Lyme disease occurs in specific geographic regions of the United States. We present a method for defining high-risk counties based on observed versus expected number of reported human Lyme disease cases. Applying this method to successive periods shows substantial geographic expansion of counties at high risk for Lyme disease.

Jumping is often achieved using propulsive legs, yet legless leaping has evolved multiple times. We examined the kinematics, energetics and morphology of long-distance jumps produced by the legless larvae of gall midges (Asphondylia sp.). They store elastic energy by forming their body into a loop and pressurizing part of their body to form a transient 'leg'. They prevent movement during elastic loading by placing two regions covered with microstructures against each other, which likely serve as a newly described adhesive latch. Once the latch releases, the transient 'leg' launches the body into the air. Their average takeoff speeds (mean: 0.85 m s −1 ; range: 0.39-1.27 m s −1) and horizontal travel distances (up to 36 times body length or 121 mm) rival those of legged insect jumpers and their mass-specific power density (mean: 910 W kg −1 ; range: 150-2420 W kg −1) indicates the use of elastic energy storage to launch the jump. Based on the forces reported for other microscale adhesive structures, the adhesive latching surfaces are sufficient to oppose the loading forces prior to jumping. Energetic comparisons of insect larval crawling versus jumping indicate that these jumps are orders of magnitude more efficient than would be possible if the animals had crawled an equivalent distance. These discoveries integrate three vibrant areas in engineering and biologysoft robotics, small, high-acceleration systems, and adhesive systemsand point toward a rich, and as-yet untapped area of biological diversity of worm-like, small, legless jumpers.

No abstract

Strong sexual selection by receivers can lead to the evolution of elaborate courtship behaviors in signalers. However the process by which receivers sample signalers and execute mate choice under complex signaling conditions-and thus the realized strength of sexual section-is poorly understood. Moreover, receivers can vary in condition, which can further influence mate sampling strategies. Using wild female frogs we tested two hypotheses at the intersection of these important problems: that some of the individual variation in mate sampling is explained by (1) the reproductive urgency hypothesis, which predicts that receivers in a more urgent reproductive state will sample mates less and/or (2) the reproductive investment hypothesis, which predicts that receivers that have invested less in the current reproductive effort will sample mates less. Eastern gray treefrogs, Hyla versicolor, were collected in amplexus and repeatedly tested for phonotaxis behavior using a dynamic playback assay. To evaluate if hormonal mechanisms explained variation in the mate sampling, three steroid hormones, estradiol, progesterone, and corticosterone, were collected using a noninvasive water-borne hormone assay, validated for this species in the present study. Finally, we measured clutch size (investment) and the duration of time required for each female to oviposit after being reunited with their male mate (urgency). We found repeatability in many of the behaviors, including mate sampling. We found that females with higher concentrations estradiol and corticosterone made quicker choices, and that females with higher progesterone sampled mates more. We also found that female frogs in a more urgent reproductive state had lower concentrations of progesterone and estradiol, thereby providing the first evidence of a relationship between gonadal hormones and reproductive urgency. Collectively we found some support for the reproductive urgency but not the investment hypothesis. Thus, even though a female frog's reproductive readiness is a highly transient life history stage, fine scale variation in her reproductive timeline could mitigate the strength of directional selection.

The rosette galls on Solidago bicolor were indeed induced by an undescribed species of the genus Asphondylia, as identified by Netta Dorchin (University of Tel Aviv, Israel). However, in some populations of S. bicolor, the galls induced by Asphondylia are occupied by individuals of the gall-midge genus Contarinia, which usurp and replace the Asphondylia larvae in some or all of the chambers of a gall. The gall-midge larvae measured were not individuals of the gall-inducing Asphondylia, but were inquilines of the genus Contarinia. The authors thank Raymond J. Gagné (Systematic Entomology Laboratory, USDA, Washington DC, USA) for reporting the misidentification. This error in identification does not affect any of the measurements or inferences regarding the kinematics, energetics or morphology of jumping presented in the article. However, the implications regarding the ecology of the jumping behaviour were misapplied to Asphondylia. Larvae of Asphondylia pupate inside galls and are incapable of jumping if removed from their gall chambers. Larvae of Contarinia leave the galls to pupate underground. Therefore, the jumping behaviour of the larvae makes sense in terms of quickly finding an appropriate site for pupation and for evasion of potential predators while searching for a site to pupate. Also, several entries were incorrect in Table 2. For Steinernema carpocapsae (nematode), body mass should be 2.18×10 -4 (not 2.18×10 -6 ) and jump distance should be 4.8±0.