Extended holding period and yeast hydrolysate in pre-release diet increase abundance of mature sterile Queensland fruit fly males in the field

Journal of Pest Science - Queensland fruit fly (Q-fly), Bactrocera tryoni (Froggatt), is a significant pest of horticultural crops in Australia. The sterile insect technique (SIT) is currently...     

Sterile insect technique and <Emphasis Type="Italic">Wolbachia</Emphasis> symbiosis as potential tools for the control of the invasive species <Emphasis Type="Italic">Drosophila suzukii</Emphasis>

Drosophila suzukii, a vinegar fly originated from Southeast Asia, has recently invaded western countries, and it has been recognized as an important threat of a wide variety of several commercial soft fruits. This review summarizes the current information about the biology and dispersal of D. suzukii and discusses the current status and prospects of control methods for the management of this pest. We highlight current knowledge and ongoing research on innovative environmental-friendly control methods with emphasis on the sterile insect technique (SIT) and the incompatible insect technique (IIT). SIT has been successfully used for the containment, suppression or even eradication of populations of insect pests. IIT has been proposed as a stand-alone tool or in conjunction with SIT for insect pest control. The principles of SIT and IIT are reviewed, and the potential value of each approach in the management of D. suzukii is analyzed. We thoroughly address the challenges of SIT and IIT, and we propose the use of SIT as a component of an area-wide integrated pest management approach to suppress D. suzukii populations. As a contingency plan, we suggest a promising alternative avenue through the combination of these two techniques, SIT/IIT, which has been developed and is currently being tested in open-field trials against Aedes mosquito populations. All the potential limiting factors that may render these methods ineffective, as well as the requirements that need to be fulfilled before their application, are discussed.     

Pre-exposure to sex pheromone did not affect mating behavior in the sweetpotato weevil <Emphasis Type="Italic">Cylas formicarius</Emphasis>

In sterile insect technique (SIT) programs, the released sterile males are important for their effectiveness. The use of sex pheromones to collect males is economical; however, pre-exposure to sex pheromones may affect male mating behavior, and would thus reduce the effectiveness of the SIT programs. Males exposed to sex pheromone may become attractive to other males due to pheromone adsorption on their body impregnation, prevent mating and reduce the dispersal of sterile males. We examined the effect of pre-exposure to sex pheromone on the mating behavior of male sweetpotato weevil Cylas formicarius. Pre-exposure to high-dose sex pheromone for 24 h did not affect the male mating behavior of C. formicarius, and the exposed males did not attract other males. These results suggest that male C. formicarius that were collected from a mass-rearing facility using sex pheromone can be effectively used in SIT programs.     

Description of the irradiated and nonirradiated midgut of <Emphasis Type="Italic">Ceratitis capitata</Emphasis> Wiedemann (Diptera: Tephritidae) and <Emphasis Type="Italic">Anastrepha ludens</Emphasis> Loew (Diptera: Tephritidae) used for sterile insect technique

Midguts from adult sterile male Ceratitis capitata Wiedemann and Anastrepha ludens Loew, the Mediterranean fruit fly and Mexican fruit fly, respectively, were examined microscopically to determine if radiation used in sterile insect technique (SIT) affected this non target tissue and/or the microorganisms associated with the midgut. Scanning and transmission electron microscopy were used to compare midgut tissues and microorganisms from irradiated and nonirradiated mass-reared adult flies. Observations for both fruit fly species were similar. Our comparisons revealed that newly emerged and two-day-old irradiated flies exhibited signs of damage to midgut tissue, cellular organelles, and gut microbiota not observed in nonirradiated flies of the same ages. Peritrophic membrane formation and bacterial growth appeared diminished in the midguts of irradiated flies compared to nonirradiated flies. Cellular damage of midgut tissue from irradiated flies included distorted, small nuclei that lacked nuclear material, and mitochondria that were dilated and/or vacuolated. No visual evidence of cellular damage was observed in nonirradiated flies. The impact of radiation used in SIT on fly competitiveness, referred to herein as the capability of adult flies to perform a function, is discussed, including the potential use of probiotic diets to improve damaged midgut tissue and restore midgut microbiota.     

Genetic analysis of medfly populations in an area of sterile insect technique applications

Journal of Pest Science - The sterile insect technique (SIT) is widely used in integrated pest management programs for the control of the Mediterranean fruit fly (medfly), Ceratitis capitata. The...     

Ruminal Fermentation and Nutrient Digestion in West African Dwarf (WAD) Sheep Fed Leucaena leucocephala Supplemental Diets

Dry season feeding has always posed a problem for ruminant nutrition in sub-Saharan Africa. The availability of browse plants or multi-purpose trees during this period has led to their incorporation in the farming systems. The need therefore to investigate the feeding value and fermentation profiles of WAD sheep fed grass hay with supplemental Leucaena leucocephala formed the objective of this study. Eight 18–24 months old West African Dwarf (WAD) sheep (28.8±4.2 kg body weight) were used in the study. Four of the sheep were fistulated ruminally and rumen pH, ammonia and volatile fatty acid were measured. Dried leaves of L. leucocephala were offered at two levels (25 and 50% of DMI, diets D25% and D50%, respectively) as supplement to a basal hay diet. The basal hay diet without supplement was the control diet. Diet D25% had a higher (p <0.05) ruminal ammonia concentration than the control, while diet D50% had a higher (p <0.05) total volatile fatty acid (VFA) concentration compared to both the control and D25% diets, respectively. Diet D25% had a marginal increase of 6.7% N- retention over the control diet. Organic matter digestibility (OMD) decreased (p <0.05) with level of supplementation. Animals on D50%, D25% and the control diets lost 14, 7.3 and 5%, respectively, of retained energy leading to a negative energy balance. Overall results suggest that a 25% level of supplementation with leucaena gave the best outcome even though a range of 25–50% could be fed during periods of basal diet scarcity.     

Comparative performance of the red flour beetle Tribolium castaneum (Coleoptera: Tenebrionidae) on different plant diets

Tribolium castaneum is a pest of stored foods that causes serious economic losses. Understanding insect nutritional requirements and the effects of different diets on insect development can provide tools for developing strategies to control insect and integrated pest management systems. In this work we studied the performance of the T. castaneum on different plant diets composed of Vigna unguiculata, Phaseolus vulgaris and wheat flours. The diets interfered differentially with development and insect survival. Larvae size was reduced about 60 % in larvae fed with V. unguiculata flour. A delay in pupae formation was also observed. The larval mortality of 100 % was observed in the P. vulgaris diet. Carbohydrate and triglyceride showed variations during development and with different diets. Larvae fed with wheat diets showed a high concentration of carbohydrates 21 days after hatching (DAH) and triglyceride at 15 and 21 DAH. Larvae fed with wheat diets showed α-amylase activity during development. At 15 DAH the activity of larvae fed with V. unguiculata increased about 50 %. Cysteine protease activity in larvae fed with wheat remained high throughout development. Serine protease activity also varied according to diets. These results show that the nutritional state of developing larvae varies greatly with respect to triglycerides, carbohydrate and digestive enzymes depending on the diet and larval stage. Altogether, these results show that changes in dietary nutrients can interfere with insect physiology. Therefore changes in diet composition that may deprive insects of essential nutrients or include toxic compounds might be a good control strategy for stored product pests.     

Potential impact of prickly pear cactus flour and <Emphasis Type="Italic">Salix babylonica</Emphasis> extract on cecal fermentation and methane production in horses

The cecal gas (GP) and methane (CH₄) production and cecal fermentation kinetics when corn grain (CG) was replaced with prickly cactus (PC) in a horse’s diet at different levels of Salix babylonica (SB) extract was investigated. Three total mixed rations where CG was replaced with PC at three levels (/kg): 0 g (Control), 75 g (PC75) or 150 g (PC150) were prepared and SB extract added at four levels: 0, 0.6, 1.2 and 1.8 mL/g dry matter (DM) of substrates. No ration type × SB extract dose interaction was observed (P > 0.05) for GP kinetics and CH₄ production. Increasing the level of PC in the ration quadratically increased (P < 0.01) the asymptotic GP and decreased (P < 0.01) the rate and lag time of GP. Increasing the level of PC in the ration, increased GP values (P < 0.05). Increasing the level of SB extract linearly decreased (P = 0.001) the lag time of GP of all diets without affecting the asymptotic GP or the rate of GP. Ration type and SB level had no effect (P > 0.05) on CH₄ production; however, at 36 h of incubation, SB extract decreased CH₄ production. The rations PC75 and PC150 increased cecal pH compared with the control ration. The PC150 ration had the highest (P < 0.05) DM degradability, short chain fatty acids production, and gas yield after 24 h of incubation, with no effect (P > 0.05) of SB inclusion on all investigated fermentation kinetic parameters. It is concluded that increasing the level of PC in the diet of horse and replacing CG up to 60%, increased GP and improved cecal fermentation kinetics without affecting CH₄ production. Inclusion of S. babylonica extract in the tested rations had weak effects on fermentation kinetics although it decreased the lag time of GP.     

昆虫人工饲料配方研究概况及问题探讨

昆虫人工饲料是昆虫学研究的基本技术。100多年来，在饲料配方的改良、廉价成型剂的筛选、防腐剂和抗菌素的筛选、叶粉的添加效果、刺激和抑制取食物质、人工饲料的含水率和酸碱度等方面均取得了重要的进展。本文简述了昆虫人工饲料研究所取得的进展，分析了当前昆虫人工饲料中存在的问题，并提出了人工饲料的前景和发展方向。     

响应面法优化森吉木霉M75菌株发酵培养条件

目的 利用响应面法优化森吉木霉M75菌株的液体发酵培养条件,使其无菌滤液拮抗松枯梢病病原菌松球壳孢菌的抑菌活性得到有效提高,获得森吉木霉M75高效抑菌的发酵培养基配方。 方法 采用Plackett-Burman试验设计、最陡爬坡试验,结合响应面设计法优化森吉木霉M75的发酵培养基,采用Design Expert 11.0软件对试验数据进行处理分析。 结果 得到了培养基配方中对森吉木霉M75发酵滤液抑菌活性影响最显著的3个主要因素：葡萄糖、温度和转速,同时得到了最佳发酵培养浓度为：葡萄糖2.75%,胰蛋白胨1.2%,硫酸锌0.2%,马铃薯浸汁1 000 mL,温度31.0 ℃、转速195 r·min−1,接种量5%,装液量180 mL,发酵培养5 d。 结论 获得了在实验室条件下森吉木霉M75菌株高效抑菌的发酵培养基配方和培养条件,为森吉木霉菌株后续的研究提供了有效依据。     

Sexual communication and related behaviours in Tephritidae: current knowledge and potential applications for Integrated Pest Management

Tephritidae are an enormous threat to fruit and vegetable production throughout the world, causing both quantitative and qualitative losses. Investigating mating sequences could help to unravel mate choice dynamics, adding useful information to improve behaviour-based control strategies. We review current knowledge about sexual communication and related behaviours in Tephritidae, with a focus on six key agricultural pests: Anastrepha ludens, Bactrocera cucurbitae, Bactrocera dorsalis, Bactrocera oleae, Ceratitis capitata and Rhagoletis pomonella. We examine features and the role of male–male combat in lekking sites, cues affecting mating dynamics, and some fitness-promoting female behaviours that occur at oviposition sites [the use of oviposition marking pheromones (OMPs) and female–female fights for single oviposition sites]. We outline future perspectives and potential contributions of knowledge about sexual communication to Integrated Pest Management programs for tephritid pests. Sexually selected traits are frequently good indicators of male fitness and knowledge of sexual selection processes may contribute to the improvement of the sterile insect technique (SIT), to select genotypes with high reproductive success and to promote sexually selected phenotypes through mass-rearing optimization. Furthermore, males’ exposure to parapheromones, such as phenyl propanoids (PPs), ginger root oil and trimedlure can enhance the mating success of sterile flies used in SIT programs. PPs are also a powerful tool to improve reduced-risk monitoring dispensers and the male annihilation technique, with low side effects on non-target insects. Lastly, we outline the possibility to sensitise or train mass-reared parasitoids on OMPs during the pre-release phase, in order to improve their post-release performance in the field.     

Performance of pre-commercial release formulations of spinosad against five stored-product insect species on four stored commodities

Two liquid and one dry pre-commercial release spinosad formulations were evaluated at the labeled rate of 1?ppm against five stored-grain insect species on wheat, short-grain rice, long-grain rice, and maize. Except on maize, efficacy of spinosad was compared with a currently registered grain protectant, chlorpyrifos-methyl (3?ppm) plus deltamethrin (0.5?ppm). The 7- and 14-day mortalities of the lesser grain borer, Rhyzopertha dominica, were 99.0-100.0% on spinosad and chlorpyrifos-methyl plus deltamethrin-treated wheat, short-grain rice, and long-grain rice. Adult progeny of R. dominica after 42?days on these commodities decreased by 99.7-100.0% relative to progeny production on untreated wheat. Mortality and reduction in adult progeny of the rice weevil, Sitophilus oryzae, on the three commodities, and that of the maize weevil, Sitophilus zeamais, on maize and the red flour beetle, Tribolium castaneum, on wheat were 100.0% only with chlorpyrifos-methyl plus deltamethrin. The liquid spinosad formulations were most effective against the Indianmeal moth, Plodia interpunctella, on maize and wheat. Except for R. dominica, the effectiveness of spinosad on the other species varied with the formulation, exposure time, and commodity. Chlorpyrifos-methyl plus deltamethrin was effective against insect species on the commodities tested.     

Stable isotopes for reliable identification of wild and mass-reared Queensland fruit flies in sterile insect technique programs

Journal of Pest Science - Queensland fruit fly is one of the most economically important horticultural pests in Australia. Sterile insect technique (SIT) is now being reconsidered and upscaled to...     

邓恩桉茎段组织培养试验初探

采集邓恩桉茎段进行组织培养。试验结果表明:半木质化或刚木质化的茎段用浓度为0.1%Hgcl2消毒6min,用无菌水冲洗3～4次,再用Hgcl2消毒2 min效果最好,杀伤率低,获得率高达67.5%;芽分化及增殖培养基用改良MS+3%糖+3%的琼脂+VC0.01 mg∕L+VB20.015 mg∕L+BA0.5 mg/L+NAA0.25 mg/L,增殖系数达4倍,芽生长正常,不产生"玻璃化"苗;在IBA0.5 mg/L+ABT0.25 mg/L及IBA0.5 mg/L+NAA0.5 mg/L两种激素组合对邓恩桉不定根诱导有一点作用,但效果不理想,生根率只有20%,愈伤头大,上杯不容易成活。     

筋骨草内昆虫蜕皮激素类似物对杨干象的杀虫作用

从不同地点、不同时间采集的多花筋骨草植株不同部位中提取出昆虫蜕皮激素类似物,通过向幼虫人工饲料中添加昆虫蜕皮激素类似物的方法,研究了筋骨草中植物源蜕皮激素对杨干象2龄幼虫的杀虫作用。实验结果表明:(1)在人工饲料中加入1-3 ml的筋骨草提取物,在24天内可以杀死 58%~100%的幼虫;(2)从开花前的筋骨草中提取出的物质的杀虫效果明显优于从花期和开花后的植物中提取出的物质的杀虫作用, 其1 mL、2 mL和3 mL剂量全株提取物的杀虫效果分别达到65.22%、85.07%和98.11%(幼虫校正死亡率);(3)植株的根部提取的昆虫蜕皮激素类似物的杀虫效果要比茎部或叶部提取的好,1 mL、2 mL、3 mL剂量提取物的杀虫效果分别达到100%、98.20%和98.32%;(4)筋骨草提取物的杀虫速度较慢,处理杨干象2龄幼虫16天后杀虫率才超过50%;(5)幼虫取食加有筋骨草提取物的饲料时间长短直接影响幼虫死亡率,16天的取食,幼虫死亡率达到80%以上。筋骨草采集地点和填加植物源蜕皮激素的方式对杀虫效果的影响较小。图3表3参21。     

Effect of adult nutrition and insect density on the performance of spotted stem borer, <Emphasis Type="Italic">Chilo partellus</Emphasis> in laboratory cultures

The spotted stem borer, Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) is being successfully reared on artificial diets for screening programmes. Besides quality characteristics of the diet, rearing density and adult nutrition have significant implications on the successful mass multiplication of lepidopterans. The performance of C. partellus moths was assessed on different adult diets (water and sugar solution) and compared with unfed adults. Further, three pairing densities, viz. 2, 5 and 8 pairs/oviposition jar (1177.5 cm³) were compared for their effect on C. partellus longevity and fecundity. In another experiment, different larval densities (100, 150 and 200 neonate larvae/diet jar) were evaluated for their effect on the larval survival. Water-fed moths (both males and females) lived longer (7.32 and 7.26 days, respectively) and showed higher fecundity (307.17 eggs) than the sugar-fed or unfed moths. The latter, however, showed better egg hatchability (76.55%) than the water- or sugar-fed moths (60.45 and 50.59%, respectively). The longevity (5.67 days) and fecundity (258.46 eggs) were significantly greater at pairing density of 2 pairs/jar. The larval survival was higher (58.50%) at rearing density of 100 larvae/jar. The neonate larval release into diet jars was compared with conventional egg release and both modes were no different with respect to larval survival.     

Nutritional requirements for larval development of the dry wood borer <Emphasis Type="Italic">Trichoferus holosericeus</Emphasis> (Rossi) in laboratory cultures

Despite the dangerousness of the dry wood-boring beetle Trichoferus holosericeus (Rossi) (=Hesperophanes cinereus (Villiers)) (Coleoptera: Cerambycidae), little is known about its biological and nutritional requirements. The aim of this research was therefore to investigate into the dietary preferences of this insect, in order to determine if carbohydrates can be considered as its main nutritional source, to clarify whether this cerambycid is specialised on hardwoods and finally to select a suitable diet for laboratory cultures. Different substrates were tested and the decay grade, as well as the survival of larvae, was recorded after 3 and 6 months. Chemical analyses were also carried out on excrements, residues of wood after larvae excavation and sound wood. Results indicated that T. holosericeus fed mainly on glucose and peptone added to an artificial diet, while on natural wood it preferred structural carbohydrates constituting the hemicelluloses and the non-crystalline cellulose. Furthermore, Scots pine sapwood had no toxic effect to the beetle. In terms of number and dimensions of emerged larvae, the artificial diet resulted to be the most suitable substrate for laboratory cultures of T. holosericeus among those tested.     

园林废弃物木质素降解真菌的筛选、鉴别及其能力研究

目的 为获得能够高效降解园林废弃物的真菌并研究其降解能力,从经过堆肥处理的园林废弃物中分离和筛选出1株木质素降解能力较强的真菌。 方法 经过形态分析、ITS分子序列分析,构建系统发育树,鉴定出该株木质素降解真菌种属,并利用该菌株进行固态发酵实验,研究其在固态发酵过程中漆酶、锰过氧化物酶的酶活力变化及其对不同园林废弃物中木质素的降解能力。 结果 从经过堆肥处理的园林废弃物中共挑选出真菌18株,筛选出1株高效的木质素降解真菌,编号为菌株No.11,经鉴定该菌株为构巢曲霉（Aspergillus nidulans（Eidam）G.Winter）。以冬青卫矛叶、冬青卫矛枝、圆柏叶、圆柏枝、连翘枝叶为底物的模拟固态发酵的漆酶酶活力峰值分别为388.7、326.3、461.4、342.7、588.5 U·L-1,锰过氧化物酶酶活力峰值分别为138.3、121.1、104.6、128.6、73.3 U·L-1。添加菌株No.11使冬青卫矛叶、冬青卫矛枝、圆柏叶、圆柏枝、连翘枝叶40 d后木质素降解率分别提高了20.40%、22.44%、29.90%、25.28%、15.77%。 结论 筛选出的构巢曲霉对北京地区常见园林废弃物冬青卫矛、圆柏和连翘枝叶中的木质素具有较好的降解能力,在降解园林废弃物方面可能更具有优势。     

黄斑星天牛人工饲料研究

本文对6种人工饲料的配方作了详细比较、分析和讨论,找出了用于饲养黄斑星天牛幼虫的饲料最佳配方,其主要成分是干酪素、纤维素、蔗糖、黄豆粉;利用此种饲料饲养,黄斑星天牛幼虫期缩短、存活率达86.2％,蛹重增加,产卵量提高,寿命延长;试脸还表明,不同成分的饲料不仅影响幼虫存活率和生长发育,而且还明显影响其物质与能量代谢活动。     

Changes in water status and proline and abscisic acid concentrations in developing somatic embryos of pedunculate oak (Quercus robur) during maturation and germination

Somatic embryos of oak (Quercus robur L.) were matured on P24 media differing in gel strength (0.8, 0.9 and 1.0% (w/v) agar). Viscosity and osmotic potential (Psipi,medium) of the media were determined. Developing cotyledonary embryos were analyzed at maturity Stages I-III for water content, osmotic potential (Psipi,embryo) and concentrations of abscisic acid (ABA) and proline. Proliferation of embryogenic tissue, germination rates and the number of embryos formed were also determined in order to relate embryo quality to physiological parameters. Viscosity increased with agar concentration, a phenomenon apparently related to water availability. Many Stage III embryos with high germination potentials were obtained on P24 medium containing 1.0% agar. Embryo water content decreased progressively from 94 to 80% during embryo maturation. Stage I and II embryos that matured on media containing 0.8 or 0.9% agar had similar values of Psipi,embryo, whereas Psipi,embryo of Stage III embryos that matured on medium containing 1.0% agar was significantly lower, although Psipi,medium was unaffected by gel strength. Stage III embryos showed a nearly 16-fold increase in proline concentration and a 50% decrease in ABA concentration compared with Stage I embryos. We conclude that tissue water status and a complex relationship between ABA and proline concentrations, modulated by medium gel strength, are important factors in the maturation process and the quality of oak somatic embryos.