Acta Agronómica (Dec 2006)
Redescription of Immature Stages of Phyllophaga menetriesi (Blanchard) (Coleoptera: Melolonthidae) and its Distribution in the Colombian Andean Mountains Redescripción de inmaduros y distribución de la Chisa Phyllophaga menetriesi (Blanchard) en los Andes colombianos. (Coleoptera: Melolonthidae)
Abstract
<p>To facilitate their recognition, the larvae, pupae, and adults of the rhizophage <em>Phyllophaga</em> menetriesi were described. Taxonomic keys were also prepared for immature stages of this pest, which are also commonly known as white grub. Light traps were used to collect adults in Caldono, Department of Cauca, Colombia (2º 81' N and 76º 55' W, 1450 m above sea level, 2191 mm annual precipitation), which were confined in plastic containers with legume foliage until. The immature stages of the pest were obtained and the biological cycle culminated. This work was complemented with observations and the breeding of larvae collected in the field. Body parameters measured were cephalic and body width and length. Samples of larvae and exuviae, as well as of adults, were fixed in formalin for morphological study. The larvae had convergent palidia with 22-26 pali, bullae of the respiratory stigmata with a melanized band, epipharynx with acanthoparia of 14-16 short spines, and plegmatia with 13-14 plegmata. The pupae had prominent annular respiratory stigmata II, III, and IV, with pigmented and truncated peritreme, notorious atrophied abdominal respiratory stigmata VIII, but as high as wide, and equally pigmented dioneiform Vand VI structures. Based on these characters, <em>P. menetriesi</em> can be differentiated from P. obsolete, the other species whose larvae have been described and which present a sympatric condition in several altitudinal borderline areas. The geographical distribution of this pest in Colombia covers the departments of Antioquia, Caldas, Cauca, Huila, Quindio, Risaralda, and Tolima, at altitudes ranging between 1050 and 2100 m above sea level, with the highest population between 1300-1800 m, asl which corresponds to the coffee-growing region of the Colombia's Western and Central Cordilleras. </p><p>Key words: <em>Phyllophaga</em> menetriesi; Melolonthidae; rhizophagous pest; larvae; pupae; taxonomic keys; Colombia. </p><p>Con el objetivo de facilitar el reconocimiento de la chisa rizófaga <em>P. menetriesi</em> se describió la larva, pupa, adulto y se realizaron claves taxonómicas para estados inmaduros. Adultos recolectados con trampas de luz en Caldono, Cauca (2º 81' norte y 76º 55' oeste, 1.450 msnm, 2.191 mm de precipitación anual), se confinaron en recipientes plásticos con follaje de leguminosas hasta obtener estados inmaduros y culminar ciclo, esto se complementó con observaciones y cría de larvas recolectadas en campo; los parámetros corporales medidos fueron anchura cefálica, anchura y longitud corporal; muestras de larvas y exuvias junto al adulto fueron fijados en formol para estudio morfológico. La larva presenta palidia convergente con 22-26 pali, bulla del estigma respiratorio con banda melanizada, epifaringe con la acanthoparia de 14-16 espinas cortas y plegmatia con 13-14 plegmas; la pupa presenta estigmas respiratorios II, III y IV prominentes anulares, con peritrema pigmentado y truncado, estigma respiratorio abdominal VIII atrofiado, pero notable, tan alto como ancho y estructuras dioneiformes Vy VI igualmente pigmentadas: con estos caracteres se puede diferenciar de <em>P. obsoleta</em>, la otra especie cuyas larvas se han descrito y que presenta condición simpátrica en algunos márgenes altitudinales; la distribución geográfica incluye Antioquia, Caldas, Cauca, Huila, Quindio, Risaralda y Tolima, entre 1.050-2.100 m.s.n.m., con mayor concentración de datos entre 1.300 a 1.800 m.s.n.m., correspondiente al clima cafetero de las cordilleras Occidental y Central de Colombia. </p><p>Palabras claves: <em>Phyllophaga</em> menetriesi; Melolonthidae; plaga rizófaga; larva; pupa, claves taxonómicas; Colombia. </p>
