5 research outputs found
Rapid survey of Dragonflies (Insecta: Odonata) of Kribi forest and Campo Ma'am national Park, Southern Cameroon
A five day survey was carried out to assess the odonate fauna associated with the riverine sections of two forests (Kribi Forest and Campo Maâam National Park) of southern Cameroon. The primary objective of the study was to determine the species composition and community structure of the odonate fauna occurring in the forests. The goal is to infer the health status of the two forests. Three study sites were selected, one in each of the main water bodies in the forests (Rivers Kienke and Linde in Kribi forest, and River Bitande in Campo Maâam National Park). All the specimens collected were identified to the lowest taxonomic level. A total of one hundred and ninety four (194) individuals of Odonata were collected in the forests comprising 10 families, 24 species of Anisoptera and 30 species of Zygoptera. Anthropogenic activities were less prevalent at Campo Maâam National Park, an area in which all the 10 families were incidentally recorded.The community structure of the southern forest revealed that only River Bitande with Shannon-Wiener diversity index (H`) of 3.80 was having a stable environmental condition. Others were close to stable condition (River Kienke H` 2.99 and River Linde H` 2.95) with mild disturbance caused by human activity. Simpson index range (0.94 â 0.98) at the three study sites revealed that the vegetation was matured and stable. The distribution of dragonflies and damselflies revealed a stable environment (Evenness 0.90 â 0.95). Kribi Forest appears to be more impacted by anthropogenic activities as fewer (six) families were recorded there. The relative distribution of the species in the two forest ecosystems seemed to have some relationship with human interference therein. Key Words: Damselfly, Dragonfly, Diversity, Forest, Rive
Challenges associated with the honey bee (Apis Mellifera Adansonii) colonies establishment in South Western Nigeria
The southwestern part of Nigeria is a tropical rainforest region having many local beekeepers. These beekeepers have experienced decline in colony establishment in the recent past. A study carried out in Lagos, Ogun and Osun states between December 2009 and September 2011 examined 14 randomly selected commercial bee farms for problems associated with decline in colony establishment. Sampling and treatments were split equally between each apiary and three colonies were selected in each. All the colonies were housed in Tanzania/local top bar hives. There were 58.34, 44.84 and 40.61 average percentage declines in colony establishment in Lagos, Ogun and Osun States, respectively. Presence of pests and diseases, pesticide poisoning, poor hive and seasonal management, ecological problem and lack of queen rearing were potential problems identified by the beekeepers. All the apiaries had pests like Crickets, Ants (Companotus pennsylvanicus), Small Hive beetle (Aethina tumida), Termites (Macrotermes spp) and Spider (Lactrodectus mactan). Varroa mite infestations were found in 33 (78.57%) of apiaries sampled. There was no significant difference between the levels of Varroa infestation in all the colonies during the dry and wet seasons at confidence interval of 95 percent (t = 1.542, df = 13, p = 0.147 (p> 0.05). Nosema spores were found in 27 (64.29%) colonies examined. The number of spores range from 16 x 103 to 30.4 x 103. There were no significant differences in the infection from colony to colony, apiary to apiary and between dry and wet seasons (t = - 0.094 df = 11, P = 0.927 (P > 0.05). Diseases like American and European foulbrood were absent while chalkbrood disease was prevalent. Environmental factors of high temperature, high rainfall and high relative and hive humidity enhanced the spread of pests and disease pathogens. Many insecticides were constantly applied by the farmers on the crops in the surrounding farmland. Two of the commonly used insecticides DDVP (Dichlorvos) and Cyperforce (Cypermetrin) were discovered to have increased mortality on worker honey bees with progressively larger doses. It was obvious that insecticide toxicity had a significant effect on the colony. Hence, ecological and management problems had contributed to the decline in colony establishment in this area.Keywords: colony, decline, varroasis, infestation, toxicityAfrican Journal of Food, Agriculture, Nutrition and Development, Volume 13 No. 2 April 201
Longitudinal river zonation in the tropics: examples of fish and caddisflies from endorheic Awash river, Ethiopia
Primary Research PaperSpecific concepts of fluvial ecology are
well studied in riverine ecosystems of the temperate
zone but poorly investigated in the Afrotropical
region. Hence, we examined the longitudinal zonation
of fish and adult caddisfly (Trichoptera) assemblages
in the endorheic Awash River (1,250 km in length),
Ethiopia. We expected that species assemblages are
structured along environmental gradients, reflecting
the pattern of large-scale freshwater ecoregions. We
applied multivariate statistical methods to test for differences in spatial species assemblage structure and
identified characteristic taxa of the observed biocoenoses
by indicator species analyses. Fish and
caddisfly assemblages were clustered into highland
and lowland communities, following the freshwater
ecoregions, but separated by an ecotone with highest
biodiversity. Moreover, the caddisfly results suggest
separating the heterogeneous highlands into a forested
and a deforested zone. Surprisingly, the Awash
drainage is rather species-poor: only 11 fish (1
endemic, 2 introduced) and 28 caddisfly species (8
new records for Ethiopia) were recorded from the
mainstem and its major tributaries. Nevertheless,
specialized species characterize the highland forests, whereas the lowlands primarily host geographically
widely distributed species. This study showed that a
combined approach of fish and caddisflies is a
suitable method for assessing regional characteristics
of fluvial ecosystems in the tropicsinfo:eu-repo/semantics/publishedVersio
Challenges Associated With The Honey Bee (Apis Mellifera Adansonii) Colonies Establishment In South Western Nigeria
The southwestern part of Nigeria is a tropical rainforest region having
many local beekeepers. These beekeepers have experienced decline in
colony establishment in the recent past. A study carried out in Lagos,
Ogun and Osun states between December 2009 and September 2011 examined
14 randomly selected commercial bee farms for problems associated with
decline in colony establishment. Sampling and treatments were split
equally between each apiary and three colonies were selected in each.
All the colonies were housed in Tanzania/local top bar hives. There
were 58.34, 44.84 and 40.61 average percentage declines in colony
establishment in Lagos, Ogun and Osun States, respectively. Presence of
pests and diseases, pesticide poisoning, poor hive and seasonal
management, ecological problem and lack of queen rearing were potential
problems identified by the beekeepers. All the apiaries had pests like
Crickets, Ants (Companotus pennsylvanicus), Small Hive beetle (Aethina
tumida), Termites (Macrotermes spp) and Spider (Lactrodectus mactan).
Varroa mite infestations were found in 33 (78.57%) of apiaries
sampled. There was no significant difference between the levels of
Varroa infestation in all the colonies during the dry and wet seasons
at confidence interval of 95 percent (t = 1.542, df = 13, p = 0.147
(p> 0.05). Nosema spores were found in 27 (64.29%) colonies
examined. The number of spores range from 16 x 103 to 30.4 x 103. There
were no significant differences in the infection from colony to colony,
apiary to apiary and between dry and wet seasons (t = - 0.094 df = 11,
P = 0.927 (P > 0.05). Diseases like American and European foulbrood
were absent while chalkbrood disease was prevalent. Environmental
factors of high temperature, high rainfall and high relative and hive
humidity enhanced the spread of pests and disease pathogens. Many
insecticides were constantly applied by the farmers on the crops in the
surrounding farmland. Two of the commonly used insecticides DDVP
(Dichlorvos) and Cyperforce (Cypermetrin) were discovered to have
increased mortality on worker honey bees with progressively larger
doses. It was obvious that insecticide toxicity had a significant
effect on the colony. Hence, ecological and management problems had
contributed to the decline in colony establishment in this area