# Endophytic Colonization of Pepper (_Capsicum annum_) Controls Aphids (_Myzus persicae_ Sulzer)
## 4 Discussion  
Research indicates that biocontrol agents such as _Beauveria_, _Metarhizium_ and _Isaria_ generate systemic resistance against herbivorous insects [2; 21; 22]. A significant decrease in the population of _M. persicae_ in endophystically colonized pepper plants was recorded in our experiment. Similar findings were reported by [PERSON] and [PERSON] [23] for _Aplis fabae_ (Hemiptera: Aphididae) and [PERSON] et al. [24] for _Dichroplus muculipennis_ (Orthoptera: Acrididae). The literature suggests that endophytic entomopathogenic fungi, particularly _B. bassiana_, induce plant defenses which, in turn, suppress insects. Analogous results were also observed for _C. annum_ in this study. Following research on different kinds of grass, endophytes seem to negatively affect herbivores through several mechanisms, ranging from antiscenosis and/or antibiosis to the plant generating secondary compounds and/or to the endophytes producing secondary metabolites [1; 2; 25]. Infection by endophytes is conditional upon the genetic and environmental make-up of the insect population. The host plant's odor or taste comes from nutrients and odd compounds that are transformed into complex sensorial inputs in herbivore insects [26]. These inputs are interpreted by the insect's central nervous system to determine whether a given plant is a suitable host [13]. It is also assumed that endophytes modify the chemical profile of the plant by altering its phytosterol composition and that they compete with insects for nutritional compounds [27]. In positively colonized _B. bassiana_ plants, the overall aphid population was decimated after 14 DAE. Similar results were obtained for the other colonized plants, with the reduction found to be significant compared with the  
Figure 5: _C. annum_ growth in terms of (**A**) height of pepper plants and (**B**) number of pepper leaves. Mean \(\pm\) sd values with the same superscript letter are not different in a significant way (Bonferroni’s test: \(p\) < 0.05). aphid population in control plants. It is yet to be established how endophytic fungi may protect plants from insect herbivores. The production of secondary metabolites by endophytes is not necessarily the reason for the negative impact on the aphids which was observed in our study. These negative effects are evident in the high proportion of aphids terminating and the low proportion of aphids surviving in colonized plants, compared to the high proportion surviving in control plants. Moreover, cumulative proportion surviving at end of the interval in colonized plants was significantly lower compared to the control plants. The hazard rate of colonized plants was significantly higher, especially at 14 DAE, in comparison with control plants. Systemic spread was previously documented by [PERSON] and [PERSON] [28], [PERSON] and [PERSON] [11], [PERSON] and [PERSON] [29; 30], [PERSON] et al. [31], [PERSON] et al. [4], [PERSON] and [PERSON] [32], [PERSON] and [PERSON] [33], [PERSON] [34], [PERSON] et al. [35], [PERSON] et al. [2], [PERSON] and [PERSON] [36; 37], and [PERSON] and [PERSON] [38]. In the current study, the plant displayed no obvious signs of disease after conidia had been sprayed onto the leaves. Viable conidia are known to adhere to the surface of the plant instead of floating in the solution, even after application of surfactants [32]. Aphids possess a simple body structure, whereby insects feed and reproduce efficiently, while the larger part of the nutrient intake is invested in the production of nymphs [36]. In studies published so far, mycosis has either not been tested or not observed in the endophytic phase of entomopathogenic fungi. [PERSON] et al. [4] have reported mycosis of more than 60% of _Cosmopolites sordidus_ (Coleoptera: Curculionidae) adults in their herbivore developmental stages, feeding on inoculated banana plants. Larvae of _Helicoverpa zea_ (Lepidoptera: Nocutiidae) in tomato plants [39], _Helicoverpa armigera_ (Lepidoptera: Nocutiidae) in faba plants [25] and _D.