Browsing by Author "Sewlal, Jo-Anne N"

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    Addendum - Four more Trinidadian Spider (Araneida) families
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2007) Sewlal, Jo-Anne N; Alayón, Giraldo
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    Annotated List of Spider Families (Araneida) of Trinidad and Tobago
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2003) Sewlal, Jo-Anne N; Cutler, Bruce
    The spider families of the neotropical islands of Trinidad and Tobago are reviewed. Forty one families are definitely recorded, while an additional 12 families are considered as likely, based on their presence in the nearby South American mainland. Biological and recognition characters are noted for most of the families.
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    Checklist of Orb-Weaving Spiders of Trinidad and Tobago Belonging to the Families Araneidae, Nephilidae and Tetragnathidae.
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2010) Sewlal, Jo-Anne N
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    Karyotype and male reproductive system in Arachnocoris trinitatus Bergroth. First data on the tribe Arachnocorini (Heteroptera: Nabidae: Nabinae). Folia Biologica (Kraków)
    (Folia biologica (Kraków), 2007) Kuznetsova, Valentina G.; Grozeva, Snejana; Sewlal, Jo-Anne N; Nokkala, Seppo
    As an extension of the ongoing cytogenetic studies of the bug family Nabidae (Heteroptera:Cimicomorpha), the first evidence for the tribe Arachnocorini (the subfamily Nabinae), with reference to the Trinidad endemic, Arachnocoris trinitatus Bergroth, is provided. This is an attempt to gain a better insight into the evolution, systematics and within-family relationships of the family Nabidae. The studies were conducted using a number of cytogenetic techniques. The male karyotype (chromosome number and size; sex chromosome system; NOR location; C-heterochromatin amount, distribution and characterization in terms of the presence of AT-rich and GC-rich DNA), and male meiosis with particular emphasis on the behavior of the sex chromosomes in metaphase II are described. Also investigated are the male and female internal reproductive organs with special reference to the number of follicles in a testis and the number of ovarioles in an ovary. A. trinitatus was found to display a number of characters differentiating it from all hitherto studied nabid species placed in the tribe Nabini of the subfamily Nabinae, and in the tribe Prostemmatini of the subfamily Prostemmatinae. Among these characters are chromosome number 2n = 12 (10 + XY), the lowest within the family, nucleolus organizer regions (NORs)situated on the autosomes rather than on the sex chromosomes as is the case in other nabid species, and testes composed of 3 follicles but not of 7 as in other nabids. All the data obtained suggest many transformations during the evolution of A. trinitatus.
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    New Record of Pholcid genera for Lesser Antilles, West Indies.
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2008) Sewlal, Jo-Anne N; Starr, Christopher K
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    An observation of nest relocation in the ant Cephalotes atratus
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2004) Starr, Christopher K; Sewlal, Jo-Anne N
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    An observation of nest relocation in the ant Cephalotes atratus.
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2004) Starr, Christopher K; Sewlal, Jo-Anne N
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    Observations of nest and colony structure of the neotropical ant Dolichoderus attelaboides (Formicidae: Dolichoderinae)
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2004) Sewlal, Jo-Anne N; Starr, Christopher K
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    Observations of nest and colony structure of the neotropical ant Dolichoderus attelaboides (Formicidae: Dolichoderinae)
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2004) Sewlal, Jo-Anne N; Starr, Christopher K
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    Observations of the insect Arachnocoris trinitatus (Heteroptera: Nabidae) as an inquiline in the webs of the spider Mesabolivar aurantiacus (Araneae: Pholcidae)
    (Caribbean Journal of Science, 2008) Sewlal, Jo-Anne N; Starr, Christopher K
    —The pholcid spider Mesabolivar aurantiacus (Mello-Leitão 1930) is common in forests of Trinidad, West Indies. Its webs are often found to contain the nabid bug Arachnocoris trinitatis (Bergroth 1916). In a lowland forest in August-September 2003 (wet season) we censused 81 M. aurantiacus webs for occupancy by the spider and the insect. A. trinitatis showed no significant preference for webs occupied by either juvenile or adult spiders. However, it showed a preference for empty webs, suggesting that it utilizes these as a ready-made preycapture device, and possibly as a site for finding mates.
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    Observations of the insect Arachnocoris trinitatus (Heteroptera: Nabidae) as an inquiline of the spider Coryssocnemis simla (Araneae: Pholcidae) in West Indies.
    (Zoosystematica Rossica., 2009) Sewlal, Jo-Anne N; Starr, Christopher K
    The nabid bug Arachnocoris trinitatus (Bergroth, 1916) is often found in webs of the pholcid spider Coryssocnemis simla Huber, 2000. Thirty-one webs of C. simla were checked for occupancy by the spider and the insect in April 2008 in a deciduous seasonal forest in Trinidad, West Indies. Arachnocoris trinitatus showed no significant preference either for webs occupied by juvenile versus adult spiders, or for empty webs versus those occupied by C. simla.
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    Preliminary Survey for Spiders on Antigua, West Indies.
    (The College of The Bahamas Research Journal, 2009) Sewlal, Jo-Anne N
    Spiders have a worldwide distribution that comprises all land environments except at the polar extremes. There are now 40,700 named, described species of spiders (Platnick, 2009), thought to represent about one-fifth of the true total. On a faunistic level, the spiders of some regions are reasonably well known, but this is far from the case in the New World tropics, including the West Indies. At present, we have species-level surveys for Cuba (Alayón, 1995), Barbados (Bryant, 1923; Alayón and Horrocks, 2004), St. Vincent and the Grenadines (Simon, 1894; de Silva, Horrocks and Alayón, 2006), Anguilla (Sewlal and Starr, 2006), Nevis (Sewlal and Starr, 2007), St. Kitts (Sewlal, 2008) and Grenada (Sewlal, 2009a), and a familylevel list for Trinidad (Cutler, 2005, Sewlal and Cutler, 2003, Sewlal and Alayón, 2007, Sewlal, 2009b). Additional information on the family Pholcidae of some of the Lesser Antilles is provided by Sewlal and Starr (2008). The present short communication serves to expand on Bryant’s (1923) list of 23 species from Antigua and to treat the species distribution on the island with respect to habitats. This survey adds 18 species and 11 families to the list compiled by Bryant (1923).
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    A Preliminary Survey for Spiders on Grenada, West Indies
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2009) Sewlal, Jo-Anne N
    During a two-week period in 2008, a wide variety of habitats on the island of Grenada, West Indies were surveyed for the presence of spiders. Contrary to the results of previous surveys in the Eastern Caribbean, Grenada exhibited a higher species richness in natural habitats. Members of the families Araneidae and Tetragnathidae comprised of almost half the species found. Some 12 localities were surveyed from 11 habitats, including six man-made habitats. Ten families representing 22 species were collected.
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    A Preliminary Survey for Spiders on Montserrat, West Indies.
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2010) Sewlal, Jo-Anne N
    During a two-week period in September 2009, a wide variety of habitats on the island of Montserrat, West Indies, were surveyed for the presence of spiders. When compared to the results of previous surveys in the Eastern Caribbean islands, natural habitats in Montserrat at a high altitude showed a higher species richness than those at a lower altitude. Also, like a previous survey in Grenada, Montserrat produced a higher species in natural habitats compared to those that were man-made or influenced by human activity. Members of the families Araneidae and Salticidae comprised almost half of the species found. Twenty-one localities were surveyed from 13 habitats, including five man-made habitats. Seventeen families representing 43 species were collected.
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    Preliminary Survey for Spiders on Nevis, West Indies
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2007) Sewlal, Jo-Anne N; Starr, Christopher K
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    Preliminary Survey for Spiders on St. Kitts, West Indies with Comparative Notes on Nevis.
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2008) Sewlal, Jo-Anne N
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    Presence of the Spider Family Titanoecidae in Trinidad and Tobago.
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2010) Sewlal, Jo-Anne N
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    Two Additional Spider (Arachnida:Araneida) Families for Trinidad and Tobago
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2009) Sewlal, Jo-Anne N
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    Web height as a niche separator in two orb-weaving spiders.
    (Living World, J. Trinidad and Tobago Field Naturalists’ Club, 2006) Starr, Christopher K; Sewlal, Jo-Anne N