in
Greece in May and June 2001. Larvae and the progeny of wild-caught
females were individually reared to obtain samples of all life stages
for integrated morphological and molecular study. Specimens were
identified on the basis of egg morphology and correlation of their ITS2
rDNA sequences with those in GenBank. The adult, pupal, larval
(fourth-instar) and egg stages are described, and all stages except the
egg are illustrated. Partial sequence data are provided for the
mitochondrial cytochrome c oxidase I (COI) gene and complete sequences
for the nuclear ITS2 region. Additionally, the bionomics and
distribution of the species are reviewed, and its taxonomy and
systematics are discussed. This study provides the first fully
integrated morphological and molecular assessment of An. maculipennis,
the nominotypical member of the Maculipennis Complex, and the type
species of genus Anopheles, and serves as a foundation for further
studies of the complex and subfamily Anophelinae
Aedes albopictus (Skuse, 1895) (Diptera: Culicidae) in Greece: 13 years of living with the Asian tiger mosquito
Molecular characterization of the Anopheles maculipennis complex during surveillance for the 2004 Olympic Games in Athens
Specimens belonging to the Anopheles maculipennis complex were collected
as larvae or resting adults from May 2003 to November 2004 in the area
of the Athens 2004 Olympic Rowing Centre in Schinias, Attiki, Greece,
and identified by morphological and molecular analyses. Of the 201
specimens collected, 199 were found to be Anopheles sacharovi Favre and
two were An. maculipennis Meigen s.s. on the basis of similarity to
published sequence data for the rDNA internal transcribed spacer (ITS2)
region and the mitochondrial cytochrome c oxidase I gene (COI). Sequence
data from a number of specimens were obtained for both genes and
compared with corresponding GenBank data derived from diverse
geographical areas. A high degree of homology in ITS2 sequences was
found in both species, ranging from 99.5% to 100% in An. sacharovi and
99.4% to 100% in An. Maculipennis, with no intraspecific variation in
either of the two species in our study. The degree of homology in the
COI sequences was 94.8-99.8% in An. sacharovi and 95.0-99.8% in An.
maculipennis. The 522-bp fragment produced a rather high degree of
intrapopulation polymorphism for An. sacharovi, generating nine
different haplotypes, five of which were singletons. Intraspecific
variation for these sequences ranged from 0.2% to 1.4%, but was much
lower (0.77%) for the two An. maculipennis sequences. These findings
represent the first characterization of the An. maculipennis complex in
the area of Schinias
Surveillance study of vector species on board passenger ships, risk factors related to infestations
Background: Passenger ships provide conditions suitable for the survival
and growth of pest populations. Arthropods and rodents can gain access
directly from the ships’ open spaces, can be carried in shiploads, or
can be found on humans or animals as ectoparasites. Vectors on board
ships may contaminate stored foods, transmit illness on board, or,
introduce diseases in new areas. Pest species, ship areas facilitating
infestations, and different risk factors related to infestations were
identified in 21 ferries.
Methods: 486 traps for insects and rodents were placed in 21 ferries.
Archives of Public Health Authorities were reviewed to identify
complaints regarding the presence of pest species on board ferries from
1994 to 2004. A detail questionnaire was used to collect data on ship
characteristics and pest control practices.
Results: Eighteen ferries were infested with flies (85.7%), 11 with
cockroaches (52.3%), three with bedbugs, and one with fleas. Other
species had been found on board were ants, spiders, butterflies,
beetles, and a lizard. A total of 431 Blattella germanica species were
captured in 28 (9.96%) traps, and 84.2% of them were nymphs. One ship
was highly infested. Cockroach infestation was negatively associated
with ferries in which Hazard Analysis Critical Control Point system was
applied to ensure food safety on board (Relative Risk, RR = 0.23, p =
0.03), and positively associated with ferries in which cockroaches were
observed by crew (RR = 4.09, p = 0.007), no cockroach monitoring log was
kept (RR = 5.00, p = 0.02), and pesticide sprays for domestic use were
applied by crew (RR = 4.00, p = 0.05). Cockroach infested ships had
higher age (p = 0.03). Neither rats nor mice were found on any ship, but
three ferries had been infested with a rodent in the past.
Conclusion: Integrated pest control programs should include continuing
monitoring for a variety of pest species in different ship locations;
pest control measures should be more persistent in older ships. HACCP
system aids in the prevention of cockroach infestations on board