Cocoon Construction Research Articles

The Cocoon of the Honey Bee, Apis mellifera L.

AbstractDuring cocoon construction the predominant movement made by larvae of the three honey bee castes is a forward somersault which is made dorsal side outermost. Worker, drone, and queen larvae complete one somersault in 52, 46 or 67 (at two different times), and 32 minutes respectively with the total number of somersaults made during cocoon construction being 27-37, 40-50, and 40-80 respectively; the larvae take 37, 54, and 30 hours respectively to complete their cocoons. Weight changes of larvae before and after the cocoons are made are given.Worker and drone larvae build completely enclosed cocoons directly on the side walls and end walls of cells, but queen larvae leave spaces between the cappings and the cocoons and do not cover the bases of their cells with cocoon material.Cocoons consist of silk gland secretion (in thin sheets and threads), a colourless material, a light yellow material, and a more solid brown material (faeces); the last three are discharged from the larval anus. When, how, and where these various secretions and excretions are placed in the cocoon, and their probable origins, are described. Possibly some brood food is incorporated into the cocoon but skin secretions or larval blood are not.

Cocoon Construction By the Cecropia Silkworm Iii. the Alteration of Spinning Behavior By Chemical and Surgical Techniques

behavior of the Cecropia silkworm were found to be triggered and modulated by stimuli arising from external and internal environments (VAN DER KLOOT and WILLIAMS, I953a; 1953b). Yet the fact remains that the detailed architecture of the cocoon is a property of the species: in the presence of similar environments, different species of silkworms spin dissimilar cocoons. The end product of the behavior is as distinctive as the structure of the insect itself, and by a simple inspection of a series of cocoons one may identify the genera and species of the insects that spun them. The organization of the central nervous system is obviously responsible for this specificity of behavior. Inflowing/stimuli are dealt with according to a hereditary plan built into the central nervous system. The present study was directed toward an experimental analysis of this central mechanism. The Cecropia silkworm provides certain unusual advantages for a study of this type. The cocoon is sufficiently complex to reveal deviations from the normal which one may induce experimentally. Moreover, the insect's central nervous system is particularly accessible to surgical procedures. It consists of an elongate chain of ganglia lying internal to the ventral body

Cocoon Construction By the Cecropia Silkworm I. the Role of the External Environment

The Cecropia silkworm spins a stereotyped cocoon consisting of an outer and an inner envelope, separated by a spongy intermediate layer. Each envelope has a localized weakness at its upper end which serves as an escape valve for the emergence of the adult moth. The valves are oriented by gravitational and tactile stimuli. Late in the last larval instar the silkworm ceases to feed, empties its gut, and then wanders for several hours before spinning begins. During this period of wandering the caterpillar will pass by locations suitable for cocoon construction. The caterpillar may be forced to spin in a variety of unlikely situations where the construction of a normal cocoon is impossible. Two mutually exclusive movement patterns, the stretch-bend and the swing-swing, are responsible for the spinning of the envelopes. Periodically, one of these patterns stops, the animal turns around, and the second pattern begins. If the animal is prevented from turning around, only the stretch-bend movement pattern, which is responsible for spinning the valve end of the cocoon, is observed. In abnormal environments the prevention of turning may force the silkworm to spin a cocoon shaped like a cylinder rather than a cone, or a cocoon from which the animal excludes itself. Double cocoons, which are occasionally found in nature, are shown to be expressions of the normal movement patterns under the abnormal condition of crowding. It is concluded that the behavior patterns are compounded of reflex-like responses to external stimuli and of emitted behavior independent of external stimulation.

Cocoon Construction By the Cecropia Silkworm Ii. the Role of the Internal Environment

Cocoon Construction By the Cecropia Silkworm Ii. the Role of the Internal Environment

THE VALUE OF INSTINCT AS A TAXONOMIC CHARACTER IN SPIDERS

Previous article FreeJournal ArticlesTHE VALUE OF INSTINCT AS A TAXONOMIC CHARACTER IN SPIDERSALEXANDER PETRUNKEVITCHALEXANDER PETRUNKEVITCH Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Biological Bulletin Volume 50, Number 5May 1926 Published in association with the Marine Biological Laboratory Article DOIhttps://doi.org/10.2307/1536614 © 1926 Marine Biological LaboratoryPDF download Crossref reports no articles citing this article.