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