Biology subjects

Cheek, M.

Publications and source records attributed to Cheek, M..

At least 37 records · Page 2Linked to original sources

bioRxiv2024

Afrothismia ugandensis sp. nov. (Afrothismiaceae), Critically Endangered and endemic to Budongo Central Forest Reserve, Uganda

The fully mycotrophic Afrothismia ugandensis (Afrothismiaceae), formerly described as A. winkleri var. budongensis Cowley, is renamed, redescribed and illustrated from the Budongo Forest in Western Uganda. This change in status is supported by eight newly elucidated qualitative morphological diagnostic characters despite the overall similarity with A. winkleri, a species restricted to Cameroon and Gabon. Afrothismia ugandensis is remarkable in the genus for occurring in semi-deciduous (not evergreen) forest and for having ellipsoid or ovoid (vs. globose) root bulbils. It has only been recorded twice, first in August 1940, and most recently in June 1998, despite targeted searches in recent years. In both 1940 and 1998, only single individuals appear to have been detected. A single site for the species is known with certainty. It is here assessed as Critically Endangered (CR B2ab (iii); D1) using the IUCN 2012 categories and criteria. Afrothismia ugandensis is threatened by forest degradation and clearance due to illegal selective small-holder logging for firewood and charcoal, timber and limited agriculture.

plant biology↗

bioRxiv2024

Keetia nodulosa sp. nov. (Rubiaceae - Vanguerieae) of West - Central Africa: bacterial leaf nodulation discovered in a fourth genus and tribe of Rubiaceae.

Keetia nodulosa Cheek, a cloud forest climber nearly endemic to Cameroon, with a single record from Nigeria, is described and illustrated. It is remarkable as the first known species to be recorded with bacterial leaf nodules (BLN) in the genus Keetia, and also, in the tribe Vanguerieae. Other genera in Rubiaceae with BLN are Psychotria (Psychotrieae), Sericanthe (Coffeaeae) and Pavetta (Pavetteae). The BLN in Keetia (Vanguerieae) are illustrated for the first time here. The characteristics and significance of bacterial leaf nodulation in Keetia nodulosa are discussed in the context of rapidly growing knowledge on the subject in flowering plants. Keetia nodulosa is provisionally assessed using the 2012 IUCN standard as Endangered (EN B2ab(iii). The importance of its conservation, and options for achieving this are discussed in the context of recent extinctions of other plant species in Cameroon. This discovery of a new cloud forest species is discussed in relation to other cloud forest plant species described in the last twenty years which are also distributed over the highlands of the western half of Cameroon.

plant biology↗

bioRxiv2023

The endemic plant species of Ebo Forest, Littoral Region, Cameroon with a new Critically Endangered cloud forest shrub, Memecylon ebo (Melastomataceae-Olisbeoideae)

We emphasise the urgent need to conserve the Ebo forest (Littoral Region, Cameroon), which holds 10 strict endemic plant species and 15 near endemics for a total of 25, a very high number far exceeding the threshold for its recent status as an Important Plant Area (IPA). We describe a further strict endemic species from the Ebo Forest, Memecylon ebo sp. nov. (Melastomataceae-Olisbeoideae) placed in sect. Afzeliana due to its ellipsoid blue-green fruits. The yellow petals and jade green anther-connectives of M. ebo are unique in the genus Memecylon as a whole, among its >400 species ranging overall from Africa to the western Pacific. Memecylon ebo is assessed as Critically Endangered (CR) using the 2012 IUCN standard due to the small range size and the extremely high and ongoing threats of logging at Ebo, and also due to subsequent threats of potential oil palm plantation and mining projects. With the addition of Memecylon ebo, the tally of Critically Endangered plant species recorded from Ebo forest is now the highest of any IPA in Cameroon, equalling that of, Ngovayang with 24 CR species.

plant biology↗

bioRxiv2023

A new cloud forest tree Lychnodiscus bali (Sapindaceae), Critically Endangered from the Bali-Ngemba Forest reserve, N.W. Region, Cameroon.

We describe Lychnodiscus bali (Sapindaceae) a new species to science, from the Bali Ngemba Forest Reserve of NW Region Cameroon, the last major remnant of cloud forest in the Bamenda Highlands of Cameroon, recently evidenced as a Tropical Important Plant Area (TIPA or IPA). Confined on current evidence to upper submontane forest, the species is threatened by expanding habitat clearance for farms and is assessed as Critically Endangered. A small tree, attaining 3 - 4 m height, it is the first new species to be added to this Guineo-Congolian tree genus in 50 years, the third recorded from Cameroon, and takes the number of species in the genus to eight. It has the highest known altitudinal range (1700 - 1950 m alt.), of any species of the genus. Previously identified as Lychnodiscus grandifolius, the new species differs in the shorter length of the distal leaflets (12 - 18 cm vs 22 - 39 cm long), in the abaxial surface lacking glands (vs glands flat and conspicuous), tertiary nerves hairy (vs glabrous), flowers at anthesis 8 - 11 mm long (vs 5 - 7 mm long). Lychnodiscus bali is described, illustrated and its extinction risk assessment as Critically Endangered is presented. We discuss its discovery in the context of other recently discovered and highly threatened or even extinct plant species in the Cameroon Highlands, and the importance of their conservation. We present an updated key to the identification of the species of the genus,and discuss its classification in the context of recent molecular phylogenomic studies. Previously placed in Cupanieae by Radlkofer, the authors contend that Lychnodiscus should now be placed in the reconstituted Nepheliaeae in the revised 2021 intrafamilial classification of Buerki et al., probably close to the genera Aporrhiza and Laccodiscus. However, until the genus is included in molecular studies this cannot be confirmed and its sister relationship remains speculative.

plant biology↗

bioRxiv2023

Gymnosiphon fonensis (Burmanniaceae) a new Critically Endangered species from Simandou, Republic of Guinea, W. Africa.

A new species of Gymnosiphon Blume (Burmanniaceae), G.fonensis Cheek is formally described from the Foret Classee de Pic de Fon, Simandou Range, Guinee-Forestiere, Republic of Guinea (Guinee-Conakry) in West Africa. The new species was formerly confused with and resembles G. bekensis Letouzey of central Africa in the broad flat outer tepal lobes, perianth tube >10 mm long, and (sub)sessile flower. It differs e.g. in that the length of the corolla tube, (13-)14-18 mm, exceeds the corolla diameter (10-11 mm) (vs length of the corolla tube (12 mm) < the corolla diameter (12-15 mm)), the anthers inserted c. 4 mm deep in the corolla tube (vs inserted at the corolla mouth) and the rhizome lacks scale-leaves (vs scale leaves present). Gymnosiphon fonensis is the first known species of its genus and family in which secondary pollen presentation has been recorded. The species is known from five sites, all with threats, in a single threat-based location, accordingly it is assessed as Critically Endangered (CR B1ab(iii)) using the IUCN 2012 standard, making it the most threatened species of Gymnosiphon in continental Africa. The new species is illustrated by colour photos and line-drawings and is mapped. An identification key is provided to the ten species of the genus now known from Africa-Madagascar.

plant biology↗

bioRxiv2023

New to Ehretiaceae: Keraunea. Re-evaluation of a genus of climbers from Brazil.

We definitively place Keraunea, a genus of showy forest climbers from remnants of the Mata Atlantica of Brazil, in Ehretiaceae. Previously Keraunea had been ascribed to Convolvulaceae based on morphology, or divided between Malpighiaceae and Ehretiaceae based on molecular analyses (polyphyletic). Keraunea is morphologically anomalous in the Ehretiaceae, having fruits which are held in the centre of a large wing-like bract by adnation of the pedicel, and due the stem-twining habit of some species. However, morphologically Keraunea shares two apomorphies with monotypic Cortesia Cav., halophytic shrubs of Argentina: 1) "two parted endocarps" (the fruit contains two endocarps each with two 1-seeded cells, while four 1-seeded endocarps are plesiomorphic in Ehretiaceae) and 2) a large bract that subtends the flower (absence of bracts is plesiomorphic in Ehretiaceae). A combined tree using four markers (ITS, trnL-F, rbcL and matK) places the three species of Keraunea sampled unambiguously in a clade with Ehretia + Cortesia + Halgania and monophyly for Keraunea is shown with high support. In an ITS tree Keraunea is sister to Cortesia with low support. We expand the generic description of Keraunea including the first account of the internal fruit structures and the seed, and present new data on the vegetative architecture including variation within the genus, some species being stem twiners while one species at least, is described as a scandent shrub. Keraunea lombardiana, previously included within K. brasiliensis, is formally described from Minas Gerais and Bahia as the third species of the genus and both these species are described. In all five species are recognised but two, known to us only from digital images, are not formally described because sufficiently detailed descriptions cannot be made. All five species are mapped, and provisional conservation assessments are recorded, of either Endangered or Critically Endangered. The state of Bahia, with three species, has the highest species diversity, mainly in dry forest. Three species appear confined to moist coastal forest, extending southwards from Bahia to the state of Rio de Janeiro. Keraunea remains incompletely known. Not one of the species has both anthetic flowers and fruits described. Studies on pollen, germination, anatomy, embryology and phytochemisty are entirely lacking. Field observations of pollination, seed dispersal and phenology are also required. However, the most urgent requirement is undoubtedly a formal taxonomic revision based on a full herbarium search and targeted fieldwork, with full IUCN 2012 extinction risk assessments for each taxon. This is urgent because it seems that all the taxa that we present in this paper (and more that can be expected to be found) appear to be highly range restricted and generally not to occur in protected areas, and so appear to be highly threatened.

plant biology↗

bioRxiv2023

Barking up the wrong tree: the importance of morphology in plant molecular phylogenetic studies

Background and aimsKeraunea is a genus recently described in Convolvulaceae, though it has sat uncomfortably in this family. A recent molecular phylogenetic study suggests that its two morphologically almost identical species actually belong to different families, Malpighiaceae (Superrosids) and Ehretiaceae (Superasterids), although with little-to-no morphological evidence to support it. Material and methodsSequences of matK, rbcL, and ITS for all the 77 currently accepted genera of Malpighiaceae, K. brasiliensis and Elatinaceae (outgroup) were compiled from Genbank and analysed with Maximum Likelihood and Bayesian Inference criteria for nuclear, plastid and combined datasets. Additional database and herbarium studies were performed to locate and analyse all duplicates of the holotype of K. brasiliensis to check for misidentified or contaminated materials. Key resultsOur examination of expanded DNA datasets and herbarium sheets of all K. brasiliensis isotypes revealed that an error in tissue sampling was, in fact, what led to this species being placed in Malpighiaceae. Kews isotype had a leaf of Malpighiaceae (likely from Mascagnia cordifolia) stored in the fragment capsule, which was unfortunately sampled and sequenced instead of the actual leaves of K. brasiliensis. ConclusionsDNA sequences can be helpful in classifying taxa when morphology is conflicting or of a doubtful interpretation, with molecular phylogenetic placement becoming a popular tool that potentially accelerates the discovery of systematic relationships. However, good knowledge of plant morphology is essential for formulating the phylogenetic hypotheses to be tested and for a critical re-interpretation of the results in the context of biological information of the species or families. Thus, these techniques are, much like any others, prone to methodological errors. We highlight the crucial need to observe plant morphology alongside molecular phylogenetic results, particularly when the new hypotheses are in disagreement with the existing classification and at risk of incurring gross taxonomic mistakes.

plant biology↗

bioRxiv2023

Afrothismiaceae (Dioscoreales), a new fully mycoheterotrophic family endemic to tropical Africa

Afrothismia is a genus of non-photosynthetic mycoheterotrophs from the forests of continental tropical Africa. Multiple phylogenetic inferences using molecular data recover the genus as sister to a clade comprising mycoheterotrophic Thismiaceae and the photosynthetic family Taccaceae, contrary to earlier placements of Afrothismia and Thismiaceae within Burmanniaceae. Morphological support for separating Afrothismia from the rest of Thismiaceae has depended on the zygomorphic flowers of Afrothismia (although some South American species of Thismia are also zygomorphic) and their clusters of root tubers, each with a terminal rootlet. The number of described species of Afrothismia has recently increased substantially, from four to 16, which has provided additional morphological characters that support its distinction from Thismiaceae. Most notably, the ovary in Afrothismia has a single stalked placenta, and circumscissile fruits from which seeds are exserted by placental elevation (in Thismiaceae, in contrast, there are three placentas, a deliquescing fruit lid, and the seeds are not exserted). Afrothismia stamens are inserted in the lower perianth tube where they are attached to the stigma, and individual flowers are subtended by a single large dorsal bract (in Thismiaceae, stamens are inserted at the mouth of the tube, free of and distant from the stigma, and each flower is subtended by a loose whorl of (2-)3(-4) bracts). Here we formally characterise Afrothismiaceae and review what is known of its development, seed germination, interactions with mycorrhizal Glomeromycota, biogeography, phylogeny and pollination biology. All but one (Afrothismia insignis; Vulnerable) of the 13 species assessed on the IUCN Red List of Threatened Species are either Endangered or Critically Endangered; one species (A. pachyantha Schltr.) is considered to be extinct.

plant biology↗

bioRxiv2022

Chemotaxonomy supports morphology in the identification of Vepris hemp (Rutaceae) a new species of Critically Endangered deciduous forest shrub from Usambara Mts, Tanzania.

Hemp 7152, a sterile herbarium plot voucher of a shrub from a rare type of deciduous forest in the Usambara Mts, Tanzania was tentatively identified using morphology as a new species of Vepris (Rutaceae). To gain further support for its placement its chemistry was investigated. The compounds isolated from Hemp 7152 were four quinoline alkaloids, kokusaginine (1), N-methylplaty-desminium ion (9), ribalinium ion (10), and isoplatydesmine (11), and seven acridone alkaloids, arborinine (2) 1,2,3-trimethoxy-N-methylacridone (3), 1,2,3,5-tetramethoxy-N-methylacridone (4), 1,3-dimethoxy-N-methylacridone (5) and toddaliopsis A (6), evoxanthine (7) and tecleanthine (8). In addition, lupeol and ferulic acid were isolated from this plant. The combination of quinoline and acridone alkaloids is restricted to the Rutaceae family, confirming beyond reasonable doubt the placement of this material in the Rutaceae. Within Rutaceae in tropical Africa, only the genus Vepris is unarmed, with trifoliolate leaves. Using an identification key, and herbarium specimen matching, Hemp 7152 was morphologically placed as close to Vepris uguenensis, sharing xerophytic characters unusual in the genus. The species are geographically close, occurring in adjoining mountains in northern Tanzania. However, Vepris uguenensis contains 13 alkaloids which are not present in Hemp 7152, nor in any other species of Vepris that has been studied, supporting species recognition for Hemp 7152 which is formally named as Vepris hemp, morphologically characterised, illustrated and assessed as Critically Endangered using the IUCN 2012 standard. The new species appears restricted to an almost extinct type of deciduous forest, characterised in this paper.

plant biology↗

bioRxiv2022

Cola Subgenus Disticha subg. nov. (Malvaceae-Sterculiaceae) of tropical Africa, a synoptic taxonomic revision with seven new species

A new subgenus, Subg. Disticha is erected for 14 species of simple-leaved Cola sharing unique characters within the genus which are presumed synapomorphies: distichous phyllotaxy; petioles lacking pulvini; petioles of uniformly short length, <10 mm long; male flowers with short androphores <1(- 2) mm long; stamens 4 - 5; stem indumentum where present, dominated by short simple translucent hairs (except in C. philipi-jonesii where stellate), and in many species dark purple to black stems with contrasting bright white lenticels. All species have fruit with small globose, unsculptured orange mericarps c. 1 cm diam. (where fruits are known). The species of this subgenus range from SE Nigeria in the west to coastal Kenya and Tanzania in the east and Malawi in the south, but are absent from the Congo basin. Species diversity is highest in the Cross-Sanaga and Eastern Arc-Coastal Forest biogeographic areas, consistent with these taxa being Pleistocene refuge species. The species are mainly monoecious, but dioecy cannot yet be ruled out in some species. In two species where sufficient material was available for investigation (Cola chlorantha, C. roy), the simple cymes were found to be bisexual, the terminal flower being female, the two lateral flowers often being male, a pattern previously unreported in the genus. All species are understorey shrubs or small trees of evergreen lowland or submontane forest, except C. uloloma of coastal semi-deciduous forest in E Africa and which is unique in showing xerophilic characteristics. The species can be divided into group A: five species mainly in E Africa with rapidly glabrescent or glabrous stems, conspicuously asymmetric leaves, few-flowered, pedunculate cymes (C. uloloma, C. chlorantha, C. roy sp.nov., C."udzungwa", C. asymmetrica sp. nov.); group B: in Lower Guinea (Atlantic coast of Africa) with hairy stems, symmetric or inconspicuously asymmetric leaves, sessile, fasciculate inflorescences: (Cola mayimbensis, C. philipi-jonesii, C. metallica, C.moussavoui, C. stigmatosa, C. takamanda sp.nov. C. toyota sp. nov, C. "campo-maan", C. zanaga sp. nov.). Of the seven new species to science, two are named informally since the material is so incomplete (sterile), and five are formally named. Species diversity is highest in Cameroon and Tanzania, each with four species, followed by Gabon with three species. It is expected that additional new species will be found in poorly-surveyed surviving evergreen forest habitat in each of these three countries. Conservation assessments are given for each species using the IUCN 2012 standard. All species are considered threatened, with ten species being Critically Endangered (the highest category of threat), each known from a single location, with their forest habitat threatened mainly by clearance for agriculture.

plant biology↗

bioRxiv2022

A new Critically Endangered cloud forest tree Microcos (Grewiaceae-Malvaceae) from the Rumpi Hills of S.W. Region Cameroon.

We describe Microcos rumpi (Grewiaceae-Malvaceae) as a new species to science from the Rumpi Hills of SW Region Cameroon, a proposed Tropical Important Plant Area. Confined on current evidence to submontane forest, the species is threatened by expanding habitat clearance for farms and is assessed as Critically Endangered. A massive tree, attaining 35 - 40 m height, and 80 cm trunk diameter at 1.3 m above ground, its biomass is calculated as in the range of 7 - 8 metric tonnes. It is the third tree species of the genus recorded from Cameroon and only the fourth recorded west of D.R. Congo. A key to these four species is presented. The concept of Microcos in Africa in relation to Grewia is discussed, and three new combinations are made, transferring three species names from Grewia to Microcos: Microcos louisii (Wilczek) Cheek, M. evrardii(Wilczek) Cheek and M.schmitzii (Wilczek) Cheek.

plant biology↗

bioRxiv2022

A taxonomic synopsis of unifoliolate continental African Vepris (Rutaceae) with three new threatened forest tree species from Kenya and Tanzania

Descriptions and illustrations are presented for three new species to science, Vepris udzungwa Cheek, V. lukei Cheek (both Udzungwa Mts, Tanzania) and V. robertsoniae Cheek & Q. Luke (SE Kenyan kaya forests) in the context of a synoptic taxonomic revision, with an identification key to all the known unifoliolate taxa of Vepris in continental Africa. The remaining species are given skeletal taxonomic treatments (lacking descriptions). One widespread species in montane eastern Africa is renamed as Vepris simplex Cheek because its previous name, Vepris simplicifolia (Engl.)Mziray is predated by Vepris simplicifolia Endl. (basionym of Sarcomelicope simplicifolia (Endl.)T.G. Hartley, a widespread species of Australia, Lord Howe and Norfolk Islands, and of New Caledonia). Conservation assessments are presented for all species, or provisional conservation assessments are presented. Of the 13 taxa, 11 are considered threatened, of which six are VU, two EN and three CR, of which two are possibly extinct globally in the Uluguru Mts of Tanzania although not yet Red Listed on iucnredlist.org.

plant biology↗

bioRxiv2022

Monanthotaxis bali (Annonaceae) a new Critically Endangered (possibly extinct) montane forest treelet from Bali Ngemba, Cameroon

Monanthotaxis bali is the only known, solely montane (occurring solely above 2000 m alt.) species of the genus. It joins Monanthotaxis orophila (Rwanda) and M. discolor (Tanzania), two other species that can also occur above 2000 m alt. Monanthotaxis bali is an addition to the small number (28) of the tree species of the surviving montane forests of the Cameroon Highlands of which only eight other species are endemic. Due to its supra-axillary inflorescences, and petals arranged in one whorl but with the outer petals overlapping the inner petals distally, and rounded flower buds, the new species is placed in Hoekstras clade B of Monanthotaxis. The new species is unusual in being a treelet in a predominantly lianescent genus, and in lacking the glaucous underside of the leaf-blades that usually characterises the genus. Monanthotaxis bali takes the number of continental African species of the genus to 80, and makes Cameroon, with 30 species, the most species-diverse country for the genus. Monanthotaxis bali is known only from the Bali Ngemba Forest Reserve, a forest remnant under pressure of degradation and clearance in the Bamenda Highlands of Cameroon. It may already be extinct due to logging and agricultural activities. Here it is described, illustrated, mapped and assessed as Critically Endangered (Possibly Extinct) using the IUCN 2012 criteria.

plant biology↗

bioRxiv2022

The generic status of Anacolosa (Olacaceae) in Africa with A. deniseae a new species to science of Endangered submontane forest liana from Simandou, Republic of Guinea.

Anacolosa deniseae Cheek (Olacaceae) a submontane gallery forest canopy liana is described as a new species to science and assessed as Endangered using the IUCN 2012 standard due to threats of habitat destruction connected with mining. The roots smell of benzaldehyde when scraped, and the plant reproduces from root suckers. The species is restricted globally to two locations in the Loma-Man Highlands of the Republic of Guinea, all records but one being in the Pic de Fon Foret Classe of the Simandou Range. We show that this and the only other continental African species ascribed to the genus Anacolosa, A. uncifera of DRC, Gabon & C.A.R., differ in so many architectural, floral and vegetative characters from the remaining species of the genus, which occur from Madagascar to the Western Pacific, including the type A. frutescens (S.E. Asia and Indo-China), that they clearly represent a separate genus. The African genus represented by these two species is unique within the Olacaceae (excluding Erythropalaceae) in being a climber (vs. shrubs or trees in Anacolosa sensu stricto). Climbing in the two African species is achieved by perennial hook-like structures formed by a combination of five separate traits each of which is unknown elsewhere in the Olacaceae. We formally delimit and describe this new genus, discussing its characteristics, but in the absence of molecular phylogenetic data, refrain from naming it.

plant biology↗

bioRxiv2022

A new, Critically Endangered species of Impatiens (Balsaminaceae) from the coastal plain of the Republic of Congo

Impatiens moutsambotei is described from a herbarium specimen collected at a waterfall in forest on the coastal plain, below the Mayombe Mts of the Republic of Congo. Sharing many distinctive characters with Impatiens floretii of the Doudou Mts of Gabon, it is abundantly distinguished inter alia by the leaf-blades which are lanceolate or narrowly elliptic, not ovate, their bases acute, not obtuse or broadly rounded to truncate; the reduced, peduncular bracts bearing long, filiform setae, and not entire; the proximal (upper) of the lateral united petals are entire, not bifid; the spur is curved at the base and overlaps the lower sepal, not curved through its length to describe a semi-circle and held below the lower sepal. Both species are placed in the Impatiens macroptera species aggregate. Impatiens moutsambotei is known from a single site, where it was collected nearly 30 years ago and not seen since. The new species is assessed as Critically Endangered due to threats of habitat clearance from mining and road widening, and may be already be extinct.

plant biology↗

bioRxiv2022

Impatiens banen sp. nov. & I. etugei sp. nov. (Balsaminaceae), threatened lowland species of the Cross-Sanaga Interval, Cameroon

We describe two range-restricted new species to science from the genus Impatiens (Balsaminaceae), both threatened, from the Cross-Sanaga Interval of western Cameroon. The first, Impatiens banen, appears to be restricted to an open seepage microhabitat on granitic inselbergs in the lowland-submontane forest zone of the Ebo Forest in Littoral Region and is provisionally assessed using the 2012 IUCN standard as Vulnerable. Sharing characters with Impatiens burtonii and I. mannii, it differs from both, and appears to be unique in Cameroon inter alia 1) in the bicolored united lateral petals, the upper petals being white, while the lower petals are an intense pink-purple, 2) the hairy, filamentous spur, purple with a white apex, is curved along its length (through nearly 360{degrees}), almost describing a circle. Inselberg-specific species are unusual in Impatiens. The second species, Impatiens etugei, of the I. macroptera aggregate, is restricted to rocks in the Mutel River of the Kom Wum Forest Reserve of NorthWest Region and is assessed as Critically Endangered. Having similarities with I. mackeyana and I. letouzeyi, it differs from other species in the aggregate inter alia by having opposite leaves (vs always alternate), flower exterior white (vs pink or pink-purple), and in the dorsal petal having a pair of lateral projections (vs projections absent).

plant biology↗

bioRxiv2022

Immune defense in Drosophila melanogaster depends on diet, sex, and mating status

Post-mating immunosuppression has been widely accepted as a female trait in Drosophila melanogaster. Our results challenge this notion by presenting a mating-immunity trade-off in males as well as in females. When inoculated with the fungal pathogen, Beauveria bassiana, both males and females die faster compared to inoculated virgins, and survival is lower when inoculated flies are continuously mated compared to a single day of mating. Past studies with Beauveria bassiana have shown females to be more susceptible to infection than males. Our results challenge this finding as well, showing that the direction of sexual dimorphism in immune defense depends on mating status, specific Beauveria bassiana strain, and fly genotype. Moreover, we show that survival after fungal infection is largely influenced by diet, and that post-infection dietary improvements can help enhance survival. Post-mating suppression in Drosophila survival of B. bassiana infection presents study opportunities with potential applications for biological control of insect vectors of human disease and insect crop pests.

physiology↗

bioRxiv2021

Two new threatened species of Rinorea (Violaceae), forest trees from East and South Regions, Cameroon

Two tree species are described as new to science: Rinorea spongiocarpa Achound. sp. nov (placed in Rinorea [unranked] Brachypetalae) and Rinorea dimakoensis Achound. sp. nov.( placed in Rinorea [unranked] Ilicifolieae). Both species are endemic to Cameroon, occurring south of the Sanaga river, the first from South and East Regions, occurring in evergreen forest from Ebolowa to Dja, while the second occurs in the northern part of East Region in semi-deciduous forest towards the interface with woodland habitats in the Dimako-Bertoua area. The two species are illustrated, and their affinities and conservation status according to the 2012 IUCN categories and criteria are discussed. Both species are threatened with extinction due to habitat destruction, the first is assessed as Vulnerable, the second Endangered.

plant biology↗