Chrysopodes (Chrysopodes) lineafrons Adams & Penny, 1987

Silva, Patricia S., Tauber, Catherine A., Albuquerque, Gilberto S. & Tauber, Maurice J., 2013, Larvae of five horticulturally important species of Chrysopodes (Neuroptera, Chrysopidae): shared generic features, descriptions and keys, ZooKeys 262, pp. 39-92 : 65-72

Chrysopodes (Chrysopodes) lineafrons Adams & Penny, 1987 Figs 2 –419– 22

Discussion.

Chrysopodes (Chrysopodes) lineafrons occurs widely throughout South America where it frequently has been reported from cropping systems, especially tropical fruit orchards ( Adams and Penny 1985, González Olazo et al. 1999, Freitas and Penny 2001, Silva et al. 2007). It is a relatively small-bodied species that can be recognized by its facial markings, parallel and dark gradate veins, and distinctive genitalia (male and female). Adults can be identified using the keys in Adams and Penny (1985) and Freitas and Penny (2001).

Known geographic distribution.

Argentina ( González Olazo et al. 1999); Brazil ( Adams and Penny 1985, Freitas and Penny 2001, Silva et al. 2007).

Larval diagnosis.

The dorsal head markings of Chrysopodes (Chrysopodes) lineafrons larvae are similar to those of Chrysopodes (Chrysopodes) divisus (Figs 2-4). However, Chrysopodes (Chrysopodes) lineafrons (Semaphoront A) can be differentiated from Chrysopodes (Chrysopodes) divisus by the smaller number of robust, thorny setae on the posterior fold (R1) of the metathorax (n = 4) and the smaller number of smooth, hooked SMS on abdominal segments A1-A5 (n = 16). A dense coating of spinules on the dorsal integument gives the Chrysopodes (Chrysopodes) lineafrons larval body (Semaphoront B) a distinctive dark brown hue (most notable on the thorax and abdominal segments A1-A6, including the pleural and ventral regions). Other distinguishing characteristics of Chrysopodes (Chrysopodes) lineafrons Semaphoront B are the thorny cranial setae S1, S4, S6, S11, the large, dark brown pronotal plates (Sc1), and the presence of secondary sclerites on the pronotal midline.

First instar.

(Semaphoront A). Body (Fig. 19A) 2.5-2.6 mm long; surface predominantly white to cream-colored, with some, small, light brown to brown markings.

Head (Figs 2D, 19B) 0.40-0.41 mm wide; mandibles 0.35-0.37 mm long (ratio, mandible length: head width = 0.85-0.90: 1). Cranium mostly brown, with elongate, white to cream-colored area posteromesally extending from margin of cranium anteriorly to base of frontal markings, pair of white to cream-colored areas between lateral arm of epicranial marking and postfrontal marking. Epicranial marking light brown mesally, darker brown laterally, with mesal and lateral arms fused posteriorly; lateral arm extending around antennal sockets, above eyes; mesal arm fused with postfrontal marking. Postfrontal marking diffuse, darker brown than most of epicranial marking, contiguous basally with distal margin of epicranial marking (mesal arm), extending anteriorly almost to mesal margin of antennal base. Frontal markings thin, dark brown, paired but fused mesally, extending laterally across anterior of head to middle of mandibular base, merged with brown intermandibular coloration. Cranial setae light amber; S1, S4, S6, S11 thorny; S1, S11 long, others shorter; Vx setae very small.

Gena, ventral margin of head capsule brown, with small clear patch within genal mark. Labial palpus tinged with light brown, slightly darker distally. Mandibles light brown. Antenna with light brown scape, pedicel white basally, brown distally; flagellum brown.

Thorax (Figs 2D, 19A) mostly cream to white, with sclerotized structures light brown to brown; episternum brown. Legs white, with base of coxa brown, femur (especially distal half) tinged with brown, dorsum of tibia tinged with light brown; tarsal claws, empodia, brown. LS light amber; other setae cream to light amber.

T1: Row of three small setae (R1) near base of LT not observed. Sc1 brown throughout, but slightly lighter mesally; S2Sc1 small, immediately above S1Sc1. S1 long; S3 intermediate-length, slightly thorny. T2: Spiracle with lip of atrium raised above integumental surface. Sc1, Sc2 transparent: Sc3 marked with light brown; S2Sc3 variable, from medium-length to long, S2 smaller than S2Sc3. T3: S1Sc1 present, S2Sc1 (sometimes absent), S1Sc2 very small. S2Sc2 absent. Raised posterior fold with row (R1) of four long, thorny, pointed setae on chalazae with ovate, light brown marks anteriorly.

Abdomen (Figs 19 C–D) white to cream-colored, with LTs, LDTs tinged with light brown, chalazae of most dorsal setae brown.

A1-A2: Dorsum with four to six SMS in anterior row, with 12 to 16 SMS in posterior row. Spiracles far lateral to anterior row, with SSp mesally. A3-A5: Anterior and posterior rows of SMS largely coalesced, with four to six SMS in anterior row, ten to 14 SMS in curved, posterior row. Spiracle with SSp near anteromesal margin. A6: Anterior region with row of two to six SMS, pair of small, straight setae lateral to SMS. Spiracle with pair of small SSp mesally. A7: Anterior region without setae or microsetae. Spiracle with SSp mesally. A8: Venter with two pairs of medium-length setae posteriorly, one pair of short setae anteriorly.

Second and third instars.

(Semaphoront B). Body (Figs 20E, 21 A–B) length 3.3-3.9 mm (L2), 5.8-6.8 mm (L3); surface white to cream-colored, with dense brown integumental spinules throughout, especially dense, dark on pronotum, mesonotum; primary pronotal, mesonotal sclerites brown to dark brown; dark brown marks ante rior and posterior to lateral tubercles; sclerites anterior to coxae dark brown, lateral section of abdomen mostly light brown to brown.

Head (Figs 3D, 4D, 20 A–B, 21 C–D) dorsum cream-colored, with brown to dark brown markings. Epicranial marking brown, with mesal and lateral arms in broad contact mesally; both arms in contact with posterior margin of head; lateral arm extending from distolateral margin of cranium to upper level of eye, distal part tapering, broken, almost surrounding dorsal margin of eye; mesal arm extending from base of head, almost confluent with postfrontal marking. Postfrontal marking dark brown, narrow throughout, extending toward inner margin of scape. Frontal marking dark brown, basal arms confluent with each other, forming broad central mark, extending from midsection of head, beyond tentorial pits to intermandibular marking; base of each arm rounded. Intermandibular marking dark brown, broad mesally, tapering laterally, at base of mandibles. Clypeolabral region cream to white. Gena cream-colored, with large, brown, forked marking near base of cranium, with tips of fork reaching approximately 3/4th distance to eye. Mandible, maxilla amber basally, mesally, dark brown laterally, distally. Labial palpus: basal section cream-colored with very slight tinge of brown laterally; mesal segment tinged with brown laterally, cream-colored mesally, with terminal subsegment brown; terminal segment brown. Antenna: scape amber; basal section of flagellum cream-colored with slight tinge of brown; distal 1/4th of pedicel, flagellum, darker brown. Venter amber, with large, white central area; margin of cranium, cardo dark brown; mentum with rectangular, brown spot basally.

All cephalic setae present; S1, S11 long; S2-S10, S12 medium length to short; S1 thorny; S4, S6, S11 lightly thorny (thorniness difficult to see except under high magnification, especially on L2); other setae smooth. Vx setae relatively short. Ante rior margin of head straight, with angled lateral margins; mesal pair of anterior setae medium-length, lateral two pairs short or very short.

Head width across eyes, 0.55-0.61 mm (L2), 0.91-0.96 mm (L3); mandible length, 0.49-0.55 mm (L2), 0.96-1.00 mm (L3); ratio mandible length to head width = 0.87-0.93 (L2), 1.02-1.07 (L3). Tip of mandible with six teeth mesally.

Cervix brownish, with dense covering of spinules; sides with pair of broad brown patches; venter brown throughout, darker laterally.

Thorax (Figs 3D, 4D, 20C, 20E, 21 A–B, 22A) brown dorsally, laterally, ventrolaterally, tinged by dense covering of brown spinules; sclerites, chalazae dark brown; LTs white, with LS white to light brown; chalazae cream-colored. Venter white to cream-colored mesally, with tinge of brown anteriorly, laterally, where spinules extend to ventral surface, without marks. Pleural region with small brown marks near the base of LTs. Legs: coxa white, with dark brown on dorsal surface; trochanter cream-colored to white, femur brown basally, dark brown distally; tibia white to tinged with very light brown, with light brown setae; tarsus tinged with very light brown; empodium, base brown; claws amber. Episternum with large brown mark; epimeron with small brown mark(s).

T1: LT with 15-19 (L2), 18-24 (L3) LS. Sc1 extending around posterior base of LT, dark brown laterally, mesally, with cream-colored to light brown, elongate streak with broad base. Three sclerites on midline: Sc2 triangular, cream-colored, with two brown spots anteriorly, mesal brown spot posteriorly, two smaller, light brown sclerites anterior to Sc2 [not all apparent on L2]. S2, S3 thorny. T2: Anterior sclerite (Sc1) brown; spiracle on small protuberance. Posterior subsegment with Sc2 transparent; Sc3 pronounced, dark brown. LT with 12-16 (L2), 14-18 (L3) thorny, robust LS, most long, several basal ones shorter. T3: LT with 12-16 LS (L2, L3). Posterior fold with 12-13 robust, thorny setae.

Abdomen (Figs 20 D–F, 21 A–B, 22 B–C) dorsum light brown to brown throughout, LTs of A2-A5 with dark brown anterior spots, sometimes posterior spots; LS white to amber, with dark brown chalazae; chalazae of dorsal setae dark brown. A6, A7 each with pair of large, dark brown marks dorsal to LTs, pair ventral to LTs; dark brown marks surrounding anterior lateral margins of LDTs; LDTs white with dark brown chalazae; SMS amber-colored. A8 with pair of dark brown marks mesal to spiracles. A9 with dorsum almost entirely dark brown. A10 with dark brown, inverted V-shaped mark; light brown laterally. Sides of A2-A6 with large, diffuse, brown patch below each LT; venter lightly tinged with brown, light brown mesally, darker brown laterally; A7-A8 mostly white ventrally; A9 light brown ventrally; venter of A10 with pair of small, contiguous, triangular dark brown marks.

A1: Dorsum with 40-76 (L2), ~128-150 (L3) SMS in two double-triple transverse bands between spiracles; bands not extending laterally beyond spiracles. A2-A5: Dorsum with 41-102 (L2), 119-173 (L3) SMS in two broad transverse bands. LT with 10-15 (L2), 18-30 (L3) LS: five to seven robust, thorny, blunt LS of various lengths, on distal surface; remaining LS less robust, smooth, hooked in patch on dorsal surface. A6: Dorsum with transverse band of 16-28 (L2), 28-38 (L3) SMS across anterior of segment; midsection with two pairs of smooth setae, mesal pair hooked, long, lateral pair pointed, shorter. LT with 9-11 (L2), 11-17 (L3) robust, thorny, blunt LS of various sizes. A7: Dorsum with two pairs of short setae between spiracles. LT with 8-10 (L2), 10-13 (L3) LS of various sizes. Venter with setal number and size variable, usually with two pairs of setae anteriorly (both small, smooth), three pairs of sublateral setae posteriorly (two lateral-most pairs robust, thorny, mesal pair small, smooth). A8: Dorsum with two pairs of small setae between spiracles; four pairs of small setae in transverse row between LTs. Venter with scattered, small setae anteriorly, two robust, thorny setae on small chalazae between LTs. A9: Dorsum with one pair of very small setae anteriorly. Middle and posterior regions with two transverse rings of setae extending around segment; each ring with ~14-16 setae of various sizes, several in each ring robust. A10: Dorsum with one pair of setae anteriorly, two pairs mesally, patch of several setae distally; one pair of small setae posterior to V-shaped anterior sclerites. Lateral region with two pairs of robust setae, two to three pairs of smaller setae. Venter with ~two pairs of robust setae, five pairs of small setae.

Egg.

At oviposition, green, with white micropyle; ovoid, 0.92 to 0.99 mm long, 0.40 to 0.44 mm wide. Stalk smooth, hyaline, 3.1 to 6.2 mm long.

Larval specimens examined.

Several lots, each originating from a single gravid female collected in Brazil, Bahia: Cruz das Almas, VI-19-96 (Tauber Lot 96:020B). Rio de Janeiro: Campos dos Goytacazes, Estação Experimental Pesagro, VI-20-2006 (Albuquerque Lot 2006:08).

Biology.

Adults of Chrysopodes (Chrysopodes) lineafrons are commonly found in citrus and other orchards (see summary in Silva et al. 2007).

In the lab, eggs were deposited separately (with isolated stalks), in small groups with no particular pattern. During the first 24 hours of oviposition, the eggs were bright green, with dark green blotches. On the second day, they began to develop a bluish brown tone, with brownish mottling; by the third day the eggs were greyish blue to pinkish, with brown mottling. At 24 ± 1°C, hatching occurred within six days (n = 12).

Larvae of Chrysopodes (Chrysopodes) lineafrons carry dense packets of woody plant material and other dry debris; they exhibit a side-to-side rocking motion. Development of the various stages (population from the state of Bahia: Cruz das Almas, 24 ± 1°C, n = 14) required: L1, 4-5 days; L2, 3 days; L3, 3-4 days; cocoon, 15 days; complete development from oviposition to adult emergence, 32 days. These data coincide well with the results from extensive rearings of Chrysopodes (Chrysopodes) lineafrons from the state of Rio de Janeiro (Campos dos Goytacazes) (see Silva et al. 2007).

Experimental life history studies of Chrysopodes (Chrysopodes) lineafrons in the laboratory and the field (southeastern Brazil) indicate: that the species can undergo development and reproduction all-year-round without interruption or dormancy; that during this time up to eight generations can be produced; and that temperature conditions play an important role in determining the rates of reproduction and development both in the lab and in the field ( Silva et al. 2007). The species is considered to have excellent potential for mass rearing and for use in the biological control of pests in fruit orchards ( Silva et al. 2007).