ABSTRACT
Studies were conducted in tropical greenhouses to elucidate the role of ultraviolet light (UV) for the orientation and flight behavior of the thrips, Ceratothripoides claratris, an important pest on tomato in the hot and humid tropics of South-East Asia. Four greenhouse types characterized by different combinations of UV absorbing or transmitting plastic films and nets on the roof and sidewalls, respectively, were used in these studies. In choice experiments C. claratris always preferred the environment with higher UV intensity. Furthermore natural thrips populations around the greenhouses were captured during the majority of control dates in lower numbers on sticky traps on the outer sidewalls of greenhouses clad with UV absorbing materials compared to UV transmitting ones. The immigration of thrips into the UV absorbing greenhouses was also impeded, as measured by sticky traps on the inner side walls. UV absorbing plastic roofs showed the most pronounced deterrent effect for thrips movement towards greenhouses, and the UV absorbing net effectively reduced thrips numbers crossing the net barrier into the greenhouse. A simple extension of UV absorbing plastic roof around conventional greenhouses clad with UV transmitting plastic and net reduced thrips capture rates inside the greenhouse up to 77  % when thrips was released at 1 m distance from the net walls. These results are discussed in the context of wavelength dependent insect vision and the dilemma of tropical greenhouse constructions, i.e. physical pest exclusion vs. appropriate ventilation to assure a conducive microclimate for plant growth.

ABSTRACT
The toxicities of 1, 5, 10 and 14 day old residues of azadirachtin (5 and 10 ml/lw), spinosad (2 and 4 ml/lw) and avermectin (2 and 4 ml/lw) on tomato plants was evaluated against foliage-inhabiting life stages of L. sativae Blanchard in air-conditioned rearing rooms and greenhouses in central Thailand (Bangkok). Azadirachtin and spinosad caused no deterrent or ovicidal effects and the hatching rates of eggs were not different from control (water) treatments. Irrespective of applied dosage, avermectin severely reduced egg deposition and affected embryonic development. All three pesticides severely affected the survival of immature stages (i.e. L1, L2 and L3) of L. sativae, with mortality rates up to 100% for fresh (one day old) residues and adult eclosion completely stopped. Spinosad and avermectin had a longer persistency (up to 14 days) both under laboratory and greenhouse conditions compared to azadirachtin, the activity of which decreased significantly with residual age and especially under greenhouse conditions.

ABSTRACT
NeemAzal®-U, a formulation containing 17% azadirachtin developed for soil treatments, was tested in air conditioned laboratories and net greenhouses in Thailand to control Liriomyza sativae Blanchard (Diptera: Agromyzidae) on tomatoes (Lycopersicon esculentum). The substrates of potted tomato plants were drenched with set volumes of neem solutions of altered concentrations. All tested neem concentrations had very low effects on oviposition and egg hatching. Strong systemic effects however were recorded in the larval stages attaining mortalities up to 100% when high dose drenching solutions containing 3 g NeemAzal®-U l–1 water equivalent to 0.5 g l–1 azadirachtin A were implemented. First instar larvae were found to be most susceptible to all dosages tested. Activity of NeemAzal®-U was persistent since application of even seven days before infestation resulted in mortalities extending between 40 to 70%. Leafminer late 3rd instar surviving on treated plants and moving as so called prepupa to pupate in treated soils endured a very high mortality during pupal stage ensuing in few adult emergences even when the lowest NeemAzal®-U concentration of 0.75 g l–1 water was used. The direct effects of soil treatment were elucidated by rearing leafminers on untreated plants but treating the substrate used for pupal development. Significant mortalities were only obtained when soil treatment was performed immediately before prepupa moved to the soil.

ABSTRACT
Thirty-three isolates of entomopathogenic fungi were bioassayed to determine their efficacy against thrips (Ceratothripoides claratris), mealybug (Pseudococcus cryptus) and whitefly (Bemisia tabaci), the most destructive insect pests of tomatoes cultivated in netted greenhouses in Thailand. Most effective fungi against thrips proved to be Paecilomyces fumosoroseus (BCC7058, FWA3 and FWA5), against mealybug Metarhizium anisopliae (KKU2) and against whitefly P. fumosoroseus (FWA3) and Fusarium solani (FWA1). The infection process of the fungi was visualized using a scanning electron microscope. White-rice, brown rice, broken-milled rice, corn and sorghum grains were evaluated for their capability to serve as solid substrate for fungus mass production. Results indicated that white-rice and broken-milled rice accounted for the highest conidial yield. Maximum conidial yield on most of the substrates could be achieved with 10 days incubation time. With most effective isolates from bioassays, pest-infested tomato plants were sprayed in insect screen cages to evaluate the potential as bio-insecticide in on-plant trials and to determine effective dose rates for spray application in greenhouses. The LC50 of P. fumosoroseus (FWA3) against C. claratris and B. tabaci were 9.51×10⁴ conidia/ml and 9.41×10⁴ conidia/ml respectively and the LC50 of M. anisopliae (KKU2) against P. cryptus was 2.35×10⁶ conidia/ml. These two isolates provide high potential as biocontrol agents for IPM approaches for the most important insect pests in tropical greenhouses.

ABSTRACT
Direct and residual toxicity of NeemAzal-T/S (azadirachtin), Success (spinosad), and abamectin was tested against different life stages of sweetpotato whitefly, Bemisia tabaci (Gennadius) (Homoptera:Aleyrodidae),under air-conditioned laboratory conditions and in a tropical net greenhouse. NeemAzal-T/S and abamectin deterred the settling of adults on tomato, Lycopersicon esculentum Mill (Solanaceae), plants and consequently reduced egg deposition. No such effect was detected for Success. All three pesticides influenced egg hatch. Effects of NeemAzal-T/S were significantly altered if applied to different-aged eggs (1, 3, and 5 d old). In contrast,abamectin-treated eggs failed to hatch at any given age class. All three products caused heavy mortality of the three nymphal stages of B.tabaci, with the first in stars being most susceptible. Abamectin-treated nymphs died within 24 h postapplication. In contrast, 100% nymphal mortality with NeemAzal-T/S and Success was reached 6-9 d postapplication. Abamectin caused 100% immature mortality at all residue ages (1, 5, 10, and 15 d)in the laboratory and greenhouse as well. Persistence of Success was comparably high in the laboratory, but in the greenhouse a faster decline of activity was evident by increased egg deposition, egg hatch, and reduced rates of immature mortality. Toxicity of NeemAzal-T/S however gradually declined under greenhouse conditions with time (5 d) postapplication. The findings are discussed within the context of integrated management of whitefly under protected cultivation in the humid tropics.

ABSTRACT
Persistence of neem-based products against sweetpotato whitefly Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) was tested in air conditioned rearing rooms and tropical netted greenhouses (GHs). Two commercial neem products, NeemAzal®-T/S (1% azadirachtin) and NeemAzal®-U (17% azadirachtin), were used. Foliar application, under room conditions at dose-rates of 7 and 10 ml NeemAzal®-T/S, induced an immature mortality of 32 and 44%, respectively, whereas 7 days post-application, under GH conditions, mortality rates declined to 5 and 7%, respectively. This result indicated rapid dissipation of the active ingredients. However, systemic application by soil drenching resulted in more stable eVects under both laboratory and GH conditions. After soil drenching with solutions of 3.0 g NeemAzal®- U until 7-day, immature mortality declined from 88% for the Wrst day to almost half (45%) by day-7 in the GH, and from 90% on Wrst day to 64% by day-7 under laboratory condition. Similar response trends for B. tabaci were obtained for other parameters such as adult colonisation, egg deposition, and egg hatch. The loss of eYciency of the neem products was clearly related to dose-rate, methods of application, and environment (temperature and UV). Soil application is therefore, a convenient approach to achieve high eYciency and persistence with neem products under the conditions in tropical GH environments for whitefly management.

ABSTRACT
Ceratothripoides claratris (Shumsher) is an important pest in the tropics, damaging a wide range of crops. Therefore, the effects of soil-applied neem products on C. claratris were investigated on tomatoes (Lycopersicon esculentum) cultivated under tropical conditions in greenhouses in Thailand. NeemAzal-U (NA-U) soil applications resulted in strong systemic effects against C. claratris on young tomato plants when high azadirachtin (AZA) concentrations (400 mg AZA/L) were repeatedly applied. Different application schedules (every second week, weekly, twice a week) as well as organic matter content of typical growing substrates resulted in no significant influence on thrips control. However, plant age did have an influence. The younger the plants were the stronger were the effects after neem soil treatments. A delayed soil application with AZA resulted in increasing thrips population numbers. Of the different Neem products tested, Thai Neem Oil 111 showed the lowest efficiency compared to NA-U and Thai Neem Pellet 222.

ABSTRACT
We studied the effect of UV-blocked greenhouses made from netting and plastics on the movement and pest status of three important pest of tomatoes: whitefly (Bemisia tabaci), thrips (Ceratothripoides claratris), and aphid (Aphis gossypii). Under UV-blocked greenhouses, fewer whiteflies, aphids, and thrips entered the greenhouse compared with the ones having more UV intensity. Similarly, signifcantly fewer alate aphids and adult B. tabaci/leaf were counted in greenhouses with low UV intensity. Although thrips were the most abundant pest, they also were signifcantly less abundant in greenhouses with lower UV intensity. Consequently, significantly lower levels of leaf infestation were recorded under these greenhouse conditions. During open gates experiments, virus infection levels reached 96 -100% underUVnonblocking greenhouses compared with 6-10% infection levels in greenhouses whereUVirradiation was blocked. In addition, the appearance of virus symptoms was considerably delayed under greenhouses made from the UV-blocking roof material, although the majority of the plants tested positive for the tospovirus, capsicum chlorosis virus (CaCV; AIT isolate). The results are discussed in context of improved management of sucking insect pests of tomatoes inthe humid tropics.

ABSTRACT
Side effects of two azadirachtin formulations [NeemAzal-U (17% azadirachtin) and NeemAzal®-T/S (1% azadirachtin)] and two biorationale pesticides - Success® (Spinosad) and Abamectin (Avermectin) on two endoparasitoids Opius (Opiothorax) chromatomyiae and Neochrysocharis formosa of Liriomyza sativae were investigated under laboratory conditions. The eggs of O. chromatomyiae, and the eggs, larvae and pupae of N.formosa within the host or within the plant/host complex were exposed to NeemAzal, Success and Abamectin at different dose rates. Adult emergence of O. chromatomyiae from parasitized L. sativae in NeemAzal-U (0.75, 1.5, 2.25 and 3 g/l water) drenched soil was only slightly lower than from untreated control hosts. In contrast, adult emergence of unparasitized L. sativae was almost completely inhibited by NeemAzal-U, indicating a high, direct toxicity. Development of O. chromatomyiae within L3 of L. sativae was very much affected from topical applications of NeemAzal®-T/S, Success® and Abamectin at particular dose rates. Spraying of tomato leaves with NeemAzal®-T/S revealed no detrimental effect on the adult emergence of N. formosa developing in mining L2 of L. sativae. This was in contrast to Success® and Abamectin which strongly affected N. formosa adult emergence when applied at different immature developmental stages of N. formosa.

Thrips such as Frankliniella occidentalis and Ceratothripoides claratris (Thysanoptera: Thripidae) are important pests causing high economic damage in a wide range of crops worldwide. Their characteristic life cycle with plant- and soil-dwelling stages, cryptic feeding behaviour, short generation time and high mobility led to a fast development of resistances against insecticides, which makes thrips control very difficult.

The presented studies were carried out in protected vegetable cultivation in temperate zone in Germany and in the tropics in Thailand. Different thrips species, vegetable crops and environmental conditions in general were used to acquire that way a more complex analysis on the potential use of soil-applied neem ingredients in pest control.

To study the systemic effects of active neem ingredients the substrate of bean plants was treated with NeemAzal-U (NA-U) solutions (17% azadirachtin (AZA)). Afterwards the translocation and persistence of AZA, 3-tigloyl-azadirachtol, salanin and nimbin and the effects on F. occidentalis were studied. Residues of the active components from substrates with different contents of organic matter (pure culture substrate (CS), CS-sand mixture) and from various plant parts were quantified by HPLC-MS. The dissipation trend of AZA and 3-tigloyl-azadirachtol was similar within the same substrates. A slower decline of both active ingredients was measured with CS versus CS-sand mixture. The residue analyses from bean plants showed that only small proportions of the initial amount of the active ingredients applied to the substrate were measured in the plant (0.3% – 8.8%). Variable amounts of residues of the active components in relation to plant parts and time of analysis indicated a different translocation pattern of active ingredients. Mortality of F. occidentalis after NA-U soil applications reached up to 95% on CS-sand mixture compared to 86% in CS.

In the second part, the efficacy of soil treatments using AZA in combination with the two different predatory mite species Amblyseius cucumeris (Acari: Phytoseiidae) and Hypoaspis aculeifer (Acari: Laelapidae) to control F. occidentalis was tested. The study also looked at side effects on the antagonists and was conducted in the laboratory and greenhouses using Phaseolus vulgaris. The release of a single predatory mite species resulted in unreliable and varying reductions of thrips numbers. Antagonist combinations improved efficiencies ranging from 54% to 85%. NA-U caused mortalities from 70% to 98% after soil application. A combination of AZA with predatory mites enhanced not only consistency in thrips control but also resulted in efficacies up to 99%. No detrimental effects of NA-U on the survival of both predators were recorded. However, a significant reduction in population development of H. aculeifer was noted.

Moreover, the effects of soil-applied neem products on C. claratris were investigated on Lycopersicon esculentum cultivated under tropical conditions in greenhouses in Thailand. NA-U soil applications demonstrated strong systemic effects against C. claratris. More than 85% mortality on young tomato plants was achieved when high AZA concentrations were repeatedly applied. Different application schedules as well as organic matter content of typical growing substrates resulted in no significant influence on thrips control. However, plant age did have an influence on the outcome. The younger the plants the stronger were the effects after neem soil treatments. A delayed soil application with AZA resulted in increasing thrips populations. Of the different Neem products tested Thai Neem Oil 111 showed the lowest efficiency compared to NA-U and Thai Neem Pellet 222.

Studies on three different neem treatment methods (seed, soil and foliar) and two different commercial neem products (NeemAzal T/S 1% azadirachtin and NeemAzalU 17% azadirachtin) against sweetpotato white fly (WF) Bemisia tabaci Gennadius (Hom., Aleyrodidae) on tomato plants were conducted in cages in air-conditioned cultivation rooms. All three methods of neem treatments resulted in reduced colonization and oviposition. Overall oviposition intensity was significantly reduced (44%) by the treatment of tomato seeds but an even higher reduction (74%) was achieved through soil drenching both with 3.0 g/l NeemAzalU and foliar spraying (82%) with 10 ml/l of NeemAzal TS compared with control treatments. In contrast, soil and foliar treatment increased fecundity per female up to 33% and 32%, respectively, at the highest tested concentrations. Reduced egg hatch could be observed only at high neem concentrations; 62% and 51% of deposited eggs hatched at the highest dose rates of NeemAzalU in case of seed and foliar treatments, respectively; whereas only 43% of deposited eggs hatched in case of foliar treatments at highest dose rates of NeemAzal T/S. Seed (35%), foliar (93%) and soil treatments (91%) caused high mortality rates of immatures and reduced number of hatching adults compared with control plants treated with a blank formulation or water. The mortality among immatures increased in relation to azadirachtin concentrations. Concerning susceptibility of different developmental stages, young larvae were the most sensitive. Foliar treatment was the most effcient, with 100% mortality for all three larval stages at high concentrations (10 ml/l of NeemAzal T/S) compared with 78 - 87% mortality with soil treatment (at 3.0 g/l NeemAzalU). The findings are discussed in the context of integrated control of WF in protected cultivation environments in the humid tropics.