Terrestrial
Permanent URI for this community
Browse
Browsing Terrestrial by Title
Now showing 1 - 20 of 69
Results Per Page
Sort Options
Item Absence of Escherichia coli O157 in a survey of wildlife from Trinidad and Tobago.(2012-08-27) Adesiyun, A.A.Item Abundance and Seasonal Migration of Birds at Port of Spain Sewage Ponds.(2012-08-28) White, G.Item Additional Notes on the Fauna Recorded for the Off-shore Islands North-West of Trinidad.(2012-08-15) Boos, Hans; Quesnel , Victor C.Item Advances of legume physiology and genetics in the Caribbean and their impact on development of selection criteria and screening/breeding strategies.(2012-08-10) Umaharan, P.; McDavid, C.R.Item The agro-ecology of cocoa in Trinidad and Tobago.(2012-08-09) Butler, D.R.; Sukha, D.A.; Maharaj, K.Item Artificial introductions, evolutionary change and population differentiation in Trinidadian guppies ( Poecilia reticulata : Poeciliidae)(2012-08-15) Carvalho, G.R.; Shaw, P.W.; Hauser, L.; Seghers, B.H.; Magurran, A.E.Item An association of mangrove mutation, Scarlet Ibis, and mercury contamination in Trinidad, West Indies.(2012-08-28) Kumarsingh, K; Siung-Chang, A.M; Temple, S.A.; Klekowski, E.J.Item Biochemical monitoring of organophosphorus and carbamate insecticide resistance in Aedes aegypti mosquitoes from Trinidad(2012-08-15) Vaughan, A.; Chadee, D.D.; Ffrench-Constant, R.Item The common frugivores of Trinidad and Tobago(2012-08-10) Laurence, G. A.Item Comparative Abundance of Birds in Trinidad's Northern Range.(2012-08-27) ffrench, Richard; ffrench, MargaretItem The compilation and analysis of a descriptor list for cocoa (Theobroma cacao L.).(2012-06-22) Bekele, Frances LouiseThe usefulness of several cocoa descriptors was assessed in this study. Thirty-five quantitative descriptors were analyzed to determine whether, and to what extent, they differentiate between fifty-three accessions. The latter represent a range of diversity. All the descriptors were discriminative. However, the leaf descriptors were more influenced by environment than the reproductive ones and the fruit descriptors displayed the most variability within the populations studied. There were several correlations between these descriptors. For the purpose of quick identification of accessions, the most discriminative were retained and those correlated with them discarded. The resulting subset of descriptors includes pod weight and length, total bean weight, bean length and width; staminode, petal and sepal lengths, ovule number; total leaf length and leaf apical angle. Information on the diversity of the accessions was important for assessing the usefulness of these descriptors. Seven homogeneous groups of accessions were identified by clustering with sixty-eight mixed variables. The presence of diversity was demonstrated and the accessions could be differentiated according to their geographic origin. No subsets of descriptors provided a classification identical to that of the full complement. However, a subset of thirty-four mixed descriptors furnished a similar classification. It may be appropriate for quick classification in the International Cocoa Genebank, Trinidad. Subsets of descriptors may be useful for differentiating between distinct accessions. However, as large a group of descriptors, as is practicable, is recommended for the reliable determination of the relationships between the accessions.Item Contribution to the Biology of the Vermilion Snapper, Rhomboplites aurorubens, in Trinidad and Tobago, West Indies(2012-08-28) Manickchand-Heileman, Sherry C.; Phillip, Dawn A.T.Item Crane flies (Diptera: Tipulidae) in Trinidad Caves.(2012-08-15) Darlington, J.P.E.C.; Gelhaus, Jon K.Item Distributional ecology of selected plants and animals on Trinidad’s Five Islands archipelago.(2012-08-15) Temple, Stanley A.Item Diversity, abundance and seasonality of birds in a Caribbean pine plantation and native broad-leaved forest at Trinidad, West Indies.(2012-08-15) Hayes, F.E.; Samad, I.Item Doubtful origin in some Bird Species Recorded from Trinidad and Tobago.(2012-08-15) ffrench, RichardItem Ecological observations on the caddisflies (Insecta: Trichoptera) from Trinidad and Tobago (W. Indies)(2012-08-14) Botosaneanu, Lazare; Sakal, DexterItem The ecology of selected aquatic insects in the Maracas River.(2012-06-22) Maharaj, Lorraine DavinaSeasonal fluctuations in the composition and abundance of the macroinvertebrate fauna of the Maracas River were examined between December 1987 and January 1989. Additionally, the life-cycle patterns of the Elmidae (Coleoptera) and Helicopsychidae (Trichoptera) inhabiting the stream were investigated. Eight replicate benthic samples were taken monthly along with measurements of depth, temperature, current velocity and dissolved oxygen. Monthly light trapping for adult aquatic insects was done each month between January 1988 and January 1989. Water chemistry analyses were conducted once during the dry and once during the wet season. Monthly rainfall data for the area were obtained from the Division of Water Resources. Benthic organisms from 15 orders and adults from 8 aquatic insect orders were collected. Abundances of most benthic groups increased to a maximum during the dry season, while peaks in emergence of adult aquatic insects occurred during the late dry/early wet season. The Bray-Curtis similarity terms analysis indicated high levels of similarity between dry and wet season samples and that seasonal differences were more the result of changes in the average abundance of each taxon, rather than changes in species composition. Cluster analysis and MDS ordination demonstrated that these changes in abundance were well correlated with rainfall and current velocity which may have influenced benthic numbers either as a result of increased scouring, or by depletion of food resources during the wet season. Life cycles of three species of Elmidae (Hexacylloepus smithi (Grouvelle), Macrelmis clypeata (Hinton) and Microcylloepus carinatus Hinton) and one helicopsychid (Helicopsyche margaritensis Botosaneanu) were studied. Six instar stages of H. smithi, M crinatus and H. margaritensis and eight stages of M. clypeata were identified. All four species were found to have two periods of first instar recruitment, one major period during the dry season and a second, smaller one during the wet season, suggesting bi-voltine life cycles. In all cases, maximum larval recruitment and abundance occurred during the dry season, possibly related to the increased availability of food material during this period.Item The ecology of the bromeliad-inhabiting mosquitoes of Jamaica and Trinidad.(2012-06-28) Mundle, Marcia S.Item The effect of extracts from Serjania paucidentata (D.C.) on feeding, growth and mortality of the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera : Noctuidae).(2012-06-22) Peterkin, Dorothy DianneGreen plants have developed protective secondary compounds or allelochemicals from evolutionary association with phytophagous animals. These chemicals occur in a range of chemical groups and may be toxins, antifeedants or insect hormone analogues which can be used in novel approaches to insect pest management. The extract from a local plant Serjania paucidentata contains saponins and is toxic to Brine Shrimp (ED50 = 0.32 mg/ml). The properties of S. paucidentata were investigated on the Fall Armyworm, Spodoptera frugiperda. The effect produced by the aqueous methanolic fraction and the crude extract were the same. These had ED50’s of 3.27 mg/ml and 2.355 mg/ml respectively when incorporated into a defined diet. A concentration of 11.43 mg/g diet produced 100% mortality in 10 days. Reduced feeding, decreased growth rates and pupal weights, and increased developmental periods were produced in S. frugiperda at sub-lethal doses. Insects were deterred from feeding on corn leaf squares treated with 1% extract in choice tests. Toxicity and antifeedant properties are dosage dependent. Typical of unpurified plant extracts, S. paucidentata extracts exhibited multiple modes of action as a stomach poison, antifeedant and possible growth retardant. Phytochemicals from local plants are unexplored resources, which must be documented and utilized. There is much scope in this area for further study.