The isolation and identification of pathogenic fungi from Tessaratoma papillosa Drury (Hemiptera: Tessaratomidae)

PeerJ. 2017 Oct 6:5:e3888. doi: 10.7717/peerj.3888. eCollection 2017.


Background: Litchi stink-bug, Tessaratoma papillosa Drury (Hemiptera: Tessaratomidae), is one of the most widespread and destructive pest species on Litchi chinensis Sonn and Dimocarpus longan Lour in Southern China. Inappropriate use of chemical pesticides has resulted in serious environmental problems and food pollution. Generating an improved Integrated Pest Management (IPM) strategy for litchi stink-bug in orchard farming requires development of an effective biological control agent. Entomopathogenic fungi are regarded as a vital ecological factor in the suppression of pest populations under field conditions. With few effective fungi and pathogenic strains available to control litchi stink-bug, exploration of natural resources for promising entomopathogenic fungi is warranted.

Methods & results: In this study, two pathogenic fungi were isolated from cadavers of adult T. papillosa. They were identified as Paecilomyces lilacinus and Beauveria bassiana by morphological identification and rDNA-ITS homogeneous analysis. Infection of T. papillosa with B. bassiana and P. lilacinus occurred initially from the antennae, metameres, and inter-segmental membranes. Biological tests showed that the two entomopathogenic fungi induced high mortality in 2nd and 5th instar nymphs of T. papillosa. B. bassiana was highly virulent on 2nd instar nymphs of T. papillosa, with values for cadaver rate, LC50 and LT50 of 88.89%, 1.92 × 107 conidia/mL and 4.34 days respectively.

Discussion: This study provides two valuable entomopathogenic fungi from T. papillosa. This finding suggests that the highly virulent P. lilacinus and B. bassiana play an important role in the biocontrol of T. papillosa in China. These pathogenic fungi had no pollution or residue risk, and could provide an alternative option for IPM of litchi stink-bug.

Keywords: Biological control; Entomopathogenic fungi; Pathogenicity; Tessaratoma papillosa.

Grants and funding

This research was supported by the Science and Technology Planning Project of Guangdong Province, China (2014A020208079; 2015A020209091); the Science and Technology Planning Project of Guangzhou, Guangdong Province, China (201610010002); the Guangdong Aacademy of Sciences Outstanding Young and Scientific Talent Foundation (rcjj2015); and the GDAS Special Project of Science and Technology Development (2017GDASCX-0107). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.