Published: 18.08.2018 15:07

Magnetoreception in eusocial insects an update

«Magnetoreception in eusocial insects an update» in pictures.

Pitch and Yaw Control of a Robotic Insect using an Onboard

In many recent and historical instances of unusual colony mortality, an unexpected spring or fall chill preceded the event.

Analysis of Magnetic Gradients to Study Gravitropism

To quantify these differences in output shape, a histogram of the output was made at a point in time when the stimulus was active and the network activity had evolved to a steady state (figures 9(b) and (c) ). The number of points in the upper tail was recorded and normalized by the total number of sensors in the neural field. Because this approach quantifies the shape of the neural output, specifically how flat certain sections of the output are, (see figure 9 ), we refer to this measure as a 'flatness index' or


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Analysis: T he intermittent appearance of CCD does not match the steady proliferation of cell phone and other electromagnetic transmissions. More importantly, CCD occurred in areas in which you couldn’t get cell reception conversely, plenty of apiaries thrived immediately adjacent to cell phone and radio towers, and under electrical transmission lines.

Biological plausibility: Allow me to quote from the original CCD report, back when it was still called “Fall Dwindle Disease” 7 :

Figure 5(a) shows sample simulated and hardware inputs into the multidirectional sensor array. In particular, the simulated input is a graphical example of equation ( 6 ). For the multidirectional array, based on the sample input data and the results of Taylor ( 7566 ), we predicted that the flatness index should vary logarithmically with the magnetic intensity for both the simulation and hardware experiments. It is possible that a power law may apply.

For more information on these research topics, please refer to the following Web site:
( Note : This link will take you to a non-federal site)

In both the multi and unidirectional simulated sensor arrays, 79 sensors were used. For the multidirectional array, this corresponds to the sensors being spaced apart in increments. Examples of equations ( 6 ) and ( 7 ) are plotted in figures 5(a) and (c).

Honey bee colonies can handle a lot of insults so long as they get enough high-quality forage (Fig. 6) to maintain vigorous broodrearing, and are not hamstrung by parasites. Those beekeepers who make sure that their colonies are always well fed, especially with protein, and never allow varroa infestation to exceed a few percentage points, appear to have far fewer problems than others. In some areas, treatment against nosema also appears to help.

Figure 5. Land use in the United States. The yellow pie slices indicate the proportion of each area allocated to cropland–the most biologically productive acreage. Fully two thirds of that cropland is planted to only a handful of crops– corn, soy, hay, wheat, and cotton, which produce forage for bees for only brief periods, if ever. Sources: USDA, Economic Research Service calculations based on data from Major Uses of Land in the United States, 7557