|
| ||
|
|
||
Acacia Nilotica Ssp. Indica (acacia + nilotica_ssp._indica)
Selected AbstractsPrioritising potential guilds of specialist herbivores as biological control agents for prickly acacia through simulated herbivoryANNALS OF APPLIED BIOLOGY, Issue 1 2009K. Dhileepan Abstract Understanding plant response to herbivory facilitates the prioritisation of guilds of specialist herbivores as biological control agents based on their potential impacts. Prickly acacia (Acacia nilotica ssp. indica) is a weed of national significance in Australia and is a target for biological control. Information on the susceptibility of prickly acacia to herbivory is limited, and there is no information available on the plant organ (i.e. leaf, shoot and root in isolation or in combination) most susceptible to herbivory. We evaluated the ability of prickly acacia seedlings, to respond to different types of simulated herbivory (defoliation, shoot damage, root damage and combinations), at varying frequencies (no herbivory, single, two and three events of herbivory) to identify the type and frequency of herbivory that will be required to reduce the growth and vigour. Defoliation and shoot damage, individually, had a significant negative impact on prickly acacia seedlings. For the defoliation to be effective, more than two defoliation events were required, whereas a single bout of shoot damage was enough to cause a significant reduction in plant vigour. A combination of defoliation + shoot damage had the greatest negative impact. The study highlights the need to prioritise specialist leaf and shoot herbivores as potential biological control agents for prickly acacia. [source] A systematic approach to biological control agent exploration and prioritisation for prickly acacia (Acacia nilotica ssp. indica)AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 4 2006K Dhileepan Abstract, Agent selection for prickly acacia has been largely dictated by logistics and host specificity. Given that detailed ecological information is available on this species in Australia, we propose that it is possible to select agents based on agent efficacy and desired impact on prickly acacia demography. We propose to use the ,plant genotype' and ,climatic' similarities as filters to identify areas for future agent exploration; and plant response to herbivory and field host range as ,predictive' filters for agent prioritisation. Adopting such a systematic method that incorporates knowledge from plant population ecology and plant,herbivore interactions makes agent selection decisions explicit and allow more rigorous evaluations of agent performance and better understanding of success and failure of agents in weed biological control. [source] Rearing and release of Homichloda barkeri (Jacoby) (Coleoptera: Chrysomelidae: Alticinae) for the biological control of prickly acacia, Acacia nilotica ssp. indica (Mimosaceae) in AustraliaAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 3 2003Catherine J Lockett Abstract Prickly acacia, Acacia nilotica ssp. indica, a major weed of the Mitchell Grass Downs of northern Queensland, has been the target of biological control projects since the 1980s. The striped leaf-feeding beetle, Homichloda barkeri (Coleoptera: Chrysomelidae: Alticinae), was the third insect approved for release for the control of this weed in Australia. However, mass rearing this insect under glasshouse conditions proved to be difficult and time consuming as there were problems associated with low egg-hatching rates and poor larval survival. Eggs in diapause were stimulated to hatch by repeated wetting and drying. Larvae were fed on potted prickly acacia plants in cages. Late-instar larvae were collected and transferred to a mix of sand, peat moss and vermiculite for pupation and adult emergence. Over 10 500 adults were released at 28 sites in north Queensland between November 1996 and December 1999. Initial releases of insects confined to gauze cages resulted in limited adult survival, oviposition and development of first-generation larvae. First-generation larvae were observed at two sites where cages were not used. However, later inspections of release sites, including those made in April and December 2000, April 2001 and late March 2002, failed to find any trace of the insect, which is assumed to have failed to establish. Possible reasons for this failure are discussed. [source] | ||||||||||