Development of semiochemical-based tools for the management of the African citrus trizoid (ACT) Trioza erytreae, a component of the Strengthening Citrus production systems through the introduction of IPM measures for pests and diseases (SCIPM)

The SCIPM project addresses the most important and pressing insect pest and disease problem on citrus in Africa – mainly the African citrus triozid (ACT), Trioza erytreae, the false codling moth (FCM), Thaumatotibia leucotreta and Greening or Huanglongbing (HLB) disease vectored by T. erytreae.

Th initiative is a response to accumulating evidence that managing these damaging pests and disease on citrus will increase production and improve the income generation capacity, food and nutritional security of small and medium scale producers in the 2 target countries. Direct feeding by ACT can cause the death of developing citrus flush shoots or abscission of leaves and up to 65% of such infestations are common. However, ACT is most importantly known for its transmission of the phloem-limited bacteria (Candidatus Liberibacter africanus [CLaf]) responsible for HLB, the most devastating disease of citrus which can cause 25 to 100 % citrus yield loss (Kilalo et al., 2009; Pole et al., 2010). The yield of affected trees is not only reduced considerably by continuous fruit drop, dieback, and tree stunting, but also by the poor quality of fruits remaining on the trees. Larvae of FCM also directly damage citrus by tunneling into fruits causing premature fruit drop resulting in 34-68% fruit loss (Ekesi, 2012). In addition to the direct damage, ACT and FCM are major quarantine pests limiting export of citrus to lucrative, quarantine sensitive markets.

Within SCIPM, the Behavioural and Chemical Ecology Unit is contributing towards developing ecologically sustainable management methods for ACT and associated HLB disease, and FCM, through studies to establish behavioural evidence for kairomonal and female-produced sex attractant and repellents in ACT and develop tools for monitoring and suppression.


  • German Ministry of Economic Cooperation and Development (BMZ)


  • Center for Development Research (ZEF), University of Bonn
  • Texas A&M University-Kingsville, TX, USA
  • Citrus Research International, Nelspruit, South Africa
  • Kenya Plant Health Inspectorate Service (KEPHIS)
  • Kenya Agricultural Research Institute (KARI)
  • University of Nairobi
  • Ministry of Agriculture, Food Security & Cooperative (MAFSC)
  • Mikocheni Agricultural Research Institute
  • Real IPM Ltd., Kenya