Repellent effect of guava leaf volatiles on settlement of adults of citrus psylla, Diaphorina citri Kuwayama, on citrus

• Published in: Insect science Vol. 17; no. 1; pp. 39 - 45
• Main Authors: Zaka, Syed Muhammad, Zeng, Xin-Nian, Holford, Paul, Beattie, George Andrew Charles
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Blackwell Publishing Asia 01.02.2010
• Subjects: Asiatic citrus psyllid; Citrus; Diaphorina citri; Hemiptera; huanglongbing (HLB); insect behavior; Kuwayama; Psidium guajava; Psyllidae; volatile compounds; 挥发物; 柑桔木虱; 柑橘木虱; 番石榴叶; 驱避作用
• ISSN: 1672-9609; 1744-7917
• DOI: 10.1111/j.1744-7917.2009.01271.x

The Asiatic citrus psyllid （Diaphorina cirri Kuwayama [Hemiptera： Sternorrhyncha： Psyllidae] is a vector ofhuanglongbing （citrus greening）, a devastating disease of citrus caused by phloem-limited bacteria. Growing guava （Psidium guajava） as an intercrop appears to be a successful means of reducing psyllid numbers within citrus orchards; however, the mechanism by which such a reduction is achieved is unknown. To determine the repellent effect of guava leaf and factors attributed to this activity, responses of adult psyllids to guava leaf and its odor were evaluated in cage tests and Y-tube olfactometer test. The results showed that guava leaf possessed a repellent effect against the adult citrus psyllids. Fewer psyllids were found on citrus leaves in the presence of guava foliage than in its absence. Young and old guava leaf showed equal repellent activity. By covering the guava shoots with net cloth, it was revealed that the repellent effect of guava leaf against adult psyllids on citrus was attributed to the volatile compounds, rather than physical factors. The olfactometer response of adult psyllids to guava leaf odor was dosage-dependent. Between guava odor and control, only 35.00%, 25.00% and 16.25% of the psyllids moved toward guava odor when presented with 5.0, 10.0 and 15.0 g of guava shoots, respectively. The olfactometer experiments also showed that both male and female psyllids responded similarly to the guava leaf odor.