Sanitizing Equipment and Personnel to Prevent the Spread of Hibiscus Mealybug [Nipaecoccus viridis (Hemiptera: Pseudococcidae)] in Florida Citrus.

Hibiscus mealybug (Nipaecoccus viridis, Newstead) is an emerging and serious pest of citrus in Florida. Preventing the spread of hibiscus mealybug by sanitizing personnel and equipment such as individual protective covers can help limit new infestations. Two mealybug life stages, first instars (crawlers) and eggs inside ovisacs, were tested as they are the most likely to be accidentally transported on people and tools. Isopropanol sprays in 3 commercially available concentrations (50%, 70%, and 90%) were tested against crawlers and ovisacs, and steam treatments and hot water immersion were tested against ovisacs. All concentrations of isopropanol resulted in >90% incapacitation of mealybug crawlers, especially when two sprays of isopropanol were applied. However, no concentration of isopropanol reliably killed all mealybug eggs within ovisacs. Steam treatments and hot water immersion for 10 min or longer at 49°C and for 5 min or longer at 54.5°C resulted in 100% mortality of mealybug adults and eggs inside ovisacs. However, adults and ovisacs insulated inside of individual protective covers did not experience 100% mortality until 30 min or longer at 49°C, 10 min or longer at 54.5°C, and 5 min or longer at 60°C for steam treatments. Isopropanol sprays can effectively incapacitate the majority of hibiscus mealybug crawlers on personnel and tools, but are not effective against ovisacs. Steam treatments and hot water immersion can reliably lead to 100% mortality of ovisacs, but longer times and higher temperatures must be used for steam treatments if ovisacs are insulated by equipment.

Floral Plantings in Large-Scale Commercial Agroecosystems Support Both Pollinators and Arthropod Predators.

Beneficial insect populations and the services that they provide are in decline, largely due to agricultural land use and practices. Establishing perennial floral plantings in the unused margins of crop fields can help conserve beneficial pollinators and predators in commercial agroecosystems. We assessed the impacts of floral plantings on both pollinators and arthropod predators when established adjacent to conventionally managed commercial potato fields. Floral plantings significantly increased the abundance of pollinators within floral margins compared with unmanaged margins. Increased floral cover within margins led to significantly greater pollinator abundance as well. The overall abundance of arthropod predators was also significantly increased in floral plantings, although it was unrelated to the amount of floral cover. Within adjacent potato crops, the presence of floral plantings in field margins had no effect on the abundance of pollinators or predators, although higher floral cover in margins did marginally increase in-crop pollinator abundance. Establishing floral plantings of this kind on a large scale in commercial agroecosystems can help conserve both pollinators and predators, but may not increase ecosystem services in nearby crops.

Single-molecule investigation of G-quadruplex folds of the human telomere sequence in a protein nanocavity.

Human telomeric DNA consists of tandem repeats of the sequence 5'-TTAGGG-3' that can fold into various G-quadruplexes, including the hybrid, basket, and propeller folds. In this report, we demonstrate use of the α-hemolysin ion channel to analyze these subtle topological changes at a nanometer scale by providing structure-dependent electrical signatures through DNA-protein interactions. Whereas the dimensions of hybrid and basket folds allowed them to enter the protein vestibule, the propeller fold exceeds the size of the latch region, producing only brief collisions. After attaching a 25-mer poly-2'-deoxyadenosine extension to these structures, unraveling kinetics also were evaluated. Both the locations where the unfolding processes occur and the molecular shapes of the G-quadruplexes play important roles in determining their unfolding profiles. These results provide insights into the application of α-hemolysin as a molecular sieve to differentiate nanostructures as well as the potential technical hurdles DNA secondary structures may present to nanopore technology.