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Tetranychinae—Key feature pages

Empodial claw

The pretarsi of the Tetranychinae often reflex their use, especially modifications for walking on silksilk:
fine threads spun by acariform mites to form a molting chamber (cocoon), protect or attach eggs, or a loosely defined to finely woven web.
. Economically important genera in the two tribes of Tetranychinae with agricultural pests can be separated partially on the structure of the empodial clawclaw:
like - having a distal hook; resembling a claw.
 and proximoventral hairsproximoventral hairs:
the hair-like processes on the empodia of some spider mites; apparently represents a finely divided empodium, and not tenent hairs.
:

  • The empodiaempodium:
    (pl. empodia) an unpaired structure arising between the tarsal claws, ranging from pad-like to claw-like and often bearing structures such as tenent hairs, dense setulae, or taking the form of a featherclaw (Eriophyoidea)..
     has a clawclaw:
    like - having a distal hook; resembling a claw.
    -like hookhook:
    (as in cheliceral hook) the distal hook-like tips of chelicerae in the Mesostigmata, as opposed to cheliceral teeth.
     in Oligonychus, Panonychus, and Allonychus.

  • Schizotetranychus has the empodial clawclaw:
    like - having a distal hook; resembling a claw.
     bifurcate distally.

  • In the Eurytetranychini the empodial clawclaw:
    like - having a distal hook; resembling a claw.
     is so small as to seem absent in the genera Eutetranychus and Aponychus.

  • In Eotetranychus, Amphitetranychus, and most Tetranychus the empodial clawclaw:
    like - having a distal hook; resembling a claw.
     is split distally into 2–3 pairs of 'proximoventral hairs' (a term also used for similar processes produced ventrally on the empodial clawclaw:
    like - having a distal hook; resembling a claw.
     in Oligonychus, Panonychus, and Allonychus). Just to keep things confusing, some Tetranychus have a dorsal spurspur:
    a projection, usually tooth- or spine-like, from the body or limbs.
     that may look like an empodial clawclaw:
    like - having a distal hook; resembling a claw.
    .

claw-like (hooked)  
claw-like (hooked)
bifurcate  
bifurcate
weak spur or absent  
weak spur or absent
divided distally  
divided distally
Feature pages