## 3 Results and Discussion
### Laboratory Bioassays  
_Euwallacean perbrevis_ females were significantly more attracted to _Fusarium_ sp. nov. than to AF-8. When given a choice between AF-8 and _Graphium_ sp., females were significantly more attracted to AF-8, but no significant differences were observed when females were offered the _Fusarium_ sp. nov. and _Graphium_ sp. (\(p=0.12\)) (Figure 6). _trans-p_-Menth-2-en-1-ol, detected in the volatiles of all three test fungi, is the main component of the quercivorol lure that is attractive to _E. perbrevis_[13; 16] and other _Euwall  
Figure 5: Emissions of _cis-_ and _trans-p_-menth-2-en-1-ol quantified over time from cultures of _Graphium_ sp. Volatiles were isolated by Super-Q collection (15 min adsorption), followed by GC-FID analysis (DB-5 column). Figure 6: Avocado sawdust disks inoculated with symbiotic fungi and offered to _E. perbrevis_ in dual-choice assays. Mean number of _E. perbrevis_ in, on or next to the disk after 12 h. (**A**) AF-8 vs. _Fusarium_ sp. nov., (**B**) _Fusarium_ sp. nov. vs. _Graphium_ sp., (**C**) AF-8 vs. _Graphium_ sp. \({}^{\star}\) Indicates significant difference in attraction between the two choices (\(p<0.05\)). lacea_ species [28]. The _cis_-isomer, also present in the quercivorol lure, was only detected in the emissions from _Graphium_ sp. _cis_-_p_-Menth-2-en-1-ol did not increase the attraction of _E. perbrevis_ to _Graphium_ sp., suggesting that the _trans_-isomer is the primary attractant of _E. perbrevis_ and possibly of other _Euwallacea_ spp. Furthermore, _trans_-_p_-menth-2-en-1-ol was the only volatile compound detected in the emissions from all six symbiont cultures (Table 1). Under natural conditions, the fungal gardens of _E. perbrevis_ would consist of mixed cultures of all six symbionts, which would emit a strong 'bouquet' of _trans_-_p_-menth-2-en-1-ol. The two minor components in the commercial lure [16], \(\alpha\)- and \(\beta\)-phellandrene, were also detected in the emissions from fungal symbionts. \(\alpha\)-Phellandrene was present in emissions from the _Graphium_ sp. cultures, and \(\beta\)-phellandrene was emitted by both _Graphium_ sp. and AF-8; however, neither compound appeared to increase attraction of female _E. perbrevis_ in choice assays. (\(-\))\(\beta\)-Phellandrene is the predominant monoter in the phloem tissue of lodgepole pine (_Pinus contorta_ [PERSON]) and a known kairomone attractant for several species of bark beetle, including the economically important pine engraver, _Ips_ _pini_ ([PERSON]) [29]. _Graphium_ sp. was the least attractive symbiont despite emissions of _trans_-_p_-menth-2-en-1-ol. This suggests that other volatiles from _Graphium_ sp. may include potential repellents. For instance, _cis_-_p_-menth-2-en-1-ol and _trans_-pipertol are known to have repellent activity against _Musca domestica_ L. and _Haematobia irritans_ L. [30; 31], and terpinen-4-ol has insecticidal and repellent activities against three stored-product insects: _Tribolium castaneum_ [PERSON], _Lasioderma serricorne_ [PERSON], and _Liposcelis bostrychophila_ [PERSON] [32]. However, other volatiles produced by _Graphium_ sp., like _p_-cymene and \(\beta\)-elemene, are involved in the attraction of _X. glabatus_ to Lauraceous trees [33]. More research is needed to understand the effects of these and other volatiles from _Graphium_ sp. as potential attractants or repellants of _E. perbrevis_. Identification of effective repellents would facilitate development of a pest management strategy using a 'push-pull' approach; a repellent applied to host trees would push pests away, while surrounding traps baited with attractant (i.e., the combination of _trans_-_p_-menth-2-en-1-ol and \(\alpha\)-copaene [5]) would reduce numbers of host-seeking females [34]. _Fusarium_ sp. nov. was the most attractive amongst the tested fungi. Besides _trans_-_p_-menth-2-en-1-ol, the only other volatile detected from _Fusarium_ sp. nov. was limonene. Therefore, limonene is likely a secondary attractant of _E. perbrevis_, not present in the other two symbionts.