Thomisus is a genus of crab spiders (family Thomisidae) with around 140 described species. The genus includes species that vary widely in their ecology, with some that are ambush predators that feed on insects visiting flowers. Like several other genera in the family Thomisidae, they are sometimes referred to as flower crab spiders, from their crab-like motion and their way of holding their front legs, reminiscent of a crab spreading its claws as a threat.
Description and behavior
As with most Thomisidae species, Thomisus exhibit sexual size dimorphism: females are in length, whereas males are only . Many species are brightly colored, usually matching the color of the flower in which they are waiting in ambush. Not all species are flower-dwelling, but among those that are, at least some species can change their colour over a period of some days to match the flower colour. Studies suggest that bees are inclined to avoid a flower that contains a spider-sized object of a non-matching colour; whether this is specifically a mechanism for avoiding crab spiders, or simply that they are not attracted to flowers whose nectar guides are obscured however, is a more difficult question. The colour changes that such species can achieve are typically in ranges of white, pink, and yellow.
For example, in Thomisus spectabilis, the method of camouflage is similar to the Misumena vatia, though T. spectabilis are visible to their prey, but not their predators. This species of crab spiders is UV reflective while the flower is UV absorbing creating a contrast between the spider and flower through the eyes of the pollinator. The contrast created greatly attracts pollinators such as honeybees. This evolutionary method of camouflage increased the likelihood the crab spiders encountered prey, which in turn effects the fitness of the crab spiders. Due to the increased encounter rate of prey the spiders are able to focus energy on reproduction therefore leading to increased fitness in the spiders. The evolutionary method of camouflage greatly increases the survivability and fitness of crab spiders.
Distribution The distribution of Thomisus species is almost worldwide, with the notable exception of most of South America. Although Thomisus species can be found almost anywhere on earth, most species occur in the tropics and the warmer regions of the Old World, with fewer species in the region from New Guinea to Australia and the New World. Only Thomisus guadahyrensis is known from South America (in Peru).
Species , this genus includes 137 species and five subspecies.
Species with articles on Wikipedia:
Thomisus australis Comellini, 1957 – DR Congo, Burundi, Tanzania, Malawi, Mozambique, South Africa, Lesotho Thomisus blandus Karsch, 1880 – Sub-Saharan Africa, Yemen Thomisus callidus (Thorell, 1890) – Sri Lanka, Singapore, Indonesia (Sumatra, Nias Is., Java) Thomisus citrinellus Simon, 1875 – Mediterranean, Africa, Seychelles, Yemen (mainland, Socotra), Iraq, Iran? Thomisus congoensis Comellini, 1957 – Cape Verde, DR Congo, Angola, South Africa, Eswatini Thomisus dalmasi Lessert, 1919 – Guinea, Cameroon, DR Congo, Rwanda, Tanzania, Malawi, Mozambique, South Africa Thomisus daradioides Simon, 1890 – Africa to India Thomisus ghesquierei Lessert, 1943 – DR Congo, South Africa Thomisus granulatus Karsch, 1880 – Zambia, Malawi, Namibia, Botswana, South Africa, Eswatini Thomisus granulifrons Simon, 1906 – India, Sri Lanka Thomisus guadahyrensis Keyserling, 1880 – Peru Thomisus kalaharinus Lawrence, 1936 – Sub-Saharan Africa, Yemen Thomisus kitamurai Nakatsudi, 1943 – Japan (Ryukyu Is.) Thomisus labefactus Karsch, 1881 – Korea, Japan, China, Taiwan, Thailand Thomisus machadoi Comellini, 1959 – Cape Verde, Angola, South Africa Thomisus marginifrons Schenkel, 1963 – China Thomisus natalensis Lawrence, 1942 – Zimbabwe, South Africa Thomisus nepenthiphilus Fage, 1930 – Indonesia (Sumatra) Thomisus okinawensis Strand, 1907 – Thailand to Japan (Ryukyu Is.), Philippines, Indonesia Thomisus onustus Walckenaer, 1805 – Savage Islands, Europe, North Africa, Turkey, Caucasus, Russia (Europe to South Siberia), Israel, Jordan, Iran, Kazakhstan, Central Asia, China, Korea, Japan (type species) Thomisus schultzei Simon, 1910 – Namibia, Botswana, South Africa Thomisus scrupeus (Simon, 1886) – Sub-Saharan Africa Thomisus socotrensis Dippenaar-Schoeman & van Harten, 2007 – Yemen (Socotra) Thomisus spectabilis Doleschall, 1859 – India to Australia Thomisus spiculosus Pocock, 1901 – Nigeria, DR Congo, Tanzania, Zimbabwe, Mozambique, South Africa Thomisus stenningi Pocock, 1900 – Africa, Seychelles, Yemen Thomisus zuluanus Lawrence, 1942 – South Africa
Thomisus albens O. Pickard-Cambridge, 1885 – Pakistan, China, (Yarkand) Thomisus albertianus Strand, 1913 – Gabon, DR Congo, Uganda, Angola T. a. guineensis Millot, 1942 – Guinea, Angola T. a. maculatus Comellini, 1959 – Cameroon, DR Congo T. a. verrucosus Comellini, 1957 – DR Congo Thomisus albohirtus Simon, 1884 – Sudan, Ethiopia, Somalia, Yemen, Iran? Thomisus amadelphus Simon, 1909 – Vietnam Thomisus andamanensis Tikader, 1980 – India (mainland, Andaman Is.) Thomisus angulatulus Roewer, 1951 – Gabon Thomisus angustifrons Lucas, 1858 – Gabon Thomisus arabicus Simon, 1882 – Yemen Thomisus armillatus (Thorell, 1891) – India (Nicobar Is.) Thomisus aruni Biswas & Raychaudhuri, 2023 – Bangladesh Thomisus ashishi Gajbe, 2005 – India Thomisus australis Comellini, 1957 – DR Congo, Burundi, Tanzania, Malawi, Mozambique, South Africa, Lesotho Thomisus baghdeoi Gajbe, 2004 – India Thomisus bargi Gajbe, 2004 – India Thomisus benoiti Comellini, 1959 – DR Congo Thomisus bhagabatii Biswas & Raychaudhuri, 2024 – Bangladesh Thomisus bicolor Walckenaer, 1837 – United States Thomisus bidentatus Kulczyński, 1901 – West Africa, Saudi Arabia, Yemen Thomisus bigibbosus Keyserling, 1881 – United States Thomisus blandus Karsch, 1880 – Sub-Saharan Africa, Yemen Thomisus boesenbergi Lenz, 1891 – Madagascar Thomisus bonnieri Simon, 1902 – Oman Thomisus bueanus Strand, 1916 – Cameroon Thomisus bulani Tikader, 1960 – India Thomisus callidus (Thorell, 1890) – Sri Lanka, Singapore, Indonesia (Sumatra, Nias Is., Java) Thomisus candidus Blackwall, 1866 – south-east equatorial Africa Thomisus castaneiceps Simon, 1909 – Vietnam Thomisus cavaleriei Schenkel, 1963 – China Thomisus citrinellus Simon, 1875 – Mediterranean, Africa, Seychelles, Yemen (mainland, Socotra), Iraq, Iran? Thomisus congoensis Comellini, 1957 – Cape Verde, DR Congo, Angola, South Africa, Eswatini Thomisus dalmasi Lessert, 1919 – Guinea, Cameroon, DR Congo, Rwanda, Tanzania, Malawi, Mozambique, South Africa Thomisus danieli Gajbe, 2004 – India Thomisus daradioides Simon, 1890 – Africa, India T. d. nigroannulatus Caporiacco, 1947 – Tanzania Thomisus dartevellei Comellini, 1957 – DR Congo, Ethiopia, Malawi Thomisus dentiger (Thorell, 1887) – Myanmar Thomisus destefanii Caporiacco, 1941 – Ethiopia Thomisus dhakuriensis Tikader, 1960 – India Thomisus dhananjayi Gajbe, 2005 – India Thomisus duriusculus (Thorell, 1877) – Indonesia (Sulawesi) Thomisus dyali Kumari & Mittal, 1997 – India Thomisus elongatus Stoliczka, 1869 – India Thomisus eminulus Tang & Li, 2010 – China Thomisus galeatus Simon, 1909 – Vietnam Thomisus ghesquierei Lessert, 1943 – DR Congo, South Africa Thomisus godavariae Reddy & Patel, 1992 – India Thomisus gouluensis Peng, Yin & Kim, 2000 – China Thomisus granulatus Karsch, 1880 – Zambia, Malawi, Namibia, Botswana, South Africa, Eswatini Thomisus granulifrons Simon, 1906 – India, Sri Lanka Thomisus guadahyrensis Keyserling, 1880 – Peru Thomisus guangxicus Song & Zhu, 1995 – China Thomisus hararinus Caporiacco, 1947 – Ethiopia Thomisus hui Song & Zhu, 1995 – China Thomisus hunanensis Peng, Yin & Kim, 2000 – China Thomisus ilocanus Barrion & Litsinger, 1995 – Philippines Thomisus iswadus Barrion & Litsinger, 1995 – Philippines Thomisus italongus Barrion & Litsinger, 1995 – Philippines Thomisus janinae Comellini, 1957 – DR Congo, Tanzania Thomisus jocquei Dippenaar-Schoeman, 1988 – Malawi Thomisus kalaharinus Lawrence, 1936 – Sub-Saharan Africa, Yemen Thomisus katrajghatus Tikader, 1963 – India Thomisus keralae Biswas & Roy, 2005 – India Thomisus kitamurai Nakatsudi, 1943 – Japan (Ryukyu Is.) Thomisus kiwuensis Strand, 1913 – Central Africa Thomisus kokiwadai Gajbe, 2004 – India Thomisus krishnae Reddy & Patel, 1992 – India Thomisus labefactus Karsch, 1881 – Korea, Japan, China, Taiwan, Thailand Thomisus laglaizei Simon, 1877 – Myanmar, Philippines, Indonesia (Java, Sumatra) Thomisus lamperti Strand, 1907 – Madagascar Thomisus leucaspis Simon, 1906 – India, New Caledonia Thomisus litoris Strand, 1913 – DR Congo and/or Uganda Thomisus lobosus Tikader, 1965 – India Thomisus ludhianaensis Kumari & Mittal, 1997 – India Thomisus machadoi Comellini, 1959 – Cape Verde, Angola, South Africa Thomisus madagascariensis Comellini, 1957 – Madagascar T. m. pallidus Comellini, 1957 – Madagascar Thomisus magaspangus Barrion, Barrion-Dupo & Heong, 2013 – China (Hainan) Thomisus manishae Gajbe, 2005 – India Thomisus manjuae Gajbe, 2005 – India Thomisus marginifrons Schenkel, 1963 – China Thomisus meenae Gajbe, 2005 – India Thomisus melanostethus Simon, 1909 – Vietnam Thomisus mimae Sen & Basu, 1963 – India Thomisus modestus Blackwall, 1870 – Italy Thomisus natalensis Lawrence, 1942 – Zimbabwe, South Africa Thomisus nepenthiphilus Fage, 1930 – Indonesia (Sumatra) Thomisus nirmali Saha & Raychaudhuri, 2007 – India Thomisus obscuratus Caporiacco, 1947 – Eritrea Thomisus obtusesetulosus Roewer, 1961 – Senegal Thomisus ochraceus Walckenaer, 1841 – Algeria Thomisus odiosus O. Pickard-Cambridge, 1898 – Mexico Thomisus okinawensis Strand, 1907 – Thailand, Japan (Ryukyu Is.), Philippines, Indonesia Thomisus onustus Walckenaer, 1805 – Savage Islands, Europe, North Africa, Turkey, Caucasus, Russia (Europe to South Siberia), Israel, Jordan, Iran, Kazakhstan, Central Asia, China, Korea, Japan (type species) Thomisus oscitans Walckenaer, 1837 – United States Thomisus pateli Gajbe, 2004 – India Thomisus pathaki Gajbe, 2004 – India Thomisus penicillatus Simon, 1909 – Vietnam Thomisus perspicillatus (Thorell, 1890) – Borneo (not specified) Thomisus pooneus Tikader, 1965 – India Thomisus pritiae Gajbe, 2005 – India Thomisus projectus Tikader, 1960 – India Thomisus pugilis Stoliczka, 1869 – Pakistan, India Thomisus rajani Bhandari & Gajbe, 2001 – India Thomisus retirugus Simon, 1909 – Vietnam Thomisus rigoratus Simon, 1906 – India Thomisus rishus Tikader, 1970 – India Thomisus roeweri Comellini, 1957 – Tanzania Thomisus schoutedeni Comellini, 1957 – DR Congo Thomisus schultzei Simon, 1910 – Namibia, Botswana, South Africa Thomisus scrupeus (Simon, 1886) – Sub-Saharan Africa Thomisus shillongensis Sen, 1963 – India Thomisus shivajiensis Tikader, 1965 – India Thomisus sikkimensis Tikader, 1962 – India Thomisus simoni Gajbe, 2004 – India Thomisus socotrensis Dippenaar-Schoeman & van Harten, 2007 – Yemen (Socotra) Thomisus spectabilis Doleschall, 1859 – India, Australia Thomisus spiculosus Pocock, 1901 – Nigeria, DR Congo, Tanzania, Zimbabwe, Mozambique, South Africa Thomisus stenningi Pocock, 1900 – Africa, Seychelles, Yemen Thomisus stigmatisatus Walckenaer, 1837 – United States Thomisus stoliczkai (Thorell, 1887) – Myanmar Thomisus sundari Gajbe & Gajbe, 2001 – India Thomisus swatowensis Strand, 1907 – China Thomisus telanganaensis Pravalikha & Srinivasulu, 2015 – India Thomisus tetricus Simon, 1890 – Yemen Thomisus transversus Fox, 1937 – China Thomisus tripunctatus Lucas, 1858 – West Africa Thomisus tuberculatus Dyal, 1935 – Pakistan Thomisus unidentatus Dippenaar-Schoeman & van Harten, 2007 – Yemen, Iraq, Iran, Pakistan, India Thomisus venulatus Walckenaer, 1841 – Algeria