Wild silk production provides an ecologically compatible alternative to forest destruction
and invests the rural communities in conserving their natural heritage. This study permitted
acquisition of data on various biological aspects to allow local communities to harvest the silk of
the Malagasy endemic saturniid silkworm Antherina suraka (Boisduval, 1833) as a source of
ecologically sustainable income. The current study provided information to local farmers about the
available host plants optimal for rearing the local silkworm and therefore worth conserving.
Documentation and field surveys were undertaken from 2008 to 2011 in different regions
of Madagascar. Food plant species from 23 families were recorded. The discovery of ten newly
recorded host plant species endemic to Madagascar showed that, although A. suraka has adapted
to feed on non-native species, it remains reliant on native forests. Host availability in different
study sites was documented. Despite the efforts undertaken during this study, fewer records of
host plants were found in the dry areas, in contrast with other regions of Madagascar. Further
studies of A.suraka in these special ecosystems along the year were then suggested.
About A.suraka itself, three forms currently recognized as the subspecies suraka,
australis and comorana differ in geographical distribution, body size and color. The taxonomic
status of these subspecies was assessed. Records from museums and field investigation (2007-
2012) showed that A. suraka is widely distributed in all bioclimatic zones of Madagascar and the
Comoros archipelago. The Folmer region of mitochondrial cytochrome oxidase I was used to test
for differences among geographic samples. Three clades comprising the three subspecies were
supported. As only 43 specimens in limited regions were analyzed, further studies are needed to
understand geographic variation in A. suraka. Results of Mantel and partial Mantel tests on ten
iii
samples with known host plants showed correlations between genetic and geographical distance.
Isolation by distance could explain the observed phylogenetic structure.
Structural and mechanical properties of the cocoon of A.suraka were also assessed. Using
environmental scanning electron microscopy, I found that the cocoon was characterized by
multiple threads with crossover points. Use of a tensile strength testing instrument revealed that
Wild silk production provides an ecologically compatible alternative to forest destructionand invests the rural communities in conserving their natural heritage. This study permittedacquisition of data on various biological aspects to allow local communities to harvest the silk ofthe Malagasy endemic saturniid silkworm Antherina suraka (Boisduval, 1833) as a source ofecologically sustainable income. The current study provided information to local farmers about theavailable host plants optimal for rearing the local silkworm and therefore worth conserving.Documentation and field surveys were undertaken from 2008 to 2011 in different regionsof Madagascar. Food plant species from 23 families were recorded. The discovery of ten newlyrecorded host plant species endemic to Madagascar showed that, although A. suraka has adaptedto feed on non-native species, it remains reliant on native forests. Host availability in differentstudy sites was documented. Despite the efforts undertaken during this study, fewer records ofhost plants were found in the dry areas, in contrast with other regions of Madagascar. Furtherstudies of A.suraka in these special ecosystems along the year were then suggested.About A.suraka itself, three forms currently recognized as the subspecies suraka,australis and comorana differ in geographical distribution, body size and color. The taxonomicstatus of these subspecies was assessed. Records from museums and field investigation (2007-2012) showed that A. suraka is widely distributed in all bioclimatic zones of Madagascar and the
Comoros archipelago. The Folmer region of mitochondrial cytochrome oxidase I was used to test
for differences among geographic samples. Three clades comprising the three subspecies were
supported. As only 43 specimens in limited regions were analyzed, further studies are needed to
understand geographic variation in A. suraka. Results of Mantel and partial Mantel tests on ten
iii
samples with known host plants showed correlations between genetic and geographical distance.
Isolation by distance could explain the observed phylogenetic structure.
Structural and mechanical properties of the cocoon of A.suraka were also assessed. Using
environmental scanning electron microscopy, I found that the cocoon was characterized by
multiple threads with crossover points. Use of a tensile strength testing instrument revealed that
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