Steneotarsonemus

Ganguly, Moumi, Mondal, Priyankar & Karmakar, Krishna, 2022, Complementary description of three species of Steneotarsonemus (Acari: Tarsonemidae) from rice agroecosystems of Eastern India with notes on their taxonomic status, spatial distribution, intraspecific variation and species composition, Zootaxa 5138 (5), pp. 501-532 : 519

Key to Steneotarsonemus species present in the rice agroecosystems of Eastern India

1. Adult female with elongated atrium; stigmatal opening anterior to v1; poststernal apodeme absent or inconspicuous. Adult male with conspicuous flange on femorogenu IV and seta v'F setiform............................................... 2

- Adult female with globular or rounded atrium; stigmatal opening posterior to v1; poststernal apodeme present. Adult male without flange on femorogenu IV and seta v'F stout, characteristically bifurcate.................................... 3

2. Adult female with dorsal hysterosomal setae c1 and d sparsely barbed; apodemes 2 strongly developed, inwardly curved and fused with prosternal apodeme; sejugal apodemes indistinct; setae 3b located proximad apodemes 4. Adult male with prodorsal setae v1 longer than v2; coxisternal plates smooth; flange on femorogenu IV often with faint punctations. Monophagous species, infesting only leaf sheath and developing grains of Oryza sativa ............................ Steneotarsonemus spinki

- Adult female with dorsal hysterosomal setae c1 and d smooth; apodemes 2 weakly meet with prosternal apodeme; sejugal apodemes vestigial and present as sclerotized peg like remnants; setae 3b located near distal end of apodemes 4. Adult male with prodorsal setae v1 shorter than v2; coxisternal plates strongly reticulated; flange on femorogenu IV ornamented with faint striation. Polyphagous species; principally inhabiting inner surface of leaf sheath of Cynodon dactylon .................................................................................................. Steneotarsonemus konoi

3. Both adult male and female with distance between bases of setae sc2 always more than its length. Adult female with bothridial setae sc1 present; v2 vestigial; coxisternal setae 3a and 3b subequal in length; remnants of sejugal apodeme as long as apodemes 2; poststernal apodeme short, not broken. Adult male with dorsal setae v2, sc1, sc2, c1, d and f sparsely barbed; seta d on tibia I serrate; v'Ti on leg IV smooth. Polyphagous species; largely infest Elusine indica (L.), Apluda mutica (L.) and other graminaceous weeds in rice agroecosystem and wet land habitats.......................... Steneotarsonemus furcatus

- Both adult male and female with distance between bases of setae sc2 shorter than its length. Adult female with bothridial setae sc1 absent; v2 sparsely barbed; coxisternal setae 3a nearly thrice the length of 3b; remnants of sejugal apodeme shorter apodemes 2; poststernal apodeme broken. Adult male with all dorsal setae smooth; seta d on tibia I smooth; v'Ti on leg IV serrate. Monophagous species; principally inhabit inner surface of leaf sheaths of Oryza sativa .................................................................................................... Steneotarsonemus subfurcatus