ZOOLOGIA 30 (2): 200–210, April, 2013 http://dx.doi.org/10.1590/S1984-46702013000200010 Species composition and temporal activity of Arctiinae (Lepidoptera: Erebidae) in two cerrado vegetation types Scheila Scherrer1, Viviane G. Ferro2,4, Marina N. Ramos1 & Ivone R. Diniz3 1 Programa de Pós-graduação em Ecologia, Instituto de Ciências Biológicas, Universidade de Brasília. 70910-900 Brasília, DF, Brazil. 2 Departamento de Ecologia, Instituto de Ciências Biológicas, Universidade Federal de Goiás. 74001-970 Goiânia, GO, Brazil. 3 Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade de Brasília. 70910-900 Brasília, DF, Brazil. E-mail: [email protected] 4 Corresponding author. E-mail: [email protected] ABSTRACT. Arctiinae moths include nearly 11,000 species worldwide, of which approximately 700 species occur in the Brazilian Cerrado. The aim of this study was to describe the species composition of Arctiinae, as well as the variation in annual and nightly moth activity, in two Cerrado vegetation types. We sampled moths one night per month from September 2008 to June 2009, in the gallery forest and in the cerrado sensu stricto in the Jardim Botânico de Brasília. We collected 395 tiger moths belonging to 65 morphospecies; 74% of the species belonged to the tribe Arctiini and 26% to Lithosiini. Thirty-one species (47.7%) occurred only in the gallery forest, 13 (20%) occurred only in the cerrado sensu stricto, and 21 (32.3%) occurred in both vegetation types. Additionally, we found the greatest species richness between 7:00 p.m. and 8:00 p.m., and these hours were associated with 21 and 22 species, respectively. Most species (51.8%) were active for up to three hours during the night. In general, the species composition differed between the dry and rainy seasons, and the similarity of the fauna also varied hourly. Based on our results, we suggest that rapid inventories of Arctiinae be performed in both rainy and dry seasons, and sampling should be carried out the entire night. KEY WORDS. Cerrado sensu stricto; gallery forest; moths; seasonality; time of activity. Species richness and abundance vary in time and space. The distribution of food resources and climate predictability Several factors may influence this variation, including the cli- (dry and rainy seasons) in the Cerrado may partially explain mate; the formation or rupture of geographical barriers; hu- these variations, as suggested by WOLDA (1988) for tropical in- man activities (e.g., deforestation, fire, and introduction of sects. exotic species); the characteristics of the species (e.g., dispersal Adult lepidopterans in the Cerrado are evenly distrib- and reproductive capability); habitat structural complexity; the uted throughout the year, but with a peak abundance in the availability, amount, or quality of resources; and interspecific early rainy season (PINHEIRO et al. 2002, OLIVEIRA & FRIZZAS 2008), interactions (SILVEIRA NETO et al. 1995, DYER et al. 2007, NOVOTNY while caterpillars are most abundant in the first half of the dry et al. 2007). season (MORAIS et al. 1999). The richness and abundance of spe- Some studies have shown that, in regions with a seasonal cies of several families of Lepidoptera vary throughout the year climate, the abundance and activity of insects and other as well as among sites, habitats, and biomes. The Sphingidae arthropods are related to climatic variables. For example, the from the Atlantic Forest do not vary seasonally (DUARTE JÚNIOR abundance of several insect orders and spiders peak during the & SCHLINDWEIN 2005). However, the occurrence of species of rainy season in the Caatinga and Cerrado Brazilian biomes Sphingidae from the Caatinga (GUSMÃO & CREÃO-DUARTE 2004) (PINHEIRO et al. 2002, OLIVEIRA & FRIZZAS 2008, MINEO et al. 2010, and the Cerrado (AMORIM et al. 2009) has been found to be VASCONCELLOS et al. 2010). Insect orders and families respond markedly seasonal, and their population fluctuations are cor- differently to temporal variations in the Cerrado, as do imma- related with rainfall. In one forest in southern Ecuador, the ture and adult insects. The abundance of species of Coleoptera, abundance of Arctiinae has been found to not vary seasonally Hymenoptera, and Isoptera is related to temperature variation (HILT et al. 2007), whereas abundance and richness peaks of and is greater in the early rainy season (SILVA et al. 2011). Simi- Arctiinae species in Altamira (state of Pará, Brazil), an anthro- larly, the greatest abundance of Cecidomyiidae (Diptera) gall pized site of the Amazon rainforest, happen in June and July, midges occurs in the early rainy season (ARAÚJO & SANTOS 2009). during the less rainy period (TESTON & DELFINA 2010). © 2013 Sociedade Brasileira de Zoologia | www.sbzoologia.org.br | All rights reserved. Species composition and temporal activity of arctiinae in two cerrado vegetation types 201 Studies on the temporal scale of diversity are important Cabeça de Veado (FONSECA & SILVA JÚNIOR 2004) in the Cerrado in helping us understand the stability of communities, and to biome (RATTER et al. 1997). predict the responses of organisms to environmental changes, Sampling was performed during one year, from Septem- as well as providing information for pest management and ber 2008 to August 2009, in two Cerrado vegetation types: gal- control. Studies addressing the temporal variation of species lery forest and cerrado sensu stricto. Moths were sampled one richness are rarer than those addressing spatial variation. Some night per month in each vegetation type (always in new moon reasons for this discrepancy may be the time required for the nights). The period between October and March was consid- former type of research and the higher financial cost it involves. ered the rainy season, and the dry season was between April However, there has been an increase in funding for the devel- and September (following RATTER et al. 1997). Moths were col- opment of long-term ecological research (LTER) both in Brazil lected from 7:00 pm to 5:00 am using a light source (mercury- and abroad, especially in the last two decades (SOUSA et al. 2007, vapor lamp 250 W) hanging at 1.6 m reflected on a white sheet. ARAÚJO et al. 2010). All tiger moths were collected, killed in jars containing ammo- Insects are considered good models for temporal activity nium hydroxide, and separated into plastic vials labeled with studies due to their short life cycles and rapid response to envi- the date and time. Individuals were measured, mounted, la- ronmental changes. In addition, the abundance of insects can beled, and identified by comparison to reference collections vary over the long (between years) and short terms (e.g., weeks; and with the aid of taxonomists. The moths were deposited in WOLDA 1978, COOK & GRAHAM 1996). Moths have been used the Coleção Entomológica do Departamento de Zoologia da worldwide as model organisms for diversity studies (SILVEIRA NETO Universidade de Brasília (UnB 041581-041976). et al. 1995, CAMARGO 1999, KITCHING et al. 2000, SCHWARTZ & MARE The Shannon-Wiener diversity index, Simpson domi- 2001, BECK et al. 2002, BREHM et al. 2003, TESTON & CORSEUIL 2004, nance index, and Chao 2 and Jackknife 1 richness estimators HILT & FIEDLER 2005, SIHVONEN & SILIJANDER 2005, SPECHT et al. were calculated. A circular analysis (Rayleigh test) (ZAR 1996) 2005, AXMACHER et al. 2009), and are considered to be good in- was performed to test for concentrated peaks of abundance dicators of species richness and habitat disturbances and richness throughout the year or night. A cluster analysis (SUMMERVILLE et al. 2004). was performed using UPGMA (the unweighted pair-group Little is known about temporal patterns of insect richness method using arithmetic averages) with the Simpson index as and abundance in the Cerrado, and how biotic and abiotic fac- a distance measure to evaluate the similarity between months tors influence the seasonal distribution of this group (PINHEIRO et and hours. All tests were performed for each vegetation type, al. 2002, OLIVEIRA & FRIZZAS 2008). However, it is known that the for each hour of the night, and for all species. Circular analysis mean monthly temperature is significantly related to the distri- was performed using Oriana 3 software (KOVACH COMPUTING SER- bution of lepidopteran populations (OLIVEIRA & FRIZZAS 2008). VICES 2011), and the remaining analyses were performed using Studies addressing the daily activity of insects are also rare. In PAST (HAMMER et al. 2007). this study, we used moths of the subfamily Arctiinae (Lepidoptera: Erebidae) as model organisms. Arctiinae is a good model for RESULTS understanding the mechanisms determining the diversity of tropical insects. These moths are highly diverse, easily sampled, Overall, we collected 395 tiger moths belonging to 65 have a relatively well-resolved taxonomy, and have already been morphospecies, of which 69.2% were identified to species (Table studied in the tropics (e.g., FERRO & DINIZ 2007, 2010, HILT et al. I). Seventy-four percent of the identified species (n = 45) be- 2007, FERRO et al. 2010). Despite the high diversity of Arctiinae longed to the tribe Arctiini and 26% (n = 16) to Lithosiini. Five in the Cerrado (FERRO & DINIZ 2007, 2010), little is known about species represented new records for the Distrito Federal: the natural history and behavior of the species in this group. Dolichesia rufa Schaus 1899, Hyperthaema signata (Walker, 1862), The goal of this study was to assess how the species richness, Lamprostola hercyna Druce 1885, Nodozana coresa Schaus 1896, abundance, and composition of Arctiinae vary annually and and Thrinacia temenus (Stoll, 1781). The last two species were throughout the night in two Cerrado vegetation types (gallery also the first records for the Cerrado. Singletons (species repre- forest and cerrado sensu stricto). sented by one individual) accounted for 38.5% (n = 25) of the species recorded. The observed richness was 62.7% to 68.6% of MATERIAL AND METHODS the estimated richness (Chao 2 = 103.7 and Jackknife 1 = 93.4).