Polistes gallicus

Appearance

''P. gallicus'' can be spotted due to its distinct markings of bright yellow and black. Its relatively small in size compared to other native ''Polistes''. Curled antennas are a common characteristic in the genus for males, despite being shorter in length in comparison to wasps of other species. Their faces are also completely yellow in color. This species of wasps feeds its brood after visiting numerous flowers, collecting nectar in addition to feeding them meat. Due to its dimensions it is still likely that they transfer pollen to the stigma, despite the fact that ''P. gallicus'' have bodies that are almost bald which leads to few or no pollen grains stuck on them after foraging. This specific body type can help with identification.

Distribution

Due to the extensive range ''Polistes gallicus'' resides, this species survives in a variety of climates and habitats, although ideally it prefers to nest in warm and dry areas. In Italy, nests are typically built in open areas hanging from branches with the cells opened towards the ground. In the colder conditions north of the Alps, metal scraps such as pipes serve as protective enclosures to ''P. gallicus'' nests. When it comes to distribution, these wasps are the most abundant ''Polistes'' in Spain. ''P. gallicus'' also inhabits parts of Paris, although the farther north, the more rare this species becomes. It’s conservation status in general has not been evaluated yet, although in it's inhabited regions it is common."Polistes Gallicus ." Polistes Gallicus. European Environment Agency, n.d. Web. 22 Sept. 2014.

Nest structure can consist of numerous cells, with some nests reporting as many as 500 cells. These nests are constructed from a mix of oral secretions and plant fibers to make a paper pulp. Bigger nests are more commonly found in southern regions of countries. For example, a study of two wasp nests in Cambridge, Massachusetts found a nest constructed inside a stop sign pole that was 8 cm high and 5 cm wide and consisted of 134 cells. A second nest, that contained 153 cells within the same nest dimensions, was found suspended from a pipe. The nests of ''P. gallicus'' tend to be smaller than those of comparative ''Polistes''. Nest size also depends on the location, with nests in more sheltered areas tending to be larger.

Habitat

Due to the extensive range ''Polistes gallicus'' resides, this species survives in a variety of climates and habitats, although ideally it prefers to nest in warm and dry areas. In Italy, nests are typically built in open areas hanging from branches with the cells opened towards the ground. In the colder conditions north of the Alps, metal scraps such as pipes serve as protective enclosures to ''P. gallicus'' nests. When it comes to distribution, these wasps are the most abundant ''Polistes'' in Spain. ''P. gallicus'' also inhabits parts of Paris, although the farther north, the more rare this species becomes. It’s conservation status in general has not been evaluated yet, although in it's inhabited regions it is common."Polistes Gallicus ." Polistes Gallicus. European Environment Agency, n.d. Web. 22 Sept. 2014.

Nest structure can consist of numerous cells, with some nests reporting as many as 500 cells. These nests are constructed from a mix of oral secretions and plant fibers to make a paper pulp. Bigger nests are more commonly found in southern regions of countries. For example, a study of two wasp nests in Cambridge, Massachusetts found a nest constructed inside a stop sign pole that was 8 cm high and 5 cm wide and consisted of 134 cells. A second nest, that contained 153 cells within the same nest dimensions, was found suspended from a pipe. The nests of ''P. gallicus'' tend to be smaller than those of comparative ''Polistes''. Nest size also depends on the location, with nests in more sheltered areas tending to be larger.

Reproduction

After a hierarchy is established, the dominant wasp remains the sole reproducer in the colony due to the inhibition of endocrine activity within the subordinate wasps. Various factors contribute to the possibility of inhibition, which might also lead to differences in endocrine activity. If subordinates happen to lay eggs after the hierarchy is formed, the dominant foundress will eat the eggs to ensure all laid eggs are of her own genes.

Defense

''Polistes'' are known to use the sting and venom as a means of colony defense. However, this venom seems to be costly to produce as ''Polistes'' will only release it after the sting in certain situations. Dangerous stimuli must first be perceived before they go out of their way, leaving a nest unattended, to attack. In some situations ''Polistes gallicus'' are know to exhibit aggressive behavior to wasps of a foreign colony. While venom from a basic standpoint is used by solitary species to capture prey, it has served a greater purpose of defense in social colonies against colony vertebrate and invertebrate offenders.

When it comes to alarm systems, ''Polistes'' can communicate with others through vibrational and visual signals. It might actually be beneficial for a smaller colony of wasps to switch from alarm pheromones, common with Polistes wasps, to these alternative signals when the colony grows in size. Alarm pheromones mixed in with the composition of the venom can also be released. However, it has yet to be determined if this release occurs following the act of ejecting venom by the signaling wasps or if it’s due to the actual release of the venom during the sting.Knowing venom chemistry from these species of wasps can lead to human advantages from a pharmaceutical standpoint. The chemical breakdown of venom allows for synthesis of progress in immunology therapy due to the creation of more reliable and effective treatments for people with allergies. Studies which analyzed the way venom interacts with victims provided a mechanism for drugs to permeate cell membranes. Further studies on wasps could provide a mechanism to control overpopulation through the creation of artificial sex attractants.

Allergic reaction induced IgE- mediated anaphylaxis is commonly a result of Hymenoptera stings. The composition of venom from a sting can even affect the types of treatment a patient should be given. Differences have been found between the composition of American and European ''Polistes'' venoms. Response to different epitope spectrums depends on the type of ''Polistes'' that did the stinging. ''Polistes gallicus'' venom was found to be a combination of four major allergens: Ag5 , hyaluronidase, phospholipase, and protease. This discovery has led to the addition of these allergens into a standard ''Polistes'' mix containing venom from North American species in order to improve diagnosis and therapy for European patients with ''Polistes'' allergies.