First identified “wild shot” photographs of Cautethia yucatana (Clark, 1919) on the Internet (: : Macroglossinae: Macroglossini) Primeras fotografías de campo identificadas en la red de Cautethia yucatana (Clark, 1919) (Lepidoptera: Sphingidae: Macroglossinae: Macroglossini)

Ben Trott

Amateur Entomologist specializing in Sphingidae of the Western Palearctic, the Nearctic, and the Neotropic Expert of the Sphingidae Galleries on BiodiversidadVirtual.org – Essex (United Kingdom) – [email protected]

ABSTRACT: Cautethia yucatana has been reported from Southern California and Southern Texas to Costa Rica. This note presents the first ‘wild shot’ photographs of this species on the Internet, (there are photographs of imagos of this species from pinned collections), and provides a data held on distribution, habitat and biology of this species, although it should be noted that there was very little information available to assist this study. KEY WORDS: Lepidoptera, Sphingidae, Macroglossinae, Macroglossini, Cautethia yucatana , Cautethia spuria , Southern California, Southern Texas, Mexico (Yucatán Peninsula), Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, Chiococca alba and Exostemma mexicanum (larval hostplants), Rubiaceae, Lantana camara , Verbenaceae .

RESUMEN: Cautethia yucatana está presente desde el sur de Texas y California hasta Costa Rica. La presente nota muestra las primeras fotografías de campo identificadas de esta especie en Internet (hay fotografías de imagos de esta especie en una colección), y proporciona una recopilación de los datos que se tienen sobre esta especie en cuanto a distribución, hábitat y biología, aunque hay que precisar que había poca información disponible para este estudio. PALABRAS CLAVE: Lepidoptera, Sphingidae, Macroglossinae, Macroglossini, Cautethia yucatana , Cautethia spuria , sur de California, sur de Texas, México (Península del Yucatán), Belice, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, Chiococca alba e Exostemma mexicanum (plantas nutricias de la larva) , Rubiaceae, Lantana camara , Verbenaceae.

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Figs. 1 & 2: Cautethia yucatana . Imago (male, wingspan 34 mm) at rest, 25-I-2013, (TROTT , 2013). http://www.biodiversidadvirtual.org/insectarium/details.php?image_id=435518

Figs. 3 & 4: Cautethia yucatana . Imago (female, wingspan 38 mm) at rest, 16-I-2013, (TROTT , 2013). http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img435023.html

27 Introduction

During November and December of 2012, I uploaded photographs to the BiodiversidadVirtual.org website of imagos of a belonging to the Sphingidae family and Macroglossini subfamily, seen nectaring from Lantana camara (Verbenaceae). This sighting prompted the work in this study. Except for pinned imago photos in collections there are no other existing photographs, and the life- cycle is poorly documented, with no existing photographs of the ovum or early-instar larvae. After checking that the wild-shot photos were indeed the first on the internet, I decided to write this article with the collaboration and help of José Manuel Sesma, Antonio Ordóñez, and Torsten van der Heyden from BiodiversidadVirtual.org.

Material and methods

MEXICO: Playa del Carmen, 22-XII-2013, 25-XII-2012, 26-XII-2012, 27-XII-2012, 28-XII-2012, 29-XII-2012, 1-I-2013, 2-I-2013, 3-I-2013, 8-I-2013, 9-I-2013, 10-I-2013, 12-I-2013, 14-I-2013, 15-I-2013, 16-I-2013, 17-I-2013, 25-I-2013. Altitude: 3-15 m, Ben Trott. Photographs of the adults/imagos (Figs. 1-5), the egg (Fig. 6), all instars and colour forms of the larvae (Figs. 8-21), the hostplant Chiococca alba (Figs. 7 & 26), the pupae (Fig. 22-25), and habitats (Figs. 27 & 28).

Cautethia yucatana

This species was described by Clark as a member of the genus Cautethia, Grote, 1865: Cautethia yucatana (Clark, 1919).

Description (type locality: North-Eastern Yucatan Peninsula, Mexico)

Imago: Wingspan: 32-38 mm. Variable, sexually dimorphic, male and female are similar in size, the female having a much stouter body, being slightly larger, and generally much darker in colour. Another remarkable difference is that the male has black dashes on the forewings which are aligned with the black detail on the end of the abdomen, thus breaking the moth’s outline. Forewing base colour is made up of a variety of greys with darker markings and spots, with off-white markings, with an intermediate white and grey border along the posterior margin. The hindwings are orange or rusty orange, with large black borders which cover more than 50% of the wing. The upperside of the body is mainly grey, with black details and patches; the thorax is grey with thin black lines. A black and dark grey central abdominal belt is present, highlighted by paler, adjacent segments, which are more contrasted in males, with the last body segments being white in males and grey in females. The side and underside of the body is mainly white from the head down to the central abdomen, where the abdominal black belt is still present; the rest of the lower abdomen is grey. This hawkmoth can be confused with one other species in the same genus; Cautethia spuria , found in the same countries, except for the State of Oklahoma both species share the same habitat, but C. spuria hasn’t been reported in California as far as I know. I suspect that the sightings in the southern U.S. are vagrants. C. yucatana females are differentiated from C. spuria females by having off white patches on the forewings, and C. yucatana males are much lighter, although, in flight, these two species are practically impossible to tell apart. The larva of C. spuria is easily identified by its thick, laterally flat horn; C. yucatana has a thin one.

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Fig. 5: Cautethia yucatana . Imago (male, approx. wingspan 32 mm), feeding from Lantana camara , 25-XII- 2012, (TROTT , 2012). http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img432001.html

Adult biology

Occurring in local, dense colonies, where it can go unnoticed due to its very small size. A crepuscular species, it is attracted to flowers for short periods at dusk and dawn, although the females can be seen during late afternoon, searching for suitable sites for ovipositing. In the low coastal forests of the Yucatan Peninsula, Eastern Mexico, two or three can be seen at a time in a small area, visiting Lantana camara (Verbenaceae) flowers.

Ovum: 0.9 x 1.0 mm. Spherical, pale green turning bright yellow before hatching. For such a small species, the egg is surprisingly large.

Fig. 6: Cautethia yucatana. Egg on new shoot of Chiococca alba , 28-XII-2012, (TROTT , 2012). http://www.silkmoths.bizland.com/cyucatan.htm Fig. 7: The larval hostplant, Chiococca alba (vine form), 27-XII-2012, (TROTT , 2012). http://www.silkmoths.bizland.com/cyucatan.htm

29 Larva: Fully grown, 30-35 mm. Polymorphic. First instar: The newly emerged 3-4 mm long larva is bright yellow, like the egg, and turns yellow green with feeding; the horn is black and slightly upturned. The body is smooth-skinned.

Figs. 8 & 9: Cautethia yucatana . 1st instar larva on Chiococca alba , 26-XII-2012, (TROTT , 2012). http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img432234.html

Second instar: A pale yellow or white dorso-lateral line appears and runs from the horn towards the yellow head where it fades away or disappears completely. The horn takes on a dark red and orange colour and is covered in fine spikes. The body also is spotted with very fine pale dots. The sub-spiracular line is absent, and the body remains smooth skinned. Third instar: The body colour is light green spotted with white, with much more pronounced white or pale yellow dorso-lateral stripes (in some larvae they are more pronounced than the sub-spiracular stripe), that become lighter towards the head and horn. The sub-spiracular stripe appears during this instar and is also white or pale yellow. The horn is very granulose, is green or pink with black tip, covered with black spikes. The body is no longer smooth and is covered in very fine, short hairs.

Fig. 10 (left) : Cautethia yucatana . 2nd instar larva on Chiococca alba , 29-XII-2012, (TROTT , 2012). http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img432669.html Fig. 11 (right) : Cautethia yucatana . 3rd instar larva on Chiococca alba , 3-I-2013, (TROTT , 2013). http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img433588.html

Fourth instar: During this stage the larva takes on its final shape, having a thicker thorax and front end, thus tapering towards the horn and remarkably small green head. The larva is light to medium green, with the body colour between the dorso-lateral and sub-spiracular stripes either remaining uniform green or turning a greenish-blue at the horn and fading to light green towards the head. During this phase a very fine dark green or brown dorsal stripe may appear. The sub-spiracular stripe is either completely white or yellow on the last body segment and becomes white, bordered with reddish brown before turning yellow again before it

30 fades almost completely at the head. The horn is dark red at the base turning green then orange at the tip, the black spikes are more pronounced. The body is still covered in very fine, short hairs.

Fig. 12 & 13: Cautethia yucatana . 4th instar larva on Chiococca alba , 27-XII-2012, 3-I-2013, (TROTT , 2012, 2013). http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img432447.html

Fig. 14: Cautethia yucatana . 5th instar larva, blue/green form, on Chiococca alba , 1-I-2013, (TROTT , 2013). http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img432721.html

Fig. 15: Cautethia yucatana . 5th instar larva, orange/purple form, on Chiococca alba , 12-I-2013, (TROTT , 2013). http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img435379.html

31 Fifth instar: The larva takes on its final colouration; being polymorphic it can range from green to blue and green, to dark green or brown, to orange and purple; all three of the latter colour forms have seven darker, poorly defined, oblique lateral stripes. The orange and purple form, the spotted/blotched form, and the dark green form are rare, the green form being common and the brown form representing an estimated 10%. The green form can be unmarked or can be heavily spotted in the dorso-lateral area, with additional reddish blotches along the central dorsal line, and a more pronounced shape behind the head. This form is found especially on spotted Chiococca leaves. The sub-spiracular stripe is more pronounced than in the previous instars, but the dorso-lateral and dorsal lines can be faint or absent. The horn becomes shorter in relation to the body, and is more granulose than spiky. The body becomes smooth skinned again, and has lost its fine hairs. When fully grown, the dorsal area on the green form larva turns a rich pink colour prior to pupation, with the inferior half of the body remaining green; the darker colour forms however turn a uniform reddish colour, at this stage, if the larva is disturbed it will play dead. This species does not anoint prior to pupation.

Fig. 16: Cautethia yucatana . 5th instar larva, brown form, on Chiococca alba , 8-I-2013.

Fig. 17: Cautethia yucatana . 5th instar larva, spotted/blotched form, on Chiococca alba , 15-I-2013.

The larvae are active during the day and night, many larvae can be found in a small area, and can be completely absent in others. New shoots are consumed in preference to leaves. Young larvae are very sensitive and will drop from the plant when disturbed. Older larvae (3 rd instar and up), cling to the plant and adopt the shape of a leaf, appearing flat, with the sub-spiracular lateral lines acting as false midribs.

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Fig. 18: Cautethia yucatana . 5th instar larva, dark green form, on Chiococca alba , 10-I-2013, (TROTT , 2013). http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img435187.html

Fig. 19: Cautethia yucatana . 5th instar larva, green form, on Chiococca alba , 9-I-2013.

Fig. 20: Cautethia yucatana . 5 th instar prepupal larva, brown form, 14-I-2013.

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Fig. 21: Cautethia yucatana . 5 th instar prepupal larva, blue/green form, 2-I-2013.

Pupa: 20-24 mm. Shiny, reddish brown, formed in a very flimsy cocoon amongst surface debris or just below the ground’s surface. Pupation can be quite short, the female in figs. 3 & 4 hatched in twelve days.

Figs. 22 & 23: Cautethia yucatana . Male pupa, 17-I-2013.

Figs. 24 & 25: Cautethia yucatana . Female pupa, 17-I-2013.

This species is suspected to be continually brooded through the rainy seasons (October to January and April to July), as the imagos were spotted in November, and eggs and larvae were found in December and during all of January. Before the arrival of heavy rainfall in December, no eggs or larvae could be found. C. yucatana prefers to lay its eggs on the vine-form of C. alba as the newly hatched larvae can only manage new shoots on the shrub form (pers. obs.), the latter having very thick evergreen leaves during the driest months.

34 Biology & Habitat

C. yucatana is found where it’s main larval hostplants C. alba (common names include David's Milkberry, West Indian Milkberry, Cahinca and West Indian Snowberry) and Exostemma mexicanum are found, along with sufficient nectar sources, such as L. camara . C. alba prefers shaded forested habitat, where it can cling and climb up other plants, if no plants are immediately available the plant will cover the forest floor. Like the majority of Sphingidae, this species most probably feeds on other plants from the Rubiaceae family. I cannot comment on E. mexicanum as all ovum and larvae included in this study were found on C. alba .

Fig. 26: The larval hostplant, Chiococca alba (shrub form), 22-XI-2012. Fig. 27: Cautethia yucatana habitat, with Lantana camara in the foreground, 28-XII-2012.

Distribution

C. yucatana has been found in the forests of the Yucatan Peninsula (Quintana Roo), Mexico, and there are reports from 10 districts/provinces in Mexico, Southern California and Southern Texas (although it should be noted that these are probably strays), the Corozal District in Belize, Northwestern Costa Rica and Southwestern Nicaragua. This suggests that it will probably be present in Guatemala, Honduras, and El Salvador.

Fig. 28: Larval habitat of Cautethia yucatana , 28-XII-2012.

35 Acknowledgments

Many thanks to José Manuel Sesma, Antonio Ordóñez, Torsten van der Heyden and the BiodiversidadVirtual.org team and to the BV news Publicaciones Científicas Editorial Committee for publishing this article.

References

TROTT, B. (2012-2013). Cautethia yucatana . [Online database]. Photographs to be found on BiodiversidadVirtual.org in the Mexican Sphingidae Gallery: http://www.biodiversidadvirtual.org/insectarium/Familia-Sphingidae-cat14119.html , http://www.biodiversidadvirtual.org/insectarium/details.php?image_id=435518 , http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img435023.html , http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img432001.html , http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img432234.html , http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img432669.html , http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img433588.html , http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img432447.html , http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img432721.html , http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img435379.html , http://www.biodiversidadvirtual.org/insectarium/Cautethia-yucatana-img435187.html and on Bill Oehlke’s Mexican Sphingidae website : http://www.silkmoths.bizland.com/cyucatan.htm . [Access 25-1-2013].

Distribution data : http://www.silkmoths.bizland.com/Mexsphinx.htm , http://eol.org/pages/507744/maps , http://www.cate-sphingidae.org/taxonomy/Cautethia/yucatana.html . [Access 25-1-2013].

Hostplant records ( Exostemma mexicanum ): http://janzen.sas.upenn.edu/caterpillars/checklists/sphingidaelist.htm . [Access 25-1-2013].

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