Biological Aspects of Orius similis Zheng Reared on Two Preys at Three Constant Temperatures

Mass-rearing of Orius similis Zheng on two preys,Aphis craccivora Koch and eggs of Corcyra cephalonica Stainton at three constant temperatures(22,26 and 30°C)and 60%±10%RH and 16:8 L/D photoperiod under laboratory conditions was investigated to study the effect of different temperatures and different preys on the biology of O.similis.The highest survival rate(%)of nymphal stages was 81.14%and the longest oviposition period for females(20.6 d)was recorded at 26°C.Also,the highest fecundity of female also recorded at 26°C.The highest rate of nymphal feeding consumption was(122.5 individuals of A.cracivora)also,recorded at 26°C.As well as,the two preys had significant effects on the biological characteristics of O.similis.The highest survival rate for nymphal stage was recorded when O.similis nymphs fed on A.cracivora.Therefore,the longest survival rate was founded in the nymphs which fed on the individuals of A.cracivora.During the nymphal period of O.similis which consumed more individuals of A.cracivora than the eggs of C.cephalonica.These results on the effect of three constant temperatures and two preys on the biology of O.similis will share to improve the rearing of O.similis in biological control agents in China and share to suppress the population of pests in field and greenhouse.

Efficacy of Reduced-Risk Insecticides to Control Flower Thrips in Early-Season Blueberries and Their Effect on <i>Orius insidiosus</i>, a Natural Enemy of Flower Thrips

Flower thrips are one of the key pests in production of southern highbush blueberries (Vaccinium corymbosum L. × V. darrowi Camp). They feed on the reproductive parts of the flower and reduce yield. Very few insecticides are available to manage thrips population. Therefore, it is necessary to evaluate pre-existing and experimental insecticides for their efficacy against thrips. There is also a high demand for reduced-risk insecticides that are less toxic to beneficial insects and the environment. In this study, a number of conventional and reduced-risk insecticides were evaluated against flower thrips on farms in Florida and Georgia and in the laboratory. The best performing insecticides were also evaluated in the laboratory for their effects on Orius insidiosus Say, which is a common thrips’ predator in Florida. Assail 70WP (Acetamiprid) and SpinTor 2SC (Spinosad) were the most promising insecticides in reducing thrips numbers in the field as well as in laboratory experiments. SpinTor 2SC killed all of the thrips in laboratory arenas within 4 hours of application and showed low toxicity toward O. insidiosus. All of the compounds tested performed as well as the conventional pesticide malathion.

Thrips-mediated impacts from transgenic rice expressing Cry1Ab on ecological fitness of non-target predator Orius tantilus(Hemiptera:Anthocoridae)

Various rice lines have been genetically modified with genes from Bacillus thuringiensis（Bt） to continuously produce Bt insecticidal proteins against lepidopteran larvae. The Bt insecticidal protein constantly expresses in the plants to create an opportunity for non-target herbivores to acquire and convey the protein to their predators or parasitoids across trophic levels. This paper evaluates the effects of Bt rice（namely, Kemindao 1（KMD1） and Kemindao 2（KMD2）） expressing Cry1 Ab as compared to its non-Bt control line, Xiushui 11 on non-target predator Orius tantilus（a generalist predatory anthocorid of thrips） under laboratory and field conditions. To measure several biological parameters such as total nymphal duration and fecundity of this bug, it was reared on thrips and pollens of KMD1 and KMD2 as compared to their control under laboratory conditions. By comparison with the control, Bt rice did not significantly affect main life-history characteristics（total nymphal duration, female adult longevity, oviposition period and fecundity） of this anthocorid preying on Bt rice-fed thrips along with Bt rice pollens, except that the fecundity of this predator for KMD1 was distinctly lower as compared with KMD2 or the control. Enzyme-linked immunosorbent assay（ELISA） results showed that no Cry1 Ab protein was detected in this predator fed on thrips or rice pollen from Bt rice but was in Bt rice pollens. With the beat plate, plastic bag and color trap sampling methods, two-year field monitoring of O. tantilus abundance demonstrated that Bt rice had no significant detrimental effects on the population dynamics and seasonal average densities of this predatory anthocorid as compared with the control. Thus, it is suggested that growing our tested Bt rice（KMD1 and KMD2） producing Cry1 Ab will pose a negligible risk to the anthocorid, O. tantilus.

Eggs of Ephestia kuehniella and Ceratitis capitata, and motile stages of the astigmatid mites Tyrophagus putrescentiae and Carpoglyphus lactis as factitious foods for Orius spp.

Several factitious foods were assessed for rearing the anthocorid predators Orius thripoborus （Hesse） and Orius naivashae （Poppius） （Hemiptera： Anthocoridae） in the laboratory. Developmental and reproductive traits of both Orius species were examined when offered frozen eggs of the Mediterranean flour moth, Ephestia kuehniella Zeller, frozen processed eggs of the medfly, Ceratitis capitata Wiedemann, or mixed motile stages of the astigmatid mites Tyrophagusputrescentiae （Schrank） or Carpoglyphus lactis （L）. Whereas C. lactis and T. putresecentiae proved to be an inferior food for rearing O. thripoborus and O. naivashae, eggs of C. capitata fully supported development and reproduction of both predators. Results on medfly eggs were similar or slightly inferior to those on E. kuehniella eggs, which is the standard food for culturing these anthocorid bugs. O. thripoborus could be maintained for 4 consecutive generations on C. capitata eggs indicating that processed medfly eggs can be a suitable and cheaper alternative to E. kuehniella eggs for prolonged rearing of these Orius spp.

南方小花蝽控制害虫的研究现状

南方小花蝽(Orius similis Zheng)是农田生态系统中一类重要的捕食性天敌昆虫,利用其对害虫进行有效控制是当前生物防治的研究热点。本文综述了南方小花蝽控制能力及影响其控制能力的因素,并提出了提高南方小花蝽控制效果的方法,以期为小型害虫的生物防治提供参考。

吡虫啉对烟田东亚小花蝽的安全性评价

为了评估吡虫啉对烟田东亚小花蝽(Orius sauteri)的安全性,采用药膜法测定了吡虫啉对东亚小花蝽成虫和若虫的急性接触毒性,并通过计算农田内危险商值(HQ),评价了烟田喷施吡虫啉对东亚小花蝽的安全性。结果表明,吡虫啉对东亚小花蝽一龄至五龄若虫和雌雄成虫的致死中浓度分别为0.5877、1.7421、2.4335、4.4011、4.5278、6.0872、2.9424 mg(a.i.)/L。吡虫啉在烟田最大推荐剂量[45 g(a.i.)/hm^(2)]下喷施1次,对东亚小花蝽成虫和三龄至五龄若虫的HQ<5,风险可以接受;对东亚小花蝽一龄和二龄若虫的HQ>5,风险不可以接受。吡虫啉在最大推荐剂量[45 g(a.i.)/hm^(2)]下喷施2次,对东亚小花蝽成虫和四龄若虫、五龄若虫的HQ<5,风险可以接受;对东亚小花蝽一龄至三龄若虫的HQ>5,风险不可以接受。吡虫啉最大推荐剂量对东亚小花蝽卵孵化的抑制率为36.42%,风险可以接受。因此,吡虫啉和东亚小花蝽联合使用控制害虫时要避开东亚小花蝽低龄若虫(三龄以前)高峰期喷施。

Arthropods associated with medicinal plants in coastal South Carolina

Arthropods were sampled from feverfew [Tanacetum parthenium （L.） Schultz- Bip], Echinacea purpurea （L.） Moench, Echinacea pallida （Nutt.） Nutt., Valeriana officinalis L., and St. John＇s wort （Hypericum perforatum L.） during 1998-2001. In addition, arthropods were sampled on tansy （Tanacetum vulgare L.） from 2001-2004. In general, 50-60 arthropod species where collected and identified among all of the medicinal plant species. Among the predators, Orius insidiosus （Say） （Hemiptera： Anthocoridae）, Geocoris punctipes （Say） （Hemiptera： Lygaeidae） and spiders were most abundant from 1998-2004. The three-cornered alfalfa hopper, Spissistilus festinus （Say）, was the most abundant herbivore found from 1998 to 2001. Orius insidiosus and G. punctipes were 3-4 times more abundant on T. parthenium than on any other medicinal plant species. Based on the numbers of predatory arthropods found on T. parthenium, this crop could be suitable as a companion or ＂banker＂ plant to attract and maintain populations of predators, especially O. insidiosus and G. punctipes. Whitefly nymphs attacked by predators with piercing/sucking mouthparts are easily identified using a microscope because of the general appearance of the carcass left by the predators. Thus, populations of predators on T. parthenium suppressed Bemisia tabaci populations on E. purpurea when these crops were planted as companion crops.

Compatibility of early natural enemy introductions in commercial pepper and tomato greenhouses with repeated pesticide applications

Successful integrated pest management in protected crops implies an evalu-ation of the compatibility of pesticides and natural enemies(NE),as control strategies that only rely on one tactic can fail when pest populations exceed NE activity or pests become resistant to pesticides.Nowadays in Almeria(Spain),growers release NE prior to transplanting or early in the crop cycle to favor their settlement before pest arrival because this improves biocontrol efficacy,although it extends pesticide exposure periods.The pur-pose of this research was to evaluate the compatibility of two applications of pesticides with key NE in 2-year trials inside tomato and sweet pepper commercial greenhouses:Nesidiocoris tenuis(Reuter)(Hemiptera:Miridae),Orius laevigatus(Say)(Hemiptera:Anthocoridae)and Amblyseius swirskii(Athias-Henriot)(Acari:Phytoseidac).In tomato,flubendiamide and chlorantraniliprole(IOBC category 1)were compatible with N.tenuis,but chlorpyrifos.:methyl and spinosad(IOBC categories 2-3),which efectively reduced Tiuta absoluta(Meyrick)(Lepidoptera:Gelechidae)density,compromised its predatory activity.In sweet pepper,chlorantraniliprole(IOBC category 1)was the only pesticide compatible with O.laevigatus while chlorantraniliprole,emamectin benzoate,spirote-tramat and pymetrozine were harmless(IOBC category 1)to Amblyseius swirskii,and sulfoxaflor slightly harmful(IOBC category 2)to this phytoseiid predator.