The larva hardly moves at all, turning slowly in place until it bumps into the next drop of honey, pollen or royal jelly.<\/p>\n Honey bee larvae don\u2019t need to smell<\/p>\n This complete dependence grows out of social evolution, the long process that split bee life into castes and jobs. <\/p>\n Adult workers handle nearly every task in the hive, so the young are fed rather than left to feed themselves.<\/p>\n Honey bees push that care further than almost any other insect<\/a>. Because the food is delivered straight to the cell, a larva never has to search, chase, or compete for a single meal.<\/p>\n A team at the\u00a0University of Illinois Urbana-Champaign\u00a0(U. of I.<\/a>) spotted a real puzzle hiding inside all that comfort. If a young bee never has to find its own food, does it still need to smell the world around it?<\/p>\n Gene Robinson led the study with postdoctoral researcher Tianfei Peng. <\/p>\n Robinson is an entomologist who directs the\u00a0Discovery Partners Institute\u00a0(DPI<\/a>) in Chicago, and he has spent decades tracing how bee behavior is written into bee genes.<\/p>\n Larvae that cannot smell<\/p>\n The team lifted larvae out of their cells and set them loose in small dishes to watch how they moved.<\/p>\n A total of 1,230 larvae went through the first round of trials, each one followed for many hours because larvae inch along so slowly.<\/p>\n In one test, a single larva sat between a source of food on one side and plain water on the other. The larvae showed no pull at all toward the food, ending up on each side in roughly equal numbers.<\/p>\n The other trials pointed the same way, no matter what the team offered. <\/p>\n Larvae crawled right past acetic acid, a sharp smell that sends adult bees fleeing, and they took no notice of a queen\u2019s scent that normally grabs a young worker\u2019s attention.<\/p>\n The team even lined up tiny food drops just 0.2 inches from each larva, checking for a weak, close-range sense of smell. <\/p>\n It made no difference, since the larvae ate about the same amount whether the droplet sat near or far.<\/p>\n Genes turned down low<\/p>\n Smelling and tasting each run on tiny sensors, and every sensor needs a matching helper protein to switch it on. <\/p>\n One helper, called ORCO, stands behind the bee\u2019s smell sensors, or ORs; another, IR25a, works with a taste-related group called ionotropic receptors, or IRs.<\/p>\n In the larvae, the instructions for ORCO barely showed up anywhere. Deep inside a larval head the team found only eight faint traces of it, next to 234 for the taste-linked IR25a in the very same spot.<\/p>\n \u201cIn contrast, several IR genes showed relatively higher expression in larvae than other chemosensory receptors,\u201d the researchers wrote. <\/p>\n Put simply, the taste side was busy while the smell side sat idle.<\/p>\n \u201cLarval honey bees might be able to only taste, but not smell, their food,\u201d Robinson said. <\/p>\n That neat divide between the two senses fits what the bee will need much later on.<\/p>\n Smell arrives with age<\/p>\n The smell switch does not stay off for the whole of a bee<\/a>\u2018s life. It sits nearly silent in the larva, wakes up as the young bee turns into a pupa, and runs at full strength once the adult crawls out.<\/p>\n The team saw the same slow climb in all three castes, the workers, queens and drones. That timing lined up with the work waiting at the end of the road.<\/p>\n Even among grown workers, the smell genes rose and fell with a bee\u2019s age and its job. <\/p>\n A forager combing a field of flowers has far more to sort out than a nurse tending young in the dark hive.<\/p>\n A loss that reverses<\/p>\n Grown foragers have to tell hundreds of flower scents apart, so the equipment for smelling cannot simply vanish from the species. In some other animals, though, evolution does throw a sense away for good.<\/p>\n \u201cFor example, some species that live in dark environments, such as cave-dwelling fish, have permanently lost the neural and molecular machinery needed to process visual information, a phenomenon known as regressive evolution,\u201d the researchers wrote.<\/p>\n \u201cBut what we documented in honey bees is a temporary loss, for only one part of the life cycle and not the whole life cycle,\u201d Robinson said.<\/p>\n \u201cThey can\u2019t lose the gene, because the adult bee needs to be able to detect these odors, so instead they regulate expression of the gene.\u201d<\/p>\n Care across many species<\/p>\n \u201cWe discovered this developmentally regulated loss-of-function is a result of low gene expression, not gene loss,\u201d Peng said. <\/p>\n Nothing gets deleted; the colony just dials the smell genes way down while the bee<\/a> is small, then turns them back up.<\/p>\n The team also lined up 12 kinds of insects, running from lone-living flies to the most social bees and ants. The better cared for the young were, the less their bodies leaned on smell genes early in life.<\/p>\n That link was clearest in the most social insects, the ones whose nurses feed the young again and again. When food always shows up on its own, a small bee can let its sense of smell rest for a while and save the effort.<\/p>\n Keeping a keen nose costs energy, and there is little point in paying for one a well-fed larva will never use. <\/p>\n The study is published in the journal Proceedings of the National Academy of Sciences<\/a>.<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.<\/p>\n Check us out on EarthSnap<\/a>, a free app brought to you by Eric Ralls<\/a> and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"A honey bee larva does almost nothing for itself. It lies curled inside a six-sided wax cell while…\n","protected":false},"author":2,"featured_media":804114,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[64,63,128,338],"class_list":["post-804113","post","type-post","status-publish","format-standard","has-post-thumbnail","category-wildlife","tag-au","tag-australia","tag-science","tag-wildlife"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/804113","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=804113"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/804113\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/804114"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=804113"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=804113"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=804113"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n ![\"EarthSnap\"\/](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/05\/earthsnap-banner-news.webp\")
\n<\/a><\/p>\n