BIODIVERSITAS ISSN: 1412-033X Volume 21, Number 9, September 2020 E-ISSN: 2085-4722 Pages: 4016-4021 DOI: 10.13057/biodiv/d210912 High impact of PGPR on biostatistic of Aphis craccivora (Hemiptera: Aphididae) on yardlong bean HERMANU TRIWIDODO 1,♥ , LISTIHANI 2,♥♥ Department of Plant Protection, Faculty of Agriculture, Institut Pertanian Bogor. Jl. Meranti, Kampus IPB Darmaga, Bogor 16680, West Java, Indonesia. Tel.: +62-251-8629354, Fax.: +62-251-8629352,  email: hermanutr@apps.ipb.ac.id, petanimerdeka@gmail.com 2 Department of Agrotechnology, Faculty of Agriculture, Universitas Mahasaraswati. Jl. Kamboja No. 11A, Denpasar 80233, Bali, Indonesia. Tel.: +62-361-227019, ♥♥ email: listihani9@gmail.com Manuscript received: 18 May 2020. Revision accepted: 9 August 2020. Abstract. Triwidodo H, Listihani. 2020. High impact of PGPR on biostatistic of Aphis craccivora (Hemiptera: Aphididae) on yardlong bean. Biodiversitas 21: 4016-4021. Plant growth-promoting rhizobacteria (PGPR) are root colonizing bacteria that live and develop near plant roots, which boost plant growth and act as antagonist agents. This research is aimed to asses the effect of PGPR on biostatistics of Aphis craccivora Koch on yardlong bean (Vigna unguiculata subsp. sesquipedalis). The research was conducted at WiSH Laboratory in Bogor, Indonesia, by tested PGPR mixture of Rhizobium, Bacillus polymyxa, and Pseudomonas fluorescens. The research discovered that the application with seed treatment and watered of PGPR affects the biology of Aphis craccivora in terms of lengthening its stadia of second instar nymph, lengthening its life cycle, and declining its fecundity. The application of PGPR also affects the biostatistics of Aphis craccivora. PGPR applied plants have a gross reproduction rate (GRR), net reproduction rate (Ro) and intrinsic increase rate (r) of Aphis craccivora that are lower than control. PGPR could slower the doubled time (DT) of Aphis craccivora to become lengthier than control. PGPR could improve plant growth: it could increase the number and length of roots, number of root nodules, plant height, number of leaves, as well as length and density of trichome. Keywords: Induced resistance, intrinsic growth rate, life cycle, life table, physical structure, Rhizobium INTRODUCTION Plant growth-promoting rhizobacteria (PGPR) is used as an alternative to develop environment-friendly agriculture by decreasing the use of fertilizers and pesticides. Rhizobacteria are rhizosphere-competent bacteria that aggressively inhabiting plant roots; they are able to multiply and colonize on the roots (Muleta 2007). The bacterial genera such as Agrobacterium, Arthrobacter, Azotobacter, Azospirillum, Bacillus, Burkholderia, Caulobacter, Chromobacterium, Erwinia, Flavobacterium, Micrococcus, Pseudomonas and Serratia belongs to PGPR (Gray and Smith 2005). PGPR induced resistance against insect pests through synthesis of phytohormones, increase in phosphorus and nitrogen uptake, and increase in iron and mineral solubility through chelation growth (Bowen and Rovira 1996). On tomato plants, PGPR application could induct the plant’s resistance from pests since decreasing the consumption level of Bemisia tabaci (Shavit et al. 2013). At the harvesting, found that the average total yield of tomatoes treated with the PGPR significantly higher than that of the control and recorded a yield doubled compared to the control plants (Moustaine et al. 2017). Induced plant resistance coule cause distruption on insect's feeding behavior and general life. The disturbed eating activity could affect pest’s growth, development, fecundity, and mortality. Biostatistics are an basic l step in studying the growth of insect population. This research is aimed to understand the application of PGPR on yardlong bean (Vigna unguiculata subsp. sesquipedalis) and its effect on the biostatistics of Aphis craccivora Koch (Hemiptera: Aphididae). MATERIALS AND METHODS Preparation of plant A number of 260 yardlong bean seeds cv. Bonaro were separated into two treatments treated: 130 seeds were soaked in PGPR suspension of Rhizomax trademark, meanwhile the other 130 seeds were soaked in aquadest as a control application. The PGPR suspension was made by mixing 10 7 cfu/L of sterlizzed distilled water aquadest. The seeds were submerged in PGPR suspension and aquadest (control application) for 15 minutes and then dried on tissue paper for 15 minutes. Seeds were sownin 100 polybags which were filled with planting media: 60 polybags were used for observation on plant height, number of leaves and cohort maintenance of Aphis craccivora by sowing 3 seeds per polybag; and 40 polybags were used for observation on root parts and leaf trichome of yardlong bean by sowing 2 seeds per polybag. NPK fertilizer was added with a rate of 0.5 grams per polybag. The remaining PGPR suspension from the submersion process was watered to the PGPR-application planting media about 150 mL per polybag. Meanwhile, the control-application planting media were watered with water. The second watering process of PGPR-application plants with PGPR suspension and the second watering of