Full-text - Norsk entomologisk forening

The larval stages of Bembidiovz 445Second stageEssentially consistent with the third stage larva. Head broad(ee :00 = 0.61 -0.70) and number of setae on head, each halfof dorsal sclerites and ventral side about the same (on frontalpiece 7-11, on scutum of pronotum 19-30, on mesonotum24-32, on metanotum 25 -31, eighth abdominal segment with50-70 on ventral side, first abdominal tergite with 15-20 andeighth tergite with 12-13 setae). First joint of maxillary palpi:i = 1.4-1.8. Ratio between length of joints as in third stage.Nasale often not so broad as in third stage: a:b = 0.30-0.36,whereas retinaculum is larger in proportion to mandible: r:ar= 0.18-0.29.Differs from third stage larva as follows: length of head:0.45-0.52 mm, width: 0.72-0.85 mm. The antennal joints andlegs are shorter (second antennal joint: i = 1.3-2.0, third jointof antenna less than twice as long as fourth; tibia: i = 2.1-2.4).Pronotum lacks a distinct triangular, more pigmented part, buthas a more evenly distributed pale brown colour. Prescutumdistinct on meso- and metanotum and first abdominal tergitewhile it can scarcely be separated from scutum on the otherabdominal tergites.First stageLength of head: 0.30-0.35 mm, width: 0.53-0.57 mm.Colour as in second stage.Head: ee:OO = 0.58-0.64. Only four setae on frontal piececould be observed in area within and in front of ocelli. Nasale(Fig. lla and b) variable, but much narrower than in the olderlarvae. Antennae (Fig. 15) very lumpy, especially second joint:i = 1.0-1.2. Second and fourth joints about same length anddistinctly shorter than first and third joints which are of equallength. Retinaculum prominent relative to mandible (Fig. 16):r :ar = 0.23-0.31. Second joint of maxillary palpi : i = 1.2-1.6. Terminal joint of outer lobe seems a little longer than basaljoint or they are sub-equal. Eggbursters not visible at 100 X.According to Emden (1942) the eggbursters of Bembidion consistof very small, inconspicuous spinules and as B. argenteolzlmundoubtedly has eggbursters too, they are probably of a typecharacteristic of Bembidion.Only pronotum (Fig. 12) and mesonotum (Fig. 13) have distinctprescutum, diffuse on metanotum and on abdominal tergiteshardly separable from scutum (Fig. 14). Number of setaeas on the figures.Joints of legs (Fig. 7) thick, tibia not twice as long as broad,about of same length as tarsus and femura. Claw apparently notshorter in proportion to tibia than in the third stage larva.