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*Data extracted from Whitfield 1998, Whitefield 2003 and Dowton 2001

Ecological constraints and parasitoid development

Parasite lineages tend to parallel those of their hosts (Brooks and McLennan, 1993). A number of studies have shown patterns of coevolution between parasitoid wasps and their hosts. Fig-pollinating wasps, which originated from a parasitoid ancestor, appear to have evolved in response to their host plants (Machado et al., 2001).

a diagram of Co-speciation of figs and their pollinators
Co-speciation of figs and their pollinators (Courtesy of Cook and Rasplus, 2003). Phylogenies of Ceratosolen pollinators show significant congruence with their host figs.

The relationship between parasitoid and host is attributed to mortality risk (Strand, 2000). A trade-off exists between size and development time – an organism must choose between growing larger at the cost of greater mortality risk due to increased development time and developing rapidly to reduce mortality risk at the cost of reduced size (Abrams, 1996). Thus, conditions that increase development time increase risk of mortality for both the host and parasitoid. Because of this trade-off, parasitoids that face high mortality risk favor shorter development times and are smaller. Conversely, species that face low mortality risks favor size at the cost of increased development time. Parasitoids that attack exposed species appear to experience higher levels of intraguild competition than parasitoids that attack concealed hosts (Blackburn, 1991). In response to this increase in mortality risk, parasitoids that attack exposed hosts have shorter development times.

Nonpollinating fig wasps

Although this paper focuses on parasitism of insect hosts, wasps also parasitize plants. Like many other mutualisms, the fig-pollinator association has been exploited by wasp parasites (Yu, 2001). One fig species can host up to 30 different species of nonpollinating fig wasps. Niche space within the syconium is separated by different subsets of flowers, timing of oviposition, and by larval diets. Nonpollinating fig wasps can be split into different functional groups (Cook and Rasplus, 2003):

  • Large gall-inducers and their parasitoids: these wasps are much larger than pollinator wasps and oviposit from outside the syconium at or before pollination.
  • Small gall-inducers: these wasps oviposit from outside at or mostly after pollination, but the wasps are similar in size to the pollinations.
  • Internal parasites: these wasps only occur in the old World and enter figs along with similar sized pollinators.

It has been hypothesized that figs do not exclude nonpollinating fig wasps because defenses against these parasitoid wasps might also exclude necessary pollinators (Cook and Rasplus, 2003). Some parasitoid wasps use the same cues as pollinators to oviposit at the same time, and defenses against these wasps might come at the cost of attracting pollinators to disperse seeds.

Another factor related to development time is fecundity. Parasitoids must compensate for the increase in mortality risk that accompanies host exposure. Therefore, parasitoid fecundity is expected to rise as opportunities of finding hosts increases and the probability of offspring surviving to adulthood declines (Price, 1980). Early host stages such as eggs and young larvae are more abundant and exposed than later host stages, so parasitoids that attack young hosts are expected to have larger fecundities than those who attack older hosts. Conversely, parasitoids that attack concealed hosts are predicted to have lower fecundities (Price, 1980). As predicted, wasps that parasitize young larvae are associated with higher fecundities and are typically endoparasitic koinobionts, while wasps that parasitize pupae are associated with lower fecundities and are typically idiobionts (Mayhew and Blackburn, 1999).

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
Nasa has use it in the 60's, copper as water purification in the moon travel.
nanocopper obvius
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
analytical skills graphene is prepared to kill any type viruses .
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Mockingbird tales: readings in animal behavior. OpenStax CNX. Jan 12, 2011 Download for free at http://cnx.org/content/col11211/1.5
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