Kollasmosoma sentum
Kollasmosoma sentum
Kollasmosoma sentum is a Hymenoptera of the family of Brackwespen ( Braconidae ). The epithet " sentum " (Latin for " thorny, prickly " ) is derived from the unique pin-like sting from the fifth sternite of the female. The nature of parasitized ants and performs at its oviposition in the metasoma of the ant not only a remarkable movement, with the average duration of only 0.052 seconds from the beginning to the end of the oviposition this is also extremely short.
Features
The animals are 1.8 to 2.1 millimeters long and have a forewing length from 1.1 to 1.4 millimeters. They are colored black, the face, the face plate ( clypeus ), the labrum, the Malarraum ( area between the compound eyes and the Mandibelbasis ), the frons ( antero -lateral and medial), the palps, the Propleuron, the tegulae, the basal the area of the wing and the front and center legs are, however, colored white. The scape and pedicel of the sensor, and the tarsi of the hind legs are elfenbeinfärbig, the tarsi darkened dorsally. The sides of the pronotum have a brown spot laterally, in some individuals the pronotum may be brown in color also extended to the sides. The cores of the nearly transparent wings are brown, the remaining antennal segments, large parts of the Humeralplatte, the sides of the mesosoma, the Para stigma and the pterostigma are colored extended dark brown. The mesosoma is about 10 % longer than tall. When Metasoma the first tergite 0.6 times as long as at the apex (front) high. It is basal and middle flat and its grainy surface has a silken luster. Females have always 12 antennal segments.
You can type using the following characteristics distinguish it from other species of the genus Kollasmosoma: The outer spine of the rails ( tibiae ) of the hind legs is normal built in females and pointed apically; the fifth sternite on Metasoma helps the females apically a mandrel; the face is strongly convex; the compound eyes are about 3.6 times higher than the observed side temples; the dorsal side of the Propodeums is shorter than the metanotum; the pedicel is distinctly pronounced in the females and the tarsi of the front legs in the females 1.9 times as long as the tarsi of the middle legs.
Occurrence
The first male of Kollasmosoma sentum they began in May 2009 in Orgiva, in the province of Granada in Spain. The female holotype has in August 2010 in Madrid, found at the site of the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria ( INIA ) on the National Road Carretera de La Coruña, as we watched her as she followed the workers of Cataglyphis ibericus. A further seven females were caught in September 2010.
Way of life
So far, the lifestyle of the Hymenoptera of the genus Kollasmosoma only a few individual observations is known. The life of Kollasmosoma sentum is only known by the sightings of females on a nest of Cataglyphis ibericus on the grounds of INIA in Madrid. One to three wasps appeared within three weeks of each day between 12.00 und 15.30 clock at the nest when temperatures were highest at about 35 ° C. They remained between 30 and 90 minutes and flew over the nest entrances or sought workers of the ants in the vicinity. Attacks of wasps made usually when the otherwise nimble ants inserted the typical for the genus Cataglyphis short stops during locomotion. The wasps were flying extremely fast, about an inch above the ground. The attacks of the wasps were often quickly recognized by the ants, where they tried to meet with aggressive movements and open mandibles, or when approaching from behind, with ironed rear or middle legs, the wasp to fight them off. This behavior has been frequently observed and sometimes could also prevent successful parasitism by the wasp.
The wasps try the ants in an attack from the rear on both the ventral and dorsal side of the Metasomas, rare to stab her egg in its apex. From an observation of the filing is also documented in the head of an ant. Since the ovipositor is inserted through the wasps according to the longitudinal axis of the Metasomas, it can be assumed that the wasps try to make this one of the Intersegmentalhäute. To achieve this goal, two strategies of wasps are documented, which depends on the direction of flight of the attack and the degree of inclination of the Matas Grandmas of ants. Is the metasoma of the ant (largely) horizontal to the ground, the wasp keeps ants and flies it from the rear in the direction of its longitudinal axis at. She stretches while their front legs forward and finally touches the metasoma of the ant with their tarsi on the dorsal side. This grip the wasp fast on the metasoma of the ant, relying their middle and rear legs from it and folds her wings before they begin to lay eggs. Is the metasoma, however, vertically or at an angle of more than about 45 ° to the ground, she flies the ant Although well from behind, taking it differs also from the longitudinal axis of the ant, engages with its front tibiae but after the ventral the Matas Grandmas of the ant. She then makes two rotational movements, which vary depending on the direction of flight of the wasp and the inclination of the Metasomas of the ant. When the wasp in horizontal flight approaches a stretched into the air Metasoma, she performs a pirouette at oviposition. After she has metasoma touched by Vordertarsen and thus is perpendicular to it begins with a rotary movement about 180 ° along their longitudinal axis and simultaneously rotates in a vertical direction to approach the metasoma. This double rotary movement, the wasp rotates down and can pierce the ovipositor along the longitudinal direction of the Metasomas of the ant. Throughout the process, the contact of the Vordertarsen with the metasoma is maintained. So as not to lose contact during the rotational movement, the tarsi need some separated one member to the other to be positioned. If the right is above the left Tarsenglied, the wasp rotates counterclockwise, otherwise conversely. This shows that the placement of the tarsi support in the longitudinal direction of the Metasomas the rotation.
The insertion of the ovipositor always follows the same scheme. The wasp grasps the metasoma of the ant with all three pairs of legs and folds her wings together. Immediately thereafter, the wasp moves successively backwards to their body to move perpendicular to the metasoma of the ant. The tip of her Metasomas remains above the metasoma of the ant. With the position of the ant Metasomas horizontal to the ground, the body of the wasp moves backward and directed in the vertical direction. Before the vertical is reached, the tip of the Metasomas the wasp moved down where presumably it takes place oviposition. In the situation of Metasomas the ant vertically to the ground the wasp pushes the tip of her Metasomas on the metasoma of the ant, until they touch the two body parts. The wasp is in sympathy with further back, a little beyond the vertical and finally flying backwards. The spine on the fifth sternum is perhaps helping the extremely fast running oviposition to stabilize the position of the wasp and the movements of the wasp Metasomas to Support.
The entire process of oviposition from touching the ant, through to filing of the ice and the subsequent Wegflug is extremely short and takes an average of 0.052 seconds.