## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Treatment**} & \multirow{2}{*}{**Estimate**} & \multicolumn{4}{c}{**Larvae**} & \multicolumn{4}{c}{**Adults**} \\  & & **Standard** & **95\% Confidence Interval** & **Estimate** & **Standard** & **95\% Confidence Interval** \\  & & **Deviation** & **Lower** & **Upper** & **Deviation** & **Lower** & **Upper** \\  & & & **Bound** & **Bound** & & & **Bound** & **Bound** \\ \hline Control & 15,560 a & 0.278 & 15.316 & 16.104 & 15.890 a & 0.428 & 15.716 & 16.096 \\ _B. bussiana_ (147) & 14.000 c & 0.367 & 13.281 & 14.719 & 13.250 c & 0.321 & 12.771 & 14.629 \\ _B. bussiana_ (149) & 13.180 c & 0.387 & 12.922 & 13.938 & 11.290 b & 0.355 & 11.305 & 12.695 \\ _B. bussiana_ (2) & 11.120 b & 0.311 & 11.509 & 12.731 & 11.230 b & 0.300 & 10.912 & 12.588 \\ _B. bassiana_ (BB AC) & 14.160 c & 0.261 & 13.448 & 14.472 & 13.260 c & 0.480 & 12.059 & 14.441 \\ _B. bassiana_ (BB K) & 11.680 b & 0.428 & 10.802 & 12.558 & 11.860 b & 0.620 & 10.784 & 12.216 \\ _B. bassiana_ (BB) & 11.960 b & 0.411 & 11.154 & 12.766 & 13.740 c & 0.993 & 13.054 & 14.946 \\ _B. bassiana_ (Kar) & 13.680 cc & 0.448 & 12.802 & 14.558 & 13.110 c & 0.320 & 12.784 & 14.216 \\ _B. varroe_ (23) & 6.440 d & 0.201 & 6.047 & 7.833 & 11.010 b & 0.312 & 10.388 & 11.612 \\ _C. blackwelliae_ & 13.000 bc & 0.409 & 12.198 & 13.802 & 13.590 c & 0.384 & 12.947 & 14.753 \\ _C. fumosorosea_ (IS) & 10.640 b & 0.346 & 9.962 & 11.318 & 12.670 bc & 0.306 & 11.900 & 12.900 \\ _M. anisopliae_ (MET A) & 12.040 bc & 0.324 & 12.405 & 13.675 & 10.640 b & 0.389 & 10.238 & 11.762 \\ _M. anisopliae_ (MET B) & 9.120 e & 0.367 & 8.401 & 10.839 & 13.900 c & 0.359 & 13.297 & 14.703 \\ _M. anisopliae_ (MET S) & 12.640 bc & 0.346 & 11.962 & 13.318 & 8.710 d & 0.306 & 7.400 & 9.600 \\ _M. robertsii_ (MET K) & 12.280 bc & 0.482 & 11.336 & 13.224 & 11.990 b & 0.612 & 11.617 & 12.200 \\ _P. lavendulum_ (101) & 7.640 d & 0.346 & 6.962 & 8.318 & 13.140 c & 0.306 & 12.800 & 14.600 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Survival time (days) for the larvae and for adults of _O. linearis_. Ten larvae/adults were used per replicates for five replicates per isolate. Values with the same letter within a column are not significantly different (_p_ < 0.05). examine the vulnerability of _O. linearis_ to different EPF isolates, in the respect of searching for non-chemical tools for controlling a serious pest that has become a nuisance for walnut producers. The screening process involved 15 isolates from four EPF genera namely, _Beaureria_, _Cordyceps_, _Metarhizium_, and _Purpurecillium_. All of them demonstrated a substantial insecticidal effect on both larvae and adults, with mortality rates ranging from 66 to 100%. The results indicated that all the isolates of _B. bassimana_ had a lethal effect, although this was not as pronounced as in other cases. However, _B. varroae_ (23) resulted in 100% mortality on larvae and 90% on adults. This suggests that fungal virulence is not related to the genus, as observed in the case _M. anisopliae_, nor is it related to the species. It has been well established that EPF are not universally effective and different strains and isolates even of the same species vary in virulence, possibly due to genetic variability [45]. To elaborate, two _M. anisopliae_ isolates (MET S and MET A) were found to be highly potent against adults, whereas the other _M. anisopliae_ isolate (MET B) was not. The comparative analysis of _Beaureria_ and _Metarhizium_ demonstrated that the latter exhibited greater efficacy against larvae and adults of _O. linearis_. Our results cannot be directly compared with other studies due to the complete lack of previous research on the effect of EPF on _O. linearis_. Nevertheless, some information concerning the impact of EPF on wood-boring beetles has been published. More specifically, _A. glabripennis_ has suffered high adult mortality when exposed to _Beaureria_[27] and _Metarhizium_[26]. The same species recorded reduced survival times (ST\({}_{50}\)) from 5.0 (_M.