Threats and risks of parastiods:
Intraguild predation (IGP) is a primordial factor that generates consequences for theimplementation of antagonists in biological control program and the coexistence of species in natural environment. IGP is asymmetric among parastoids and predators. Because IGP exerts a strong selection pressure on the inferior parastoids it seems to be likely that these antagonists have evolved strategies to minimize IGP. 1
Parastoids and their risks:
Aphid parasitoid (Lysiphlebus fabarum):
Which is able to exploit the enemy free space in ant protected aphid community. In the current study we investigate that there are many predation risk for the developmental stages of L. fabrum and many behavioural decisions can be made under predation risk by foraging females. By testing aphidophagus predator we can predict that all the developmental stages of L. fabrum suffered from high risk of predation. However, foraging females of L. fabrum do not displayed an effective defence behaviour to predators and did not avoid the presence of predators.
When the eggs come out the aphid will die so the species of aphid will decrease quickly. 2
Fig no.01: (a) Aphid (b) damage by aphid
Braconid Wasp (Cotesia congregate):
We can examine growth rate, energy metabolism of the larvae of tobacco hornworm that was parasitized by the braconid wasp. We come to know that this larvae was parasitized at fourth-instar stage and has the lower energy rate as compared to the un-parasitized larvae at the same age and short term differences in the rate of metabolism. All there were apparent immediately after oviposition. 3
There is no differences between the parasitized and unparasitized hosts between the growth period of parasitization and the last of the fifth instar. One day prior to parasitoid emergence, the larvae stop eating and stop all spontaneously locomotors activities and there is also a decline in the metabolism. The 60% decline in energy has no any specific dynamic because the animal were not eating.
Gas exchange is highly cyclic on the day of parasitizing but the cause and phenomenon is not clear.
This energy cycling was not found in unparasitoids larvae in 6 days and not even in the larvae that was immobilized by tetrodotoxin. 3
Fig no.02: tobacco wasp is covered with wasp egg
Earwig contain forceps. Many people wonder that if earwig will bite people. Danger: The forceps of adult will bite you but it contains no venom but it rarely breaks the skin. Earwigs are actually pretty harmless to humans. The belief that earwig will crawl into your ear has no prove. They are not dangerous and have no sting. Earwigs are fairly abundant and found and found in many areas in the world. 4
It may crawl into years of ears of sleeping people and lay eggs. 5
Preventing infestations: These are found on damp places effectively controlling moisture in basement. Earwigs are usually attracted by light so switch off extra lights. Also we can prevent by sealing up small opening. 6
Fig.no 03: brown-winged earbugRed and blue beetle:
These beetles have shiny red and blue bands. These are carnivorous and act as predator. They usually consume egg and larvae of their hosts. They also consume small other soil moving insects. Their all developmental stages occur in soil. They lay egg on soil debris.
Larvae feed on small larvae and small microorganisms.
Pests attacked: they may feed on pollens of flowers. They may also feed small larvae and eggs. 7
Fig.no.04: Red and blue beetles
Orchid dupe has the same species as the caterpillar parasite. It has medium sized with orange body and black wings. They encounter in all summer crops.
Life cycle: Female egg lay egg on its host. Larvae feed on its host and do not kill them until they pupate underground.
Pests attacked: helicoverpa and armyworm larvae 8
Fig no. 05: orchid dupe
There are many other parasitoids that have their effect on their hosts. They spend some time of their life in host and they may kill the host and continue their lives.
Predation risk usually slow their growth rate and decrease foraging. 9
The control of parasitoids have been r practised from the beginning of the 20th century. Beginning was with the introductory classical controlling of apple aphid. These classical introductions were similar to the methods of other country like Latin America. The first attempt to control the sugarcane borer were begun in 1950s. Following on from this success, the most important achievement were the introduction of prospaltella opulenta by which the citrus blackfly were brought under complete control. 10
Aphids and other hemipteran pests have been successful biological control agent. The only trait that contributes much in this success also implicate an interaguild predator it poses a significant risk. 11
Toxoneuron nigriceps (Viereck) (Hymenoptera, Braconidae) is an endophagous parasitoid of tobacco budworm. Most of these pathological syndromes are induces by polydnavirus. The mechanisms involved in the host hormonal bakance is further investigated allowing the better result of the model that was previously proposed.
A functional genomic approach has been undertaken to identify TnBV genes expressed in the host and to assess their role in the major parasitoid-induced pathologies. 12 Some TnBV genes cloned so far are novel and do not show any similarity with genes already available in genomic databases, while others code for proteins having conserved domains, such as aspartic proteases and tyrosine phosphatases. Sequencing of the entire TnBV genome is in progress and will considerably contribute to the understanding of the molecular bases of parasitoid-induced host alterations.