Aug. 29, 2008 -- Baby bugs, known as larvae and nymphs, have no shame when it comes to begging.
They will do everything from kicking their mother in the face to hitting her repeatedly with--- their antennae in order to receive food, protection and attention, according to a forthcoming study.
The findings reveal how complex parent and offspring relationships can be -- even among seemingly lowly insects -- and how manipulation could have first evolved in certain creatures.
Some of the world's top manipulators and the best mothers might even be bugs.
Co-author Flore Mas described, for example, how scared treehopper nymphs will aggressively shake their plant homes to get their dutiful mother's attention. Mothers will then "protect their offspring by sitting on top of them and repelling the attacker with aggressive behaviors, such as leg kicking, wing fanning or body twisting."
Mas, a researcher at the University of Basel's Zoological Institute, and colleague Mathias Kolliker, analyzed multiple such interactions between larvae and their parents for a study that has been accepted for publication in the journal Animal Behavior.
Perhaps the most extreme begging was observed among baby burying beetles.
The beetle larvae raise their heads, wave their legs and kick their parents in the face, which stimulates the mother to regurgitate food into their mouths. Earwigs engage in similar behavior.
Even larvae that are housed in confining cells, such as Vespidae wasps, may scrape their mandibles on their cell walls to get attention and food.
"Manipulation occurs when the emitter has evolved a cue that affects the receiver, but the receiver's response has not evolved to be affected by this cue, so there is no communication," Mas told Discovery News.
She explained that such cues could be "honest," meaning that they may convey true and desperate need. Usually these signals are chemical, so when a baby bug is scared or hungry it might give off hormones that relate its state to its parents. Usually mothers respond, but fathers of assassin bugs, correid bugs and thrips help with parenting too.
The best bug fathers might very well be burying beetles, Mas suggests, since this species feeds on corpses, and the father must sit and guard the dead corpse "home" to ensure relative freshness for his family.
Begging can be dishonest, however, arising from competition between siblings and also between the parent and its offspring. The researchers found that bullies exist in the bug world too.
"It is possible, and often observed, that actually it is the strongest or the oldest that get the best spot in the nest where parents are feeding, and thus those behaviors positively correlate with competitive ability but not necessarily with true need for food," she explained.
It may even be in the best interest of larvae to hoard food and parental attention, since "the addition of more brothers and sisters does not contribute to its own survival."
"Thus, we expect in offspring selection for traits that will enhance their own chance of surviving, such as begging behaviors that influence the amount of parental care provided by parents," she added.
In another study on baby bug behavior, Bruno Gobin of the Catholic University of Leuven and his colleagues discovered that although ant larvae are legless, they've devised a clever technique for gaining the attention of their caretakers: They sway.
"In this swaying behavior, larvae raised their head and neck, and gently reached and waved towards workers or food items," Gobin and his team determined.
Mas hopes additional studies on insects may reveal more about the evolution of begging, which she believes could complement "current research on parent-offspring conflict."
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