Abstract:
Malaria control methods that aim to reduce adult vector populations by targeting their aquatic
immature stages. A better fundamental understanding of the biology and ecology of these
essential stages could contribute to the implementation of current control methods and to the
development of novel strategies. Objective of this study was to examine breeding habitat
diversity and analysis of richness, diversity and geographical distribution of Anopheline
larvae and the species composition of aquatic macro-invertebrates in their oviposition sites in
Trincomalee District.
Fifteen major permanent breeding places in five possible malaria sensitive sites
(Gomarankadawala, Ichchallampaththu, Mollipothana, Padavisiripura and Thoppur) in
Trincomalee District were selected. Anopheles larvae and macro-invertebrates were collected
using standard methods for 16 months (April, 2013-July, 2014) and they were identified
microscopically. The Shannon diversity index (H') was used to characterize species diversity
at the five study sites by its abundance and evenness of the species present. ANOVA were
used to analyze the correlation between macro-invertebrates and mosquito larval abundance.
In total, 4478 including 11 species of Anopheles larvae were identified. An. subpictus, An.
nigerrimus and An. peditaeniatus (71%) were the most abundant and widely-distributed
species. Anopheline larval diversity was highest in Mollipothana (H‘=1.986). Whereas in
Gomarankadawala, Ichchallampaththu and Thoppur where H‘=1.721, H‘= 0.857 and
H‘=0.762 respectively. In total, 28 species of aquatic macro-invertibrates were identified and
highest diversity was recorded in Mollipothana, Gomarankadawala and Ichchallampaththu
(H‘=3.14-2.56). This deduces that the species richness and diversity of Anopheles mosquitoes
and macro-invertebrates are higher in these areas. The presence of permanent breeding places
may be the factors for this phenomenon.
This study represents the first systematic update to the distribution of macro-invertebrates
associated with Anopheles mosquito oviposition sites in Trincomalee District. Knowledge
generated on the ecology of Anopheles mosquitoes will help to eliminate malaria vectors in
the country.
