Hemilecanium cedrelus Hodgson 2008

Unmounted material. Dried material quite dark brown; younger specimens with a distinct shallow longitudinal dorsal ridge and a clear, shelf-like margin; older specimens becoming strongly convex with two strong shoulders medially; venter becoming highly concave, forming an inner egg chamber. Positions of dorsal tubercles indicated by clear round areas of more brown-ochre-coloured derm scattered over dorsum. Mounted material. Oval to almost round, 2.8-6.0 mm long and 2.25-5.00 mm wide; anal cleft about 1/4th-1/5th body length. Basic structure as for diagnosis.
Dorsum. Derm mainly membranous but with a heavy sclerotised band around anterior margin of anal cleft, which expands anteriorly with age. Derm of available specimens with polygonal reticulations throughout, each reticulation with an inner areolation and a dorsal microductule; perhaps becoming sclerotised at maturity. Dorsal setae all rather spinose, quite sharply pointed, with parallel sides; frequent laterally and anteriorly to anal plates, but absent submarginally; those anterior to anal plates each 33-36 μm long, those more anteriorly and laterally smaller, down to 16-24 μm long. Preopercular pores present in an elongate triangular group anterior to anal plates, each pore conical and 8-11 μm wide; each group with 85-140 pores, extending anteriorly to about metathorax. Dorsal microductules oval, appearing bilocular but with single inner ductule arising medially, each about 2.5-3.0 μm widest, most ductules swollen proximally; abundant, present in each dorsal reticulation. Other dorsal pores absent. Dorsal tubercles large and convex, but sunken into derm; each 16-26 μm wide, with a heavily sclerotised outer cone plus 2 inner chimney-like tubes (one inside other); outermost tube with a ring of about 10-12 vertical ridges (see Discussion below adult female); innermost tube long, extending some way above tubercle; dorsum with a total of about 140-200 tubercles, randomly distributed throughout; also with about 16 submarginal “scars” and 2 pairs of submedial “scars” (in approximate positions of dorsal tubercles of 3rd instar). Anal plates each about 275-330μm long, width of single plate 115-170 μm; each plate triangular, with 4 apical setae, both inner margin setae and subapical seta 25-30 μm long, other seta appearing dorsal, about 60-72 μm long. Anogenital fold with a line of 6-8 setae along anterior margin, each fairly short but with a long seta at each corner, latter about 60-75 μm long; each lateral margin with 3 setose setae. Anal ring well developed, with many pores and probably 5 pairs of setae, each 270-360 μm long; anal tube about as long as anal plates. Eyespots not detected.
Margin. Marginal setae all sharply spinose, each 16-45 μm long, with a broad base, straight sides and narrow basal sockets; abundant, with 175-240 anteriorly between anterior stigmatic areas, 54-62 laterally between stigmatic areas and 125-195 on each side of abdomen; each anal lobe with a group of 5 or 6 longer, slightly curved setae, longest 105-115 μm long. Stigmatic clefts absent. Stigmatic spines 3, clearly diff erentiated from marginal spines, slightly curved and with a less pointed apex than marginal setae; median spine longest, 75-85 μm long, each lateral spine 28-65 μm long.
Venter. Derm membranous. Spiracular disc-pores each mainly with 5 loculi, in broad groups near margin and each peritreme but very few or even sometimes absent in between; with about 45-50 in each anterior band and 60-85 in each posterior band, latter with a small group of multilocular pores near each spiracle. Multilocular disc-pores each about 8-10 μm wide, mainly with 10 loculi, abundant across all abdominal segments and across meso- and metathorax; scarce on prothorax and head. Ventral microducts each about 3 μm wide, abundant throughout, except marginally. Ventral tubular ducts slightly variable but probably all of one type, each with an outer ductule 17-30 μm long, inner ductule 13-20 μm long, with or without a glandular end; abundant in a broad submarginal band and rather less frequently in bands across each thoracic segment; with 1 or 2 present medially on abdomen among multilocular disc-pores. Other pores types absent. Ventral setae mainly rather spinose, most about 20-26 μm long, present across each abdominal and thoracic segment but most abundant in a submedial band just laterad to spiracles and legs; with about 5 pairs of rather short inter-antennal setae, longest 40 μm long; abdominal segments V, VI and VII each with a pair of longer setae, longest on VI and VII, each about 150 μm long; submarginal setae frequent, each about 25 μm long.
Antennae each 6 segmented, total length 250-350 μm; scape with 3 setae, pedicel with 2 setae, other segments: III with 2 setae, IV with 1 fleshy seta, V with 1 fleshy seta + 1 flagellate seta and VI with 3 fleshy setae, about 5 stiff apical setae + 1 flagellate seta; length of apical seta 66-90 μm long. Clypeolabral shield 270-350 μm long, labium probably with 4 pairs of setae. Spiracles large, width of peritremes: anterior 125-165 μm, posterior 155-210 μm; muscle plate much shorter than width of peritreme. Legs well developed but small; lengths (μm) of metathoracic legs: coxae 120-130 (width of coxal base 80-100 μm); trochanter + femur 145-153; tibia + tarsus 185-210; claw 28-31; tibio-tarsal articulation not always clear, with no sclerosis; longest coxal seta about 70 μm; longest trochanter seta about 85 μm; other setae very sparse; tarsal digitules about equal to length of claw digitules; claw digitules longer than claw, with one slightly narrower than other; claw with a small denticle. Vulva probably present between abdominal segments VII and VIII.

Distribution. Hemilecanium cedrelus is currently only known from Zambia.