Patogenesitas jamur Metarhizium anisopliae terhadap belalang kembara (Locusta migratoria manilensis)

HANTORO, Gabriel Lulus Puji, Dr.Ir. Arman Wijonarko, M.Sc

2006 | Tesis | S2 Ilmu Hama Tumbuhan

Jamur Metarhizium anisopliae isolat Locusta migratoria, Oryctes rhinoceros, Cerambicidae, Plutella xylostella, dan Diaphorina citri diuji untuk mengetahui virulensinya terhadap belalang kembara (Locusta migratoria manilensis). Pemaparan isolat M. anisopliae terhadap belalang kembara dilakukan dengan cara mencelupkan nimfa instar 2, 3, 4,5 dan imago ke dalam suspensi 1010 spora/ml selama 10 detik. Pengamatan mortalitas dilakuan selama 10 hari. Dua isolat yang paling virulen dipilih untuk uji patogenesitas, pengaruh isolat terhadap daya makan, pertumbuhan isolat pada setiap stadia belalang kembara. Hasil menunjukkan bahwa kumulatif mortalitas selama 10 hari setelah perlakuan bervariasi mulai dari 10% sampai 100%. Diantara lima isolat, isolat Diaphorina citri, Oryctes rhinoceros, dan Cerambicidae dapat menyebabkan mortalitas nimfa instar 2, 3 dan 4 masing-masing 98,33; 93,33 dan 100%. Isolat yang unggul adalah isolat Diaphorina citri dan Cerambicidae. Nilai LC50 pada 10 hari setelah aplikasi untuk M. anisopliae isolat Diaphorina citri terhadap belalang kembara instar 2, 3 dan 4 adalah 1,04×107, 4,98×107, dan 1,31×107 spora/ml. Nilai LC50 M. anisopliae isolat Cerambicidae terhadap belalang kembara instar 2, 3 dan 4 adalah 1,95×106, 8,65×106 , dan 4,57×107 spora/ml. Semua isolat M. anisopliae dapat membunuh semua instar dan imago belalang kembara. Nimfa belalang kembara relatif lebih peka daripada imago. Koloni semua isolat yang diuji dapat tumbuh dengan cepat (4-5 hari) pada belalang kembara yang mati. Semakin tinggi konsentrasi spora semakin menurunkan daya makan belalang kembara.

Metarhizium anisopliae originated from Locusta migratoria, Oryctes rhinoceros, Cerambicidae, Plutella xylostella, and Diaphorina citri was screened to determine its susceptibility on migratory locust (Locusta migratoria manilensis). The 2nd, 3rd, 4th, 5th instars nymph and adults of Locusta migratoria manilensis were infected by submerging them for 10 seconds in a suspension containing 1010 spores/ml. Mortality was evaluated for 10 days. Two of the most virulence isolates were chosen for pathogenicity tests, and to examine the effects of infection on feeding activity. Cumulative mortality at 10 days after treatment varied from 10 to 100%. Metarhizium isolate of Diaphorina citri, Oryctes rhinoceros, and Cerambicidae were the most virulent against both nymphs and adults, causing 98,33; 93,33; 100% mortality on the 2nd, 3rd and 4th instar nymphs. Preeliminary assay showed that two most virulence isolates were Metarhizium isolate of Diaphorina citri and Cerambicidae and used for further experiments. The LC50 values of Metarhizium anisopliae isolate Diaphorina citri at 10 days after application for 2nd, 3rd and 4th instar nymphs were 1,04×107, 4,98×107, and 1,31×107 spores/ml respectively. The LC50 values of Metarhizium anisopliae isolate Cerambicidae for 2nd, 3rd and 4th instar nymphs were 1,95×106, 8,65×106, and 4,57×107 spores/ml respectively. Nymphs of the locusts were more susceptible against M. anisopliae than the adults stage. Nymph appearently died after four days postinoculation, and after 4 to 5 days the white mycelia developed, the green conidia had appeared around the nymph cadavers. The food consumption by all nymph instars tended to decline as a results of the Metarhizium treatments.

Kata Kunci : Belalang Kembara,Jamur Metarhizium Anisopliae, Locusta migratoria manilensis, Metarhizium anisopliae, pathogenecity