Kairomone and Camera Trapping New Zealand Flower Thrips, Thrips obscuratus

This project investigated how kairomone lures, camera traps, and counting software could together contribute to pest management. Images of cumulative daily catch of New Zealand Flower Thrips (NZFT) attracted to a ripe peach lactone (6-pentyl-2H-pyran-2-one; 6-PAP) were automatically loaded to the internet and compared with scanned bases checked weekly using in-house software and manual counting. Camera traps were able to provide thrips counts equivalent to delta traps, but daily and remotely. An 11-fold greater NZFT count occurred within 24 h in passive traps after polyethylene sachets loaded with 250 mg of 6-PAP were placed in trees. Intensive trapping, by placing 1, 2, 4, and 8 traps per tree (500 mg/trap), resulted in a maximum 32-fold increase in thrips per tree. While 6-PAP has proved to be a useful tool for monitoring NZFT numbers, our results suggest that it is not likely to be suitable for mass trapping. Future research should investigate NZFT behavior to better understand population movement on an area-wide basis. Camera traps can be a valuable tool for recording insect flight activity remotely, but the number of traps required for statistically reliable estimates may be prohibitive.

Postharvest management of New Zealand flower thrips on export apricots using ethyl formate

New Zealand flower thrips (NZFT Thrips obscuratus) is the most abundant pest on New Zealand apricots at harvest and is a quarantine pest for apricot export markets Ethyl formate (EF) is a Generally Recognised As Safe (GRAS) compound being investigated treatments against NZFT and their impact on apricot fruit quality in shipping containers NZFT adults and larvae on apricots were treated in field bins of apricots in a 282 m3 in Hawkes Bay and Central Otago respectively In Hawkes Bay the treatments resulted in 100 mortality of NZFT adults and larvae In Central Otago the treatments resulted in 100 mortality of NZFT adults and 98100 larval mortality Export grade apricot cultivars expressed no adverse effects on quality to this concentration of EFCO2

Monitoring and manipulation of New Zealand flower thrips (Thrips obscuratus) in summerfruit orchards

New Zealand flower thrips (NZFT) are a pest in New Zealand stone fruit orchards In this study NZFT density was manipulated in the field using a known kairomone It was discovered that the addition of the kairomone to any given tree within an orchard increased NZFT density in direct proportion to the amount of kairomone used It was also found that delta traps baited with kairomone must be within 15 m from each other before trap competition occurs indicating a high density of traps is required for mass trapping Daily monitoring of NZFT catch using selfreporting camera trap technology in a Clyde orchard revealed that despite large daily variation in NZFT catch the population displayed a linear growth trend This indicates that NZFT establishment in Central Otago cannot be explained by the sudden arrival of windborne adults as previously thought These results indicate that it may be possible to manipulate NZFT density within an orchard in such a way that the majority of fruiting trees are protected by trap trees during harvest

Postharvest management of New Zealand flower thrips (Thrips obscuratus) on apricots using ethyl formate or pyrethrumbased treatments

New Zealand flower thrips (NZFT Thrips obscuratus (Crawford)) were exposed to a range of ethyl formate (EF) and pyrethrumbased postharvest treatments on apricots Research showed that EFCO2 or EFN2 were effective treatments against NZFT and caused negligible damage to apricot fruit quality However pyrethrum dipping did not effectively control NZFT and caused significant internal damage to apricot fruit Lethal concentration (LC99) estimates were developed for adult and larval NZFT using a range of EF concentrations (0127 EFCO2) and temperatures (5 15 and 25C) It is estimated that treatments of 1 (307 g/m3) EF at 5 or 25C or a higher concentration of 15 (463 g/m3) at 15C will achieve 99 mortality of NZFT adults and larvae on apricot fruit with 95 confidence

Seasonal variation in the lower thermotolerance of adult New Zealand flower thrips Thrips obscuratus (Crawford)

The ability of New Zealand flower thrips (NZFT) to tolerate cold temperatures was investigated Thrips were collected from a range of natural sources in Central Otago over 2 years Some adult NZFT (predominantly females) survived for up to 2 months on peach fruit at 01C; LT 50 354 days and LT 99 707 days Plant material containing NZFT was exposed for 24 h to 10 75 5 25 and 0C and NZFT mortality measured Irrespective of the time of year when NZFT were collected mortality was similar after 24 h at 25C to that at 0C (means 46 47) but increased with decreasing temperature (mean mortality 225 at 5C 663 at 75C and 820 at 10C) From 75C downwards responses to changes in temperature varied between seasons (P

Field response of onion thrips and New Zealand flower thrips to single and binary blends of thrips lures

Tests were performed to determine whether combining two thrips lures, ethyl nicotinate (EN) and ethyl isonicotinate (EI), in the same water trap increased the numbers of New Zealand flower thrips (NZFT), Thrips obscuratus Crawford, and onion thrips, T. tabaci Lindeman (Thysanoptera: Terebrantia: Thripidae), caught in the field relative to traps with a single lure. Traps with both lures (1:1 ratio; mixture or separate adjacent vials) caught 5–9 times more female onion thrips (thelyotokous populations are the most prevalent in New Zealand) than traps with EN only (P<0.001), but in similar numbers to traps with EI only. Traps with both lures caught 2–3 times as many male and female NZFT than traps with EI only, but in similar numbers to traps with EN only. Thus, a combination of the two lures in one trap could be used to detect and monitor flying onion thrips and NZFT simultaneously.