|
For each target weed, a basic plant test list should be compiled with the assistance of a taxonomic botanist familiar with the family in which the target weed belongs. Entomologists may suggest additions to the list. Agencies representing conservationists and farmers may add further species to the list. Factors which may assist in the rational selection of these representative species include plant morphology, biochemistry, and geographic distribution.
Plant lists:
 | are different for different target weeds because plants closely related to the target species are at the greatest risk;
|
| may vary for the testing of different biological control agents against the same weed depending on the mode of feeding and oviposition of the agent or attack by fungi;
|
| may differ between countries for the testing of the same agent against the same target weed because different countries have different guidelines and have different plant species of economic or conservation importance. |
The test list should not be inflexible. There may be sound reasons for modifying the test list during testing as more is learnt about the target weed and the potential agent. Reasons for modification may include:
| if the insect shows some acceptability of a plant species, that is, if
oviposition, feeding or development occurs, then relatives of that species should be added to the list.
|
| if it is found that the agent has particular morphological requirements for development, e.g. thick stems or hard seeds, then a species with thin stems or fleshy seeds may be excluded from the list and more suitable relatives added. |
[ Next ]
Wendy Forno and
Tim Heard
|
|
