Question

Complex Interactions among ants, fungi, plants, and herbivores The Entomophthorales are often reported as causing high levels of mortality (epizootics) in nature. These fungi are highly virulent. One example of this group is Cordyceps. When a Cordyceps fungus attacks a host, the mycelium invades and eventually replaces the host tissue. The ascocarp bears many small, flask-shaped perithecia containing asci. These, in turn, contain thread-like ascospores, which usually break into fragments and are presumably infective. Some current and former Cordyceps species are able to affect the behavior of their insect host: Ophiocordyceps unilateralis (formerly Cordyceps unilateralis) causes ants to climb a plant and attach there before they die. This ensures the parasite's environment is at an optimal temperature and humidity, and that maximal distribution of the spores from the fruiting body that sprouts out of the dead insect is achieved Consider a system involving a host plant (with extrafloral nectaries, of course, to attract ants); multiple species of ants on the plant (of different genera: like carpenter ants, turtle ants, and crazy ants); several kinds of herbivores eating the plant (caterpillars, grasshoppers, and weevils); spiders and wasps that are predators on the herbivores; and one species of entomopathogenic fungus (Qphiocordyceps unilateralis described above!) Using Levin's Loop Analysis Diagrams (circles for species connecting lines for effects - positive (à) and negative (O) effects; solid and dashed linesà direct and indirect effects) diagram the interactions among the interacting species in the following scenarios: 1) The fungus is highly specific, only attacking turtle ants. 2) The fungus is specific only to ants, attacking all ant species present 3) The fungus is generalized to all types of arthropods

Answer 1

AwλωvS . Plant divict nuga tive aίνtt positive Herbivores Turtle Amts To Prida tovs d Hevbivores divect nugatve wse: divect o nugatve Fwgus Indivet negctaive Imdivect nasitive A A is builitd by A Ais harmbud By B CS Scanned with CamScanner

Plant olvect pasitive dvict pasitve (Ants Fgus divet ngatve (Plants Hevbivores, Amts Pridatovs ol HevbivoYes Funqus CS Scanned with CamScanner