Genus Mesocriconema
Andrássy, 1965
Madinema Khan, Chawla & Saha, 1976
Seshadriella Darekar & Khan, 1981
Crossonemoides Eroshenko, 1981
Neobakernema Ebsary, 1981
Pakcriconemoides Shahina & Maqbool, 1993

Photo Galleries:
9 Mile Prairie
Arena Sand Pines, WI
Burr Oak Canyon
CERA Prairie, Grinnell College
Doolittle Prairie, Iowa
Great Bend, Kansas
Ichetucknee River, Florida
Kalsow Prairie, Iowa
Konza Prairie, Kansas
Middle Loup River, NE
Missouri CAPS
Montana CAPS
Roth Prairie, Arkansas
Schluckebier Prairie, Wisconsin
Serpentine soils, Maryland
Sheeder Prairie
Spring Creek Prairie, NE
Sturgis, South Dakota
Vermont CAPS
Wakulla Springs, Florida
Williams Prairie, Iowa

    Females.  Plump nematodes, 0.3-0.6 mm long (exceptionally longer).  Cuticle with retrorse annuli, margins smooth, uneven or crenated, no posterior appendages.  First annulus seldom separated, second annulus usually wider than the first.  Submedian lobes as outgrowths of much reduced pseudolips, exceptionally absent.  Labial plates present or absent.  Vulva open, anterior vulval lip ornamented in a few species.  Postvulval body part usually short, terminus round or truncate, seldom acute.
    Males.  Anterior end rounded.  Lateral field with four grooves (lines).  Bursa usually well developed and enclosing terminus, rarely narrow and shorter.  Terminus round to acute.
    Juveniles.  With smooth, uneven or crenate posterior margins of annuli, never with appendages and annules in profile never drawn out posteriad.
The above diagnosis characterises the genus mainly by the submedian lobes and open vulva.  However, a few species apparently do not have submedian lobes, but we considered this lack as secondarily absent or lost, as understood by Lorenzen (1996).
    The genus Mesocriconema is most closely related to the genera Criconemoides and Xenocriconemella Loof & De Grisse, 1965, and can be differentiated by the following characteristics illustrated with scanning electron microscope (SEM) micrographs by Loof and De Grisse (1989).
    From Criconemoides, it differs by having an open vulva and submedian lobes arising from reduced pseudolips (in Criconemoides vulva is closed, pseudolips not reduced, forming submedian lobes themselves).
    From Xenocriconemella, it differs by structure of vulva and anterior body end (in Xenocriconemella the vulva is closed and vulval lips form a 'sleeve', the first annulus lies not anterior to the second, but inside it).
    Pakcriconemoides was proposed with the type species P. anastomoides (Maqbool & Shahina, 1985) and P. microdorus (De Grisse, 1964a) was included as another species.  The type species was transferred to Mesocriconema by Loof and De Grisse (1989).  The main diagnostic differences between Mesocriconema and Pakcriconemoides are the open vulva and anchor-shaped stylet knobs in the former, vulva closed and shorter stylet with rounded knobs in the latter.  However, the light microscope photograph of the type species suggests an open vulva, while SEM micrographs of the head end show true submedian lobes.  The second species included, P. microdorus, has an open vulva.  These characters are essential for the genus Mesocriconema as outlined by Loof and De Grisse (1989) and in the diagnosis above and therefore we, like Siddiqi (2000), synonymise both genera.  The differences in the stylet length and shape of knobs are considered to be of specific and not of generic importance.

Type species
    Mesocriconema pruni (Siddiqi, 1961) Andrássy, 1965
           subjective synonym of M. xenoplax (Raski, 1952) Loof & De Grisse, 1989.
(Description- M. W. Brzeski et al., 2002)

This genus included in the Criconematid Project

DNA Sequences Obtained
Specimen:    collected:
16547 La Selva Station, Peccary Ex-plots, Costa Rica
16546 La Selva Station, Peccary Ex-plots, Costa Rica
16544 Costa Rica
N183090 Costa Rica, pineapple
N184034 Costa Rica, palm
N184035 Costa Rica, palm
16138 La Selva Station, Cosa Rica
14268 La Selva Station, Costa Rica
N223083 9-Mile Prairie, NE
13454 9-Mile Prairie, NE
16565 Reichelt Prairie, IA
16801 Williams Prairie, IA

Species List (from Ebsary, 1991)

Species found         at:
M. crenatum Costa Rica
M. curvatum Konza Prairie, 9-Mile Prairie, Homestead
M. discus 9-Mile Prairie
M. incrassatum Great Smoky Mts.
M. ornatum Georgia
M. rusticum Konza Prairie
M. sphaerocephala Konza Prairie
M. xenoplax Konza Prairie