Behavioral Ecology of the Coffee White Stem Borer: Toward Ecology-Based Pest Management of India's Coffee Plantations

Abstract

India is the seventh largest producer of coffee with 395,000 tons of coffee exports that earn 10 billion US dollars annually. Two varieties of coffee are grown in India, Coffea arabica (arabica) and Coffea canephora (robusta). Xylotrechus quadripes, commonly known as Coffee White Stem Borer (CWSB), is a major pest of arabica, causing yearly crop damage of 17–40 million dollars. Management strategies, over 100 years in development, have provided successful, yet inconsistent solutions due to differences in local climate, elevation, natural enemies, grower diligence, and other factors. In addition, increased pesticide use affects both pests as well as their natural enemies, which has severe negative impacts on the biodiverse regions where coffee is grown. As a result, our goal is to develop an ecology-based solution for long term management of CWSB that reduces the use of pesticides and focuses on the importance of natural enemies and native hosts. In situ behavioral experiments were performed to examine the preferences of CWSB for various local species under field conditions. We found that CWSB beetles were attracted to both healthy arabica and robusta plants, and host plant volatiles played a key role in host selection. In addition, the beetles were attracted to the leaves of these coffee plants and also two species of cut stems from common shade trees; Spathodea campanulata (nandi flame) and Grevillea robusta (silver oak). Beetles were not attracted toward cut stems of Tectona grandis (teak) or Coffea arabica. GC-EAD and EAG experiments were then performed to identify host plant volatiles for these species, and these compounds were tested in field conditions to assess their effectiveness against the known chemical attractant pheromone. We found that the CWSB was attracted to our identified host volatile blend as much as the pheromone lure, although trap catches in general were very low. Having an understanding of the behavioral ecology of this pest can form the basis for new methods that use natural attractant and repellent plants to control the pests, reduce the cost of plantation pest management, and avoid the extensive use of insecticides.

An overview on possible management strategies for coffee white stem borer Xylotrechus quadripes Chevrolat (Coleoptera: Cerambycidae) in Nepal

“…The larva are 7-25 mm in length and 2.3-5 mm in width (Le Pelley, 1968;Rajbhandari, 2021). Once the first instar has reached a certain stage, it begins to tunnel the stem through the cambium and wood (Rajus et al, 2021). After six months, this larval stage develops to the pupal stage through six larval instars, and then finally pupa transitions into an adult in 30-40 days (Waller et al, 2007).…”

“…Also, females do not prefer to lay eggs on the bark of robusta coffee as its smoother bark makes the eggs more vulnerable to predation (Venkatesha and Dinesh, 2012). CWSB directly invades leaves during flight and eventually lays eggs in the stem (Rajus et al, 2021). Young trees are particularly vulnerable to stem borer damage, with severe harm to trees of less than two years.…”

“…In India and other Asian nations, a number of techniques have been used, including shade management, insecticide applications, bark scrubbing, stem wrapping to prevent oviposition, mass trapping with the aid of pheromone-baited traps, and uprooting and burning of affected plants to manage CWSB. However, it continues to be a threatening pest for Asian coffee farmers (Hall et al, 2006;Rajus et al, 2021;Venkatesha and Dinesh, 2012). The reason behind its uncontrollability could be local climate variability, altitude, lack of consistent monitoring, and the prohibitive cost of workforce required to practice those methods.…”

“…The reason behind its uncontrollability could be local climate variability, altitude, lack of consistent monitoring, and the prohibitive cost of workforce required to practice those methods. The egg-laying nature of female adult X. quadripes leads to laying eggs deep inside the stem that protects the egg, larva from non-systemic insecticides (Rajus et al, 2021). Generally, spraying of contact and systemic pesticides is not recommended as several studies have already stated that those chemical residues get accumulated in coffee beans and affect other non-targeted creatures (Reis et al, 2015).…”

Effectiveness of Using Attractants to Control Hypothenemus hampei in Coffea arabica Crop in the Ecuadorian Amazon

“…Within this context, the integrated pest management concept has been developed from which various methods of arresting or suppression of pests are applied, such as the use of various substances, called attractant, in craft traps (Donato-Ortiz & Lucio-Quintana, 2018;Mendoza-Cervantes, Guzmán-López, & Salinas-Castro, 2021;Rajus, Bhagavan, Kharva, Rao & Olsson, 2021;Sinaga, Lisnawita & Tobing, 2020). Recently different types of craft traps (INTA; BROCA; ECOIAPAR) and different combinations of attractants in different presentations, such as gel and liquid (Alarcón et al, 2017;Donato-Ortiz & Lucio-Quintana, 2018;Leiva-Espinoza, Oliva-Cruz, Rubio-Rojas, Maicelo-Quintana, & Milla-Pino, 2019) have been proved.…”