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Two Arundo donax biological control agents, Tetramesa romana, the arundo wasp, and Rhizaspidiotus donacis, the arundo scale, have been established in Texas, USA and Morelos, Mexico for ten years. A...

Guineagrass, Megathyrsus maximus (Jacq.) B.K.Simon & S.W.L.Jacobs, is an African grass that is invasive in Florida, Hawaii, southern Texas, and northeastern Mexico. Buakea kaeuae Moyal et al., a stem-boring African moth found only on M. maximus, was imported from Kenya and evaluated for its ability to feed and develop on Guineagrass naturalized in southern Texas. Neither larvae nor adults developed or reproduced on Texas Guineagrass.

An invasive grass, Arundo donax, occupies thousands of hectares of arid riparian habitat along the Rio Grande in Texas and Mexico, and has negative impacts on national security, water resources, and riparian ecosystems. The shoot-tip-galling wasp Tetramesa romana was released in 2009 between Brownsville and Del Rio, Texas, and has dispersed over 800 km along the river channel. Plots along the river were surveyed for shoot counts of arundo and all other plant species in 2016 at seven sites in regions in which prior studies had documented a 22% decline in arundo biomass (estimated from live shoot length) from 2007 to 2014. Estimated live biomass declined a further 32% between 2014 and 2016. Native plants accounted for 86% of the 44 species encountered in plots. Individual plots averaged five plant species, and arundo was most abundant in only 9 of 21 plots. Arundo live biomass and shoot density were negatively associated with plant diversity, indicating that live arundo interferes with germination a...

Summary The leaf miner Lasioptera donacis Coutin (Diptera: Cecidomyiidae) is a biological control agent of the invasive weed, Arundo donax L. (Poaceae), that was approved for release in the U.S. and Mexico. Pupae are preferred for shipment of living material to quarantine facilities. There is a question of whether emerged females would carry conidia of a potential mutualist fungus, and in particular the saprophyte Arthrinium arundinis, from the pupa or if they would have to acquire the conidia exclusively from the plant to start the oviposition process. We artificially smeared leaf-sheaths of growing plants with A. arundinis before being exposed to female midges, and maintained these host plants until the pupal stage of the midge developed. Polymerase chain reaction methods were applied to detect A. arundinis and any other potential fungi in these pupae. Only 9% of the pupae were infested by fungi or yeast, predominantly belonging to the genus Sarocladium, but not A. arundinis, confirming that the newly emerged females are free of this fungus and will have to acquire conidia present on the leaf-sheath for successful oviposition. We also tentatively tested by PCR for the presence of parasitic nematodes in these pupae. More than 42% of the pupae were shown to be infested specifically by T. gyraloura. Such high infection rate calls for developing methods to eliminate this parasite or to find a parasitefree native population prior to release of L. donacis adults in North America for biological control of A. donax. © 2018 E-flow BioOne. All rights reserved.

Clones carrying the white and topaz eye color genes have been isolated from genomic DNA libraries of the blowfly Lucilia cuprina using cloned DNA from the homologous white and scarlet genes, respectively, of Drosophila melanogaster as probes. On the basis of hybridization studies using adjacent restriction fragments, homologous fragments were found to be colinear between the genes from the two species. The nucleotide sequence of a short region of the white gene of L. cuprina has been determined, and the homology to the corresponding region of D. melanogaster is 72%; at the derived amino acid level the homology is greater (84%) due to a marked difference in codon usage between the species. A major difference in genome organization between the two species is that whereas the DNA encompassing the D. melanogaster genes is free of repeated sequences, that encompassing their L. cuprina counterparts contains substantial amounts of repeated sequences. This suggests that the genome of L. cuprina is organized on the short period interspersion pattern. Repeated sequence DNA elements, which appear generally to be short (less than 1 kb) and which vary in repetitive frequency in the genome from greater than 10(4) copies to less than 10(2) copies, are found in at least two different locations in the clones carrying these genes. One type of repeat structure, found by sequencing, consists of tandemly repeating short sequences. Restriction site and restriction fragment length polymorphisms involving both the white and topaz gene regions are found within and between populations of L. cuprina.