Zootaxa,Description of the Larvae of Corydalus Batesii Maclachlan And

Description of the larvae of Corydalus batesii MacLachlan and C. ignotus Contreras-Ramos (Megaloptera: Corydalidae) with notes on life history and behavior

CARLOS AUGUSTO SILVA DE AZEVÊDO1 & NEUSA HAMADA2 1Centro de Estudos Superiores de Caxias - CESC/UEMA, Praça Duque de Caxias, s/n Morro do Alecrim, CEP 65604-380 Caxias, MA. Divisão de Curso em Entomologia, Instituto Nacional de Pesquisas da Amazônia Manaus, AM, Brazil. E-mail: [email protected]. 2Coordenação de Pesquisas em Entomologia, Instituto Nacional de Pesquisas da Amazônia, Caixa Postal 478, CEP 69011-970 Manaus, AM, Brazil. E-mail: [email protected].

Abstract

Corydalus batesii MacLachlan is widely distributed in the Amazon region, while Corydalus ignotus Contreras-Ramos was previously known only from its type locality in French Guiana. Both species are only known as adults. Here, we describe the larvae of both species and provide notes on observations and measurements of several aspects of the life history of each species and of the adult behavior of C. batesii. Corydalus ignotus records presented herein are the first for this species in Brazil.

Key words: Brazil, Corydalus, Megaloptera, life history, behavior

Resumo

Corydalus batesii MacLachlan é amplamente distribuída na região Amazônica, enquanto que Corydalus ignotus Contreras-Ramos, era previamente conhecida somente de sua localidade tipo na Guiana Francesa. Apenas os adultos de ambas as espécies são conhecidos. No presente estudo, as larvas dessas duas espécies são descritas e notas sobre obser- vações e medidas de diversos aspectos da biologia de cada espécie e sobre comportamento dos adultos de C. batesii são fornecidas. Corydalus ignotus é registrada pela primeira vez no Brasil.

Palavras chave: Brasil, Corydalus, Megaloptera, história de vida, comportamento

Introduction

In the Neotropical region, the Megaloptera family Corydalidae includes 63 species in the following genera: Corydalus Latreille, Chloronia Banks and Platyneuromus Weele (Contreras-Ramos 1998, 1999a, 2000, 2002). In Brazil, only Corydalus and Chloronia have been reported, with 18 species. In the state of Amazonas four species of Corydalus have been reported: C. affinis Burmeister, C. amazonas Contreras-Ramos, C. batesii MacLachlan and C. nubilus Erichson (Contreras-Ramos 2006). Corydalus batesii is widely distributed in northern South America, being known from Bolivia, Brazil (Amazonas, Pará and Rondônia states), Colombia, French Guiana, Peru, Surinam and Venezuela (Contreras- Ramos 1998). Due to its reddish-brown color pattern on the body and wings, it is a species that can be easily distinguished from the others in the region. Corydalus batesi tesselatus was described as a subspecies of C.

Accepted by R. E. DeWalt: 8 Oct. 2007; published: 5 Nov. 2007 33 batesii based in a single female collected in Mérida, Venezuela, but now it is considered as a valid species: C. tesselatus Stitz (Contreras Ramos 1998), which is now thought to be unrelated to C. batesii. Species related to C. batesii are C. holzenthali Contreras-Ramos and C. neblinensis Contreras-Ramos, but the relationship between these species and their phylogenetic positions are still not well established (Contreras-Ramos 1998). Corydalus ignotus is clearly considered a member of the monophyletic C. arpi species group, and little information is available on this species. Until now this species was previously known only from its type locality in French Guiana. The female of this species is similar to C. tesselatus in its color pattern and in the sclerotization of its genitalia; however, the male is distinct (Contreras-Ramos 1998). Additionally, its anterior wing is similar to that of C. arpi Navás; however, its geographical distribution and the absence of a sharp post- ocular spine in C. ignotus can be used to distinguish them (Contreras-Ramos 1998). Studies on Megaloptera are scarce in the Neotropics, especially in Brazil (e.g. Flint 1973; Penny 1977, 1982; Contreras-Ramos 1998, 1999a, 2000, 2002; Contreras-Ramos et al. 2005; Contreras-Ramos & Harris 1998). In the Brazilian Amazon, knowledge about the immature stages is restricted to the illustration of the larva of Chloronia hieroglyphica Rambur (Penny & Flint 1982) and the larval description and bionomics of C. nubilus (Azevêdo & Hamada 2006). There is no published information on the immature stages of C. batesii and C. ignotus. In view of the scarcity of research about Corydalidae in the Amazon region, the objectives of this study are to describe the last-instar larvae of C. batesii and C. ignotus and to provide notes on observations and measurements of several aspects of the life history of each species and of the adult behavior of C. batesii, under laboratory conditions.

Material and methods

Larvae were collected between January and November 2002 in rivers and streams in Presidente Figueiredo municipality, near Federal Highway BR-174 and State Highway AM-240 (Fig. 1) and, in Manaus municipality in Reserva Florestal Adolpho Ducke, located on State Highway AM–010, Km-26, Amazonas, Brazil (Figs. 1–2).

FIGURES 1–2. Collection sites of Corydalus batesii and Corydalus ignotus (Insecta: Megaloptera). 1. Presidente Figueiredo Municipality, Igarapé da Onça; 2. Reserva Florestal Adolpho Ducke, Manaus Municipality, Igarapé Barro Branco.

Larvae for taxonomic description and for rearing in the laboratory to establish association with adults were collected by removing tree trunks, leaves, roots and stones in riffle and pool areas, using an aquatic dip-

34 · Zootaxa 1631 © 2007 Magnolia Press AZEVÊDO & HAMADA net and by direct search in the different habitats. Last-instar larvae were collected in the field and placed indi- vidually in plastic containers with leaves and roots to avoid damage to the larvae while in transport to the rearing laboratory. The methodology of Contreras-Ramos (1999b, 1999c) and Azevêdo & Hamada (2006) was used to induce pupation. Small larvae were fixed in 80% ethanol. In the laboratory, larvae received an injection of acidic ethanol in the abdomen for better preservation of the structures (Stehr 1987; Contreras- Ramos & Harris 1998). They were maintained under laboratory conditions in the rearing facilities of the Coordenação de Pesquisas em Entomologia, Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas. Larvae maintained in the laboratory were examined daily in the morning and, in the pre-pupal phase, they were also examined in the afternoon. Information on the date of collection and the date of beginning of the pre-pupae stage, pupation and emergence of adults was recorded. Larvae were fed aquatic immature stages of Diptera (Chironomidae and Culicidae), Ephemeroptera, Plecoptera and Trichoptera (Stewart et al. 1973; Con- treras-Ramos 1998; Azevêdo & Hamada 2006). Exuviae of larvae and pupae were collected from the pupal chamber and preserved in 80% alcohol. Last- instar larvae were identified by association with adults that emerged in the laboratory. The identity of last- instar larvae collected in the field was determined based on these associations. The lengths of last-instar larvae were measured dorsally from the base of epistomal suture to the end of the last abdominal segment and reported as mean ± standard deviation. Adults were maintained in a terrarium (56.4 × 58.5 × 37.1 cm) in the laboratory containing stones, leaves, branches and stream water, and they were fed a sugar solution (Contreras-Ramos 1998, 1999c; Azevêdo & Hamada 2006). We only observed the sexual behavior of C. batesii because we did not obtained males and females of C. ignotus in the laboratory at the same time. Adults were identified using the taxonomic key of Contreras-Ramos (1998) and by comparison with authoritatively identified specimens in the invertebrate collection of the Instituto Nacional de Pesquisas da Amazônia (INPA), located in Manaus, Amazonas. Male and female abdomens were detached from the thorax, cleared, and preserved in glycerin-alcohol (Contreras-Ramos 1998, 1999c; Azevêdo & Hamada 2006). All examined specimens were deposited in the INPA invertebrate collection.

In the examined material section L is the abbreviation for larvae. Ab1-10 is the abbreviation for Abdominal segment 1 – 10. Information on bionomics was obtained from 36 larvae collected in the field and maintained in the laboratory where the air temperature was 24–25º C, the same temperature range observed in rivers and streams where the larvae were collected. From these reared larvae, 20 adults of C. batesii (8 males, 12 females) and 16 adults of C. ignotus (4 males, 12 females) were obtained and observed. Days of activity are presented in the Table 1 as mean and standard deviation.

TABLE 1. Laboratory derived mean and standard deviation (± SD) days of activity of the larvae, pre-pupae, pupae and adults of two Corydalus species collected as larvae from the municipalities of Presidente Figueiredo and Manaus (Reserva Forestal Adolpho Ducke), Amazonas, Brazil.

Phases and activity period Larvae(*) Pre-pupae Pupae Adults Species male female male female male female male female Corydalus batesii 63.0±28.47 62.3±21.87 7.1 ± 0.83 7.2±0.83 13.4 ± 0.74 13.3 ±l.07 4.0 ±2.33 4.1 ±2.39 n = 8 n = 12 n = 8 n = 12 n = 8 n = 12 n = 8 n = 12 Corydalus ignotus 77.8 ±30.23 66.3 ±47.42 7.3 ± 0.50 7.0 ±0.60 14.5 ± 1.29 12. 7 ±1.23 3.3 ±0.96 3.6 ±1.72 n = 4 n = 12 n = 4 n = 12 n = 4 n = 12 n = 4 n = 12

Note: (*) Represents the activity period of larvae in the laboratory after collection in the field, without knowledge of its instar.

Last-instar larval description of Corydalus batesii MacLachlan, 1868 Dorsal and ventral habitus (Figs. 3A–B).

Diagnosis. Larvae of this species have the region between the stemmata, genal carina and the median region of the frontal suture with wide, pale-yellow bands. The apex of the submental projection is blunt and does not pass beyond the anterior edge of the mental plate. The mandible has the basal-most tooth wide, truncate and partially fused to the 2nd tooth. Abdominal tergites have black, subtriangular microsetae and pale-brown to dark macrosetae that are either claviform, tubular, or star-shaped. Larval description. Total length: mean = 7.3 ± 0.70 mm, n = 34. Head. Posterior region with color pattern similar to the thorax (Fig. 5A). Pleurostomal region and epistomal suture dark brown to black; front area of the sclerite pale brown to dark reddish; posterior median region with clear spots (Fig. 5A). Region between the stemmata, genal carina and median region of the frontal suture with wide, pale-yellow bands (Fig. 5A). Long setae present around the stemmata. Region around coronal suture brown to dark reddish (Fig. 5A). Occipital carina dark reddish brown to almost black. Occiput region with four pale-brown bands alternating with dark brown (Fig. 5A). Antenna with five segments, dark brown to black in color. Labrum longer than wide, narrowing at the anterior region, with dark spots on the lateral area. Clypeus 2.5 times wider than long, with two black lateral spots near the epistomal suture, with three longitudinal, thin, clear, stripes (Fig. 5A). Ventral region pale brown to dark reddish color, with pale-yellow pattern; areas next to the cardo, gular plate and submental projection dark brown (Fig. 6A); small setae bent toward the anterior region of the head. Gular plate with three pairs of lateral setae. Post-ocular carina with rows of short setae; lateral area of gular plate with pale-brown pattern similar to the prothorax (Fig. 6A). Anterior region of the gular plate with one pair of pale-brown spots, and apex of the submental projection approximately blunt, short and relatively wide, not passing beyond the anterior edge of the mental plate (Fig. 6A). Mandible with five teeth, dark reddish brown, to black; lateral areas of the mandible dark; apical tooth twice length of penultimate one, which is larger than the 3rd tooth; basal-most tooth wide, truncate and partially fused to the 2nd tooth (Fig. 7A). Maxilla with lateral border pale brown to dark. Long setae resembling thorns on the inner margin of the maxilla. Maxillary palp with four segments; galea with two segments; labium pale brown to dark, usually surrounded by pale setae. Glossa pale brown to dark; labial palp three-seg- mented, pale brown to dark. Thorax. Pronotum pale brown to dark, almost black, pattern similar to that of head; lateral area pale brown to dark reddish, dorsally with small setae sparsely distributed and bent toward the anterior region. Antero-median and medial area of prothorax paler than laterally (Fig. 5A). Ventrally, prothorax with anteromedian area pale brown, with short setae bent toward anterior end; lateral margin dark brown to almost black; sternellum triangular with central projection dark brown, covered with short setae. Pleural region of prothorax with short microsetae, dark brown to black. Meso- and metathorax subequal in width and length, with pattern similar to the pronotum. Both segments have a row of long, thin setae on the margins and dark areas on the anterior region with clavate microsetae which are dark brown to black. Ventrally, median region with microsetae. Legs have color pattern with alternate pale and dark brown sections. Abdomen. Lateral filaments with long setae, directed dorsally; spiracles round, with straight anterior margin and depressed medially (Fig. 8A). Ventrally, base of abdominal sternites one through seven (Ab1-7) with tufts of lateral gills decreasing in size; each gill tuft composed of three segments bearing branchial filaments (Fig. 3B). Dorsally, tergites with large number of black, subtriangular microsetae, pale-brown and dark macrosetae with shapes varying from star-shaped to claviform and tubular (Fig. 9A). Ventrally, sternites covered with microsetae and a small number of clavate and tubular macrosetae; Ab1 with one pair of long setae medially; Ab2-8 with two pairs of long setae; Ab2-7 medially with area lacking microsetae in a V-shaped

36 · Zootaxa 1631 © 2007 Magnolia Press AZEVÊDO & HAMADA pattern (Fig. 10A); Ab8 medially with two oval areas without microsetae. Ab9-10 with median sclerotized plate pale brown to dark; in the other abdominal segments, this plate is absent.

FIGURE 3. Larval dorsal (A) and ventral (B) habitus of Corydalus batesii.

Remarks. The larvae of C. batesii can be distinguished from those of C. nubilus and C. ignotus by having a pale, wide, horizontal stripe between the stemmata, genal carina and median region of the frontal suture which is absent in the latter two species. Corydalus batesii have mandibles with three apical teeth distinct and two basal teeth fused, similar to C. ignotus, while in C. nubilus the basal teeth are not fused. Corydalus batesii submental projection is blunt while in C. nubilus and C. ignotus this projection is acute. Abdominal tergites of C. batesii have subtriangular microsetae and macrosetae that are claviform, tubular, or star-shaped, while in C. nubilus and C. ignotus the microsetae are thinner and elongated and star-shaped macrosetae are lacking.

CORYDALIDAE LARVAE DESCRIPTION Zootaxa 1631 © 2007 Magnolia Press · 37 Material examined (all larvae are last instar). BRAZIL: Amazonas: Presidente Figueiredo County; Iga- rapé do ramal do Castanhal, 03°01’45”S/60°08’33”W: 3 L, 9.ix.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Hamada, N. & Pereira, D.L.V.; Igarapé da Onça, Recanto da Pantera, Highway AM 240, Km 20, 02°00’52’’S/ 60°01’43’’W: 4 L, 22.xi.2001, Azevêdo, C.A.S.; Pes, A.M.O.; Hamada, N. & Nessimian, J.L.; 2 L, 12- 13.xii.2001, Azevêdo, C.A.S. & Pes, A.M.O.; 2 L, 11.ix.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; 1 L, 16.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Igarapé do Sr. José, ramal do Km 24, Highway AM 240, 02°01’07’’S/59°49’28’’W: 2 L, 12.ix.2002, Azevêdo, C.A.S.; Pes, A.M.O. & Pereira, D.L.V.; Igarapé da SUFRAMA, Highway BR 174, Km 97, 02°08’07’’S/59°59’46’’W: 1 L, 13.ix.2002, Azevêdo, C.A.S.; Pes, A.M.O. & Pereira, D.L.V.; Igarapé II do ramal da Morena, Highway AM 240, 02°01’12’’S/59°26’19’’W: 1 L, 19.ix.2002, Azevêdo, C.A.S.; Pes, A.M.O. & Pereira, D.L.V.; Igarapé I do ramal da Morena, Highway AM 240, 02°04’15’’S/59°20’52’’W: 1 L, 19.ix.2002, Azevêdo, C.A.S.; Pes, A.M.O. & Pereira, D.L.V.; Igarapé I do ramal da Cachoeira do Boto, 02°07’06’’S/59°19’17’’W: 5 L, 12.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Igarapé afluente da Corredeira do Camarão, (Afluente do Rio Urubu), 02°01’05’’S/60°02’02’’W: 1 L, 10.x.2002, Azevêdo, C.A.S.; Pes, A.M.O. & Pereira, D.L.V.; Igarapé do Sítio São Francisco, Km 30, Highway AM 240, 02°02’30’’S/59°46’06’’W: 4 L, 15.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Igarapé da Vivenda Fênix, ramal do Rio Urubuí, 02°03’00’’S/60°05’58’’W: 1 L, 16.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Igarapé da Corredeira do Portal dos Anjos, ramal do Rio Urubuí, 02°03’38’’S/60°05’58’’W: 2 L, 16.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Manaus: Reserva Ducke: Highway AM 010, Km 26, 2º55’S/59º59´W; Igarapé Acará-Lages, 1 L, 23.i.2002, Azevêdo, C.A.S. & Pes, A.O.; Iga- rapé Bolívia-31, 1 L, 17.iv.2002, Azevêdo, C.A.S. & Pes, A.O.; Igarapé Bolívia near camp, 1 L, 23.iv.2002, Azevêdo, C.A.S. & Pes, A.O.; Igarapé Acará-I, 1 L, 20.xi.2002, Azevêdo, C.A.S. & Pes, A.O.; Igarapé Cabeça Branca, Highway BR 174, Km 24, 1 L, Azevêdo, C.A.S. & Pes, A.M.O.

Last-instar larval description of Corydalus ignotus Contreras-Ramos, 1998 Dorsal and ventral habitus (Figs. 4A–B).

Diagnosis. The epistomal suture of this species is reddish brown to black, while areas next to the stemmata, frontal suture, frontal sclerite, and coronal suture are reddish brown. Lateral areas of the coronal and occipital suture are dark brown to reddish brown and the apex of the submental projection is acute, extending beyond the anterior edge of the mental plate. Its mandibles have a wide basal tooth that is almost fused to the 2nd tooth. Abdominal tergites have thin, elongate, pale-brown microsetae, distributed sparsely among the pale-brown, clavate and tubular macrosetae. Larval description. Total length of larva: mean = 4.8 ± 0.27, n = 79. Head. Dorsally with posterior area pale brown color, with reddish pattern similar to the pronotum (Fig. 5B). Pleurostomal region dark brown to black; epistomal suture reddish brown to black; areas next to stemmata, frontal suture, frontal sclerite, and coronal suture reddish brown (Fig. 5B). Genal carina dark, stemmata surrounded dorsally by a pale-brown stripe. Post-ocular region and occipital carina with pale-brown to reddish color pattern; post-ocular carina dark brown (Fig. 5B). Lateral area of coronal and occipital suture dark brown to red (Fig. 5B). Presence of long setae on the lateral area of the post-ocular carina. Occiput region with four pale-brown stripes, alternated with dark-brown areas (Fig. 5B). Labrum wide, dark brown. Clypeus 2.5 times wider than long, pale brown to dark, with dark lateral spots and three pale longitudinal stripes. Ventral region dark-brown to reddish color. Gular plate with reddish-brown lateral area; carina and occipital sutures dark brown to red. Next to the submental projection are small, anteriorly bent setae. Submental projection with acute apex, extending beyond the anterior edge of the mental plate (Fig. 6B). Mandible pale brown with central area dark brown to reddish; borders and lateral areas of teeth dark; apical tooth longer and thinner than

38 · Zootaxa 1631 © 2007 Magnolia Press AZEVÊDO & HAMADA penultimate one, which is longer than the 3rd tooth; basal tooth wide and almost fused to the 2nd tooth (Fig. 7A). Maxilla dark reddish brown, with lateral setae similar to spine on the inner margin. Stipe of the maxilla pale brown to dark. Maxillary palp pale brown to dark reddish brown, surrounded by pale and dark setae. Labial palp pale brown to dark, with three segments.

FIGURE 4. Larval dorsal (A) and ventral (B) habitus of Corydalus ignotus

FIGURE 6. Ventral view of cardo, gular plate and lateral projection of mental plate of the larvae: A. Corydalus batesii, B. Corydalus ignotus, C. Corydalus nubilus.

Thorax. Pronotum dark brown to black; anteromedian area with pale spots (Fig. 5B) postero-median region and area adjacent to thoracic suture with color pattern similar to head, pale brown to red (Fig. 5B); lateral area dark brown, with short and long setae bent toward anterior region. Ventrally, with antero-median region pale brown to dark; triangular sternellum with short setae. Meso- and metathorax subequal in width and length. Thoracic sternite covered with tubular and clavate micro- and macrosetae, pale brown. Dorsally, with pattern similar to the pronotum, short setae on the lateral and antero-posterior areas; dark areas with long setae; claviform macrosetae. Legs pale brown to dark.

Abdomen. Dorsally, pale brown to dark. Ab1-8 with lateral filaments and small number of filamentous setae on up to half of the filament. Spiracles located dorso-laterally in the anterior region of lateral abdominal

FIGURE 8. Dorsal view of spiracle of the 1st abdominal segment of the larvae: A. Corydalus batesii, B. Corydalus ignotus, C. Corydalus nubilus.

FIGURE 9. Dorsal view of the macro and microsetae of the 5th abdominal segment in larvae: A. Corydalus batesii, B. Corydalus ignotus, C. Corydalus nubilus.

FIGURE 10. Ventral view of the 5th abdominal segment with V-shaped pattern in larvae: A. Corydalus batesii, B. Cory- dalus ignotus, C. Corydalus nubilus.

CORYDALIDAE LARVAE DESCRIPTION Zootaxa 1631 © 2007 Magnolia Press · 41 filaments. Spiracles almost straight in the anterior region; posterior region more elevated than anterior (Fig. 8B). Tergites with thin, elongated, pale brown to dark microsetae, distributed sparsely among the pale-brown, clavate and tubular macrosetae (Fig. 9B). Sternites, with large number of dark microsetae and pale-brown macrosetae. Ab1 sternum with one pair of long setae medially; two pairs of long setae on Ab1-8 sternites; areas of Ab1-7 without microsetae forming a V-shaped pattern medially (Fig. 10B); Ab8 with two rounded areas without microsetae and two long filamentous setae. Ab9-10 with median sclerotized plate pale brown to dark, in the other abdominal segments, this plate is absent. Macro- and microsetae present on base of abdominal filaments. Ab1-7 with gill tufts, decreasing in size posteriorly, each side of gill tuft composed of three segments bearing gill filaments (Fig. 3B). Material examined (all larvae are last instar). BRAZIL: Amazonas: Presidente Figueiredo County: Iga- rapé do Km 13, Comunidade Marcos Freire, Highway AM 240, 1 L, 29.ii.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé do ramal do Canoas-Ponte, Highway BR 174, 01°49’18’’S/60°10’07’’W: 1 L, 10.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Hamada, N. & Pereira, D.L.V.; Igarapé da Onça, Recanto da Pantera, High- way AM 240, Km 20, 02°00’52’’S/60°01’43’’W: 1 L, 11.ix.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Pereira, D.L.V.; Igarapé do ramal do Km 24, Sr. José, Highway AM 240, 02°01’07’’S/59°49’28’’W: 3 L, 12.ix.2002, Azevêdo, C.A.S.; Pes, A.M.O. & Pereira, D.L.V.; Igarapé II do ramal da Morena, Highway AM 240, 02°00’58’’S/59°51’33’’W: 1 L, 14.ix.2002, Azevêdo, C.A.S.; Pes, A.M.O. & Pereira, D.L.V.; Igarapé do Mutum, ramal da Porteira, Highway AM 240, 02°02’15’’S/59°54’53’’W: 1 L, 14.ix.2002, Azevêdo, C.A.S.; Pes, A.M.O. & Pereira, D.L.V.; Igarapé da Cachoeira de Iracema, Highway AM 240, Km 17, 01°59’10’’S/ 60°03’44’’W: 4 L, 9.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Igarapé da Corre- deira do Camarão (afluente), Highway BR 174, KM 110; 02°01’05’’S/60°02’04’’W: 1 L, 10.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Rio Urubuí, Highway BR 174, Km 110; 02°01’05’’S/ 60°02’04’’W: 2 L, 10.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Igarapé II do Km 60, Highway AM 240, 01°59’27’’S/59°31’35’’W: 1 L, 13.x.2002, Azevêdo, C.A.S.; Pes, A.M.O. & Bobot, T.E.; Pereira, D.L.V.; Igarapé I do ramal da Maroca, Highway AM 240, Km 17, 02°00’58’’S/59°51’33’’W: 5 L, 11.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Igarapé II do ramal da Maroca, Highway AM 240, Km 17, 02°00’58’’S/59°51’33’’W: 5 L, 11.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Igarapé I do ramal da Cachoeira do Boto, 02°07’06’’S/59°19’17’’W: 5 L, 12.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Igarapé da Corredeira Pedra Furada, Highway AM 240, Km 57, 01°59’34’’S/59°33’26’’W: 5 L, 13.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Igarapé do Balneário Água Viva, Highway AM 240, Km 12, 02°03’11’’S/59°55’24’’W: 1 L, 15.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V.; Igarapé da Vivenda Fênix, ramal do Rio Urubuí, 02°03’00’’S/60°06’09’’W: 1 L, 16.x.2002, Azevêdo, C.A.S.; Pes, A.M.O.; Bobot, T.E. & Pereira, D.L.V. Manaus: Reserva Ducke: Highway AM 010, Km 26, 02º55’S/59º59`W; Igarapé Barro Branco; 1 L, 30.i.2001, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Acará-31, 1 L, 31.i.2002; Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Barro Branco; 2 L, 18.ii.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Barro Branco; 1 L, 9.iv.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Bolívia-31; 1 L, 16.iv.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Bolívia-13; 3 L, 18.iv.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Bolívia-12; 2 L, 19.iv.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Bolívia-21; 1 L, 19.iv.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Ipiranga-14; 7 L, 24.iv.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Ipiranga-21; 2 L, 26.iv.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Ipiranga-12; 1 L, 27.iv.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Ipiranga-11; 1 L, 28.iv.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Acará-32; 2 L, 5.iv.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Uberê-21; 2 L, 10.v.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Uberê-11; 1 L, 13.v.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Acará-12; 1 L, 5.vi.2002; Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Tinga-12; 1 L, 7.v.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Tinga-14, 1 L, 11.vi.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Uberê-13; 1 L, 12.v.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Tinga-32; 1 L, 13.vi.2002, Azevêdo, C.A.S. & Pes,

42 · Zootaxa 1631 © 2007 Magnolia Press AZEVÊDO & HAMADA A.M.O.; Igarapé Tinga; 1 L, 13.vi.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Acará-23; 1 L, 1.vi.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Barro Branco; 2 L, 6.viii.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Bolívia-16; 2 L, 7.viii.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Barro Branco; 2 L, 8.viii.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Acará-Lages; 2 L, 9.viii.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Bolívia-14; 1 L, 14.viii.2002, Azevêdo, C.A.S. & Pes, A.M.O.; Igarapé Acará I; 1 L, 20.xi.2002, Azevêdo, C.A.S. & Pes, A.M.O. Remarks. Corydalus ignotus larva can be distinguished from the other two species of Corydalus, with known larvae by the anteromedial region of its head being dark brown to reddish, while C. nubilus larvae have two light brown dorsal spots centrally and C. batesii has a pair of pale, wide, horizontal stripes anteriorly. Corydalus ignotus has mandibles with three apical teeth distinct and two basal teeth fused, similar to that of C. batesii, while in C. nubilus the basal teeth are not fused. Corydalus ignotus has the submental projection acute, similar to C. nubilus, while in C. batesii this projection is blunt. Abdominal tergites of C. ignotus have thin, elongate, pale-brown to dark microsetae, sparsely distributed among the pale-brown macrosetae, while in C. nubilus the microsetae are also elongate and thin, but they are darker and densely distributed. Conversely, C. batesii has subtriangular microsetae and pale-brown to dark macrosetae that are either claviform, tubular, or star-shaped.

Bionomic aspects of larvae, pupae and adults in the laboratory

Since larvae collected in the field were not the same age, the length of time they were kept in the laboratory varied considerably (Table 1). Larvae of C. batesii were kept in the laboratory for a maximum of 134 days, while C. ignotus were maintained under the same conditions for a maximum of 163 days (Table 1). Azevêdo & Hamada (2006) observed that C. nubilus males were maintained in the laboratory for a period 30.6% longer than females. The mean period for development of the pre-pupae of both species and both genders under laboratory conditions was seven days (Table 1). A similar period was observed for development of the pre-pupae of C. nubilus (Azevêdo & Hamada 2006) and Platyneuromus (Contreras-Ramos 1998, 1999b) under laboratory conditions. The pupal period of C. batesii and C. ignotus, for both genders, was between 13 and 14 days (Table 1). Contreras-Ramos (1998, 1999b) reported that Platyneuromus and Corydalus remained eight to nine days in this stage under laboratory conditions. Azevêdo & Hamada (2006) observed that C. nubilus females required a pupation 35.7% longer than did males. In the Nearctic region, the reported mean for Neohermes, Pro- tochauliodes and Chauliodes is between seven and 14 days (Neunzig & Baker 1991; Evans & Neunzig 1996). Adults of C. batesii held under laboratory conditions had a mean lifespan of four days, varying from three to eight days for males and one to eight days for females (Table 1). The mean time for this period in C. ignotus was three days for both genders (Table 1). In C. nubilus, females lived twice as long as males (Azevêdo & Hamada 2006). Chandler (1956), Parfin (1952) and Contreras-Ramos (1998, 1999b) reported approximately eight days for this stage in Corydalus cornutus Linnaeus and Platyneuromus under laboratory conditions. Penny (1982), based on studies of C. cornutus and C. cognatus Hagen, suggested that greater female longev- ity occurs due to the time needed for egg maturation, while in males the short life span would be due to the mandible length. Corydalus batesii males, similar to C. nubilus males (Contreras Ramos 1998), have longer mandibles and reduced dentition than do the females. However, in C. ignotus there was no sexual dimorphism in mandible length or structure (n= 16). Sexual dimorphism in mandible length is common in species of the genus Cory- dalus (Contreras-Ramos 1998), while in Chloronia and Platyneuromus it is absent. Some species of Platy- neuromus have strong sexual dimorphism in relation to the postocular flanges, located on the lateral margin of

CORYDALIDAE LARVAE DESCRIPTION Zootaxa 1631 © 2007 Magnolia Press · 43 the head which develops in a disproportional way (especially in males) conferring an unusual appearance to this genus (Glorioso & Flint 1984; Contreras-Ramos 1998). Before pupation, larvae construct a pupal chamber where they remain motionless (“lethargic” behavior) for two to three days, maintaining the abdomen curved towards the dorso-lateral position. The exarate pupae are active, moving daily in their pupal chambers. Emergence of both species, C. batesii and C. ignotus, occurs in the evening to early-morning hours, as described for C. nubilus (Azevêdo & Hamada 2006). The male of C. batesii curves its abdomen above the wings and makes frequent movements with its wing and abdomen, while walking, chasing the female. When the male reaches the female, it places its head over the female’s wings, touching her with his antennae; in this position, the female remains still. Then, the male uses his mandibles to raise the female’s wings, he moves to the side and bends his abdomen laterally, apparently trying to find the female’s genitalia; also, in this position the male raises his wings. Copulation occurs with the male on the side of the female, always with the heads facing in opposite directions. After copulation, the male places its head over the female’s wings, remaining still for a brief period of time. Contreras Ramos (1998) referred to active behavior of males in the mating process, involving flights, threat postures, and wing fluttering and female pursuit described by Parfin (1952) for C. cornutus, by Evans (1972) for C. tex- anus Banks (as C. cognatus). Contreras-Ramos (1999b) recorded similar behavior for Platyneuromus soror Hagen. In this study, we reported for the first time the presence of C. ignotus in Brazil and described its last-instar larva; additionally, we described the last-instar larva of C. batesii. We have also contributed knowledge of the mating behavior of C. batesii and on the life history of these two Neotropical Megaloptera.

Acknowledgments

The authors thank the National Council for Scientific and Technological Development (CNPq) for providing fellowships to the authors. Financial support was provided by the Ministry of Science and Technology/INPA/ PPI and CNPq (Edital Universal, processo # 479258/2001-5). Deyse Queiróz made the line drawings presented in this paper. Dr. A. Contreras-Ramos confirmed the identification of C. ignotus. Dr. P.M. Fearnside previewed an early draft of the manuscript and two anonymous reviewers provided helpful insights on this paper.

References

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