SANIDAD VEGETAL Y PROTECCIÓN DE CULTIVOS

¹ Entomologist. Institut National de la Recherche Agronomique, Centre Antilles-Guyane, Domaine Duclos, FR - 97170 Petit-Bourg, Guadeloupe.Jean.etienne2@wanadoo.fr
² Entomologist. Musèum National d'Histoire Naturelle, Dèpartement de Systèmatique & Evolution, UMR 7205, MNHN-CNRS: ISYEB, Institut de Systèmatique, Evolution, Biodiversitè, CP 50, FR - 75231Paris Cedex 05. dmatile@mnhn.fr
³ Entomologist. Corporación Colombiana de Investigación Agropecuaria (Corpoica), Centro de Investigación Palmira, Calle 23, Carrera 37, Palmira, Valle, Colombia. tkondo@corpoica.org.co

Fecha de recepción: 30/03/2014. Fecha de aceptación: 19/05/2014

ABSTRACT

The croton scale, Phalacrococcus howertoni Hodges & Hodgson (Hemiptera: Coccoidea: Coccidae) is newly reported from the island of Guadeloupe, French West Indies, on several host-plants, including some new host records, i.e., on Spondias cytherea Sonnerat; (Euphorbiaceae), Ocotea membranacea (Sw.) R.A. Howard (Lauraceae), Miconia furfuracea (Vahl) Griseb (Melastomataceae), Ficus citrifolia Mill. (Moraceae) and Piper dilatatum Rich. (Piperaceae).

Key words: Coccid, scale insect, soft scale, Phalacrococcus howertoni.

RESUMEN

La escama blanda del croton Phalacrococcus howertoni Hodges & Hodgson (Hemiptera: Coccoidea: Coccidae) se reporta por primera vez en la isla de Guadeloupe, Antillas Francesas, sobre varias plantas, incluyendo nuevos hospedantes, i.e., Spondias cytherea Sonnerat; (Euphorbiaceae), Ocotea membranacea (Sw.) R.A. Howard (Lauraceae), Miconia furfuracea (Vahl) Griseb (Melastomataceae), Ficus citrifolia Mill. (Moraceae) y Piper dilatatum Rich. (Piperaceae).

Palabras claves: Cóccido, insecto escama, escama blanda, Phalacrococcus howertoni.

INTRODUCTION

The croton scale, Phalacrococcus howertoni Hodges & Hodgson (Hemiptera: Coccoidea: Coccidae) is a highly polyphagous soft scale species, hitherto reported on 72 host plants in 34 botanical families (Amarasekare & Mannion, 2011; Ben-Dov et al., 2014; Hodges & Hodgson, 2010; Williams, 2010). This species was described in 2010 based on specimens collected on ornamental croton in the State of Florida, USA (Hodges & Hodgson, 2010) and soon after it was recorded in Guatemala (Williams, 2010) and Barbados (Anonymous, 2011). The adult female of P. howertoni (Fig. 1A, 1B) is approximately 4 mm long and 2 mm wide, green to yellow-green in color, with dark striations on dorsum (Hodges & Hodgson, 2010). Phalacrococcus howertoni is ovoviviparous; females go through three nymphal stages before reaching the adult stage; males go through four nymphal stages, including a pre-pupal (third instar) and a pupal stage (fourth instar) before becoming an alate male (Fig. 1B) (Amarasekare & Mannion, 2011). In Florida, P. howertoni has multiple overlapping generations per year, averaging about one generation a month; it overwinters as adult female; each which can lay about 400 eggs (Hodges & Hodgson, 2010). Hodges & Hodgson (2010) listed several natural enemies, namely Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae), Laetilia coccidivora (Comstock) (Lepidoptera: Pyralidae) and the parasitoid Metaphycus flavus (Howard) (Hymenoptera: Encyrtidae). The present paper aims to report P. howertoni for the first time on Guadeloupe Island, French West Indies, and provide a list of new host plants for this species.

MATERIALS AND METHODS

The first author ( J.E.) collected specimens of a soft scale insect on ornamental croton, Codiaeum variegatum (L.) Rumph. ex A. Juss. (Euphorbiaceae), which differs from all known species on Guadeloupe Island. The first author sent photographs of the undetermined coccid to the third author (T.K.) who based on its external morpholog y tentatively identified the species as Phalacrococcus howertoni Hodges & Hodgson (Hemiptera: Coccidae). Specimens were slide-mounted following the method described by Williams & Granara de Willink (1992) and identified as P. howertoni based on its cuticular morphology by the first ( J.E.) and second author (D.M.F.) using the original description by Hodges & Hodgson (2010) and by comparison with slide mounted adult females of P. howertoni received from the Florida State Collection of Arthropods. The material studied is deposited in the Musèum National d'Histoire Naturelle, Paris, France (MNHN). Host plants were identified following Fournet (2002).

Material studied

Phalacrococcus howertoni. Guadeloupe: Baie-Mahault, Calvaire, ex Psidium guajava, 5.II.2013, coll. J.E., in alcohol (MNHN), ex Spondias cytherea, 23.IV.2014, coll. J.E., in alcohol (MNHN); Baie-Mahault, Daubin, ex Codiaeum variegatum, coll. J.E., in alcohol (MNHN); Deshaies, Grande Anse, ex C. variegatum, 13.V.2013, coll. J.E., in alcohol (MNHN); Lamentin, Ravine Chaude, ex C. variegatum, 21.XI.2012, coll. J.E., MNHN 14829, 7 slides, 12 specimens, 17.I.2013, coll. J.E., in alcohol (MNHN), ex Psidium guajava, 18.I.2013, coll. J.E., in alcohol (MNHN), ex Piper dilatatum, 18.I.2013, coll. J.E., in alcohol (MNHN), id., 26.II.2014, coll. J.E., in alcohol (MNHN 14872), ex Citrus citrifolia, 19.I.2013, coll. J.E., 8 specimens, 4 slides (MNHN), ex Acalypha wilkesiana, 24.I.2013, coll. J.E., in alcohol (MNHN), ex Mangifera indica, 1.III.2013, coll. J.E., in alcohol (MNHN); Lamentin, route Duclos, ex Miconia furfuracea, coll. J.E., in alcohol (MNHN); Morne-à-L'Eau, Perrin, ex C. variegatum, coll. J.E., in alcohol (MNHN); Pointe-à-Pitre, Boissard, ex Mangifera indica (fruits), coll. J.E., in alcohol (MNHN); Sainte-Rose, ex C. variegatum, 13.V.2013, coll. J.E., in alcohol (MNHN); Petit-Bourg, Duclos, ex Ocotea membranacea, 22.II.2013, coll. J.E., in alcohol (MNHN); Petit-Bourg, Prise d'Eau, ex C. variegatum, 26.I.2013, coll. J.E., in alcohol (MNHN).

RESULTS AND DISCUSSION

The polyphagous croton scale, P. howertoni was first discovered in Guadeloupe on November 21, 2012, at the locality of Ravine Chaude, in the municipality of Lamentin, on the leaves of ornamental croton, C. variegatum. A year later, the same species was collected again on C. variegatum in several other sites of Guadeloupe. On January 26, 2013, it was found in the locality of Prise-d'Eau in the municipality of Petit-Bourg ; on January 29, in the locality of Daubin in the municipality of Baie-Mahault; and on May 13, in the locality of St. Rose. Other infestations on the same host plant were also found on May 13 in the locality of Grande Anse, municipality of Deshaies; on May 15 in the locality of Perrin, municipality of Morne-à-L'Eau, and on June 25 in the locality of Boissard, municipality of Pointe-à-Pitre. The record of P. howertoni increases the number of known soft scales on the island to 27 species. In Guadeloupe, 18 months after its discovery on the island, P. howertoni has been found on the following host plants [new host records for P. howertoni are marked with an asterisk (*)]: Anacardiaceae: Mangifera indica L., *Spondias cytherea Sonnerat; Euphorbiaceae: Acalypha wilkesiana Müll.-Arg., Codiaeum variegatum (L.) Rumph. ex A. Juss.; Lauraceae: *Ocotea membranacea (Sw.) R.A. Howard; Melastomataceae: *Miconia furfuracea (Vahl) Griseb; Moraceae: *Ficus citrifolia Mill.; Myrtaceae: Psidium guajava L.; Piperaceae: *Piper dilatatum Rich.

The adult female of P. howertoni may be confused with Philephedra tuberculosa Nakahara & Gill (Fig. 1C) which also occurs on ornamental croton in Guadeloupe and have similar coloration. However, the two species can be easily differentiated in the field since the mature adult female of P. tuberculosa has a white ovisac which is about twice as long as its body, with wax partially covering the dorsum (Nakahara & Gill, 1985), whereas the mature adult female of P. howertoni is mottled, green to yellowish in color, with dark specks and have no ovisac nor white wax partially covering the body.

In Guadeloupe Island, P. howertoni is found mainly on the young shoots of its host plants. Amongst cultivated plants, the most affected are C. variegatum, P. guajava and S. cytherea. Hedges of C. variegatum are particularly affected resulting in the dieback of many of them. This soft scale insect produces abundant honeydew, which induces the growth of fungi that cause symptoms of sooty molds, especially on ornamental croton and guava. The family Coccidae (Hemiptera: Coccoidea) on the island of Guadeloupe, was hitherto represented by 26 species (Matile-Ferrero & Etienne, 2006); with the addition of P. howertoni, the number of soft scale insect species on the island is increased to 27. It is expected that in the coming years this soft scale insect will invade most of the Caribbean islands and it is likely that some of these islands are already infested by this new insect pest.

CONCLUSIONS

The croton scale, Phalacrococcus howertoni Hodges & Hodgson (Hemiptera: Coccoidea: Coccidae) occurs in the New World and is known from Barbados, Guadeloupe, Guatemala and the USA (Florida). Five plant species are recorded as new host plants for P. howertoni, increasing the number of known host plant species of P. howertoni to 77 species in 34 botanical families.

ACKNOWLEDGEMENTS

The authors thank Dr. Ana Lucia Peronti (Unesp-FCAV, Jaboticabal, SP, Brazil), Dr. M. Bora Kaydan (Çukurova Üniversity, Adana, Turkey), and anonymous reviewers for kindly reviewing the manuscript. Thanks to Dr. Greg Hodges (Florida DPI) for contacting Mr. Jeff Lotz (FDACS-DPI) who kindly provided Figures 1 A and B of Phalacrococcus howertoni. Thanks also to Dr. Ian Stocks, Florida State Collection of Arthropods, Gainesville, USA, for providing a gift to the MNHN Paris, composed of several slide mounted adult females of P. howertoni and material in 70% alcohol.

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