Entomopathogenic fungi often used as bioinsecticides to control pest insects. Entomopathogenic fungi infect through penetrating cuticles of insect or inedible. Entomopathogenic fungi can be found in the rhizosphere. The purpose of this study was to explore the types of entomopathogenic fungi in various rhizosphere of horticultural plants in Padangsidimpuan. This research was conducted at the Agrotechnology Laboratory, Faculty of Agriculture, South Tapanuli Muhammadiyah University. The results showed that the use of Tenebrio molitor as bait, can effectively obtain entomopathogenic fungi from the soil. The highest mortality of Tenebrio molitor where infected by entomopathogenic fungi was 64% on soybean plant and the lowest mortality due to infection of entomopathogenic fungi was 11% on mustard plants. There was only one genus of entomopathogenic fungi found in this study was Metarhizium sp. Keywords: soil, Metarhizium, Tenebrio molitor, infect, moist chamber

Asiatic citrus psyllid Diaphorina citri Kuwayama has been considered as one of important citrus pests and a vector of a serious citrus disease as well, greening disease or known as Huanglongbing (HLB). Among entomophatogenic fungi which can be used to control those pest insects isBeauveria bassiana.The objective of this study was to measure the infectivity ofB. bassianaagainst adult of D. citri.B. bassianaconidia that used were 10³, 10⁴, 10⁵, 10⁶, 10⁷, and 10⁸conidia/ml.The experiment was repeated three times and arranged in a completely randomized design (CRD). Mean was analized by Duncan's multiple range test correction at the level α=0.05. B. bassianacaused mortality of D. citriat rate of 10%, 15%, 18.33%, 26.67%, 33.33% and 53.33% respectively. The result showed that LC₅₀ of B. bassianawas 1.52 x 10⁸conidia/ml.

Spodoptera exigua is a migrant pest that attacks onions simultaneously in groups. The utilization of papaya leaves to control pests due to papaya leaves have toxic compounds that can kill pests. This study aims to measure the ability of papaya leaves to control S. exigua larvae. This research was conducted using a completely randomized design (CRD) experimental method with two treatment factors. The first factor was papaya leaf concentration (0 g / l, 30 g / l, 70 g / l, 100 g / l, 120 g / l), and the second factor is a mixture of kerosene. The treatment was repeated three times. The study was conducted at the Agrotechnology Laboratory, Agriculture Faculty Muhammadiyah University, South Tapanuli. The results showed that papaya leaves could kill S. exigua larvae. The highest mortality of S. exigua worms There were statistically significant non-treatments among treatments.

Insect pathogens that are often used to control insect pests are fungi Beauveria bassiana and Metarhizium anisopliae. One of the agar media, which is often used in the entomopathogenic function of propagation in the laboratory, is PDA (potato dextrose agar). The price of instant PDA is quite high, starting from Rp. 750,000 per 250 g doing the research costs quite large. Cheap and easily obtained abundant natural resources can be used as an alternative medium for microorganism growth to reduce the overall costs to be incurred in research. Carbohydrate sources used in this study were potatoes, cassava, sweet potatoes, corn, and rice, which were made into the agar media. Observation parameters were viability rates, colony growth rates, and sporulation of B. bassiana and M. anisopliae fungi isolates. The experiments are used in a completely randomized design (CRD) with two treatment factors. The data obtained were processed with variance and continued with the DNMRT test at 5% significance level. The results showed that cassava agar caused the highest germination at 24 hours. The highest diameter was fungi grown on potato dextrose agar. The highest sporulation was fungi grown on corn agar.

Green ladybug (Nezara viridula L.) is an important pest in some plants, including soybeans. N. viridula attacks cause a decrease in yield of up to 80%. Environmental friendly pest control studies are needed to overcome the problem of resurgence caused by N. viridula, among others by utilizing entomopathogenic fungus as their natural enemies. This study discusses about the efficacy of entomopathogenic fungi against N. viridula imago. The research is conducted at the Agricultural Agrotechnology Laboratory, Muhammadiyah University of South Tapanuli. The study uses a completely randomized design, nine treatments (control and eight isolates of entomopathogenic fungus) with three replications. The conidia density used is 108 conidia / ml. The entomopathogenic fungus application was performed on N. viridula imago. The results shows that MetKP fungus isolates are able to kill N. viridula imago with the highest mortality rate of 78.33%. The isolates of MetKM fungi and M. anisopliae caused the lowest imago mortality of 61.67%. Isolate of B. bassiana fungus had the lowest LT50 with a time of 5.66 HSA and the isolate of the MetTmM fungus had the highest LT50 with a time of 7.27 HSA. In the immature body part of N. viridula infected with fungus is enveloped by entomopathogenic fungal mycelium.