Featured Research

from universities, journals, and other organizations

Sex Is Thirst-quenching For Female Beetles

Date:
August 29, 2007
Source:
University of Exeter
Summary:
Female beetles mate to quench their thirst according to new research. The males of some insect species, including certain types of beetles, moths and crickets, produce unusually large ejaculates, which in some cases can account for around 10% of their body weight. The study shows that dehydrated females can accept sexual invitations simply to get hold of the water in the seminal fluid.

Beetles mating. Thirsty females beetles accept sexual invitations simply to get hold of the water in the male's seminal fluid, researchers found.
Credit: Image courtesy of University of Exeter

Female beetles mate to quench their thirst according to new research by a University of Exeter biologist. The males of some insect species, including certain types of beetles, moths and crickets, produce unusually large ejaculates, which in some cases can account for around 10% of their body weight. The study shows that dehydrated females can accept sexual invitations simply to get hold of the water in the seminal fluid.

Related Articles


Dr Martin Edvardsson, whose research is published in the journal Animal Behaviour (August 2007), studied the bruchid beetle Callosobruchus maculatus, a serious pest in warmer parts of the world. Some females were given unlimited access to water while others were not. All females were free to mate with males and the study found that thirsty females mated 40% more frequently than those with free access to water.

Female bruchid beetles can absorb the water in the seminal fluid through their reproductive tracts and need to mate less frequently the more water they take from each mating. This is to a male's advantage because the longer the female goes without mating with another male, the greater his chance of successful fertilization. By transferring a large amount of water with the sperm, a male can help ensure his sperm has more time to fertilize the eggs without having to compete with the sperm from future matings. Dr Martin Edvardsson of the University of Exeter says: 'The large ejaculates may have evolved because males can make it less beneficial for females to remate by providing them with a large amount of water.'

From morsels of food to less useful offerings like dried leaves or balls of silk, insects' nuptial gifts are thought to perform the role of enticing a female to mate or investing in the resulting offspring. However, this study shows that males can also prevent females from mating with other males by giving them a valuable nuptial gift. Dr Edvardsson says: 'This research offers an alternative theory on the function of 'nuptial gifts', which are an important part of insect courtship and mating.'

Dr Edvardsson argues that the trade-off between the costs and benefits of mating is essential to the mating behaviour of female bruchid beetles. The males have spines on their genitalia that puncture the females' reproductive tract as they mate. Because of the damage this causes, females must carefully trade off the costs and benefits of mating, and limit the number of times they mate depending on their need for water and sperm.

Because there are always costs as well as benefits associated with mating, similar trade-offs are likely to be important in many species where males provide their mates with material resources. 'The key thing' says Dr Edvardsson 'is that the resource provided by males is less beneficial to females the more of it they already have, like water or food for example.'

Though Dr Edvardsson believes these findings may be relevant to many other animal species, he does not think the study has any implications for our understanding of sexual behaviour in all other animals. He concludes: 'This is unlikely to occur in say, mammals and birds, because it is impossible for a male to give a female a gift that would fulfill her needs for food or water for such a long period of time. Also, while many female insects can store live sperm inside for long periods of time, females of these species need relatively fresh sperm to fertilize their eggs.


Story Source:

The above story is based on materials provided by University of Exeter. Note: Materials may be edited for content and length.


Cite This Page:

University of Exeter. "Sex Is Thirst-quenching For Female Beetles." ScienceDaily. ScienceDaily, 29 August 2007. <www.sciencedaily.com/releases/2007/08/070828084414.htm>.
University of Exeter. (2007, August 29). Sex Is Thirst-quenching For Female Beetles. ScienceDaily. Retrieved November 25, 2014 from www.sciencedaily.com/releases/2007/08/070828084414.htm
University of Exeter. "Sex Is Thirst-quenching For Female Beetles." ScienceDaily. www.sciencedaily.com/releases/2007/08/070828084414.htm (accessed November 25, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Tuesday, November 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Cambodian Capital's Only Working Elephant to Retire in Jungle

Cambodian Capital's Only Working Elephant to Retire in Jungle

AFP (Nov. 25, 2014) Phnom Penh's only working elephant was blessed by a crowd of chanting Buddhist monks Tuesday as she prepared for a life of comfortable jungle retirement after three decades of giving rides to tourists. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com
Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Buzz60 (Nov. 24, 2014) A Swedish Adventure racing team travels to try and win a world title, but comes home with something way better: a stray dog that joined the team for much of the grueling 430-mile race. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins