Olive fruit fly [Bactrocera (Dacus) oleae (Rossi) (Diptera: Tephritidae)] adult rearing diet without antibiotic

The olive fruit fly [Bactrocera (Dacus) oleae (Rossi) (Diptera: Tephritidae)] adult diet since its development in the 1960’s regularly incorporates antibiotic. Considering recent findings on the importance and function of the indigenous microbial flora of insects, the effects of antibiotic removal were measured on the survival and egg laying of wild flies derived from McPhail trappings and from field infested olive fruits. In the first case wild flies fed no antibiotic laid significantly greater numbers of eggs for two generations (in 5 out of 10 and 2 out of 10 counting dates for G1 and G2 respectively), while there were no significant differences in survival in either test (P = 0.221 for P generation, P = 0.988 for G1 generation from McPhail traps, P = 0.056 for flies from infested fruits). Percent egg–pupa recovery and adult emergence were not significantly affected by lack of antibiotic. An antibiotic‐free strain has been maintained for eight generations, showing acceptable performance when compared to the long‐reared standard ‘Laboratory’ strain. Overall results suggest the feasibility of an adult diet free of antibiotic without negative effects on colony survival and performance.     

Competitive Interactions between Immature Stages of Bactrocera cucurbitae (Coquillett) and Bactrocera tau (Walker) (Diptera: Tephritidae) under Laboratory Conditions

The melon fly, Bactrocera cucurbitae (Coquillett), and the pumpkin fly, Bactrocera tau (Walker), are economically important pests that attack mainly cucurbitacean fruits. The two fruit fly species have similar natural distributions, host ranges, and population growth capacities. This study was designed to assess the asymmetrical competitions through resource exploitation between the larvae of B. cucurbitae and B. tau at different density levels and temperatures, and on different hosts by comparing the relative effects of interspecific and intraspecific interactions on four life history parameters: survival rate, puparial mass, puparial duration, and developmental duration. Our results showed that intraspecific and interspecific competitions occurred under some laboratory conditions, and B. cucurbitae took advantage over B. tau at the high-density level and at low and high temperatures on pumpkin, bitter gourd, and bottle gourd when interspecific competition took place. Intraspecific and interspecific competitions mainly affected the puparial mass and the survival rate of the two fruit fly species but had no marked effect on the puparial duration or development duration.     

桔小实蝇和番石榴实蝇对6种寄主果实的产卵选择适应性

植食性昆虫对寄主植物的选择适应性是研究昆虫和植物协同进化关系的核心内容之一。评估寄主植物对植食性昆虫种群的适合度,需要综合分析昆虫对寄主的产卵选择性和寄主对昆虫的取食适合性。以桔小实蝇和番石榴实蝇为研究对象,分别测定了这两种实蝇对6种寄主果实:番石榴、香蕉、杨桃、木瓜、甜橙、番茄的产卵选择性以及幼虫取食后对其生长发育的影响。寄主产卵选择性实验分别采用完整寄主果实直接供试产卵和块状寄主果实气味引诱产卵两种处理方式;在生长发育适应性实验中,以幼虫和蛹的存活和生长发育等相关参数作为评价指标。实验结果表明,寄主的供试方式不同,两种实蝇的选择性均有明显差异;对寄主气味选择性强的寄主更适合于两种实蝇后代的生长发育。两种实蝇对6种寄主果实的产卵选择性和后代发育适合性两者相关性不显著,与许多文献报道单一地采用发育适合性(如发育历期、存活率或蛹重等)作为评价寄主选择性的结果不一致。两种实蝇之间对6种寄主果实的产卵选择和幼虫取食适合性既具相似性也具差异性,表明这两种实蝇在寄主生态位上既有重叠性又有分化性。     

Genetic structure and demographic history of the melon fly Zeugodacus cucurbitae (Coquillet) (Diptera: Tephritidae) in Thailand

相似文献   

植物果实、颜色和形状对橘小实蝇产卵选择的影响

橘小实蝇Bactrocera dorsalis(Hendel)是近几年入侵江苏南部地区,严重危害当地水果、蔬菜的重要害虫。为深入了解其在该地区果树、蔬菜上的产卵特性,进行植物果实、颜色和形状对其产卵选择影响的研究。实验室中"纸杯法"的产卵选择试验结果表明,橘小实蝇对不同水果的产卵偏好性由高到低依次为:柑橘、香蕉、芒果、枣、石榴、苹果、桃子、梨、李、葡萄、柿;对不同蔬菜的产卵偏好性由高到低依次为:丝瓜、豇豆、苦瓜、黄瓜、茄子、南瓜、青椒、番茄。对不同寄主颜色和形状的产卵选择特点为,雌虫常选择桔黄色、绿色,以及圆球形的寄主产卵,而较少选择黑色、方形的寄主产卵。从试验结果可以看出,寄主果实散发出的气味,及其颜色和形状对橘小实蝇的产卵选择有影响。     

Trapping tephritid fruit flies (Diptera: Tephritidae) in citrus groves of Fujian Province of China

Certain tephritid fruit flies, such as the oriental fruit fly, Bactrocera dorsalis, the Chinese citrus fly, B. minax and the Japanese orange fly, B. tsuneonis (Diptera: Tephritidae: Dacinae), are destructive citrus pests in China. A two-year trapping study was conducted in pomelo, Citrus maxima, groves in Fujian Province of China. The objectives of this study were to investigate the species, the abundance of tephritid fruit flies in the orchards, as well as the efficacy of the selected lure traps to these flies. Four lure traps or devices, i.e. methyl eugenol + Steiner trap (ST), cuelure + ST, ammonium acetate + putrescine + ST, and sticky spheres, were deployed from June to November 2017 and April to October 2018. Six economically significant Dacini pests were trapped during the period. These flies are B. dorsalis, the melon fruit fly, Zeugodacus cucurbitae, the pumpkin fruit fly, Z. tau, the Malaysian fruit fly, B. latifrons, and other two species - B. rubigina and Z. scutellatus. B. dorsalis was the most abundant, accounting for more than 50% of the capture, followed by Z. cucurbitae. The remaining four species accounted for less than 2% of the total capture. B. minax and B. tsuneonis, two destructive citrus-damaging tephritid fruit flies in China, were not found during the trapping period. Methyl eugenol trapped the highest number of fruit flies, followed by cuelure.     

Polymorphic microsatellite markers in the guava fruit fly, Bactrocera correcta (Diptera: Tephritidae)

Bactrocera correcta (Bezzi) is one of the most destructive insect pests of fruits and vegetables in tropical and subtropical regions. At present, this fly is primarily distributed in Southeast Asia. Twelve microsatellite loci were isolated from an enriched genomic library based on a biotin/streptavidin capture protocol. The polymorphism of these loci was tested on 74 individual flies from two natural populations. Allele number ranged from 6 to 14 and 10 loci demonstrated a polymorphic information content (PIC) greater than 0.5. The pairwise F _ST value between the two populations was 0.0048 (P > 0.05). These microsatellite loci have potential utility for studies of population genetic structure in this species.     

Suppression of melon fly (Diptera: Tephritidae) populations with releases of Fopius arisanus and Psyttalia fletcheri (Hymenoptera: Braconidae) in North Shore Oahu, HI, USA

Field experiments and surveys were conducted to evaluate the efficacy of releasing Fopius arisanus (Sonan) and Psyttalia fletcheri (Silvestri) parasitoids for suppression of Bactrocera cucurbitae (Coquillett) infesting wild Coccinia grandis L. In 2003 and 2004, P. fletcheri releases combined with natural emergence from wild fly populations resulted in better fly suppression, compared to the control site. While P. fletcheri developed freely on melon fly, F. arisanus was less successful at producing its own progeny, yet causing mortality and a twofold decrease in pupae recovered from ivy gourds. Concurrent releases of both parasitoids exerted a compounded suppressive effect on the melon fly population 2–3 times higher than during the pre-release phase. A similar, less obvious, pattern occurred in 2004, due to reduction of the ivy gourd fruit canopy. In 2005, only P. fletcheri was released, with greatly reduced impact, due to ivy gourd destruction and by growers leaving crop culls in fields, producing large numbers of melon flies unaffected by parasitoid releases.     

Fruit fly (Diptera: Tephritidae) diversity in cucurbit fields and surrounding forest areas of Himachal Pradesh,a north-western Himalayan state of India

During the course of studies, Bactrocera (Bactrocera) latifrons (Hendel), B. (B.) nigrofemoralis White and Tsuruta, Dacus (Callantra) longicornis Wiedemann, Dacus (Callantra) sphaeroidalis (Bezzi), Cyrtostola limbata (Hendel) and Pliomelaena udhampurensis Agarwal and Kapoor were recorded for the first time in Himachal Pradesh in a cucurbit ecosystem. Apart from these, other species viz. Bactrocera tau, Bactrocera cucurbitae, Bactrocera dorsalis, Bactrocera zonata, Bactrocera scutellaris, Bactrocera diversa and Dioxyna sororcula (Wiedemann) were also identified. Distribution records of B. (B.) dorsalis (Hendel), B. (B.) zonata (Saunders), Bactrocera (Hemigymnodacus) diversa (Coquillett), B. (Zeugodacus) cucurbitae (Coquillett), B. (Z.) scutellaris (Bezzi) and B. (Z.) tau (Walker) has been described.     

Susceptibility of the Mediterranean fruit fly (Ceratitis capitata) and the Natal fruit fly (Ceratitis rosa) to entomopathogenic nematodes

The potential of entomopathogenic nematodes, Heterorhabditis bacteriophora, Heterorhabditis zealandica and Steinernema khoisanae, to infect pupariating larvae, pupae and adults of Ceratitis capitata and Ceratitis rosa was investigated in laboratory bioassays. Pupariating larvae and adult flies were susceptible to nematode infection, with no infection recorded for the pupae. Pupariating larvae of C. capitata were generally more susceptible to infection than those of C. rosa. Significantly more larvae of C. capitata were infected by H. bacteriophora. For C. rosa, highest infectivity of larvae was obtained with H. zealandica. In contrast, adults of both species were highly infected by S. khoisanae.     

蝇蛹俑小蜂对寄主及果实的趋性反应

【背景】蝇蛹俑小蜂是实蝇类害虫蛹期重要的寄生蜂之一。有关植物果实和寄主挥发物在蝇蛹俑小蜂寻找寄主过程中的作用尚不明确。【方法】采用"Y"型嗅觉仪测试了寄主和果实(健康果实和虫害诱导果实)对蝇蛹俑小蜂的引诱作用。【结果】虫伤1 d的番石榴和杨桃果实对蝇蛹佣小蜂雌蜂具有显著的引诱作用;寄主蛹——3日龄橘小实蝇蛹和4日龄瓜实蝇蛹对蝇蛹俑小蜂雌蜂也具有显著的引诱作用。蝇蛹俑小蜂雌蜂对雄蜂有显著的吸引作用。橘小实蝇性诱剂甲基丁香酚对蝇蛹俑小蜂的搜索行为则无显著影响。【结论与意义】寄主蛹和幼虫危害1 d的果实能释放对蝇蛹俑小蜂有引诱作用的物质,这可为利用蝇蛹俑小蜂防治实蝇类害虫提供基础信息。     

Host location by the fruit fly parasitoid Diachasmimorpha krausii: role of fruit fly species,life stage and host plant

• 1 Diachasmimorpha krausii is a braconid parasitoid of larval tephritid fruit flies, which feed cryptically within host fruit. At the ovipositor probing stage, the wasp cannot discriminate between hosts that are physiologically suitable or unsuitable for offspring development and must use other cues to locate suitable hosts.
• 2 To identify the cues used by the parasitoid to find suitable hosts, we offered, to free flying wasps, different combinations of three fruit fly species (Bactrocera tryoni, Bactrocera cacuminata, Bactrocera cucumis), different life stages of those flies (adults and larvae) and different host plants (Solanum lycopersicon, Solanum mauritianum, Cucurbita pepo). In the laboratory, the wasp will readily oviposit into larvae of all three flies but successfully develops only in B. tryoni. Bactrocera tryoni commonly infests S. lycopersicon (tomato), rarely S. mauritianum (wild tobacco) but never C. pepo (zucchini). The latter two plant species are common hosts for B. cacuminata and B. cucumis, respectively.
• 3 The parasitoid showed little or no response to uninfested plants of any of the test species. The presence of adult B. tryoni, however, increased parasitoid residency time on uninfested tomato.
• 4 When the three fruit types were all infested with larvae, parasitoid response was strongest to tomato, regardless of whether the larvae were physiologically suitable or unsuitable for offspring development. By contrast, zucchini was rarely visited by the wasp, even when infested with B. tryoni larvae.
• 5 Wild tobacco was infrequently visited when infested with B. cacuminata larvae but was more frequently visited, with greater parasitoid residency time and probing, when adult flies (either B. cacuminata or B. tryoni) were also present.
• 6 We conclude that herbivore‐induced, nonspecific host fruit wound volatiles were the major cue used by foraging D. krausii. Although positive orientation to infested host plants is well known from previous studies on opiine braconids, the failure of the wasp to orientate to some plants even when infested with physiologically suitable larvae, and the secondary role played by adult fruit flies in wasp host searching, are newly‐identified mechanisms that may aid parasitoid host location in environments where both physiologically suitable and unsuitable hosts occur.

     

Local Enhancement of Alighting in the Melon Fly, Bactrocera cucurbitae: Effect of Olfactory, Visual, and Acoustical Stimuli

In studies conducted in Hawaii under both greenhouse and field conditions, we evaluated the propensity of melon fly females, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), to alight on either fruit mimics (agar spheres) or host fruit that were or were not occupied by conspecific resident females. We also examined the extent to which occurrence of local enhancement of alighting found in B. cucurbitae females was affected by a variety of factors such as the presence or the absence of host fruit odor (zucchini or ivy gourd), the number of conspecifics present on a host, the degree of isolation of assayed females from other females prior to testing, and the kinds of stimuli (acoustical, visual, olfactory) emanating from conspecifics present on a host mimic. In addition, we asked whether local enhancement might be operative in the food-foraging behavior of melon flies. We found that in a variety of situations, melon fly females alighted in significantly greater numbers at resources (food, fruit mimics, or host fruit) occupied by conspecific females than at unoccupied resources. Such positive influence of resident conspecific females was more pronounced in greenhouse cage assays when one or two rather than four residents were present on a host mimic (but was more pronounced when four rather than one or two residents were present on a host fruit in a field test), and was more evident when test females were grouped with conspecific females than when test females were isolated from conspecific females for 5 days before testing. Rather than acoustical or olfactory stimuli associated with resident conspecific females, the mere physical presence (visual stimulus) of a motionless dead resident melon fly female provided sufficient stimulation for test females to alight in significantly greater numbers at resources occupied by conspecific females than at unoccupied resources. We consider our findings as good evidence of local enhancement in the melon fly and discuss our results in relation to monitoring tactics for adult melon flies.     

Fluctuations in fruit fly abundance and infestation in sweet gourd fields in relation to varied meteorological factors

The study was conducted with the aim of furthering our understanding of seasonality in the population dynamics and infestation rates of the fruit fly Bactrocera spp. in sweet gourd (Cucurbita moschata) during winter and summer in 2017. We also investigated the effects of using methyl eugenol traps on fly abundance and infestation. Two fruit fly species, namely, B. cucurbitae and B. dorsalis, were present in the sweet gourd field, and we observed fluctuations in their abundance. Compared to B. dorsalis, B. cucurbitae was significantly more abundant in both winter and summer. Infestation level was found to be the highest in fields lacking methyl eugenol traps in both seasons. Fruit fly larval population per infested fruit was higher in summer than in winter. Fly abundance was significantly and positively correlated with mean temperature and rainfall but significantly and negatively correlated with light intensity. Relative humidity was insignificantly but positively correlated with fly abundance. The temperature, light intensity, relative humidity, and rainfall individually explained 48.9, 24.1, 0.8, and 1.6% of variation in fruit fly abundance, respectively. The combined effect of the weather parameters on fruit fly abundance was 75.4% and was significant predictor of fruit fly abundance.     

Population structure of the melon fly, Bactrocera cucurbitae, in Reunion Island

The melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) is an agricultural pest of major significance worldwide that primarily attacks cucurbit crops. In Reunion Island, it represents the main tephritid pest on cucurbits. In this paper, we provide a genetic characterization of populations of B. cucurbitae from Reunion Island and investigate their geographical origin using ten microsatellite loci at two mitochondrial gene fragments. Microsatellites reveal the occurrence of three different genetic clusters of B. cucurbitae in Reunion Island, all clearly distinguishable from their African and Asian relatives. These three clusters are sympatric and show no signs of recent bottlenecks. Levels of gene flow among clusters are relatively high, yet gene flow also occurs with populations from the African continent and, to a lesser extent, from Asia. The B. cucurbitae clusters show distinct distributions across eastern and western locations in Reunion Island (but not at different altitudes or between wild and cultivated host plants or between sampling periods), and their abundance is also correlated with the average amount of rainfall. Microsatellite and sequence analyses suggest Africa as the most probable source area for populations of B. cucurbitae in Reunion Island.     

Response of female melon fly, Bactrocera cucurbitae, to host-associated visual and olfactory stimuli

In a series of studies conducted in Hawaii under seminatural conditions, we quantified the response of sexually mature, host‐seeking female melon flies, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), to different types of visual and chemical host‐associated stimuli with the main aim of developing a monitoring device for females. Experiments were conducted using Tangletrap‐coated fruit mimics of either spherical (8 cm diameter) or cylindrical (4.3 cm diameter; 15 cm length) shapes coated with different artificial color pigments both at the ground level and at the tree‐canopy level so as to take into account the foraging behavior of adult melon flies. Females were particularly attracted to objects of spherical shape colored either yellow, white, or orange; these three pigments offered the highest reflectance values. Cucumber (Cucumis sativus L.) (Cucurbitaceae) odor was more attractive to females than odors of three other cultivated host fruit [zucchini, Cucurbita pepo L. var. medullosa Alef. (Cucurbitaceae); papaya, Carica papaya L. (Caricaceae); or tomato Solanum lycopersicum L. (Solanaceae)] or of ivy gourd [Coccinia grandis (L.) Voigt (Cucurbitaceae)], one of the major wild hosts of melon fly in Hawaii. A combination of both visual and olfactory stimuli was needed to elicit high levels of response compared to each stimulus offered alone. We discuss our results in relation to the potential implementation of improved female monitoring and/or attract‐and‐kill strategies for melon flies in Hawaii.     

Taxonomic Identity of the Invasive Fruit Fly Pest,Bactrocera invadens: Concordance in Morphometry and DNA Barcoding

In 2003, a new fruit fly pest species was recorded for the first time in Kenya and has subsequently been found in 28 countries across tropical Africa. The insect was described as Bactrocera invadens, due to its rapid invasion of the African continent. In this study, the morphometry and DNA Barcoding of different populations of B. invadens distributed across the species range of tropical Africa and a sample from the pest''s putative aboriginal home of Sri Lanka was investigated. Morphometry using wing veins and tibia length was used to separate B. invadens populations from other closely related Bactrocera species. The Principal component analysis yielded 15 components which correspond to the 15 morphometric measurements. The first two principal axes contributed to 90.7% of the total variance and showed partial separation of these populations. Canonical discriminant analysis indicated that only the first five canonical variates were statistically significant. The first two canonical variates contributed a total of 80.9% of the total variance clustering B. invadens with other members of the B. dorsalis complex while distinctly separating B. correcta, B. cucurbitae, B. oleae and B. zonata. The largest Mahalanobis squared distance (D² = 122.9) was found to be between B. cucurbitae and B. zonata, while the lowest was observed between B. invadens populations against B. kandiensis (8.1) and against B. dorsalis s.s (11.4). Evolutionary history inferred by the Neighbor-Joining method clustered the Bactrocera species populations into four clusters. First cluster consisted of the B. dorsalis complex (B. invadens, B. kandiensis and B. dorsalis s. s.), branching from the same node while the second group was paraphyletic clades of B. correcta and B. zonata. The last two are monophyletic clades, consisting of B. cucurbitae and B. oleae, respectively. Principal component analysis using the genetic distances confirmed the clustering inferred by the NJ tree.     

Combination of edible vegetable oil and artificial fruit to reduce Bactrocera dorsalis oviposition in chilli fruits

Bactrocera dorsalis (Hendel) is a major pest of a wide variety of fruits and vegetables. This study aimed to evaluate the potency of combining edible vegetable oil application and artificial fruit provision to reduce the oviposition of B. dorsalis in chilli fruits. Experiments were conducted in laboratory using a 20‐L plastic container provided with chilli fruits and in semi field using a fruit‐bearing chilli plant caged with insect screen. The laboratory test revealed that the combination of coconut oil application and artificial fruit provision significantly reduced fruit fly visits, eggs laid and the number of infested chilli fruits no matter when the chilli fruits were without prepuncture or with prepuncture. Further study using a caged chilli plant also found that this combination had significant effects on fruit fly visits and infestation in chilli fruits. These results provide an indication that coconut oil and artificial fruit can work together to reduce fruit fly attacks on chilli fruits. Combining the use of coconut oil and artificial fruit is likely to create an integrated behavioural manipulation (push and pull) of female B. dorsalis that lead to a much lower fruit fly infestation in chilli fruits.     

Faster (or slower) developers have a shorter (or longer) circadian period in Bactrocera cucurbitae

A clock controlling circadian rhythm may relate to another clock controlling development time. The relationship between the two clocks remains open to discussion. Genetic correlation between developmental and circadian periods is observed in two Dipteran species (Bactrocera cucurbitae and Drosophila melanogaster), whereas it is not observed in a Coleopteran species (Callosobruchus chinensis). No studies, however, are available that report on the phenotypic correlation between the two traits. In the present study, free‐running circadian periods are compared between individuals that develop fastest and slowest within a population of B. cucurbitae. The measurement of circadian periods is replicated using five populations of B. cucurbitae with different geographical and rearing histories. The results demonstrate that the flies developing more slowly have significantly longer circadian periods compared with the flies developing more quickly in two of five populations examined in B. cucurbitae, and thus the phenotypic correlation is dependent on population.     

寄主对桔小实蝇耐寒性的影响

为了研究寄主营养对桔小实蝇耐寒性的作用,测定了以15种果蔬饲养的桔小实蝇1日龄蛹的过冷却点(supercooling points,SCP); 再选取南瓜、西红柿、柑桔、番石榴和杨桃等5种果蔬,测定了桔小实蝇3龄老熟幼虫、1日龄蛹、3日龄蛹、5日龄蛹、7日龄蛹和雌雄成虫的过冷却点,并观察了1日龄蛹的低温存活力。结果表明：（1）15种果蔬饲养所得的桔小实蝇1日龄蛹SCP均值在-11.03℃～-13.17℃,不同寄主发育的桔小实蝇SCP值存在显著性差异,其中以取食蒲桃的最高,为-11.03℃,取食苦瓜的最低,为-13.17℃。（2）5种果蔬饲养所得的桔小实蝇各虫态的SCP均值存在极显著差异(F_(4,863)＝35.6,P<0.01); 同一寄主上的桔小实蝇不同虫态之间SCP均值也达到极显著性差异(F_(6,863)＝392.9,P<0.01); 且寄主和发育龄期之间存在着极显著的交互作用(F_(24,863)＝9.4,P<0.01)。（3）桔小实蝇各发育阶段,SCP值表现一定变化： 老熟幼虫发育至1日龄蛹,SCP值变化不大; 蛹发育至3、5和7天过冷却能力明显增强,降至-20℃左右,但他们之间没有明显区别; 羽化后3～5天的成虫SCP值又升高至-10℃左右。老熟幼虫、1日龄蛹和2～3日龄成虫与3日龄、5日龄和7日龄蛹的SCP值之间有显著性差异。（4）将5种果蔬饲养所得的桔小实蝇1日龄蛹置于6℃和-3℃下进行较长时间(1～8天)和较短时间(1～8 h)的低温处理,发现番石榴、杨桃和南瓜发育的蛹经低温处理后的校正羽化率较西红柿和柑桔发育的蛹高; 同样在0℃、3℃、6℃和9℃处理(2天)的实验中,得出相似的结果。因此,本实验结果表明桔小实蝇幼虫由于生活寄主的不同使得其下一代蛹的耐寒性产生了差异,引起其差异的原因值得进一步研究。