Syn.:
|
Acarinocola Warren, 1941 (= genus dubiuma)
Tylenchinema Goodey, 1930 |
|
Definition: Allantonematinae. Cuticle annulated; lateral fields present. Head slightly offset by being narrower than body. Tails conoid to pointed tips. Female with well-developed, knobless spear; dorsal and subventral glands open close together not far behind the spear base. Nerve ring and excretory pore further back. Vulva posterior; single anterior gonad with ovary in undeveloped state and large uterus often full of sperm. No post-vulval sac. Rectum and anus distinct. Male without spear and details of gland openings not determinable. Spicules and gubernaculum present. Bursa usually present. Testis single, outstretched, producing many sperms. The parasitic female is a mere reproductive sac, considerably enlarged, in which, of the gut, only the spear and anus remain visible.
Type species: Howardula benigna Cobb, 1921
(Description-Goodey, 1963)
Diagnosis
Allantonematinae. Single generation cycle;
male lacking a stylet. Entomoparasitic female: In body cavity or ovary
of insect host. Inert or with slight mobility, obese, worm-like,
white, not turning yellow or brown. Vulva almost terminal.
Oviduct and ovary coiled. Uterus enormous, packed with juveniles
in ovoviviparous species and with eggs in oviparous species. Stylet
obscure in type species, but seen in others, rod-like without knobs, often
sunken in body. Oesophagus degenerate. Produces enormous
numbers of eggs or juveniles (up to 20,000). Juveniles moult twice
or thrice in the host, reach ovary and oviduct to escape through ovipositer
or reach gut and escape through anus. Partially free-living forms:
About 0.5 -0.6 mm long. Cuticle finely striated; lateral fields narrow,
with incisures. Cephalic region continuous; sclerotization slight
or absent. Excretory pore anterior to nerve ring in type species,
but may be posterior to it. Female stylet stout, 12 -24 um long,
often without basal knobs or thickenings; orifice of dorsal oesophageal
gland half to more than one stylet length behind stylet base. Vulva
near anus. Ovary rudimentary; uterus acts as a reservoir for sperm.
Tail elongate-conoid. Male without a stylet or rarely with
one which is degenerate. Oesophagus degenerate. Spicules about
one anal body width long. Gubernaculum weakly developed or absent.
Bursa poorly developed, reaching terminus, or absent. The male dies
after inseminating the preadult female. The latter penetrates the
host's larva or pupa, remains within and develops through metamorphosis
to become adult in the haemocoel of the adult insect.
(Description- Siddiqi, 2000)
Hosts
Coleoptera: Apion, Carpophilus, Colaspis, Diabortica,
Monolepta, Phyllotreta.
Diptera: Copromysa, Oscinella, Sepsis, Drosophila.
Siphonaptera: Ctenophthalmus.
Acarina: Cosmolaelaps, Euryparasitus, Haemogamasus,
Parasitus, Poecilochirus.
Type species
Howardula
benigna Cobb, 1921
Species found: at:
H. benigna | University of Missouri Sample |