scholarly journals THE RELATIONSHIP BETWEEN DIET AND LARVAL DEVELOPMENT OF PALAEMONETES ,

1957 ◽  
Vol 112 (2) ◽  
pp. 162-170 ◽  
Author(s):  
A. C. BROAD
Parasitology ◽  
1995 ◽  
Vol 110 (4) ◽  
pp. 409-427 ◽  
Author(s):  
M. G. Basáñez ◽  
J. H. F. Remme ◽  
E. S. Alley ◽  
O. Bain ◽  
A. J. Shelley ◽  
...  

SUMMARYA previous paper reported that the intake of Onchocerca volvulus microfilariae (mff) by different species of Simulium is essentially proportional to the parasite load in the skin of infected carriers. This paper examines the fate of the ingested mff in susceptible vectors to assess the relationship between parasite intake and infective larval output in blackfly species with and without well-developed cibarial armatures. Analysis is based on data from 3 onchocerciasis endemic areas: Guatemala (S. ochraceum s.l.), West Africa (S. damnosum s.l./S. sirbanum) and the Amazonian focus between South Venezuela and Northern Brazil (S. guianense and S. oyapockense s.l.). The data, which include published and unedited information collected in the field, record experimental studies of parasite uptake by wild flies maintained in captivity until the completion of the extrinsic incubation period. The relationship between L3 output (measured as the mean number of successful larvae/fly or, as the proportion of flies with infective larvae) and average microfilarial intake, was strongly non-linear. This non-linearity was best represented by a sigmoid function in case of armed simuliids (S. ochraceum s.l., S. oyapockense s.l.), or by a hyperbolic expression in that of unarmed flies (S. damnosum s.l., S. guianense). These results are compatible, respectively, with the patterns of ‘initial facilitation’ and ‘limitation’ described in culicid vectors of lymphatic filariases. A maximum mean number of 1–3 L3/fly was observed in all 4 vectors. It is concluded that O. volvulus larval development to the infective stage is regulated by density-dependent mechanisms acting at the early phase of microfilarial migration out of the blackfly's bloodmeal. Damage by the bucco-pharyngeal armature may also be density dependent. A hypothesis, based on this density dependence is forwarded to explain initial facilitation, so far only recorded in vectors with well-developed cibarial teeth. Our results provide quantitative support for the conjecture that chemotherapy alone is likely to have a greater impact on reducing onchocerciasis transmission in endemic areas where the main vector has a toothed fore-gut than in foci where the vectors have unarmed cibaria.


1973 ◽  
Vol 105 (3) ◽  
pp. 471-478
Author(s):  
M. K. Mukerji ◽  
J. C. Guppy

AbstractChanges were recorded in dry matter content and in the metabolism of lipids and nitrogen during the postembryonic development of Pseudaletia unipuncta (Haw.) on corn. The study revealed that 22 to 24% of the lipids were used during moulting and pupal–adult transformation and that nitrogen was not lost during such periods. The coefficient of apparent utilization of nitrogen remained more or less constant; however, that of lipids decreased with larval development. No significant difference was evident in the relationship between lipid consumption and weight gain, and nitrogen consumption and weight gain during larval development. A direct linear relationship was obtained between nitrogen and lipid utilization during all instars. In terms of heterauxesis, the accumulation of lipids during larval development was opposed to that of nitrogen.


Zootaxa ◽  
2008 ◽  
Vol 1967 (1) ◽  
pp. 36-52 ◽  
Author(s):  
T. GOTTFRIED PILLAI

A new brackish-water serpulid polychaete species belonging to the genus Ficopomatus from Thailand is described. It had previously been identified as another known species belonging to the same genus. Taxonomic problems within the subfamily Ficopomatinae to which it belongs and the relationship of the genus Marifugia and its single known species which occurs in freshwater are discussed. While the other known genera of the subfamily possess seven thoracic chaetigers, Marifugia has six, but agrees with the former with regard to all other important characters. Likewise, among typically marine taxa, the genus Pomatoleios has six thoracic characters but agrees with the genera Pomatoceros and Spirobranchus with regard to all other important characters. As there are also other known serpulid genera having six thoracic chaetigers, an analysis was undertaken of 10 genera, six of them having six thoracic chaetigers and the remaining four seven. It revealed that Marifugia is the sister to the clade containing the other two genera of the Ficopomatinae (Neopomatus and Ficopomatus) and Pomatoleios is sister to the clade containing Pomatoceros and Spirobranchus. The usefulness of opercular insertion/derivation from a particular branchial radiole as a character in serpulid taxonomy is discussed. As observed in adults and juveniles of species belonging to ficopomatine genera, as well on available evidence on post-larval development, their opercular insertion is in the position of the first branchial radiole, unlike in genera such as Pomatoceros and Hydroides where it is on the second. A key to the known taxa of the subfamily is provided. Although they may be geographically separated by oceanic and/or terrestrial barriers, their common characters, including their ability to survive and propagate in their respective typically non-marine habitats, are indicative of their monophyly.


2015 ◽  
Vol 2 (7) ◽  
pp. 150170 ◽  
Author(s):  
Michael Ben-Yosef ◽  
Zohar Pasternak ◽  
Edouard Jurkevitch ◽  
Boaz Yuval

Ripe fruit offer readily available nutrients for many animals, including fruit fly larvae (Diptera: Tephritidae) and their associated rot-inducing bacteria. Yet, during most of their ontogeny, fruit remain chemically defended and effectively suppress herbivores and pathogens by high levels of secondary metabolites. Olive flies ( Bactrocera oleae ) are uniquely able to develop in unripe olives. Unlike other frugivorous tephritids, the larvae maintain bacteria confined within their midgut caeca. We examined the interaction between larvae, their associated bacteria, and fruit chemical defence, hypothesizing that bacterial contribution to larval development is contingent on the phenology of fruit defensive chemistry. We demonstrate that larvae require their natural complement of bacteria ( Candidatus Erwinia dacicola: Enterobacteriaceae) in order to develop in unripe olives. Conversely, when feeding on ripe fruit, larval development proceeds independently of these bacteria. Our experiments suggest that bacteria counteract the inhibitory effect of oleuropein—the principal phenolic glycoside in unripe olives. In light of these results, we suggest that the unique symbiosis in olive flies, compared with other frugivorous tephritids, is understood by considering the relationship between the fly, bacteria and fruit chemistry. When applied in an evolutionary context, this approach may also point out the forces which shaped symbioses across the Tephritidae.


Sign in / Sign up

Export Citation Format

Share Document