Nav: Home

Wasp larvae jump to the dark side

December 21, 2015

Jumping is not about fun and games for insect larvae. They must do it to survive. This manoeuvre is all about finding a shady spot to develop in, according to researchers from Kyushu University in Japan, who led research into the jumping behavior of a minute parasitic wasp, published in Springer's journal The Science of Nature.

The use of jumping as a means of movement has only been observed in a few species of parasitic wasp larvae, suggesting that this behavior does not easily evolve. One such wasp is the three millimeter long Bathyplectes anurus. This parasite is used as a form of biological pest control against alfalfa weevil (Hypera postica), a destructive agricultural pest that attacks legumes.

Adult Bathyplectes anurus wasps lay their eggs in alfalfa weevil larvae. When the wasp larva develops, it crawls out from inside its host and promptly feeds on it. It then spends ten months in a self-spun cocoon inside the cocoon of the alfalfa weevil larva it has eaten, before developing into a pupa. During this time, the wasp larva performs whip-like twitches against the interior of the cocoon causing the entire structure to move approximately five centimeters at a time.

Lead researcher, Yoriko Saeki, and her team conducted a series of experiments on 100 Bathyplectes anurus larvae to understand if this behavior is a survival technique, and whether it comes at a cost to the insects. They examined the effects of different light intensities, temperatures, as well as levels of humidity under different laboratory and field conditions.

The Bathyplectes anurus cocoons exposed to light jumped nearly three times more often than those kept in darkness. Jumping activity increased during rapid temperature increases, and was 60 percent higher at conditions of low humidity. When the cocoons were allowed to jump freely in an area of gradient light going from dark to bright, more cocoons ended up in shady areas. Cocoons in the shady area were more likely to survive, compared to the cocoons left out in brighter light.

The cocoons jumped and moved about 83 percent more when they were placed near Japanese giant ants, known predators of this type of larvae, compared to when there were no danger elements in the vicinity. The frequency of movements decreased once the predators made direct contact with the cocoons.

The results suggest that the larvae respond to environmental stresses by jumping to more favorable habitats that allow them to develop unrestrictedly. The body mass of the individuals that jumped was lower compared to those that did not. The researchers suggest that this is because jumping behavior comes at a cost as it requires more energy use.

Further studies of cocoon structures and the physical mechanisms that allow for such jumping in related species will help entomologists to fully understand the evolution of this behavior.
-end-
Reference: Saeki, Y. et al (2015). Costs and benefits of larval jumping behaviour of Bathyplectes anurus, The Science of Nature, DOI 10.1007/s00114-015-1324-1

BioMed Central

Related Behavior Articles:

Religious devotion as predictor of behavior
'Religious Devotion and Extrinsic Religiosity Affect In-group Altruism and Out-group Hostility Oppositely in Rural Jamaica,' suggests that a sincere belief in God -- religious devotion -- is unrelated to feelings of prejudice.
Brain stimulation influences honest behavior
Researchers at the University of Zurich have identified the brain mechanism that governs decisions between honesty and self-interest.
Brain pattern flexibility and behavior
The scientists analyzed an extensive data set of brain region connectivity from the NIH-funded Human Connectome Project (HCP) which is mapping neural connections in the brain and makes its data publicly available.
Butterflies: Agonistic display or courtship behavior?
A study shows that contests of butterflies occur only as erroneous courtships between sexually active males that are unable to distinguish the sex of the other butterflies.
Sedentary behavior associated with diabetic retinopathy
In a study published online by JAMA Ophthalmology, Paul D.
Curiosity has the power to change behavior for the better
Curiosity could be an effective tool to entice people into making smarter and sometimes healthier decisions, according to research presented at the annual convention of the American Psychological Association.
Campgrounds alter jay behavior
Anyone who's gone camping has seen birds foraging for picnic crumbs, and according to new research in The Condor: Ornithological Applications, the availability of food in campgrounds significantly alters jays' behavior and may even change how they interact with other bird species.
A new tool for forecasting the behavior of the microbiome
A team of investigators from Brigham and Women's Hospital and the University of Massachusetts have developed a suite of computer algorithms that can accurately predict the behavior of the microbiome -- the vast collection of microbes living on and inside the human body.
Is risk-taking behavior contagious?
Why do we sometimes decide to take risks and other times choose to play it safe?
Neural connectivity dictates altruistic behavior
A new study suggests that the specific alignment of neural networks in the brain dictates whether a person's altruism was motivated by selfish or altruistic behavior.

Related Behavior Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...