Baby Bugs Bully Parents for Food, Protection

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.