Titanochrysa trespuntensis Sosa & Freitas, 2012

Tauber, Catherine A., Albuquerque, Gilberto S. & Tauber, Maurice J., 2012, The Neotropical genus Titanochrysa (Neuroptera, Chrysopidae): larval descriptions, biological notes, a new species, and taxonomic changes, Zootaxa 3514, pp. 1-26 : 2-12

Titanochrysa trespuntensis Sosa & Freitas, 2012

Figs 1–7

All instars. Body cream-colored, with light brown integumental spinules, brown to dark brown dorsal, lateral markings on thorax and abdomen. Shape of body in lateral view: head and thorax relatively flat dorsally, body becoming thicker posteriorly; metathorax not noticeably raised; abdomen raised, dome-like through segment 6; segments 7 – 10 becoming narrow and tubular distally, not withdrawn. All spiracles brown, sessile, with deep, narrow atrium. Two types of chalazae: (1) small, delicate, unmodified basally or (2) robust, with enlarged base, often with brown coloration on anterior surface. All setae smooth except some long, robust setae slightly granulate under high power (x200).

Third instar. Body. 7.3 – 7.5 mm long.

Head ( Figs 2 A – C, 3A, 4, 5A). Cephalic setae smooth, straight, pointed; all primary cephalic setae present: S1, S11 long, S2 – 10, S12 of medium-length, S5 shortest; large patch of approximately 50 very short secondary setae in transverse row across mid-section of cranium; Vx setae more robust than secondary setae, beneath cervical membrane. Anterior margin of head rounded, with three pairs of medium-length setae, mesal pair longer than two lateral pairs. Mandibles slightly shorter than width of head; head width across eyes, 0.81 – 0.82 mm; mandible length, 0.73 – 0.77 mm (ratio, mandible length to head width = ~0.93). Labial palpus: basal segment with one small dorsal seta, two short mesal setae, one long ventral seta; middle segment with six long setae distally, seven to eight shorter setae basally; distal segment without setae, ventral surface with two small, longitudinal sensory organs. Palpiger with two medium-length to long ventral setae. Mentum with two pairs of long setae anteriorly below palpiger, one pair of long setae laterally above stipes, two pairs of medium-length setae posteriorly. Stipes elongate, folded inward on longitudinal axis; cardos elongate, narrow.

Head coloration: Dorsum cream-colored, with brown to dark brown markings. Epicranial marking brown, divided into two narrow, elongate sections, both in contact with posterior margin of head; lateral section extending from distal margin of posterior cranial suture, reaching to level of middle of eye; mesal section extending from base of head, becoming confluent with postfrontal marking, which extends to inner base of scape. Postfrontal marking very dark at confluence with mesal section of epicranial marking, narrow throughout. Frontal marking dark brown, with each arm narrow, separate, extending from midsection of head, beyond tentorial pits to anterior margin of clypeolabral region. Intermandibular marking light brown, narrowly transverse, small, separate from frontal marking. Clypeolabral region cream-colored. Stemmata black; integument surrounding anterior stemmata black, around posterior stemmata white. Gena cream-colored, with elongate, brown marking from base of eye to posterior margin of cranium, bifurcated anteriorly. Mandible, maxilla brown to dark brown. Labial palpus: basal segment light brown; mesal segment mostly brown, with cream mesally and between subsegments; terminal segment dark brown basally, light brown distally, with concentric rings throughout, terminal ring cream-colored. Antenna: scape cream-colored, with tinge of brown; basal section of pedicel brown, with cream mesally and between subsegments, distal section brown throughout; flagellum brown, ringed, with terminus cream-colored. Venter cream-colored, except interior margin of cranium with longitudinal brown mark; center of mentum white to cream-colored, with large light brown patch mesally.

Thorax ( Figs 1 A, D, 3A, 4, 5B). Cervix cream-colored, with pair of submarginal brown stripes; venter creamcolored; sides with dark brown stripe. Thoracic dorsum white to cream-colored, with pair of light to dark brown, elongate, curved, submesal stripes, small, scattered, brown marks. Lateral tubercles (LTs) white to cream-colored, with setae (LS) golden to light brown. Venter cream-colored to white, unmarked. Legs: coxa white, with brown marking on basolateral surface; femur cream basally, anterior surface becoming brownish distally, ventral surface white; tibia brownish to amber; tarsus, empodium, brown to dark brown.

LTs well sclerotized, rounded, each bearing 12 to 16 LS: six to ten large chalazae located on distal part of LT usually bearing long, slender and tapering, pointed (occasionally hooked) LS, five to six smaller chalazae located dorsally or basally, usually bearing shorter, robust, pointed LS ( Fig. 1 D). Dorsal setae straight ( Fig. 1 A).

T1: Notum with pair of narrow, longitudinal, brown stripes submesally, oblong brown mark mesally; pleuron with dark brown band; anterior margin with three short setae (R1), extending from below anterior fold of integument. LT with slightly elongated base, extending to middle of cervix, with ~9 – 10 long LS apically, ~5 – 6 shorter LS basally. Paired sclerites (Sc1) large, obtuse, marked with very light brown laterally, with dark brown mesally. S1Sc1 long; S2Sc1 shorter, anterior to S1Sc1; two to three pairs of short, secondary setae mesal to Sc1. Mesal sclerite (Sc2) marked with brown, less than one-half length of Sc1, almost as wide as long. Primary setae S1, S2, S3, S4 long; S5 absent.

T2: Anterior subsegment with pair of brown submesal stripes; spiracles with small spiracular seta (SSp) anteriorly. Anterior sclerite (Sc1) with three associated setae—one mesal (S1Sc1), two lateral (S2Sc1, S3Sc1). Posterior subsegment with broken sections of submesal stripe; anterior mark light brown, posterior mark dark brown anteriorly, lighter brown posteriorly. Sclerite on anterior margin (Sc2) with two, very small, associated, lateral setae (S1Sc2, S2Sc2); mesolateral sclerite (Sc3) with two associated setae—S1Sc3 intermediate-length, on mesal margin, S2Sc3 small, on anteromesal margin. S1 short, mesal to LT; S2 intermediate-length, mesal to S1, with three small, secondary setae nearby; S3 long, mesal to Sc3, with one secondary seta on each side. LT with six to eight long LS, ~six short LS, patch of five to six small setae on anterior surface of base. Pleural region marked with large dark brown mark behind, below LT.

T3: Dorsum with dark brown spot anteromesal to LT, pair of large brown marks midway between LT and midline. Small sclerite on anterior margin (Sc1) with one small seta (S1Sc1); mesolateral sclerite (Sc2) with one small associated seta (S1Sc2). S1 intermediate-length, anteromesal to Sc2; S2 very small, lateral to S1; posterior row of five pairs of robust, relatively straight setae, stemming from brown chalazae with pear-shaped brown markings beneath. LT with six to eight long LS, ~six short LS, patch of four to five short setae on anterior base of LT.

Abdomen ( Figs 1 A – C, 3B, C, 4, 5C, D). Dorsum, venter white to cream-colored, with brown to dark brown markings. Spiracles brown, circular, sessile, with narrow, conical atria. Dorsal markings: A1 – A5 each with pair of submesal brown marks near anterior margin, pair of dark brown, transversely elongate marks behind posterior row of setae. A6, A7 each with pair of large, dark brown marks, pair of lighter brown marks extending onto top of LTs. A8 white, with small, elongate, brown spot mesally, pair of smaller spots laterally; A9 white, with pair of dark brown marks anteriorly. A10 white anteriorly, brown distally, with dark brown, inverted U-shaped mesal mark. LTs white, with brown, basal marks anteriorly and posteriorly: A2 with anterior mark dark brown, posterior mark light brown, A3, A4, with both marks dark brown, A5 with anterior mark light brown, posterior one dark brown. A1 – A7: area ventral to LTs marked with large, dark brown to brown marks, especially A2, A3. A8, A9 white laterally. Venter white to cream-colored, with large, dark brown lateral marks on A1 – A4, small brown marks on A5, very small on A6, tip of A10 with transverse, rectangular, brown, mark.

Abdominal LTs (A2 – A7) well sclerotized, with short, straight sides, rounded distally, each with approximately six long LS on large distal chalazae, four medium-length LS slightly basal on LT, four smaller LS further basal on LT. LS mostly straight or with gentle curve, small terminal hook. Dorsal abdominal setae of four main types: (1) short or medium-length, thin, pointed, with small, unmarked chalazae (e.g., A1: anterior two pairs), (2) elongate, robust, hooked, with large chalazae marked with brown anteriorly [e.g., A1: anterior row of submedian setae (SMS)], (3) elongate, thin, hooked, with small, unmarked chalazae (e.g., A2 – A5: first and second rows of SMS), (4) short, robust, hooked, with large chalazae marked with brown anteriorly (A2 – A4: posterior rows of SMS) ( Fig. 1 A – C, stp, erh, eth, srh).

A1: Dorsum (from anterior to posterior) with two pairs of short setae near anterior margin, row of six to seven pairs of elongate, robust, hooked SMS arising from large chalazae with brown, teardrop-shaped marks on anterior surface, patch or three to four pairs of elongate, thin, hooked SMS on small, brown chalazae, lateral to robust chalazae; row of ~nine to ten pairs of elongate, thin, hooked SMS arising from small, brown chalazae without anterior marks. Spiracle with two to three slender, hooked spiracular setae (SSp) mesally.

A2 – A4: Dorsum of each segment with three transverse rows of SMS, all hooked. Anterior row with 15 to 20 pairs of elongate, thin SMS arising from small, brown chalazae in double line. Middle row with four to five pairs of elongate, thin SMS arising from small chalazae in single line. Posterior double row with 12 to 14 pairs of short, robust SMS arising from large, brown chalazae in double line (chalazae with brown, teardrop-shaped marks anteriorly) and three to four pairs of elongate, thin SMS on small chalazae in anterior section of row. Patch of 14 to 16 (A2) to 24 to 26 pairs (A4) of elongate, thin SMS on brown chalazae lateral to mesal and posterior rows, extending to spiracle (A2) or beyond to base of LT (A4). No identifiable SSp.

A5: Dorsum with three transverse rows of SMS, all elongate, thin, hooked. Anterior row with four to five pairs of SMS arising from small chalazae in regular, single, anteromesal line, nine to ten pairs of slightly larger SMS on more robust chalazae, in irregular line close behind. Middle row with two pairs of smaller SMS arising from small chalazae mesally. Posterior row with 14 to 16 pairs of elongate, thin to more robust SMS arising from small chalazae in irregular double line, pair of small laterodorsal tubercles (LDTs) midway in row, each bearing one elongate, robust hooked seta (LDS), one shorter, more slender LDS. Four to five pairs of small setae mesal and posterior to spiracles; no identifiable SSp.

A6: All setae straight, pointed; dorsum with one pair of medium-length, slender SMS arising from small chalazae anteriorly; pair of large LDTs posteriorly, each bearing three elongate, robust LDS, three to four shorter LDS; pair of medium-length, slender setae between LDTs; no identifiable SSp.

A7: All setae straight, pointed; dorsum with two pairs of very short setae anteriorly, between spiracles; pair of LDTs posteriorly, each with one long LDS, two medium-length LDS, two short LDS; pair of setae between LDTs; pair of small setae (SSp) mesal to spiracles.

A8: LTs rounded, without straight sides, with one long LS, eight to nine medium-length to short LS; two pairs of small anterior setae; posterior row with three pairs of medium-length SMS; no identifiable SSp.

A9: Dorsum with two transverse rows of short to medium-length SMS, one almost midway down segment with four to five pairs of short to medium-length setae, one posterior, with five to six pairs of short to mediumlength setae.

A10: Dorsum with ~five pairs of short setae, most lateral, two pairs posterior; patch of microsetae at terminus. Terminus with two membranous pouches, eversible laterally.

Second instar. Similar to third instar with following exceptions. Body. 4.2 – 4.6 mm long.

Head ( Fig. 6 A – C). Mandibles slightly shorter than width of head; head width across eyes, 0.59 – 0.60 mm; mandible length, 0.48 – 0.49 mm (ratio, mandible length to head width = ~0.82). Cranium with fewer secondary setae (~25). Labial palpus: basal segment lacking one short mesal setae; middle segment with four annulations: basal annulation with three short setae, one long seta, second and third annulations without setae, fourth (distal) annulation with three long setae. Palpiger with two medium-length to long ventral setae. Mentum with only one pair (not two) of medium-length setae posteriorly; others as on third instar.

Thorax ( Fig. 6 B – D). LTs each with approximately six to eight long LS, four to five shorter LS. T1: Notum with only one pair of secondary setae. T2: Notum without SSp, S1, S3Sc1, S2Sc3, S3Sc3, secondary setae. T3 without secondary setae.

Abdomen ( Fig. 6 B, C, E, F). LTs each with approximately four long, robust LS on large chalazae, five pairs of shorter LS on smaller chalazae. A1: Posterior row with seven to eight pairs of robust, elongate SMS, one pair of more slender, long SMS near lateral edge. A2 – A4: Anterior row with two to three pairs of elongate, thin SMS arising from small, brown chalazae; mesal row with two pairs of elongate, thin SMS; posterior row with seven to eight pairs of short, robust SMS arising from large chalazae with brown, teardrop-shaped marks; patch of two to three pairs of elongate, thin SMS lateral to mesal and posterior rows; two pairs of setae (SSp) mesal to spiracles. A5: Anterior row with four to five pairs of slightly robust, medium-length SMS arising from small, robust chalazae in slightly irregular line; posterior row with four to five pairs of medium-length, robust SMS arising from large chalazae in irregular line, pair of laterodorsal tubercles, each with one long and one shorter, smooth, straight seta (LDS); two pairs of setae (SSp?) mesal to spiracles. A6: Dorsum with one to two pairs of medium-length setae anteriorly; middle row with two pairs of very small setae; LDTs each bearing one long and one shorter seta (LDS), one seta immediately anterior; pair of setae (SSp?) mesal to spiracles. A7: LDTs each with one long and one short seta (LDS); pair of setae (SSp?) mesal to spiracles. A8: LTs each with one medium-length LS, two to three shorter LS; anterior setae very small; pair of setae (SSp?) posteromesal to spiracles.

First instar. Body. 2.3 – 2.9 mm long, predominantly white to cream-colored, with small light brown to brown spotty markings; venter white, without markings. LS light amber to amber; dorsal setae pale.

Head ( Fig. 7 A – C, F, G). Mandibles slightly shorter than width of head; head width across eyes, 0.40 – 0.42 mm; mandible length, 0.32 – 0.35 mm (ratio, mandible length to head width = ~0.82). Cranial setae smooth, straight, pointed, golden to light brown. Epicranial marking divided, with pattern resembling that of L3, L2; mesal section light brown, elongate, narrow, longitudinal stripe, contiguous with postfrontal marking; lateral section diffuse, elongate, very light brown, Intermandibular marking absent. Postfrontal marking dark brown, extending anteriorly to mesal base of antenna. Frontal marking paired, separate, dark brown, narrow, elongate stripe extending anteriorly, bending toward inner basal margin of mandible. Genal marking brown, elongate, extending from base of cranium anteriorly almost to eye, forked anteriorly. Labial palpus amber to light brown; terminal segment darker than others. Mandible brown to dark brown. Antenna light to dark brown.

Thorax ( Fig. 7 B, C, F, H). Legs white, with amber setae; tips of tarsi, claws, empodia, brown to dark brown. LS cream to white, curved to straight, without hooks; other setae pale amber, straight, without hooks.

T1: LT with two LS, microseta dorsally. Sc1 brown, elongate; S1Sc1 long, arising from small chalaza; S2Sc1 absent. S1 short; S3 intermediate-length, S4 short; S2, S5 absent.

T2: Spiracles brown, circular, sessile. LT with three white to cream-colored, granular to slightly granular LS, microseta dorsally. Sclerites brown; associated setae S1Sc1, S1Sc2 very small; S1Sc3 medium-length. Posterior subsegment with row of four straight setae posterior to Sc3 (mesal short; lateral pair long, arising from chalazae).

T3: LT with three white to cream-colored, granular to slightly granular LS, microseta dorsally. Sclerites Sc1, Sc2 small, with S1Sc1 very small; S1Sc2 absent. Posterior region with row of four straight setae on chalazae, posterior to Sc2.

Abdomen ( Fig. 7 C – F, H). Dorsum white to cream-colored, with some very light brown mottling; chalazae of most primary dorsal setae brown; LTs with setal bases brown, with light brown marks or mottling anteriorly, posteriorly; A1 – A4 each with three pairs of setae stemming from large brown chalazae with teardrop-shaped brown marks anteriorly; spiracles uncolored, difficult to see; SSp with brown chalazae. A1: Two pairs of straight, pointed submedian setae (SMS) between pair of laterodorsal tubercles, each bearing one long, one shorter LDS. A2 – A4: SSp small; anterior row with two pairs of slender, hooked SMS; posterior row with three pairs of short, stout, hooked setae, one pair mesally, two pairs in close proximity, sublaterally; one to two pairs of short, straight, pointed setae anterolateral to posterior row. A5: Same as A4, except posterior row with lateral two setae on small laterodorsal tubercle, one LDS long, straight, pointed, one short. A6: Anterior row with one pair of very short setae; posterior row with one pair of very short setae between LDTs, each with one medium-length, straight LDS, one very short LDS. A7: Anterior region without setae; posterior section with pair of prominent LDTs, each bearing one long, straight LDS, one short LDS. A8: LTs each bearing one medium-length LS, one shorter LS; posterior section with two pairs of SMS, lateral pair longer than mesal pair. A9: In cleared specimen, segment appears subdivided; anterior section with one pair of small setae mesally, two pairs larger, more robust setae posteriorly; posterior section with one pair of robust setae mesally, one pair laterally. A10: Two pairs of short, straight setae on sides; small, eversible, membranous pouches distally.

Larval specimens & variation. Our samples were restricted to the offspring of three field-collected females from two localities in mid-coastal to southern Brazil [two lots from Rio de Janeiro: Santa Maria Madalena, Terras Frias (Tauber Lots 2003: 50, 2003: 51, TRC) and one lot from Rio Grande do Sul: Cachoeira do Sul, São Nicolau (Albuquerque Lot 0 5.13, UENF)]. Other than some differences in the size and depth of head and body markings, there was little variation of note. Specimens showed minor variation in the setal numbers mentioned in the descriptions. Many showed asymmetry in the numbers between the left and right sides of the body; such a pattern of asymmetry appears to be the norm among chrysopid species (see Mantoanelli et al. 2006; Tauber et al. 2011). We did not determine if one side or the other consistently had the higher number.

Egg. Ovoid, 2.4 – 2.7 mm long; 1.2 – 1.3 mm wide; stalk golden, 6.0 – 8.0 mm long; apparently without droplets. Color: light green to green.

Biology. Adults of this species were collected in the shadowy, lower understory of forested areas. In the laboratory, two gravid, field-collected, females laid ~25 stalked eggs per day for several days; the eggs were deposited individually, in no particular pattern. Hatching occurred within approximately five to seven days at room temperature (~21 ± 3°C). Larval development took approximately 20 to 25 days at the same temperature. During their development, the larvae were lively and fast moving; like most insects, they moved more slowly and less frequently as they approached ecdysis or spinning.

Generic comparisons. Behaviorally, T. trespuntensis shares many features with species in the two common Neotropical genera, Ceraeochrysa and Chrysopodes , that previously contained Titanochrysa species. For example, the larvae of all three genera are trash-carrying, and they have similar types of movements in placing and carrying debris on their dorsa. Moreover, females in all three genera lay their eggs individually, not in clusters with the stalks intertwined as do some species in other genera. One distinguishing feature of T. trespuntensis larvae is their agility and relatively rapid mobility; all three instars appeared to move more quickly and more frequently than species we have reared in the other two genera.

Like the larvae in other trash-carrying genera of Chrysopini , T. trespuntensis larvae have gibbous, setose bodies with well-formed lateral tubercles on the thorax and abdomen, and their dorsal setae are modified (elongate, hooked) for carrying small pieces of debris. Thus, superficially, they resemble the larvae of both Ceraeochrysa and Chrysopodes (see Tauber et al. 2000, 2001; Tauber 2003). However, the following set of traits can differentiate them:

1. Cephalic setae: all primary cephalic setae smooth (similar to Ceraeochrysa , but unlike many Chrysopodes ); numerous small secondary setae across the midsection of the cranial dorsum [a few Chrysopodes species have several (not numerous) secondary setae on the cranium; Ceraeochrysa species have none].

2. All thoracic setae smooth, except those on the lateral tubercles that may be lightly granulose (under x200 magnification) (similar to Ceraeochrysa , unlike many Chrysopodes ).

3. Metathorax with posterior subsegment bearing a row of robust, straight setae arising from brown chalazae with brown teardrop-shaped markings extending from the anterior surface (similar to Chrysopodes , but unlike Ceraeochrysa ).

4. Posterior subsegment of metathorax not raised above anterior subsegment (similar to Ceraeochrysa , but unlike Chrysopodes ).

5. Abdominal segment 1 with anterior row of robust, straight setae arising from large, brown chalazae with brown teardrop-shaped markings extending from anterior surface (unique),

6. Abdominal segments 2 – 5 each with anterior row of numerous long, smooth, hooked, submedian setae (SMS), middle row of four pairs of similar SMS (unique).

7. Abdominal segments 2 – 4 each with posterior row of three (first instar), seven to eight (second instar), or twelve to 14 (third instar) pairs of relatively short, stout, hooked setae, each extending from a brown chalaza with a teardrop-shaped, brown mark anteriorly (unique).

All of the above larval features that distinguish T. trespuntensis larvae are based on characters that are of general taxonomic value for chrysopine genera. Thus, we can use the differences to draw two general conclusions. First, although the validity of Titanochrysa as a distinct genus in the Chrysopini was well supported by adult characters ( Sosa & Freitas 2012), the above striking differences between T. trespuntensis larvae and the larval features that characterize the other two genera provide additional, strong evidence for the validity of the genus. Second, we predict that many, if not all, the character states listed here for T. trespuntensis apply generally to the genus. We hope that larvae of other Titanochrysa species will be reared and described in the near future to confirm or refute our prediction.

Figures

FIGURE 1. Titanochrysa trespuntensis, Examples of setae on dorsum (laboratory-reared third instar, from female collected in Rio de Janeiro State, Brazil). A. Two types of dorsal setae on the metathorax (posterior row) and anterior part of abdominal segment 1: elongate, robust, pointed setae (erp); short, thin, pointed setae (stp). B. Elongate, robust, hooked setae (erh) on posterior section of the abdominal segment 1. C. Two types of submedian setae on abdominal segments 2 – 4: elongate, thin, hooked setae (eth); short, robust, hooked setae (srh). D. Elongate, robust, pointed setae (erp) on the thoracic lateral tubercles.

FIGURE 2. Titanochrysa trespuntensis, Third instar (Laboratory reared from female collected in Rio de Janeiro State, Brazil). A. Head, dorsal; B. Head, ventral; C. Head, lateral.

FIGURE 3. Titanochrysa trespuntensis, Third instar (Laboratory reared from female collected in Rio de Janeiro State, Brazil). A. Head and thorax, dorsal; B. Abdominal segments 1 to 5, dorsal; C. Abdominal segments 6 to 10.

FIGURE 4. Titanochrysa trespuntensis, Third instar (Laboratory reared from female collected in Rio de Janeiro State, Brazil). A. Habitus, lateral; B. Habitus, ventral. Scale applies to both images.

FIGURE 5. Titanochrysa trespuntensis, Cleared and stained third instar, dorsum (Laboratory reared from female collected in Rio de Janeiro State, Brazil). A. Head; B. Thorax; C. Abdominal segments 1 to 5; D. Abdominal segments 6 to 10. Abbreviations: A 1 – A 10, first to last (tenth) abdominal segments; T 1, T 2, T 3, first, second and third thoracic segments.

FIGURE 6. Titanochrysa trespuntensis, Second instar (Laboratory reared from female collected in Rio de Janeiro State, Brazil). A. Head, dorsal; B. Habitus, lateral; C. Habitus, ventral; D. Thorax; E. Abdominal segments 1 to 5; F. Abdominal segments 6 to 10.

FIGURE 7. Titanochrysa trespuntensis, First instar (Laboratory reared from female collected in Rio de Janeiro State, Brazil). A. Head, dorsal; B. Head, thorax, dorsal. C. Habitus, lateral; D. Abdominal segments 1 to 5, dorsal. E. Abdominal segments 6 to 10, dorsal. F. Habitus, ventral. G. Head, cleared. H. Body, cleared.