Morphology of Mites (Acari) (Gnathosoma (capitulum) (Chelicerae (3…
Morphology of Mites (Acari)
No segmentation, can have sutures and grooves.
may be Soft, Wrinkled and Unsclerotised
Larvae : 3 pairs
Adult and nymph : 4 pairs
2 pairs anterior legs
1st pair (modified): sensory structure, capturing prey
2 pairs posterior legs
Usually 6 segmented
Attached to body
membranous or resembling a filamentous hair, pad, sucker or claw
Absence of claws
Membranous bell-like disc
Dorsal shield (2 or More)
Ventral shield (2-3)
Important in identification
Located btw posterior legs
Bear genital orifice
Stigmata- respiratory opening(1-4 pairs)
Complex branching of trachea
In mesostigmatid mites, have peritremes (elongated sclerotised processes
Circulatory system is reduced, consist of a network of sinuses (blood circulate- contraction of muscle)
Single ovary connected to genital orifice by an oviduct
A pair of testes and vasa deferentia (extended from testes) and open through median gonophore or through a chitinous penis (project through genital orifice of female)
Nymph and Larva
Male produce spermatophore and transferred to genital orifice of female using chelicerae or the legs
Male produce a staked capsule containing a droplet of semen
Female attracted by semiochemicals produced by spermatophore or by trail laid down by male
After encounter droplet, female removes the sperm from its stalked cup with genital orifice.
Absent (most species)
Simple eyes (Trombidiformes)
Palps (sensory organ) - to locate food
Prostigmata & Astigmata: 1-2 segments
Mesostigmata: 5-6 segments
Last segment- palpal claw/ apotele (claw-like)
Palps attached to both side of chamber
Chelicerae (3 segmented, btw palps)
tearing, grasping/ piercing
Highly modified (stylet-like-piercing; claw-like: tearing)
Chelae (tip of chelicerae)-claw/long/stylet-like.
Fit in a socket-like anterior chamber in the opisthosoma.
chelicherae attached to the back wall of chamber.
Buccal cone (btw palps)
Formed by a dorsal projection of the body wall (rostrum) and ventrally and laterally by the enlarged coxae of the palps.
Can extend /retract in some spp.
muscular pharynx (ingestion)