PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Picky male black widow spiders prefer well-fed virgins

Picky male black widow spiders prefer well-fed virgins
2014-04-23
(Press-News.org) New University of Toronto Scarborough research shows that male black widow spiders prefer their female mates to be well-fed virgins – a rare example of mate preference by male spiders.

The study, authored by UTSC post-doc Emily MacLeod and Maydianne Andrade, a professor in UTSC's Department of Biological Sciences, found in both controlled field studies and the wild that males overwhelmingly chose to mate with well-fed, unmated females. They also found male black widows can tell whether a potential mate is well-fed and unmated by pheromones released by females.

"This near unanimous preference by males for well-fed mates using only phermonal cues has not been documented in any other spider species," says MacLeod. "These are not visual or auditory cues they are picking up but smells they are sensing, often from far away."

Macleod says the reason males show a strong preference for females who smell like they've eaten a lot is that mating with a fatter female may result in more offspring than with less well-fed females.

"Females who have been able to eat a lot and obtain a lot of food resources can transfer those resources into egg production," says MacLeod. "It's not just that they are healthier but that they are more fertile because they can produce more egg sacks."

Another reason for male choice may be a simple matter of survival. "It's important to remember that when a female eats a lot of prey, she's less likely to eat a potential mate," says Andrade.

The study focused on Latrodectus Hesperus, a species of black widow native to western North America including parts of Canada. These black widows are not generally cannibalistic but males are much smaller than females, meaning if a female is hungry her drive to feed will be greater than her drive to reproduce. "If you have this little food item dancing on a web you may as well eat it if you don't have energy to produce eggs," adds MacLeod.

The existence of male choice in nature is unusual because of the costs associated with being picky. In a lab environment male spiders can afford to be choosey, but in nature there are risks in spending time, energy and resources finding a mate, says Andrade.

The study also shows there may be more involved to mating preference than a mere matter of what's available. "It shows that males aren't just promiscuous sperm packages, in fact they can go to great lengths to exercise choice in a mate," says MacLeod.

INFORMATION:The research, which received funding through an NSERC Canada Graduate Scholarship (CGS), is published in the journal Animal Behaviour.

[Attachments] See images for this press release:
Picky male black widow spiders prefer well-fed virgins

ELSE PRESS RELEASES FROM THIS DATE:

Halving hydrogen

Halving hydrogen
2014-04-23
RICHLAND, Wash. -- Like a hungry diner ripping open a dinner roll, a fuel cell catalyst that converts hydrogen into electricity must tear open a hydrogen molecule. Now researchers have captured a view of such a catalyst holding onto the two halves of its hydrogen feast. The view confirms previous hypotheses and provides insight into how to make the catalyst work better for alternative energy uses. This study is the first time scientists have shown precisely where the hydrogen halves end up in the structure of a molecular catalyst that breaks down hydrogen, the team reported ...

Increased infrastructure required for effective oil spill response in US Arctic

2014-04-23
WASHINGTON – A changing climate is increasing the accessibility of U.S. Arctic waters to commercial activities such as shipping, oil and gas development, and tourism, raising concern about the risk of oil spills. A new report from the National Research Council says that a full suite of proven oil response tools is needed to address potential oil spills in U.S. Arctic waters, but not all of them are readily available. While much is known about both oil behavior and response technologies in ice-covered environments, there are areas where additional research would enable ...

On the defensive

2014-04-23
People diagnosed with Huntington's disease, most in their mid-thirties and forties, face a devastating prognosis: complete mental, physical, and behavioral decline within two decades. "Mutant" protein clusters, long blamed for the progression of the genetic disease, have been the primary focus of therapies in development by pharmaceutical companies. But according to new research from Prof. Gerardo Lederkremer and Dr. Julia Leitman of Tel Aviv University's Department of Cell Research and Immunology, in collaboration with Prof. Ulrich Hartl of the Max Planck Institute for ...

ASTRO issues guideline on the role of postoperative radiation therapy for endometrial cancer

2014-04-23
Fairfax, Va., April 23, 2014— The American Society for Radiation Oncology (ASTRO) has issued a new guideline, "The Role of Postoperative Radiation Therapy for Endometrial Cancer: An ASTRO Evidence-Based Guideline," that details the use of adjuvant radiation therapy in the treatment of endometrial cancer. The guideline's executive summary is published in the May-June 2014 issue of Practical Radiation Oncology (PRO), the official clinical practice journal of ASTRO. The full-length guideline is available as an open-access article online at http://www.practicalradonc.org. ASTRO's ...

Conservation priorities released for several protected areas along US-Mexico border

Conservation priorities released for several protected areas along US-Mexico border
2014-04-23
This news release is available in French and Spanish. Montreal, 23 April 2014—Today, the CEC released its Conservation Assessment for the Big Bend-Río Bravo Region: A Binational Collaborative Approach to Conservation, which identifies 29 priority conservation areas in a region straddling the United States-Mexico border that includes 11 different protected areas in the states of Texas, Coahuila, and Chihuahua. This region features unique, highly diverse arid and semi-arid habitats inhabited by rare and endangered plants and animals, and provides a vital migratory ...

Novel compound halts cocaine addiction and relapse behaviors

Novel compound halts cocaine addiction and relapse behaviors
2014-04-23
BUFFALO, N.Y. – A novel compound that targets an important brain receptor has a dramatic effect against a host of cocaine addiction behaviors, including relapse behavior, a University at Buffalo animal study has found. The research provides strong evidence that this may be a novel lead compound for treating cocaine addiction, for which no effective medications exist. The UB research was published as an online preview article in Neuropsychopharmacology last week. In the study, the compound, RO5263397, severely blunted a broad range of cocaine addiction behaviors. "This ...

NASA sees last vestiges of Tropical Depression Jack

NASA sees last vestiges of Tropical Depression Jack
2014-04-23
Tropical Cyclone Jack had weakened to a tropical depression when NASA and JAXA's Tropical Rainfall Measuring Mission (TRMM) satellite passed above on April 22, 2014 at 1120 UTC/7:20 a.m. EDT. At that time, TRMM found that Jack was devoid of almost all rainfall near the tropical cyclone's center. Outside the center was a different story, however. That's where TRMM's precipitation radar instrument found rain falling at a rate of over 130mm/hr (about 5.1 inches) in a band of thunderstorms that stretched from east of Jack's center to the south. Some of the thunderstorms even ...

EARTH Magazine: Faking quakes at full scale

2014-04-23
Alexandria, Va. – On a muggy day in mid-July 2009, a lone seven-story condominium complex northwest of Kobe, Japan, was violently shaken by an earthquake. Onlookers watched the 23-unit, wood-frame tower sway and bounce while, inside the building, furniture toppled and plates clattered to the floor. No one was hurt during the highly localized event and there was only minimal damage, in part because the building's wooden skeleton had been augmented to better resist earthquake shaking, but also because the whole event — from the seismicity to the partially furnished building ...

Some astronauts at risk for cognitive impairment, animal studies suggest

2014-04-23
Johns Hopkins scientists report that rats exposed to high-energy particles, simulating conditions astronauts would face on a long-term deep space mission, show lapses in attention and slower reaction times, even when the radiation exposure is in extremely low dose ranges. The cognitive impairments — which affected a large subset, but far from all, of the animals — appear to be linked to protein changes in the brain, the scientists say. The findings, if found to hold true in humans, suggest it may be possible to develop a biological marker to predict sensitivity to radiation's ...

Gold nanoparticles help target, quantify breast cancer segments in a living cell

Gold nanoparticles help target, quantify breast cancer segments in a living cell
2014-04-23
WEST LAFAYETTE, Ind. - Purdue University researchers have developed a way to detect and measure cancer levels in a living cell by using tiny gold particles with tails of synthetic DNA. A team led by Joseph Irudayaraj, professor of agricultural and biological engineering, used gold nanoparticles to target and bind to fragments of genetic material known as BRCA1 messenger RNA splice variants, which can indicate the presence and stage of breast cancer. The number of these mRNA splice variants in a cell can be determined by examining the specific signal that light produces ...

LAST 30 PRESS RELEASES:

Mount Sinai Health System to honor Dennis S. Charney, MD, Dean of the Icahn School of Medicine at Mount Sinai, for 18 years of leadership and service at annual Crystal Party  

Mapping a new brain network for naming

Healthcare company Watkins-Conti announces publication of positive clinical trial results for FDA-cleared Yōni.Fit bladder support

Prominent chatbots routinely exaggerate science findings, study shows

First-ever long read datasets added to two Kids First studies

Dual-laser technique lowers Brillouin sensing frequency to 200 MHz

Zhaoqi Yan named a 2025 Warren Alpert Distinguished Scholar

Editorial for the special issue on subwavelength optics

Oyster fossils shatter myth of weak seasonality in greenhouse climate

Researchers demonstrate 3-D printing technology to improve comfort, durability of ‘smart wearables’

USPSTF recommendation on screening for syphilis infection during pregnancy

Butterflies hover differently from other flying organisms, thanks to body pitch

New approach to treating aggressive breast cancers shows significant improvement in survival

African genetic ancestry, structural and social determinants of health, and mortality in Black adults

Stigmatizing and positive language in birth clinical notes associated with race and ethnicity

Analysis of the disease spectrum characteristics of inherited metabolic liver diseases in two hepatology specialist hospitals in Beijing over the past 20 years

New insights into x-ray sterilization: Dose rate matters

Prioritized multi-task motion coordination of physically constrained quadruped manipulators

JMIR mental health invites submissions for a theme issue on AI-powered therapy bots and virtual companions

Researchers identify texture patterns associated with breast cancer risk

Expert view: AI meets the conditions for having free will – we need to give it a moral compass

Development of repetitive mechanical oscillation needle-free injection through electrically induced microbubbles

Including pork in plant-forward diets makes meals more appealing and just as healthy, study finds

‘Loop’hole: HIV-1 hijacks human immune cells using circular RNAs

New research study reveals sedentary behavior is an independent risk factor for Alzheimer’s disease

American Academy of Sleep Medicine announces 2025 award recipients

Scientists define the ingredients for finding natural clean hydrogen

New study sheds light on health differences between sexes

Scientists film the heart forming in 3D earlier than ever before

Astrophysicists explore our galaxy’s magnetic turbulence in unprecedented detail using a new computer model

[Press-News.org] Picky male black widow spiders prefer well-fed virgins