Publications

direct and indirect interactions between ants (pheidole megacephala), scales (coccus viridis) and plants (pluchea indica).	this study investigated direct and indirect interactions between the ant, pheidole megacephala (fabr.), the green scale, coccus viridis (green), and the scale's host plant, pluchea indica (l.). to examine the influence of ants on scales and host plants, scale population densities, scale mortality rates, and plant performance were studied on control host plants with ants and host plants from which ants had been removed. plants with ants present had significantly greater scale population densities ...	1991	28313840
a keystone mutualism drives pattern in a power function.	data that can be described by a power function are ubiquitous in nature. although there is consensus that such data frequently emerge generally from nonlinear complex systems, a variety of specific mechanisms may be responsible for creating the pattern in particular cases. here, we report on the distribution of a scale insect (coccus viridis) that is a common agricultural pest. its distribution in an organic coffee farm in southern mexico generally follows a power function, but there are subtle ...	2006	16484494
spatial pattern and ecological process in the coffee agroforestry system.	the coffee agroforestry system provides an ideal platform for the study of spatial ecology. the uniform pattern of the coffee plants and shade trees allows for the study of pattern generation through intrinsic biological forces rather than extrinsic habitat patchiness. detailed studies, focusing on a key mutualism between an ant (azteca instabilis) and a scale insect (coccus viridis), conducted in a 45-ha plot in a coffee agroforestry system have provided insights into (1) the quantitative evalu ...	2008	18481515
cheating on a mutualism: indirect benefits of ant attendance to a coccidophagous coccinellid.	coccinellids (coleoptera: coccinellidae) are generally unable to prey on ant-tended prey. however, particular coccinellid species have morphological, behavioral, or chemical characteristics that render them immune to ant attacks, and some species are even restricted to ant-tending areas. the benefit gained from living in close association with ants can be twofold: (1) gaining access to high-density prey areas and (2) gaining enemy-free space. here, the myrmecophily of azya orbigera mulsant (cole ...	2008	18348805
indirect interactions between ant-tended hemipterans, a dominant ant azteca instabilis (hymenoptera: formicidae), and shade trees in a tropical agroecosystem.	the occurrence, intensity, and composition of mutualisms are dependent not only on the co-occurrence of mutualists, but also the broader biotic context in which they are embedded. here, the influence of the specific nest tree identity of the ant azteca instabilis (f. smith) on the density of the green coffee scale (coccus viridis green) was studied in a coffee agroecosystem in southern mexico. the hypothesis that an indirect competitive interaction for ant attendance occurs between a scale speci ...	2008	18559179
[coccus species affecting coffea arabica in brazil (coccoideae: coccidae) and the redescription of two species].	five coccus on coffea arabica from the states of bahia, espírito santo and minas gerais were studied. females were prepared and mounted in canada balsam. coccus brasiliensis fonseca and coccus lizeri (fonseca) were redescribed and coccus alpinus de lotto, coccus celatus de lotto and coccus viridis (green) were characterized. a key to species and illustration of all of them are included. coccus alpinus and c. celatus are new records for brazil and the neotropical region.	2010	20676513
leaf alkaloids, phenolics, and coffee resistance to the leaf miner leucoptera coffeella (lepidoptera: lyonetiidae).	coffee (coffea spp.) alkaloids (caffeine and related methylxanthines) and phenolics (caffeic and chlorogenic acids) have recognized pestistatic/pesticidal activity and mediate insect-plant interactions. the present investigation assessed the resistance of 12 coffee genotypes to the leaf miner leucoptera (= perileucoptera) coffeella (guérin-méneville & perrottet) (lepidoptera: lyonetiidae) and correlated such results with the leaf content of coffee alkaloids and phenolics that probably play a rol ...	2010	20857759
the effects of nutrients and secondary compounds of coffea arabica on the behavior and development of coccus viridis.	phytochemicals may modify the food quality, reduce a plant's palatability to insects, or defend against pests. this work aimed to study 1) relationships between the nitrogen and potassium levels given to plants in nutritive solutions and the foliar phytochemical concentrations, 2) the effect of nutrients and secondary compounds of coffea arabica on the behavior of coccus viridis, and 3) tolerance of c. arabica to losses. deficient, normal, and excessive nitrogen and potassium fertilization treat ...	2012	22507006
indirect effects of a fungal entomopathogen, lecanicillium lecanii (hypocreales: clavicipitaceae), on a coffee agroecosystem ant community.	fungal entomopathogens are widely distributed across natural and managed systems, with numerous host species and likely a wide range of community impacts. while the potential for fungal pathogens to provide biological control has been explored in some detail, less is known about their community interactions. here we investigate the effects of fungal epizootics of the entomopathogen lecanicillium lecanii (zimmerman) on a keystone mutualism between azteca instabilis (f. smith), a dominant arboreal ...	2013	23905728
stage-dependent responses to emergent habitat heterogeneity: consequences for a predatory insect population in a coffee agroecosystem.	interactions among members of biological communities can create spatial patterns that effectively generate habitat heterogeneity for other members in the community, and this heterogeneity might be crucial for their persistence. for example, stage-dependent vulnerability of a predatory lady beetle to aggression of the ant, azteca instabilis, creates two habitat types that are utilized differently by the immature and adult life stages of the beetle. due to a mutualistic association between a. inst ...	2014	25473473
scale insects (hemiptera: coccoidea) on myrciaria dubia (myrtaceae) in brazil.	commercial cultivation of the fruit tree myrciaria dubia (myrtaceae) is being developed in brazil but phytophagous insects, including scale insects (hemiptera: coccoidea), can become pests in plantations. the coccids ceroplastes jamaicensis white, coccus viridis (green), parasaissetia nigra (nietner), pseudokermes vitreus (cockerell) (coccidae), and the diaspidid pseudaonidia trilobitiformis (green) were collected on m. dubia in the municipality of belém and tomé-açu, state of pará (pa), metropo ...	2016	26957084
fine-scale spatial genetic structure of a fungal parasite of coffee scale insects.	the entomopathogenic fungus lecanicillium lecanii persists in a highly dynamic network of habitat patches (i.e., a metapopulation) formed by its primary host, the green coffee scale coccus viridis. lecanicillium lecanii is an important biological control of both c. viridis and the coffee rust, hemileia vastatrix. successfully managing this biocontrol agent will depend on an increased understanding of the characteristics of its dispersal, as migration between occupied and unoccupied patches is es ...	2016	27449676