Trithemis furva

Trithemis furva, the Navy dropwing, is a species of dragonfly in the family Libellulidae. It is found in Angola, Cameroon, Chad, Ivory Coast, Equatorial Guinea, Ethiopia, Guinea, Kenya, Liberia, Madagascar, Malawi, Mozambique, Namibia, Nigeria, Sierra Leone, Somalia, South Africa, Sudan, Tanzania, Uganda, Zambia, Zimbabwe, and possibly Burundi. Its natural habitats are subtropical or tropical moist lowland forests, dry savanna, moist savanna, subtropical or tropical dry shrubland, subtropical or tropical moist shrubland, rivers, freshwater marshes, and intermittent freshwater marshes.

Trithemis furva
male, Kakamega Forest, Kenya
Female

Least Concern  (IUCN 3.1)[1]
Scientific classification
Kingdom:
Animalia
Phylum:
Arthropoda
Class:
Insecta
Order:
Odonata
Family:
Libellulidae
Genus:
Trithemis
Species:
T. furva
Binomial name
Trithemis furva
Karsch, 1899

Identification

In much of its range, mature males of T. furva are easily confused with those of the similar T. dorsalis. The key difference between the species is the shape of the hamule of the secondary genitalia. Also, in most specimens of T. furva, the outermost antenodal cross-veins do not cross the subcostal vein to join the radial vein, whereas in T. dorsalis they do.[2]

  • Mature male showing the secondary genitalia and the position of the outermost antenodal cross-vein (Ax)
  • Mature male
  • Immature male
  • Immature male
  • mature female
gollark: Basically, if I want to run a search it just goes `SELECT * FROM page_tokens WHERE token = 'one token in search query'` or something like that, and it now has a list of pages with the right token, and SQLite can execute this query relatively fast.
gollark: I mean, as far as I can tell there isn't really a faster *and* more storage-efficient way to do search than the inverted-index page_tokens thing.
gollark: ```sqlCREATE TABLE crawl_queue ( id INTEGER PRIMARY KEY, url TEXT NOT NULL UNIQUE, lockTime INTEGER, added INTEGER NOT NULL, referrer TEXT);CREATE TABLE pages ( id INTEGER PRIMARY KEY, url TEXT NOT NULL UNIQUE, rawContent BLOB NOT NULL, rawFormat TEXT NOT NULL, textContent TEXT NOT NULL, updated INTEGER NOT NULL);CREATE TABLE page_tokens ( id INTEGER PRIMARY KEY, page INTEGER NOT NULL REFERENCES pages(id), token TEXT NOT NULL, weight REAL NOT NULL);CREATE TABLE links ( id INTEGER PRIMARY KEY, toURL TEXT NOT NULL, fromURL TEXT NOT NULL, lastSeen INTEGER NOT NULL, UNIQUE (toURL, fromURL))```Here is the database.
gollark: To be fair, the text content field isn't that necessary, as for search it uses the page_tokens table anyway and it can be rebuilt from the HTML if I need it.
gollark: The frequency of every word *must* be stored for quick (O(log n) time or something) search, the raw HTML or at least might be needed if I come up with a better way to weight frequency or something, the links are useful for (future) better search ranking algorithms.

References
  1. Suhling, F. (2015). "Trithemis furva". IUCN Red List of Threatened Species. 2015. Retrieved 24 October 2017.CS1 maint: ref=harv (link)
  2. Samways, Michael J. (2008). Dragonflies and damselflies of South Africa (1st ed.). Sofia: Pensoft. ISBN 978-954-642-330-6.


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