C4 grasses are among the most productive plants and most promising cellulosic biofuel feedstocks. Successful implementation of cellulosic biofuel feedstocks will depend on the improvement of critical crop characteristics and subsequent conversion technologies. The content and composition of lignin, cellulose, and hemicellulose, their biomass yields, and their biotic and abiotic stress tolerances are critical factors which can be enhanced by molecular breeding methods, including marker-assisted selection and transgenic approaches. To maximize biomass yield, no flowering or late flowering and no grain set would be ideal for cellulosic biofuel crops. Reducing fecundity also reduces the risk of undesired gene transfer and invasiveness, thus accelerating deregulation processes and permitting faster implementation of highly improved genotypes in cellulosic feedstock production.

https://www.jstor.org/stable/info/20541033

Genetic Improvement of C4 Grasses as Cellulosic Biofuel Feedstocks

We provide a compilation of 262 species of aphids that are considered as adventive to North America north of Mexico. Included for each species, where applicable, is reference to: the location and date of introduction of the first North American record; pest status in North America; principal economic hosts; and biogeographical origin. Information is also provided for species whose presence in North America is considered erroneous or questionable and for those species that are considered Holarctic or Beringian.

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Adventive aphids (Hemiptera: Aphididae) of America north of Mexico

In the United States (US), the sugarcane aphid (SCA) Melanaphis sacchari (Zehnter) (Hemiptera: Aphididae) was introduced in the 1970s, however at that time it was only considered a pest of sugarcane. In 2013, a massive outbreak of M. sacchari occured on sorghum, resulting in significant economic damage to sorghum grown in North America including the US, Mexico, and Puerto Rico. The aim of the present study was to determine if the SCA pest emergence in American sorghum resulted from the introduction of new genotypes. To this end we used microsatellite markers and COI sequencing to compare the genetic diversity of SCA populations collected in the Americas after the 2013 SCA outbreak on sorghum (during 2013–2017) to older samples collected before the pest outbreak (during 2007–2009). Our results show that the SCA outbreak in the Americas and the Caribbean observed since 2013 belong to populations exhibiting low genetic diversity and consisting of a dominant clonal lineage, MLL-F, which colonizes Sorghum spp. and sugarcane. The comparison of MLL-F specimens collected post-2013 with specimens collected in Louisiana in 2007 revealed that both populations are genetically distinct, according to COI sequencing and microsatellite data analyses. Our result suggest that MLL-F is a new invasive genotype introduced into the Americas that has spread rapidly across sorghum growing regions in the US, Mexico, Honduras and the Caribbean. The origin of this introduction is either Africa or Asia, with Asia being the most probable source.

/pdf/invasion-of-sorghum-in-the-americas-by-a-new-sugarcane-aphid-4e4z44wmn9.pdf

Invasion of sorghum in the Americas by a new sugarcane aphid (Melanaphis sacchari) superclone

Genomics of the Saccharinae

An annotated list is provided of the most significant errors and omissions from a series of books on aphids on the world’s plants. Some of the problems of ensuring the provision of accurate scientific information, both as hard copy and on-line, are discussed.

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Additions and amendments to “Aphids on the World’s Plants”

Several aphid species are reported as newly established in Florida and/or the southeastern United States, including Acyrthosiphon kondoi Shinji, Aphis amaranthi Holman, Brachycaudus helichrysi (Kaltenbach), Coloradoa achilleae Hille Ris Lambers, Hyadaphis coriandri (Das), Hyperomyzus carduellinus (Theobald), Melanaphis sp., Schizaphis rotundiventris (Signoret), Shivaphis celti Das, Takecallis arundicolens (Clarke), and Toxoptera citricida (Kirkaldy). Further establishment records are reported for Trichosiphonaphis polygoni (van der Goot) that was previously reported from a few counties in Florida and Georgia. Recent Florida finds are reported for three native species, including Aphis minima Tissot, Kaltenbachiella ulmifusa (Walsh & Riley), and Uroleucon elephantopicola Robinson. Identification information is provided for newly introduced exotic species.

Newly established and rarely collected aphids (Homoptera: Aphididae) in Florida and the southeastern United States.

L'aphide recemment decouvert sur la Poaceae Miscanthus aux Etats Unis (Californie, Floride) est decrit comme une espece nouvelle : Melanaphis sorini. Ce puceron originaire d'Asie orientale est compare a cinq especes voisines ; ses differentes formes, sauf la fondatrice, sont decrites. M. miscanthi (Takahashi) est retabli comme espece valide et redecrit a partir de specimens de Taiwan. La fondatrice, ainsi que l'aile vivipare de M. yasumatsui (Sorin) sont decrits pour la premiere fois. M. formosana (Takahashi) est retabli comme synonyme de M. sacchari (Zehntner).

Georges Remaudiere

Papers

Newly established and rarely collected aphids (Homoptera: Aphididae) in Florida and the southeastern United States.

A new oriental Melanaphis species recently introduced in North America [Hemiptera, Aphididae].