The Southern Pine Beatle: four stages of life
The southern pine beetle has four life stages; eggs, larva, pupa and adult. These stages are important in the infestation process of the SPB. Also the infestation process of the SPB consists out of four stages; colonization, re-emergence, brood survival, and emergence. In figure ?? an overview of the process, described below, is to be found.
Thatcher, 1981
Colonization
the process of colonization involves location of a suitable host tree, identification of the tree, aggregation of enough numbers of individuals which will overcome the resistance of the tree, inoculation of the tree with microorganisms, and at last the establishment of an egg population. When a tree is successfully colonized the host will be death.
The colonization process starts with the selection of the host which are the ‘pioneers’, these initiate the attack on the tree host. The beetle will select the tree on the basis of either random or direct behaviour, this process is only poorly understood but it seems to be sure that it involves primary attractants, visual cues, and random searching. The tree selection process is guided by sophisticated behavioural mechanisms of the beetle (Thatcher, 1981). This because the requirement for identifying relatively rare susceptible hosts has important consequences for perpetuation of the insect. The selection of the host ends when adult manage to successfully
The infestation of the host is regulated by a mix of pheromones produced by both the host and the SPB (Thatcher, 1981; ?????,19??). Once the pioneers located a suitable tree the release of aggregation pheromones will start. The pheromone primarily consists out of frontalin, which in combination, with the smell of the beetle itself, will attract the male SPB for mating plus other males and females. Aggregation is increased when the other males arrive as they also release pheromones, including endo-brevicomin (????,19??). At the point sufficient numbers of beetles are attracted, there
Thatcher, 1981
Colonization
the process of colonization involves location of a suitable host tree, identification of the tree, aggregation of enough numbers of individuals which will overcome the resistance of the tree, inoculation of the tree with microorganisms, and at last the establishment of an egg population. When a tree is successfully colonized the host will be death.
The colonization process starts with the selection of the host which are the ‘pioneers’, these initiate the attack on the tree host. The beetle will select the tree on the basis of either random or direct behaviour, this process is only poorly understood but it seems to be sure that it involves primary attractants, visual cues, and random searching. The tree selection process is guided by sophisticated behavioural mechanisms of the beetle (Thatcher, 1981). This because the requirement for identifying relatively rare susceptible hosts has important consequences for perpetuation of the insect. The selection of the host ends when adult manage to successfully
The infestation of the host is regulated by a mix of pheromones produced by both the host and the SPB (Thatcher, 1981; ?????,19??). Once the pioneers located a suitable tree the release of aggregation pheromones will start. The pheromone primarily consists out of frontalin, which in combination, with the smell of the beetle itself, will attract the male SPB for mating plus other males and females. Aggregation is increased when the other males arrive as they also release pheromones, including endo-brevicomin (????,19??). At the point sufficient numbers of beetles are attracted, there