The mealybug Phenacoccus herreni feeds on cassava plant sap, inducing shrivelling. It causes extensive damage in cassava growing areas in South America. However, it can be parasitized by two wasps, Acerophagus coccois and Aenasius vexans which act out a ritual to recognize and select the individuals they are going to parasitize. A wasp moves from one side to the other of a potential victim, investigating it by palpation with their antennae. Once this “drumming and turning” procedure completed, the wasps carry out their oviposition. And when the parasites emerge, the mealybugs die.
The IRD researchers, working jointly with the International Center for Tropical Agriculture (CIAT) in Colombia, have been focusing on chemical signals which enable the wasps to recognize their victims. They showed that a kairomone, an ester called O-caffeoylserine, acts as a cue in this recognition mechanism. It is secreted by the mealybug and is present on its body surface and can be recognized when the wasp comes into contact with it. The ester makes up 0.03 nmol/mg of the mealybug body weight.
O-caffeoylserine was isolated from a sample of mashed adult female mealybugs, the development stage at which the wasps prefer to lay their eggs. This is a new result for science. Although known in an artificially-synthesized form, this ester had never been obtained before from natural biological source material.
Marie-Lise Sabrie | alphagalileo
Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences
Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences