Female cockroaches living in groups with other females are more likely to have their unfertilized eggs hatch, a research team at Hokkaido University has found, providing a possible explanation for the reason the insect has managed to survive for hundreds of millions of years.
When three female American cockroaches - a species widely found throughout the world - were placed together in a study, ootheca, or the egg case of the cockroaches, formed more quickly than when a single female was observed, the team said.
“It explains well the fact that several female cockroaches will be able to maintain a colony in a more stable manner than a single female cockroach,” which can be regarded as a sign of cooperative behavior that is optimized for reproduction seen in other insects like white ants, the research team said in a news release Monday.
A group of more than 15 female cockroaches was able to maintain a colony for more than three years, indicating that ootheca form faster the more cockroaches there are, it said.
“We found that ootheca formation is facilitated when a female cockroach recognizes another female by touching it with their antennae, which are also used for smelling and tasting,” said Ko Kato, a graduate student who took part in the study.
Osaka Prefectural Police have arrested a 35-year-old man on charges of murder after his elderly neighbor was found stabbed to death, possibly the result of a feud over a pet dog, reports TBS News. (tokyoreporter.com)
Leading parcel delivery firm Yamato Transport Co. said Friday that it will raise its basic tariff for retail customers by ¥140-¥180 excluding tax in September, marking its first rate hike in 27 years. (the-japan-news.com)
As tension spikes on the Korean peninsula, a French amphibious assault carrier sailed into Japan's naval base of Sasebo on Saturday ahead of drills that risk upsetting China, which faces U.S. pressure to rein in North Korea's arms programs. (Japan Today)