Attractiveness of Host Plant Volatile Extracts to the Asian Citrus Psyllid, Diaphorina citri, is Reduced by Terpenoids from the Non-Host Cashew

Abstract

Diaphorina citri is a vector of the bacterial causative agent of Huanglongbing (HLB = Citrus greening), a severe disease affecting citrus crops. As there is no known control for HLB, manipulating insect behaviour through deployment of semiochemicals offers a promising opportunity for protecting citrus crops. The behavioural responses of D. citri to plant volatiles, and the identity of these plant volatiles were investigated. Volatiles were collected from host plants Murraya paniculata, Citrus sinensis, C. reshni, C. limettioides, Poncirus trifoliata, and from non-host plants Psidium guajava, Mangifera indica, Anacardium occidentale. In behavioural assays, female D. citri spent more time in the arms containing volatiles from either M. paniculata or C. sinensis compared to the control arms. When D. citri was exposed to volatiles collected from A. occidentale, they preferred the control arm. Volatiles emitted from the other studied plants did not influence the foraging behaviour of D. citri. Chemical analyses of volatile extracts from C. sinensis, M. paniculata, and A. occidentale revealed the presence of the terpenoids (E)-4,8-dimethylnona-1,3,7–triene (DMNT) and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) in higher amounts in A. occidentale. In further behavioural bioassays, female D. citri spent less time in arms containing a synthetic blend of DMNT and TMTT compared to the control arms. Female D. citri also spent less time in arms containing the synthetic blend in combination with volatile extracts from either M. paniculata or C. sinensis compared to the control arms. Results suggest that higher release of the two terpenoids by A. occidentale make this species unattractive to D. citri, and that the terpenoids could be used in reducing colonisation of citrus plants and therefore HLB infection.

Distribution, degree of damage and risk of spread of Trioza erytreae (Hemiptera: Triozidae) in Kenya

“…However, we found higher mean numbers of ACT immature stages (eggs and nymphs), galls and infested leaves on citrumelo than on the other cultivars, which might be partially attributed to volatiles produced by citrumelo. This is consistent with results of Fancelli et al () who demonstrated a positive relationship between host plant volatiles and attraction of D. citri to its preferred host plants. Additional studies to address ACT‐citrumelo volatiles and their attraction are crucial to understanding the underlying mechanisms involved in their preference for feeding and oviposition on this host and for the development of attractants for ACT.…”

“…is consistent with results ofFancelli et al (2018) who demonstrated a positive relationship between host plant volatiles and attraction of D. citri to its preferred host plants. Additional studies to address ACT-citrumelo volatiles and their attraction are crucial to understanding the underlying mechanisms involved in their preference for feeding and oviposition on this host and for the development of attractants for ACT.…”

Prospects for management of whitefly using plant semiochemicals, compared with related pests

“…However, potential psyllid semiochemicals have been identified, for example, the homoterpenes DMNT and ( E,E )‐4,8,12‐trimethyltrideca‐1,3,7,11‐tetraene (TMTT). A synthetic mixture of DMNT and TMTT reduced the attractiveness of the hosts orange jasmine , Murraya paniculata and sweet orange Pera D6, Citrus sinensis , in a four‐arm olfactometer bioassay . In Y‐shaped and four‐arm olfactometer assays, dimethyl disulfide, identified from the non‐host guava, Psidium guajava , reduced the attractiveness of volatiles from C. sinensis .…”

“…A synthetic mixture of DMNT and TMTT reduced the attractiveness of the hosts orange jasmine, Murraya paniculata and sweet orange Pera D6, Citrus sinensis, in a four-arm olfactometer bioassay. 48 In Y-shaped and four-arm olfactometer assays, dimethyl disulfide, identified from the non-host guava, Psidium guajava, reduced the attractiveness of volatiles from C. sinensis. 49 Furthermore, dimethyl disulfide released from polyethylene vials reduced D. citri infestation in an orchard of Valencia oranges, C. sinensis, for up to 4 weeks.…”

Desenvolvimento de estratégias alternativas visando ao controle do huanglongbing

“…Outras linhas de pesquisas desenvolvidas são as relacionadas a substâncias (feromônio e compostos voláteis) que possam atrair (Zanardi et al, 2018;Beloti et al, 2017) ou repelir (Silva et al, 2016;Alquézar et al, 2017;Fancelli et al, 2018) o vetor. Neste sentido, foi isolado o gene de um composto volátil produzido pela goiabeira (β-cariofileno) e utilizado para a transformação genética de Arabidopsis thaliana visando à repelência ao psilídeo (Alquézar et al, 2017).…”