Promyrmococcus dilli Williams

Williams, D. J. & Hodgson, Chris J., 2013, Are some prepupae and pupae of male mealybugs and root mealybugs (Hemiptera, Coccoidea, Pseudococcidae and Rhizoecidae) mobile?, ZooKeys 364, pp. 19-28 : 22-23

Promyrmococcus dilli Williams

Promyrmococcus dilli Williams (In Dill et al. 2002: 170).

Material studied.

Sabah, Kinabalu, Poring, in nest of Dolichodorus , 18.vii.1991, M. Dill (BMNH): 7/2 prepupa (one pharate) + 5 pupae (3 pharate) (good - descriptions taken from non-pharate individuals, with details checked on others).

Prepupa

(Fig. 1)

Mounted material.

Moderate sized, body 1.23-1.38 mm long, 0.7-0.84 mm widest; oval. Body with numerous very long flagellate setae. Legs and antennae well developed; mouthparts present but lacking stylets; wing buds absent. Ostioles present both anteriorly and posteriorly.

Dorsum membranous, segmentation obvious, particularly on abdomen. Each segment densely covered in fine flagellate setae, each 40-50 μm long; also with frequent, extremely long setae with very flagellate apices, each up to about 350 μm long, distributed approximately as follows: with medial pairs on pro-, meso- and metathorax and on abdominal segments I–VI; with 1 long and 1 slightly shorter seta on each side of each segment but with more on abdominal segments VI and VII; with 1-4 slightly shorter setae anterior to each ostiole, and with intermediate fine flagellate setae (each about 100 or so μm long) sparsely throughout. Loculate pores absent but small simple pores frequent throughout, each about 2 μm wide. Ostioles each 90-95 μm wide. Anus about 45 μm wide, with two setae of intermediate length on either side and a pair on posterior body margin.

Margin not demarcated; without wing buds. Eyespot 33-35 μm wide.

Venter membranous. Circulus present medially between abdominal segments II and III. Fine, flagellate setae similar to those on dorsum, covering most of venter; extremely long flagellate setae only present submarginally on abdominal segments V and VI, and perhaps only marginally on VII; setae of intermediate length infrequent, but present sparsely on VII. Loculate pores, each 6-7 μm wide with an uncertain number of loculi, mainly present medially and submedially on thorax and anterior abdominal segments; simple pores frequent throughout.

Antennae about 515 μm long, 6 segmented but with segment II clearly partially divided and with a campaniform pore present distally on more proximal half of this segment; each segment with many flagellate setae similar to those covering most of body, but with fewest on distal half of segment II; subapical segment with 1 fleshy seta and apical segment with 3 or 4 fleshy setae. Mouthparts clearly present; tentorium barely sclerotized but quite large; labium perhaps 3 segmented, 50-65 μm long, with (on ventral surface) 2 pairs of setae on basal segment, 2 pairs on medial segment and 5 pairs on apical segment; also with 2 pairs on dorsal surface. Spiracles each with peritreme 20-24 μm wide. Legs particularly well developed, lengths (in μm for metathoracic leg): coxa about 120-135; trochanter+ femur 275-310; tibia 190 -210; tarsus 95-112; claw 35-38; each trochanter with 2 roundish campaniform pores on each side; each tibia and tarsus without tibial spurs; tarsi one-segmented; tarsi each with a tarsal campaniform pore; tarsal digitules long, extending as long as claw and capitate; claw digitules setose and barely reaching claw apex; claws without a denticle.

Pupa

(Fig. 2)

Mounted material.

Moderate sized, body 1.20-1.4 mm long, 0.63-0.73 mm widest; oval. Body with numerous very long flagellate setae. Legs and antennae well developed; mouthparts present but very reduced and without stylets; wing buds absent. Ostioles present both anteriorly and posteriorly.

Dorsum almost identical to that of the prepupa, and with 0-3 setae of intermediate length on either side of anus.

Margin not demarcated, without wing buds. Eyespot 33-35 μm wide.

Venter membranous. As for prepupa except loculate pores absent.

Antennae 6 segmented as in prepupa, length about 520-615 μm long. Mouthparts very reduced; tentorium a small, roundish membranous area and labium short, about 35 μm long, with a few setae both dorsally and ventrally. Spiracles each with peritreme 20-28 μm wide. Legs particularly well developed, lengths (in μm for metathoracic leg): coxa about 125-150; trochanter+ femur 295-330; tibia 200-225; tarsus 95-105; claw 35-38; legs otherwise as on prepupa.

Comment.

The basic morphology of the prepupa and pupa of Promyrmococcus dilli is very similar to that of the adult male ( Williams 2004; Hodgson 2012), except that they lack the genital structures, have (at most) 7-segmented antenna (9 segmented on the adult male) and their tarsi appear to be only one segmented. Reduced mouthparts lacking stylets are also present on the adult male.