Abundance and distribution of thrips (Thysanoptera: Thripidae) in mangosteen (Garcinia mangostana L.) grown in single- and mixed-cropping systems

Abstract

We investigated the abundance and distribution of thrips in a farmer’s mangosteen orchard by comparing single- andmixed-cropping systems at Nakhon Sri Thammarat province, the main planting area in southern Thailand, between April2005 and January 2006. A monitoring program at two-week-intervals was done to measure the number of thrips by usingtwenty yellow sticky traps per each cropping system. The mean number (223.5±23.4 thrips/trap) of thrips throughout theperiod of study in the monocrop mangosteen sites was significantly (P<0.01) higher than 69.1±8.3 thrips/trap in the mixedcropmangosteen sites. Scarring on the fruit surfaces damaged by thrips was visually quantified, with average percentages ofscarring 32.2% and 19.8% in the mono- and mixed-cropping systems, respectively. Distribution of thrips in the upper andlower halves of the plant canopy in the four cardinal directions was studied by assessing scarring on the fruit surfaces. Thepercentage of scarring occurring in the upper canopy was significantly (P<0.01) higher than in the lower canopy. In thesingle-crop system, the average percentages of scarring were 46.6% and 25.4% on the upper and lower canopies, respectively.In the mixed-cropping system results obtained were similar to those in the single cropping system, with 31.5% and 20.4% onthe upper and lower canopies, respectively. The severity of damage to the fruits caused by thrips seemed to be higher in theNorth and East directions than in the South and West. In conclusion, mixed-cropping mangosteen orchards are recommendedfor reducing fruit damage caused by thrips. Fruits occurring on the upper canopy, in the North and East sides, should beunderlined for thrip control to meet the criteria for high quality mangosteen production from the south of Thailand.

Keywords

• mangosteen
• thrips
• abundance
• distribution
• single-and mixed-cropping systems