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The present study attempts to investigate the role of rigid claws and smooth adhesive pads in the locust Locusta migratoria manilensis, when attaching to various substrates. We measured the attachment forces on sandpaper and silicate glass plate of locusts with intact attachment system, and those with either the pretarsal claws or the tarsal pads having been entirely destroyed, to explore the role of pads and claws when a locust is walking on various substrates. To obtain information about morphological characteristics and material properties of the claws, we examined the intact and fractured claws by scanning electron microscopy, and tested the fractural force in a fracture experiment. We proposed a mechanical model for locust climbing on a slanting surface to analyze the conduction and final result of the attachment forces generated by the attachment organs on the fore-, mid-and hindlegs. Attachment forces generated by locusts with destroyed pads were similar to those generated by locusts with intact attachment system on both substrates, which presumably indicated that the claws have a significantly important role when attaching to various substrates. The result of the fracture experiment demonstrated that the claws are made of relatively stiff material, and their shear strength ranged between 39-45 MPa. Mechanical analysis of locust climbing on slanting surface showed that the force generated by the hindlegs suspended the whole body of locust up from the surface and pushed the body forward, while the midlegs steadily suspended the centre of gravity and the forelegs pulled the suspended body forward. The results obtained contribute to the further interpretation of the interaction mechanisms between insect attachment system and substrates, and supply information for designing and manufacturing slippery plates for trapping plague locusts. locust, pads, claws, attachment force, mechanical model Citation:Wang L X, Zhou Q, Xu S Y. Role of locust Locusta migratoria manilensis claws and pads in attaching to substrates.

A previously unreported pancreatic duct was found by Liu (1989) in Pekin ducks. This duct has now been consistently found in six breeds of domestic ducks and six species of wild ducks in China. For purposes of Nomina Anatomica Avium it is hereby called the 'first pancreatic duct' (Ductus pancreaticus primus) since it enters the duodenum at or near the flexure where the descending duodenum becomes the ascending duodenum. All other pancreatic ducts enter the duodenum later, closer to where it joins the jejunum. This first pancreatic duct drains the caudal extremity of the dorsal lobe of the pancreas and can be easily exteriorized for experimental purposes. Within the parenchyma of the dorsal lobe of the pancreas this duct communicates with the dorsal pancreatic duct. In the present study of the gross anatomy of the pancreatic lobes of domestic and wild Chinese ducks we describe and illustrate variations in position and number of all biliary and pancreatic ducts.

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