New and Emerging Insect Pest and Disease Threats to Forest Plantations in Vietnam

Abstract

The planted forest area in Vietnam increased from 3.0 to 4.4 million hectares in the period 2010–2020, but the loss of productivity from pests and diseases continues to be a problem. During this period, frequent and systematic plantation forest health surveys were conducted on 12 native and 4 exotic genera of trees as well as bamboo across eight forest geographic regions of Vietnam. Damage caused by insects and pathogens was quantified in the field and laboratory in Hanoi. The threats of greatest concern were from folivores (Antheraea frithi, Arthroschista hilaralis, Atteva fabriciella, Hieroglyphus tonkinensis, Lycaria westermanni,Krananda semihyalina, and Moduza procris), wood borers (Batocera lineolata, Euwallacea fornicatus, Tapinolachnus lacordairei, Xyleborus perforans, and Xystrocera festiva), sap-sucking insects (Aulacaspis tubercularis and Helopeltis theivora) and pathogens (Ceratocystis manginecans, Fusarium solani, and Phytophthora acaciivora). The number of new and emerging pests and pathogens increased over time from 2 in 2011 to 17 in 2020, as the damage became more widespread. To manage these pests and diseases, it is necessary to further invest in the selection and breeding of resistant genotypes, improve nursery hygiene and silvicultural operations, and adopt integrated pest management schemes. Consideration should be given to developing forest health monitoring protocols for forest reserves and other special-purpose forests.

The stem borer Zeuzera multistrigata Moore (Lepidoptera, Cossidae): a serious pest undermining Eucalyptus plantations in Northern Vietnam

“…Based on the damage classification, we initially calculated damage incidence using equation 1 (Chi et al 2021): P% = (n/N) × 100…”

“…In addition, they have also been reported to cause damage in some other plant species in India including Prunus avium, Persea bombycina and Bitsaea polyantha (Bhardwaj et al 1982;Baruah et al 2020). The rapid increase in commercial Eucalyptus plantations in Vietnam, from 200,000 ha in 2013 (Arnold et al, 2020) to 400,000 ha in 2020 (Thu et al 2021) is would to be the cause of outbreaks of Z. multistrigata.…”

“…In Vietnam, many insects and pathogens have been identified as pests of E. urophylla plantations including Zeuzera coffeae (Thu et al, 2010), Sarothrocera lowi, Leptocybe invasa (Dell et al 2012) and Cryptosporiopsis eucalypti, Ralstonia solanacearum (Thu et al 2010;Dell et al 2012), and Ceratocystis manginecans (Chi et al in press;Trang et al 2022). Therefore, these plantation areas are being replaced by Eucalyptus hybrid clones (Chi et al in press) with the estimated area has increased from 200,000 ha in 2013 (Harwood & Nambiar 2014) to 400,000 ha in 2020 (Thu et al 2021). In recent years, Eucalyptus hybrid plantations in the northern provinces of the country have been attacked by other Zeuzera species.…”

Management of Needle-Eating Caterpillars Associated with Pinus massoniana and P. merkusii in Vietnam

“…Forest pests are becoming more prevalent in Vietnam [60] and pesticides are becoming more widely used to control pests in forest plantation species. Examples of pesticide use include Da.…”

A Synoptic Review of Plant Disease Epidemics and Outbreaks Published in 2021

“…Core articles: Thu et al (2021), Panzavolta et al (2021), Spears and Broders (2021) Forest tree health, globally, is affected by new and emerging pathogens and pests causing environmental and economic damage, with increasing numbers of alien invasive species being recorded in trees, plantations, and nurseries in many countries (Panzavolta et al 2021). Forest health surveys were made annually from 2011-2020 across eight forested regions of Vietnam with observations on 16 tree species (Thu et al 2021). Three plots (40 m x 25 m) in each region were put in place at least 20 m from any edge effects from roads, forest edges or gaps.…”