colombia and ecuador as well. marchitez of oil palm (elaeis guineensis) phytomonas staheli also causes disease in oil palm, namely marchitez sorpresiva (sudden wilt) and slow wilt. while in the plant host, p. staheli remains in the phloem, a trait it shares with p. leptovasorum. as in hartrot of coconut, disease symptoms first appear as yellowing of leaf tips. however, in oil palm, the lower leaves are targeted first, with upper leaves being invaded next. roots also deteriorate, starting from the growing tips and moving toward primary roots. as in coconut hartrot, fruits are also lost. within 3–5 weeks, the plant dies and leaves become dried masses of grey. p. staheli can spread between trees quickly, and can infect up to 30 trees within a few weeks. the disease has great impact across the north of latin america, but can be partially controlled with insecticide application. this is likely by virtue of killing insect vectors which are suspected to be known or new species in the genus lincus. medical importance aside from the harmful impact these organisms can have, phytomonas species can also be useful as parallel models for the study of dangerous diseases caused by organisms in other infections trypanosomatid genera. trypanosoma cruzi is the causative agent of chagas' disease, and as a member of the family trypanosomatidae, is related to organisms of the genus phytomonas. in a 2015 study, phytomonas jma was tested as a model for the expression of heterologous proteins in the dangerous t. cruzi. it was found that phytomonas was able to express gfp levels similar to that of t. cruzi, and it was concluded that organisms in the genus could be used as human-safe models for functional expression of trypanosomatid proteins. research was also done on the practical uses of antigen similarities between p. serpens and trypanosomatid pathogens. it was found that t. cruzi shares some antigens with p. serpens, and that these antigens could be recognized by rabbit and mouse sera. immunization of mice with p. serpens induced a partial immune response against t. cruzi infection. though more research is required, the phytomonads could potentially be used as vaccine agents to prime defense responses to t. cruzi antigens in order to interfere with the development of chagas' disease in humans. list of better-known described species phytomonas françai. inhabits latex ducts of cassava (manihot esculenta). the disease is known as chochamento de raizes and is characterized by very poor root development and leaf cholorsis. however, this parasite is now of lower concern, as the unha cultivar of cassava that was susceptible to p. françai infection is no longer widely grown. phytomonas leptovasorum. inhabits phloem of coffee plants, including coffea liberica, c. arabica, c. excelsa, c. stenophylla, and c. abeocutae. the disease caused is known as phloem necrosis of coffee and is characterized by deposition of callose in the sieve tubes and necrosis. lincus spathuliger is the insect suspected to be the vector. phytomonas nordicus. described in 1993 by frolov and malysehva, this species exhibits a monoxenous lifestyle. its sole host is the predatory bug troilus luridus. phylogenetic analysis using the 18s ribosomal rna demonstrated the affinity of the species to the genus. frolov also argued that the life cycle of p. nordicus was very similar to one of its dixenous relatives, p.serpens, albeit completing all stages within the insect host. phytomonas oxycareni. newly described in 2017. this species can be found in the midgut, the lumen of the salivary gland, and within the gland cells themselves of the insect host, oxycarenus lavaterae. phytomonas serpens. inhabits the fruit of tomato plants. this species has antigens that are very similar to some antigens of trypanosoma cruzi, the causative agent of chagas' disease. the species also appears to exhibit molecules similar to leishmanolysin that is common across all leishmania species. in 1986, trypanosomatids were isolated from tomato plants in brazil that could not be identified positively as phytomoas serpens. phytomonas staheli. inhabits phloem of coconut (cocus nucifera) and oil palm (elaeis guineensis). they are the causative agents of hartrot of coconut and machitez of oil palm, acute lethal wilts that are characterized by wilting of leaves followed by root and spear rot. lincus croupius and l. styliger are two insect species that appear to closely related to the spread of hartrot of coconut, and are likely vector suspects. it has also been proposed that a new species in the genus lincus is the vector for p. staheli transfer into oil palms.