Cissococcus, Cockerell, 1902

Hodgson, C. J., Millar, I. M. & Gullan, P. J., 2011, Cissococcus Cockerell (Hemiptera: Coccoidea: Coccidae), a unique gall-inducing soft scale genus on Vitaceae from South Africa, with description of a new species, Zootaxa 2996 (1), pp. 1-32 : 3-6

publication ID	https://doi.org/ 10.11646/zootaxa.2996.1.1
persistent identifier	https://treatment.plazi.org/id/03FAA75F-FF85-FFF9-FF00-0099DDA4E983
treatment provided by	Felipe
scientific name	Cissococcus
status

Treatment

CISSOCOCCUS Cockerell View in CoL

Cissococcus Cockerell, 1902: 23 View in CoL .

Type species: Cissococcus fulleri Cockerell, 1902 , by original designation and monotypy.

Generic diagnosis. Habit in life. Females induce galls ( Fig. 1A,B View FIGURE 1 ) on wild vines ( Vitaceae ) of the genus Rhoicissus , and currently are known only from the southeast to northeast areas of South Africa. Males do not induce galls but are free-living on foliage of host plants ( Fig. 1D–F View FIGURE 1 ). Young galls of females appear as small convexities on stems, each with a large hole or orifice apically. The galls expand with age, becoming 5–8 mm in diameter; the gall of the type species ( C. fulleri ) remains upright, rather round, wider than tall, with the orifice in a small indentation on the apex ( Fig. 1A,B View FIGURE 1 ), whereas that of the new species R. braini looks more like a vase lying on its side, with the orifice within an apical chamber ( Fig. 1H–J View FIGURE 1 ). Galls are green and fleshy when young (e.g., Fig. 1H,I View FIGURE 1 ) but become woody and darkened with age (e.g., Fig. 1J View FIGURE 1 ).

Adult female. When removed from gall, body salmon to burgundy pink to dark red in colour, depending on age ( Fig. 1B,C View FIGURE 1 ); body globose to slightly flattened, with a distinct upper surface consisting of half of venter plus small true dorsum closest to gall orifice, and a lower surface formed of half of venter closest to attachment of gall to stem; dorsum clearly distinguishable as almost the only dark sclerotised structure ( Fig. 1B View FIGURE 1 ) but representing only a small portion of the fully-expanded body (i.e., only about 1/40 th area of venter of mature female) ( Fig. 2 View FIGURE 2 ). Mounted material: Dorsum more or less oval, moderately sclerotised, with a large indentation medially just anterior to anal plates, from which a very large apodeme extends anteriorly. Dorsum of C. fulleri rather flat, that of C. braini probably with anterior end sharply bent upwards and posteriorly, so that anterior margin lies almost over anal plates (thus, when mounted, dorsum bends posteriorly about one third from anterior end, with anterior part overlying posterior part (see Fig. 13X View FIGURE 13 ); on C. braini , dorsal apodeme arises from deep within cavity under bentover anterior end ( Fig. 13X View FIGURE 13 ). Apodeme basically bifid anteriorly; appearing to become longer (or more of it sclerotised) with age, so that on oldest individuals each arm longer than length of dorsum; in addition, at least on some older specimens of C. fulleri , a second pair of apodemes becomes apparent extending antero-laterally (See Fig. 4X View FIGURE 4 ). Derm of dorsum heavily sclerotised, showing no signs of segmentation, but with irregularly fissured pattern, fissures arranged semi-longitudinally over posterior two-thirds, tending to radiate from median to margin on anterior third. Dorsum with small spinose dorsal setae and round pores of unknown structure, some possibly setal sockets. Preopercular pores, dorsal tubercles and dorsal tubular ducts absent. Anal plates together oval, with many large spinose setae on dorsal surface plus 1 or 2 rather larger setae near posterior apex. Anal cleft short. Details of anal ring unclear but thought to have 3 pairs of long anal ring setae; anal tube about as long as length of anal plates; setae associated with opening of anal tube unknown. Eyespots distinct, close to margin at anterior end of sclerotised dorsum; those on C. braini hidden under overhanging anterior part of dorsum. Margin. Marginal setae strongly elongate spinose, sharply pointed, extending in more or less a single line all around margin, bases almost touching. Stigmatic clefts absent; stigmatic spines not differentiated from marginal spinose setae. Venter. Membranous, greatly swollen on fully-developed adults so that almost entire insect is represented by venter. Swelling occurring mainly medially, between legs, causing great displacement of structures, so that antennae, legs, spiracles and mouthparts often lie topologically on upper surface of body. Preantennal pores absent. Derm with numerous ventral microducts, often appearing to be bilocular, each with an elongate inner ductule, present more or less throughout. Loculate pores abundant medially on venter (and therefore lying medially on lower venter); each with 5–12 loculi; similar pores also present in a sparse, broad band between spiracles and general area of true dorsum. Ventral setae abundant medially on lower venter, where mainly much larger than those more laterally on upper venter. Antennae probably with 5 or 6 segments but all highly distorted, located just anterior to anterior margin of dorsum (and thus situated over overhanging part of dorsum on C. braini , and therefore very difficult to see). Clypeolabral shield apparently of normal structure for Coccidae , but often located on upper venter and facing anteriorly towards lower venter; labium 2 segmented, with 4 pairs of setae. Spiracles large, peritreme facing towards dorsum; with a broad inner apodeme. Legs distorted and misshapen, but probably with all segments; tarsal digitules both capitate and about as long as claw; claw digitules generally longer than claw, also capitate; claw generally with a distinct denticle. Vulva not detected, almost certainly lying beneath anal plates on mounted material.

Third-instar female. Basically similar to adult female, but smaller. Dorsum with fewer pores and setae; anal plates with few spinose setae. Margin with fewer spinose setae. Eyespot more or less on margin. Venter with or without loculate pores on lower venter, and ventral setae few. Legs much better developed than on adult female, all segments clearly present, and placed near margins of mounted specimens. Antennae clearly 5 or 6 segmented. Mouthparts located on lower venter.

Second-instar female. Venter not swollen in youngest individuals but becoming somewhat swollen in more mature specimens. Dorsum membranous apart from a transverse sclerotised band just anterior to anal plates. Dorsum with 4 longitudinal rows of sunken cone-shaped secretory spines, 2 longitudinal rows of small setae and 4 longitudinal rows of simple pores. Anal plates with 4 setae. Margin with a single line of spinose setae. Venter with loculate pores near spiracles and along submargin. Ventral tubular ducts absent. No other distinctive features.

Second-instar male. Found on leaves and petioles ( Fig. 1D,E View FIGURE 1 ), becoming covered in a loose mass of white wax. Mounted specimens similar to youngest second-instar females apart from dorsum with 2 submedial groups of tubular ducts on abdominal segment IV and sunken cone-shaped secretory spines (occasionally few or absent on some specimens), and venter with tubular ducts present more or less throughout and antennae 7 segmented.

First-instar nymph. Live specimens rather flat and orange to rusty-brown in colour ( Fig. 1D View FIGURE 1 ). Mounted specimens somewhat similar to second-instar female but dorsum without sunken cone-shaped secretory spines and each anal plate with a very long apical seta; margin with blunter, more cone-shaped marginal setae; venter with a few loculate pores, restricted to near spiracles, and a small, possibly trilocular, pore present anterior to each scape.

Prepupa. Develops beneath loose, white waxy test. Mounted specimens typical of Coccidae ; lobes on abdominal segment VII rounded and very short, with a line of fleshy pleural setae; penial sheath large, about as long as basal width; loculate pores only present associated with anterior spiracles.

Pupa. Structurally similar to prepupa but with much longer antennae, legs and wing-buds.

Adult male ( Fig. 1F,G View FIGURE 1 ). Moderately large. Head with dermal reticulations almost throughout; gena without genal setae; with 2 pairs of simple eyes. Antennae slightly longer than half body length. Body rather bald, with few body setae, most hair-like setae rather similar to fleshy setae; appendages, however, hirsute, with numerous fleshy setae easily differentiated from hair-like setae. Wings large, each with an alar seta; hamulohalteres present. Legs each with 1-segmented tarsus; no tarsal campaniform sensillum and only 1 tibial spur. Abdomen with a pair of deep glandular pouches, each with 2 capitate glandular pouch setae; glandular pouches with 2 types of pores. Penial sheath long (about ¼ total body length), narrow and sharply pointed; anus surrounded by sclerotised derm.

Biology and life cycle. Although originally collected from the KwaZulu-Natal and Eastern Cape area of South Africa, more recent collections show that the genus Cissococcus probably is found throughout the range of its host genus ( Fig. 3 View FIGURE 3 ). This distribution is essentially within the coastal savanna biome or bordering onto the edge of the upland grassland biome in the south and southwest, all within the summer rainfall area. Relatively few collections have been made so far but both species have been found in the period November to January (early spring and summer), whereas C. braini also has been collected in mid-winter (July to August).

In November 2005, many examples of the galls and free-living stages of C. fulleri were collected by PJG. At this time, there were active crawlers, second-instar males and females, plus some more mature galls with adult females. The galls and the male nymphs on the foliage were attended by the ants Crematogaster (Crematogaster) desperans . The male nymphs were aggregated near the main vein on the undersides of young leaves ( Fig. 1D,E View FIGURE 1 ). When the mature galls with adult females were cut open, some had crawlers aggregated inside along with cast embryonic whitish membranes and some eggs. It is therefore clear that this species is oviparous. Five days after the collection, an adult male emerged from its puparium.

Most immature stages of the second species, C. braini , are unknown.

Generic relationships. Ferris (1920) considered that this genus was definitely a member of the Coccidae , “showing certain affinities with Ceroplastes ”. A phylogenetic study by Miller and Hodgson (1997) (based on 105 characters of the adult female, adult male and first-instar nymph and using 10 other lecanoid families as outgroups) also suggested that the Cissococcinae fell within the Coccidae . However, when Kerriidae as well as Aclerdidae and Micrococcidae were used as outgroups, the Cissococcinae fell outside the Coccidae . On the other hand, the morphological data presented above for the first-instar nymph and adult male confirm that Cissococcus is a soft scale. Furthermore, unpublished DNA sequence data place Cissococcus well within the Coccidae (T. Kondo & L.G. Cook, personal communication). Thus, although the family placement of Cissococcus has been settled, it is clearly unique in many of its character states and its relationships to other coccid taxa are unclear.