Abstract
The African citrus triozid Trioza erytreae Del Guercio (Hemiptera: Triozidae) is the most destructive citrus pest. Presently, biological data on T. erytreae are insufficient for important parameters like distribution, seasonal dynamics and entomopathogens. Therefore, we determined the temporal dynamics of T. erytreae along three different altitudinal gradients in Kenya. In low altitudes, females of T. erytreae reactivated and started laying eggs between late February and early March. The mean monthly number of immature stages of T. erytreae per flush shoot peaked in February, whereas adults peaked in March. For mid-altitudes, T. erytreae mean populations peaked in February, but adults were already present in December. In high altitudes, adults appeared in June, and females began laying eggs. Trioza erytreae population densities in shaded trees positively and significantly correlated with unshaded trees. There was a significant difference between adult density and maximum temperature, average temperature, solar radiation, evaporation and dew point. Furthermore, this study evaluated the effects of 11 Metarhizium anisopliae and 4 Beauveria bassiana fungal isolates against adult T. erytreae under laboratory conditions. Metarhizium anisopliae ICIPE 18 and ICIPE 69 were the most potent isolates, causing 97.5% and 82.5% mortalities within the shortest LT50 time of 4.4 and 5.9 days, respectively. The presence of Diaphorina citri Kuwayama (Hemiptera: Liviidae) on Zanthozylum capense requires further investigation. Our findings provide relevant information for early detection, monitoring and developing biopesticides against the pest.
Highlights
IntroductionEnvironmental, biological (including pests and diseases) and socio-economic factors are major constraints to Kenya’s citrusM
Environmental, biological and socio-economic factors are major constraints to Kenya’s citrusM
African citrus triozid was found in all the orchards whereas the distribution of D. citri, a vector of Asian strain of the citrus greening disease, was limited to elevations up to 1500 m.a.s.l. (Table 1)
Summary
Environmental, biological (including pests and diseases) and socio-economic factors are major constraints to Kenya’s citrusM. Environmental, biological (including pests and diseases) and socio-economic factors are major constraints to Kenya’s citrus. Industry (Kilalo et al 2009), with arthropod pests and diseases as the main challenge, of which the African citrus triozid (ACT) Trioza erytreae Del Guercio (Hemiptera: Triozidae) is the most damaging pest (Ekesi 2012; Khamis et al 2017). The sap-sucking hemipteran pest is native to Africa but has recently invaded Asia and Europe (Cocuzza et al 2017). Yield losses up to 100% have been associated with ACT and African citrus greening disease (ACGD) (van den Berg 1990). Several attempts have been made to prevent the spread of the pest and ACGD, for instance through intensive insecticide applications (Kilalo et al 2009), these have met with little success. One of the reasons for the latter could be the poor knowledge on the seasonal abundance of ACT in East Africa and beyond
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
