Kollasmosoma sentum
| Kollasmosoma sentum | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Kollasmosoma sentum |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Kollasmosoma sentum | ||||||||||||
| van Achterberg & Gómez , 2011 |
Kollasmosoma sentum is a hymenoptera fromthe brackish wasp family (Braconidae). Thespecific epithet “sentum” ( Latin for “thorny, prickly”) is derived from the unique thorn-shaped thorn on the fifth sternite of the female. The species parasitizes ants and not only performs a remarkable sequence of movements when laying eggs in the ants' metasoma, with an average duration of just 0.052 seconds from the beginning to the end of the egg-laying process, this is also extremely short.
features
The animals are 1.8 to 2.1 millimeters long and have a forewing length of 1.1 to 1.4 millimeters. They are colored black, the face, the frontal plate ( clypeus ), the labrum , the malar space (area between the compound eyes and the mandible base), the frons (antero-lateral and medial), the palps , the proppleuron, the tegulae , the basal However, the area of the wings and the front and middle legs are colored white. The scapus and pedicellus of the antennae and the tarsi of the hind legs are ivory in color, the tarsi being darkened dorsally . The sides of the pronotum have a brown spot on the side, in some individuals the pronotum can also be extensively colored brown on the sides. The veins of the almost transparent wings are brown, the rest of the antennae, large parts of the humeral plate, the sides of the mesosoma , the parastigma and the pterostigma are dark brown in color. The mesosoma is about 10% longer than it is tall. In the metasoma , the first tergite is 0.6 times as long as it is at the apex (front). It is basal and flat in the middle and its grainy surface has a silky sheen. Females always have 12 antennae .
The species can be distinguished from the other species of the genus Kollasmosoma on the basis of the following characteristics : The outer spine of the rails ( tibia ) of the hind legs is normally built in females and apically pointed; the fifth sternite on the metasoma has an apical thorn in the females; the face is strongly convex; the compound eyes are about 3.6 times higher than the temples viewed from the side; the dorsal side of the propodeum is shorter than the metanotum; the pedicellus is clearly prominent in the females and the tarsi of the front legs are 1.9 times as long as the tarsi of the middle legs in the females.
Occurrence
The first male of Kollasmosoma sentum was caught in May 2009 in Órgiva , in the province of Granada in Spain. The female holotype was found in Madrid in August 2010, on the grounds of the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) on the Carretera de La Coruña national road , when she was seen following workers of Cataglyphis ibericus . Another seven females were caught in September 2010.
Way of life
So far the way of life of the hymenoptera from the genus Kollasmosoma is known only from a few individual observations. The way of life of Kollasmosoma sentum is so far only known from the sightings of females at a nest of Cataglyphis ibericus on the grounds of the INIA in Madrid. One to three wasps appeared at the nest within three weeks between 12 noon and 3:30 p.m. each day, when the temperatures were highest at around 35 ° C. They stayed between 30 and 90 minutes and flew over the nest entrances or looked for ants workers in the vicinity. Attacks by wasps usually took place when the otherwise nimble ants made the short stops typical of the Cataglyphis genus while moving. The wasps flew extremely fast, about an inch above the ground. The ants often recognized attacks by the wasps quickly, attempting to repel the wasp with aggressive movements and open mandibles, or when approaching from behind, with straightened back or middle legs. This behavior has been observed frequently and has sometimes been successful in preventing the wasp from parasitizing.
When attacking from behind, the wasps try to pierce the ants on both the ventral and dorsal sides of the metasoma , less often in its apex. The deposit in the head of an ant is also documented from an observation. Since the ovipositor is inserted by the wasps along the longitudinal axis of the metasoma, it can be assumed that the wasps are trying to hit one of the intersegmental membranes. To achieve this goal, two strategies of the wasps are documented, which depend on the flight direction of the attack and the degree of inclination of the matasomas of the ants. If the metasoma of the ant is (largely) horizontal to the ground, the wasp follows the ant and flies to it from behind in the direction of its longitudinal axis. It stretches its front legs forward and finally touches the metasoma of the ant with its tarsi on the dorsal side. This grip causes the wasp to snap over the metasoma of the ant, resting its middle and rear legs on it and folding its wings before it begins to lay eggs. If, on the other hand, the metasoma is vertical or at an angle of more than approx. 45 ° to the ground, the ant flies towards the ant from behind, also deviating from the longitudinal axis of the ant, but reaches for the ventral side with its anterior tibia of Matasomas the Ant. Then it performs two turning movements, which vary depending on the flight direction of the wasp and the inclination of the metasoma of the ant. When the wasp approaches an elongated metasoma in horizontal flight, it performs a pirouette while laying eggs. After it has touched the metasoma with the anterior tarsi and is thus perpendicular to it, it begins to rotate through 180 ° in its longitudinal axis and at the same time rotates in the vertical direction in order to approach the metasoma. As a result of this double turning movement, the wasp turns downwards and can pierce the ovipositor according to the longitudinal direction of the metasoma of the ant. The contact of the anterior tarsi with the metasoma remains throughout the process. In order not to lose contact during the rotary movement, the tarsi have to be slightly separated from each other, one link positioned above the other. If the right tarsal link is above the left, the wasp turns counterclockwise, otherwise the other way around. This shows that the placement of the tarsi in the longitudinal direction of the metasoma supports the rotational movement.
The ovipositor is always pierced in the same way. The wasp grabs the ant's metasoma with all three pairs of legs and folds its wings together. Immediately thereafter, the wasp gradually moves backwards to move its body perpendicular to the ant's metasoma. The tip of its metasoma remains above the metasoma of the ant. If the metasoma of the ant is horizontal to the ground, the body of the wasp moves backwards and aligns itself vertically. Before reaching the vertical, the tip of the wasp's metasoma moves downwards, presumably during which ovipositioning takes place. With the ant's metasoma vertical to the ground, the wasp presses the tip of its metasoma onto the ant's metasoma until the two body parts touch. The wasp leans further backwards, a little beyond the vertical, and finally flies backwards. The thorn on the fifth sternum may serve to stabilize the position of the wasp and support the movements of the metasoma of the wasp during the extremely rapid oviposition.
The entire egg-laying process from touching the ant to laying the egg and then flying away is extremely short and takes an average of 0.052 seconds.
supporting documents
Individual evidence
- ↑ a b c d e f g J. M. Gómez Durán, C. van Achterberg: Oviposition behavior of four ant parasitoids (Hymenoptera, Braconidae, Euphorinae, Neoneurini and Ichneumonidae, Hybrizontinae), with the description of three new European species. ZooKeys 125: pp. 59-106, 2011. doi : 10.3897 / zookeys.125.1754
