TREE OF Solanum granuloso-leprosum ( SOLANACEAE )

The Zona da Mata region is located in southeastern Minas Gerais State, Brazil with fauna and flora diversified, including herbivorous insects and Solanaceae plants. Ithomiinae caterpillars were observed damaging tree of Solanum granulosoleprosum Dunal (Solanaceae), used for different purposes and abundant in secondary forest. The objective of this study was to identify defoliating caterpillars of S. granuloso-leprosum at the campus of Universidade Federal de Viçosa (UFV) in Viçosa, Minas Gerais State, Brazil and review host plants of Mechanitis polymnia L., 1758 (Lepidoptera: Nymphalidae). Thirteen caterpillars found damaging a tree of S. granuloso-leprosum at the campus of UFV were collected and maintained in the Laboratório de Controle Biológico de Insetos (LCBI) from UFV until adult emergence. These caterpillars were of two species, being ten of the first and three of the second species. Adult specimens of the latter species were identified as Ithomia lichyi lichyi D’Almeida, 1939 (Lepidoptera: Nymphalidae) in the Departamento de Zoologia of Universidade Federal do Paraná (UFPR) in Curitiba, Paraná State, Brazil and of the group of ten caterpillars as Mechanitis polymnia casabranca Haensch, 1905 (Lepidoptera: Nymphalidae) in the Museu de Zoologia of Universidade de São Paulo (USP) in São Paulo State, Brazil. This is the first report of M. polymnia casabranca and I. lichyi lichyi together damaging plant of S. granuloso-leprosum in the Zona da Mata region of Minas Gerais State, Brazil and 57 plants are recorded as host of M. polymnia.


INTRODUCTION
The Zona da Mata region, located in the southeastern Minas Gerais State, Brazil, with 36.058km 2 , representing 6.2% of the area of Mata Atlântica biome in this state (RESENDE et al., 2009).Its native vegetation was formed by Floresta Tropical, with dense tree cover and as an expansion of the Mata Atlântica (PORTUGAL et al., 2010).These forests were reduced to small patches and bushes on steep slopes and replaced, largely, by agricultural crops, pasture and reforestation (SOUZA et al., 2009).The precipitation of the Zona da Mata varies from 1,200 to 1,400 mm (REIS et al., 2007).The tropical climate has hot summers, temperatures reaching 25 ºC and low temperatures at altitudes of 1,000 m above sea level (SANTANA et al., 2010).The terrain is rugged, with Tavares, W. S. et al.
predominance of hills and narrow valleys and mountains formed by ancient crystalline rocks.The altitude varies between 100 m in the Rio Pomba and Paraíba do Sul valleys and 1.889 m in the Pico do Brigadeiro (NUNES et al., 2009).
Solanum granuloso-leprosum Dunal (Solanaceae) is small tree and, in naturally occurring, reaches 12 m height and diameter at breast height of 30 cm (SOUZA; VALIO, 2001).This species occurs in secondary forests colonizing devastated areas, in northeastern Argentina, Uruguay, Paraguay and south-central Brazil (POUYU-ROJAS et al., 2006).Its wood is suitable for pulp and energy, its fruits enjoyed by wildlife and its leaves used as vermifuge for horses (FLORES-AYLAS et al., 2003;JACOMASSA;PIZO, 2010).The main interest in S. granuloso-leprosum is related to plantations for recovery of degraded ecosystems (FERREIRA et al., 2007).
The Ithomiinae (Lepidoptera: Nymphalidae) subfamily has, approximately, 370 species of butterflies (GIRALDO; URIBIE, 2010) and some feed on leaves of S. granuloso-leprosum, which may reduce the rate of photosynthesis and the development of this plant.These insects can be found in the Neotropical region from northern Argentina to Mexico (WILLMOTT; FREITAS, 2006) and abundant in tropical forests, including small fragments and urban and suburban systems (BROWN JUNIOR;FREITAS, 2003).Mechanitis species adapt to a wide variety of agricultural habitats and secondary forests where its caterpillars feed on host plants (YOUNG; MOFFETT, 1979).Ithomia species are abundant and with variable patterns of coloration of the wings, including transparent.These insects can mimic other genera of Lepidoptera, as Hypothyris, Napeogenes, Oleria and Scada (MALLARINO et al., 2004).

MATERIAL AND METHODS
Thirteen caterpillars were found on April 22, 2011 damaging a plant with 4 m height of S. granulosoleprosum at the garden of the Pavilhão de Aulas (PVA I) from Universidade Federal de Viçosa (UFV) in Viçosa, Minas Gerais State, Brazil.This plant was identified after comparison with material deposited in the Laboratório de Dendrologia from UFV.These caterpillars were brought to the Laboratório de Controle Biológico de Insetos (LCBI) from UFV and placed in cage (12.5 cm height × 12.5 cm width × 30.5 cm length) with branches of this plant changed, daily, until the pupation.The stems of these branches were placed in glass tubes with water to reduce their leaves wilt.Adults from these caterpillars were fed with nutrient solution (10.5 g of honey, 1.05 l of distilled water, 350 ml of beer, 60.0 g of sucrose, 1.05 g of ascorbic acid and 1.05 g of Nipagin®) moistened in cotton swab second proposed methodology for Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae) (FERREIRA et al., 2008).Adult specimens were photographed and deposited in the LCBI from UFV. Photos of adults of the group of ten caterpillars were sent to the Museu de Zoologia of Universidade de São Paulo (USP) in São Paulo State, Brazil and the group of three, sending a female specimen to the Departamento de Zoologia of Universidade Federal do Paraná (UFPR) in Curitiba, Paraná State, Brazil, for identifies these insects.Host plants of M. polymnia were reviewed.

RESULTS AND DISCUSSION
Ten (Figure 1A -adult) and three (Figure 1B adult) caterpillars, respectively, belonged to two species.Individuals of the group of ten caterpillars become pupae after the fifth day of collection.Five normal adults and five deformed emerged from these pupae after the 12th day of pupation and the normal survived for 10 days.Adults of this group were identified as M. polymnia casabranca in the Museu de Zoologia of USP in São Paulo State, Brazil.Those of the group of three caterpillars become pupae after Mechanitis polymnia casabranca ...However, M. lysimnia was more tolerant to climate years with lower temperature and, therefore, its population spread to central Argentina, although it was absent in Bacia Amazônia Central (BROWN JUNIOR, 1977).However, these species lay eggs on host plants in Sumaré, São Paulo State, Brazil, and showed peaks of reproduction during the year, above of their caterpillars and adults have variations in the color of the body (VASCONCELOS-NETO; BROWN JUNIOR, 1982).Ithomiinae can coexist on the same host, because the extreme scarcity of a host plant in a spatial or temporal limit leads to acceptance of that most abundant (BROWN JUNIOR, 1977; VASCONCELOS-NETO; BROWN JUNIOR, 1982).In addition, Ithomiinae species with mimetic features similar can mate and reproduce after stimulation by pheromone (SCOTT, 1973).
A total of 57 host plant species was recorded for M. polymnia (Table 1).Economically important plants, cultivated by man, as Lycopersicun esculetum Mill (Solanaceae) are hosts of M. polymnia, suggesting that the devastation of the Mata Atlântica biome may make this species a potential pest in crops of plants of this family (DRUMMOND; BROWN JUNIOR, 1987;FREITAS, 1996;SILVA et al., 1968).The polyphagia of M. polymnia makes this species most adaptable to coexistence with other Ithomiinae in a same plant and the use of host species of Solanaceae plants, abundant in the Zona da Mata region of Minas Gerais State, Brazil, could increase their survival (FERREIRA et al., 2007).
The behavior of caterpillars of M. polymnia casabranca and I. lichyi lichyi was gregarious on plant of S. granuloso-leprosum.Five caterpillars of the first species and three of the second were together on the adaxial side on a same leaf of S. granuloso-leprosum.Five caterpillars of M. polymnia casabranca were in another leaf of plant of this Solanaceae.The gregariousness in Ithomiinae is an adaptation to adverse conditions of the dry season, as high temperatures and low relative humidity of air (PINHEIRO et al., 2008).The caterpillars were fed on leaves of S. granuloso-leprosum, with preference for those younger, but leaving the veins intact.Natural enemies of these caterpillars were not observed.Generalist predator ant Camponotus crassus Mayr, 1862 (Hymenoptera: Formicidae) prey Ithomiinae, but individuals of this family can produce chemical defenses, for example, toxic or nonpalatable substances, to avoid predation by natural enemies (PORTUGAL; TRIGO, 2005).

Figure 1 -Adults of Mechanitis polymnia casabranca (A) and Ithomia lichyi lichyi (B) (Lepidoptera: Nymphalidae), respectively, resting on an artificial leaf, collected in Viçosa, Minas Gerais State, Brazil after their caterpillars damaged plant of Solanum granuloso-leprosum (Solanaceae).
the fifth day of collection.Two normal adults emerged from these pupae after the 12th day of pupation and survived by 10 days.These adults were identified as I. lichyi lichyi in the Departamento de Zoologia of UFPR in Curitiba, Paraná State, Brazil.This is the first report of M. polymnia casabranca and I. lichyi lichyi damaging plant of S. granulosoleprosum in the Zona da Mata region of Minas Gerais State, Brazil.Ithomiinae common in southeastern Brazil (VASCONCELOS-NETO; BROWN JUNIOR, 1982) were, also, found in central Brazil after 24 years of the first assessment (EMERY et al., 2006), suggesting adaptation of these insects in different habitats.Insects of this group were not observed in 2004 and in some previous years, suggesting that the population dynamics of Ithomiinae may vary in different climatic years.For example, Hypothyris ninonia daeta Boisduval,1836 (Lepidoptera: Nymphalidae) was the most abundant butterfly in 2003, while M. polymnia was absent in that year, although the most abundant in 2004 (VASCONCELOS-NETO; BROWN JUNIOR, 1982).
The fact of two species of Ithomiinae were found in a same plant of S. granuloso-leprosum agrees with the observed for M. polymnia and Mechanitis lysimnia (F., 1793)

CONCLUSIONS
Mechanitis polymnia casabranca and I. lichyi lichyi have potential of defoliation and complete the life cycle on plants of S. granuloso-leprosum in the field and laboratory.Despite of the large number of hosts of M. polymnia, further studies should be conducted to evaluate the mechanisms of coexistence between these two species.