File:In species with enclosed pupae, workers consume pupal secretions directly from the cocoon.png

English: Extended Data Fig. 8: In species with enclosed pupae, workers consume pupal secretions directly from the cocoon. (a) A scanning electron microscopy image of a Ponera pennsylvanica cocoon illustrates its porous fabric. n = 1 cocoon was imaged. Similar images of Odontomachus brunneus (subfamily Ponerinae) cocoons have been published elsewhere40. (b) A P. pennsylvanica cocoon after 1 day in social isolation. The arrowhead indicates the accumulation of pupal fluid. (c) Gently touching a glass slide to the surface of a P. pennsylvanica cocoon after 1 day in social isolation produces a droplet of pupal fluid on the underside of the slide (arrowhead). This illustrates that the pupal fluid readily crosses the silken fabric of the cocoon. (d) Same as in (b) for a cocoon of Lasius neoniger (subfamily Formicinae). (e) A young white pupa (left) and an older melanized pupa (right) of Myrmecocystus mexicanus (subfamily Formicinae) enclosed in cocoons after 1 day in social isolation. The arrowhead indicates the accumulation of pupal fluid in the melanized pupa, but not the white pupa. (f) Schematic of dye injection into pupal fluid in species where pupae are enclosed in a cocoon. (g) A M. mexicanus worker drinking dyed pupal fluid from a cocoon. The arrowhead indicates ingested blue dye visible through the translucent cuticle. The dark black spots at the bottom of the cocoons in (b—g) are the larval meconia, i.e., the metabolic waste products expelled by ant larvae as they enter pupation. The experiments and observations in (b—e, g) were repeated with at least n = 3 cocoons, yielding consistent results. Representative images are shown here.