Biology of the leaf roller Salbia lotanalis and its impact on the invasive tree Miconia calvescens

Abstract

Miconia calvescens (Melastomataceae) is an invasive alien tree in native forests on some Pacific islands and a potentially invasive species in Australia. Searches for potential classical biocontrol agents have been undertaken for over a decade in the centre of origin (Central and South America). Salbia lotanalis (Lepidoptera: Pyralidae) is a leaf roller which has been recognized as a promising classical biocontrol agent for M. calvescens. This paper presents the biology and an impact study of S. lotanalis on M. calvescens. Life table parameters showed that S. lotanalis has a high reproductive capacity, with up to six generations a year. Miconia calvescens seedlings attacked by S. lotanalis caterpillars had their growth rate significantly reduced. Seedlings subjected initially to a high level of defoliation (80%) caused by caterpillars had leaf fall and a lower leaf area than controls after 210 days. Considering the high population growth rate and significant impact on young plants, S. lotanalis appears to have a high potential for use as a classical biological control agent to be used against M. calvescens.

Damage toMiconia calvescensand Seasonal Abundance ofSalbia lotanalis(Lepidoptera: Crambidae) in Costa Rica

“…By the end of the dry season in March 2007, trees had lost half their leaves compared with the previous November. Feeding by S. lotanalis larvae can make M. calvescens leaves fall off (Castillo 2009, Morais et al 2010, Castillo et al 2014; however, some loss of foliage is typical for M. calvescens during the relatively severe dry season in San José Province (Johnson, unpublished data). Thus, seasonal drought probably explains the decline of S. lotanalis densities observed in this study.…”

“…A variety of neotropical arthropods and pathogens have been evaluated as potential biological control agents of M. calvescens in recent years, but so far only a fungal pathogen has been released in Hawaii and Tahiti (Killgore 2002, Picanç o et al 2005, Badenes-Perez et al 2008, Hanson et al 2010, Conant et al 2013). Among insects evaluated as potential agents, Salbia lotanalis Druce (Lepidoptera: Crambidae), whose larvae tie leaves producing large leaf rolls within which they feed, has been the subject of biology and hostspeciÞcity studies in Brazil (Morais et al 2010(Morais et al , 2012 and Costa Rica (Castillo 2009, Castillo et al 2014. The insect has Þve larval instars and completes one generation in 60 Ð90 d (Morais et al 2010, Castillo et al 2014.…”

“…Among insects evaluated as potential agents, Salbia lotanalis Druce (Lepidoptera: Crambidae), whose larvae tie leaves producing large leaf rolls within which they feed, has been the subject of biology and hostspeciÞcity studies in Brazil (Morais et al 2010(Morais et al , 2012 and Costa Rica (Castillo 2009, Castillo et al 2014. The insect has Þve larval instars and completes one generation in 60 Ð90 d (Morais et al 2010, Castillo et al 2014. Host-speciÞcity testing in Brazil showed that third-instar S. lotanalis feed and develop successfully on M. calvescens and Clidemia hirta (L.) D. Don (Melastomataceae), but not on other Melastomataceae (Morais et al 2012).…”

“…Host-speciÞcity testing in Brazil showed that third-instar S. lotanalis feed and develop successfully on M. calvescens and Clidemia hirta (L.) D. Don (Melastomataceae), but not on other Melastomataceae (Morais et al 2012). In greenhouse experiments conducted in Brazil, defoliation by S. lotanalis larvae reduced leaf area, leaf number, and plant height in 1-yr-old M. calvescens plants ( Morais et al 2010).…”

Biology, Behavior, and Larval Morphology of Salbia lotanalis (Lepidoptera: Crambidae), a Potential Biological Control Agent of Miconia calvescens (Myrtales: Melastomataceae) from Costa Rica

“…Among these insects, Salbia lotanalis Druce (Lepidoptera: Crambidae) has been studied in its native habitat in Brazil and in Costa Rica (Castillo 2009;Morais et al 2010bMorais et al , 2012Janzen and Hallwachs 2014;Badenes-Perez et al 2014). The bi ology and behavior of S. lotanalis are still not wellknown, although the studies by Morais et al (2010Morais et al ( , 2012 have provided substantial knowledge on the biology of this species and its potential as a biological control agent of M. calvescens.…”