TEAM NEWSLETTER

No. 8 July 2010

TO OUR READERS

In couple of weeks the fruit fly community meets in banana Musa sp. (Musaceae); and citrus (Citrus Valencia Spain. TEAM will be there as well, with two limon, Citrus reticulata, and Citrus sinensis) (all major events. First, the TEAM members will meet to Rutaceae). Besides the economic impact there are discuss the future of our group, the expansion of our ecological impacts since B. invadens displaces other activities, new ideas for the involvement of younger fruit flies and becomes the dominant one at least in members, and other issues that you may wish to citrus orchards. The interaction of B. invadens with address. The venue of our next scientific meeting will other fruit flies is discussed as well as other aspects of be announced in Valencia. This will be organized in its ecology including population dynamics and Spring–Early Summer 2012 in Croatia, Greece or Italy. altitudinal distribution. In addition sexual behavior and Thanks are extended to all groups who have response to different stimuli is discussed. Last but not expressed an interest to organize the next TEAM least, Sunday and Samira provide a comprehensive meeting. Second, the TEAM steering committee will review on the management strategies and methods meet as well. Among others, the refreshment of the that should be applied to keep populations of B. steering committee will be decided. Following our invadens below economic thresholds. commitment two or three new members will join the TEAM steering committee and a respective number of In the current and future newsletter we include two the current members will resign. new columns. The first concerns presentation of recently concluded Ph.D. theses in fruit flies, and the Francesca Scholari, who recently received her Ph.D. second presents activities and a short portrait of fruit from the University of Pavia (Italy) under the fly workers. Francesca presents her recently supervision of Professor Giuliano Gasperi has joined concluded Ph.D. on the reproductive biology of the the editorial group of the TEAM newsletter. I would like highly invasive insect pest species Ceratitis capitata to welcome Francesca and I am sure she brings lot of (Diptera: Tephritidae) using neutral markers and new ideas (already contributed many) and energy to our transgenic tools. group. We also present the Nelson Mandela African Institute The invited paper of the current newsletter is of Science and Technology in Arusha (NM AIST- contributed by Sunday Ekesi and Samira Mohamed. Arusha) Tanzania, which is one of the four institutions Sunday and Samira cover a very interesting story of in the Pan-African Network of African Institutes of the rapid expansion of the distribution of Bactrocera Science and Technology located across the continent. invadens in central Africa. A thorough review on the TEAM is working with Prof. Burton L.M Mwamilla (Vice taxonomy, biology, ecology, behavior and Chancellor) to provide support for the establishment of management of B. invadens is included. Although the fruit fly research group. authors clearly distinguish B. invadens from its close relatives (Bactrocera dorsalis and B. kandiensis We are looking forward to meeting all TEAM members (Diptera:Tephritidae) they point out that some in Valencia and to welcome new members and ideas. specimens of B. invadens are almost inseparable from B. dorsalis, and that hybridization experiments Nikos Papadopoulos between B. dorsalis and B. invadens result in viable Chairman of the Steering Committee offspring at least at F1 generation. The current University of Thessaly, School of Agriculture distribution and the invasion history of B. invadens is 38442 N. Ionia (Volos) Magnisias, Greece also covered in a nice manner. It seems that the fly [email protected] originates from the broader area of Sri Lanka and has first invaded Eastern Africa. Bactrocera invadens occurs in 28 African countries including the Comoros Archipelago in the Indian Ocean as well as in Cape Verde. It is reported in southern India and Bhutan as well. The economic impact of this fruit fly is really high and varies from 30 – 80%. The main fruits affected include mango, Mangifera indica L. (Anacardiaceae);

TEAM Newsletter No. 8 (July 2010) 1

BACTROCERA INVADENS: STATE OF THE ART AND FUTURE RESEARCH DIRECTIONS

1. INTRODUCTION

Sub-Saharan Africa (SSA) is the aboriginal home to 915 fruit fly species from 148 genera, out of which 299 species develop in either wild or cultivated fruit, or both. They belong mainly to three genera: Ceratitis, Dacus, and Trirhithrum (White and Elson-Harris, 1992). For example, surveys across Africa on mango revealed that the crop is attacked by native fruit fly species such Ceratitis cosyra, C. quinaria, C. fasciventris, C. rosa, C. anonae and C. capitata causing yield losses between 30–70% depending on the locality, season and variety (Lux et al., 2003a; Ekesi and Billah, 2007). Other important native Bactrocera invadens – photo by G. Goergen). Ceratitis species in Africa include C. rubivora, C. puntata, C. discussa, C. ditissima, and C. pedestris documented invaders and rank high on quarantine that attack a variety of important fruits and vegetables. lists world-wide (Clarke et al., 2005). It is uncertain On cucurbits, several native Dacus species (e.g. D. exactly when and how B. invadens was introduced into bivittatus, D. lounsburyi, D. ciliatus, D. puntatifrons, D. Africa, since no record of the insect was observed in frontalis, D. vertebratus etc.) also inflict considerable an extensive fruit sampling program for fruit flies losses to crops (White and Elson-Harris, 1992; De before 2003 (Copeland et al., 2006). During this study Meyer et al., 2002; Ekesi and Billah, 2007). over 4000 fruit samples (~980,000 pieces of fruits) of 882 taxa and 116 plant families from coastal and Although Africa is known to be the aboriginal home of western Kenya, and from the Central Highlands were several fruit fly species and the origin of several fruit examined without any sample of B. invadens. fly introductions and establishments worldwide (the Similarly in West Africa B. invadens was not detected most notorious species being the Mediterranean fruit in intensive sampling programs on commercial mango fly, Ceratitis capitata) the continent has also become orchards in Coastal Guinea in 1992-1996 (Vayssières highly vulnerable to introduction of alien invasive fruit and Kalabane, 2000) and in Mali in 2000 (Vayssières fly species with the intensification of international fruit et al., 2004). Unfortunately no similar studies were trade. Bactrocera zonata is believed to have been in conducted at the same time in other parts of the Egypt since the early or mid last century but was African continent where the fly is currently found but misidentified for several years as B. pallida (Perkins & the presence of B. invadens before the year 2000 in May); by the late 1990s it had established across the countries were extensive studies were carried is highly country (White, 2010) causing significant damage on unlikely. mango, citrus and peach (De Meyer et al., 2007). In 2003 Bactrocera invadens was detected for the first 2. TAXONOMY, BIOLOGY AND ECOLOGY time in Africa (Drew et al., 2005) and it is now reported from over 28 African countries. In 2006, the Solanum a. Description of species fruit fly Bactrocera latifrons, a primary pest of solanaceous crops such as eggplant, pepper and During a routine fruit fly survey activity at the Coast tomato was detected in Tanzania (Mwatawala et al., Province of Kenya, three specimens of unknown fruit 2007). Although damage is currently concentrated on fly (2 from protein baited trap and one from indigenous solanum vegetables such as Solanum unidentified indigenous fruit, probably from the genus aethiopicum and S. macrocarpon (Mwatawala et al., Strychnos) were collected by the icipe-led African Fruit 2009; De Meyer et al., 2007; Ekesi et al., Fly Initiative (AFFI) in March 2003. Intensive survey unpublished); tomato seems to be most at risk. The conducted covering the major fruit growing and trading melon fly Bactrocera cucurbitae, the world’s most areas was initiated 2 day later using methyl eugenol damaging fruit fly species on cucurbits has also been (ME) (120 traps) and cue lure (15 traps) covering 75 in Africa for years without a clear date of introduction sites located in 7 out of the 8 Kenyan provinces (Lux (White and Elson-Harris, 1992). et al., 2003). Large numbers of the same fruit fly species were attracted to ME, while none was Among all the native and exotic fruit fly species listed attracted to cue lure. This coupled with the numerous here, one species, B. invadens is thought to be adult flies reared from mango at the same time responsible for causing extensive economic losses to suggested beyond doubt the new species is a member horticultural crops throughout Africa since its first of Bactrocera Macquart native to Asia. Lux et al report in 2003. This is perhaps not surprising because, (2003), using basic morphological characteristics, Asian fruit fly pests from the genus Bactrocera are concluded that this species is probably Bactrocera regarded as among the most destructive insects of dorsalis. Specimens were later shipped to Prof Dick fruits and vegetables worldwide (White & Elson-Harris, Drew in Australia who later described it in 2005 as 1992). With adult traits that can include high mobility Bactrocera invadens (Diptera: Tephritidae) denoting its and dispersive powers, high reproductive rates, and rapid invasion of the African continent (Drew et al. extreme polyphagy, Bactrocera species are well- 2005). Although the authors clearly distinguished B. TEAM Newsletter No. 8 (July 2010) 2 invadens from its close relatives (and possibly its B. dorsalis, B. kandiensis, B. oleae and B. zonata. No ancestors), e.g. Bactrocera dorsalis (Diptera: differences were observed among morphotypes. Tephritidae) and Bactrocera kandiensis Similarly, B. invadens populations and other (Diptera:Tephritidae), they however, indicated that Bactrocera species belonging to the B. dorsalis some specimens of B. invadens are almost complex could not be separated by principal inseparable from B. dorsalis, as B. invadens can have component analysis. However, the analysis separated a different array of color patterns, on scutum as well B. correcta, B. cucurbitae, B. oleae and B. zonata into as on the abdomen (Drew et al., 2005). distinct groups. Likewise, the projection of the data on the first two canonical variate axes showed a similar pattern of separation.

Khamis et al. (2008) characterized the first set of microsatellite markers available for B. invadens. The range in repeat sequence length and diversity of the markers allowed for the investigation of population structure and invasion history of the species. Subsequent studies evaluated the level of genetic diversity and the extent of the common ancestry among several African populations collected across the actual invaded area in tropical Africa from the East to the West to highlight the dynamic aspects of the invasion process after the introduction. The same data after correlation with the history of the first records of Bactrocera invadens – (Photo by R. S. Copeland). the pest in different countries enable the possible route of invasion in the African mainland to be inferred. The study included a population sample from Sri Moreover, a series of ongoing hybridization Lanka (the putative aboriginal home of the pest) in experiments conducted (under forced laboratory order to determine if Asia was the likely origin of this conditions) by IAEA between B. dorsalis and B. pest. The results showed that the Sri Lankan invadens are yielding viable eggs and F1 adult population presented the highest values of genetic offspring (A. Jessup, IAEA, personal communication). variability, with a mean number of alleles of 7.18, 16 The identity of B. invadens is therefore still private alleles at a mean frequency of 0.04, and with a controversial. However ongoing hybridization and high value of genetic diversity (HS = 0.65) indicating molecular studies may be able to clarify taxonomic that Sri Lanka is within the native range of the species identity of the pest in the nearest future (F. Khamis et (Khamis et al., 2009). The Sri Lankan sample was also al., unpublished data; A. Jessup et al., unpublished clearly genetically separated from the African data). population, and only a small percentage of its multilocus genotypes could be found in Africa. Also b. Morphometrics and molecular studies lower variability values were observed in the African populations compared with the Sri Lankan population. Within the Dacinae, the morphological characters used to define species are almost entirely based on colour Khamis et al. (2009) also demonstrated that within patterns. Drew et al. (2008) using morphological and Africa, the West African populations display a slightly biological species boundaries compared new data higher level of genetic diversity with higher numbers of from morphometric analyses of reproductive and body rare alleles, especially in the Nigerian population as parts of some members of the B. dorsalis complex. compared to the East African populations. Overall, the For the populations studied (Bactrocera carambolae, genetic data generated from the study suggest the Bactrocera dorsalis, Bactrocera occipitalis, Bactrocera presence of populations with relatively high levels of papayae, Bactrocera philippinensis, Bactrocera genetic diversity associated with limited geographic kandiensis and Bactrocera invadens) there appeared structure across West and East Africa. Interestingly, to be significant congruence between the although the invasion is a relatively recent event in morphological and biological species boundaries. Africa, no genetic footprints of bottlenecks was Within the dorsalis complex, B. carambolae, B. observed in the study, but populations appear large dorsalis, B. occipitalis, B. papayae, and B. enough to maintain a relatively high number of low philippinensis are separated from each other on a frequency alleles, especially in West Africa. combination of shape and size of the lateral Collectively the features indicate a process of rapid postsutural yellow vittae, width and shape of the costal population growth and expansion which is entirely band on the wing, colour of the femora (legs), and consistent with B. invadens characteristically high shape and size of the dark colour patterns on intrinsic rate of increase (Ekesi et al., 2006). abdominal terga III–V and Bactrocera invadens was more distinct in possessing a mostly red–brown Structure analysis depicted 3 African clusters that scutum while B. kandiensis have large dark fuscous to were interpreted as different invasion burst or black markings on the apices of all femora. Khamis outbreaks (Khamis et al., 2009). Two main outbreaks (2009) conducted morphometric study to clarify the were found to have originated in the East, probably complexity of the pest population starting with the from Kenya, supported by the high proportional separation of the different colour forms and how they ancestry values of 3 Kenyan samples. Another burst relate to other invasive or potentially invasive was thought to have originated from the West, Bactrocera species such as B. correcta, B. cucurbitae, possibly Nigeria, and appeared to be more localized

TEAM Newsletter No. 8 (July 2010) 3 and could have resulted from independent introduction d. Rearing event(s), followed by little gene flow towards Benin and other western and eastern regions. However, an Soon after the detection of B. invadens, small colony alternative plausible hypothesis was that the Nigerian of this pest was established at the icipe Animal sample represented the outcome of a bottleneck Rearing and Biocontainment Unit. The initial cohort (perhaps from Benin), and that its high number of rare was obtained from rotten mangoes collected at a local alleles is a consequence of a relatively long period of market in Nairobi, Kenya. As initiating a colony of wild genetic isolation (Khamis et al., 2009). insects on artificial diet can be quite challenging, and due to the urgency of having a clean laboratory colony c. Life history and demographic parameters of this new pest for basic behavioral and biological studies, whole mango fruit rearing was employed for On artificial diet, average duration of egg development colony establishment. Adults were fed on a diet was 1.2 days, with a survival rate of 90% (Ekesi et al., consisting of 3 parts sugar and 1 part enzymatic yeast 2006). Larval and pupal development lasted 11 and 12 hydrolysate ultrapure and water on pumice granules at days, respectively. Larval survival was 76% while that 28±1°C, 60-70% RH, and a photoperiod of 12:12 (L:D) of puparia was 81%. Larval development duration was (Ekesi et al., 2007a). After 6 generations on mango highly variable, spreading between 9-13 days to fruits, the fruit rearing was replaced by carrot based pupation, but eclosion from the pupal stage was diet by using the “diet ball methodology” (Lux, et al. spread over just 2 days. On average total 2005). Ekesi et al (2007a) described the adaptation development lasted 25 days and only 55% of eggs laid process of B. invadens when moved from whole reached the adult stage (Ekesi et al., 2006). Average mango fruit rearing to artificial diet based on wheat adult pre-oviposition period was 7.1 days; and the bran or carrot diet. The author indicated that on wheat oviposition period lasted 73 days. Life expectancy at bran three to five generations were required for the pupal eclosion was estimated at 75.1 days in females colony to reach the plateau of quality control and 86.4 days in males. Life time gross fecundity was parameters observed for rearing the insect on whole 1056.8 eggs whereas net fecundity was 794.6 eggs, mango fruit. Pupal recovery was higher on the wheat- with an average daily egg production of 18.2 eggs. based diet compared to carrot-based diet (68.8 and However due to a combination of adult mortality and 58.2, respectively). However the two rearing media an egg viability of only 76%, net fertility was 608.1. were comparable with regard to the other quality Survivorship curve showed that survival for both sexes control parameters, including pupal weight, adult was high (>80%) until day 16 and gradually declined emergence, flight ability, fecundity, and fertility. between days 25 to 60, but at a much higher rate for females beyond day 60. More males survived beyond Recently the importance of liquid diet as an excellent day 16 compared to females. Daily egg production substitute to solid based diet is being promoted peaked between days 8-25 and thereafter decreased (Chang, 2009) and to meet the growing demand for asymptotically. Percentage egg hatch was high flies both for parasitoid rearing and post harvest (>70%) between 8-22 days and then decreased, treatment studies, Ekesi et al. (2010) investigated the fluctuating widely, from 30-66% between 25-53 days. effect of two types of larval diet (liquid and carrot The intrinsic rate of increase was 0.113 with a net based solid diet) on different quality control parameter reproductive rate of 273, indicating a daily increase of of B. invadens. It was reported that B. invadens flies 11% and 273-fold increase from one generation to reared on liquid diet out performed those reared on the another. The mean generation time was 31 days and carrot-based diet in all the quality control parameter the population was estimated to double in 6 days. evaluated (egg hatability, pupal recovery, pupal weigh, fecundity, and flight ability) (Ekesi et al., 2010). Rwomushana et al. (2008a) studied the development Currently, the mother colony of B. invadens is being and survival of immature stages of B. invadens in the mass reared on the liquid diet using cheap locally laboratory at five constant temperatures of 150C, 200C, available raw materials. 250C, 300C and 350C and photoperiod of L12:D12. The developmental time for eggs was 5.71 days at e. Distribution 150C, decreasing to 1.24 days at 350C. Larval development periods decreased from 35.95 days at Shortly after the detection of B. invadens, immediate 150C to 6.64 days at 350C. Pupal development at 150C delimiting survey through an FAO emergency took 34.08 days to eclose while no adults emerged at response action detected wide distribution of the pest 350C, this being the most lethal temperature. The across Kenya, Tanzania and Uganda (Mwatawala et longest total development period occurred at 150C al., 2004, Drew et al., 2005; Lux, 2005). Bactrocera (75.74 days) and was shortest at 300C (17.76 days). invadens is now known to occur in 28 African The linear model provided a reliable fit of development countries including the Comoros Archipelago in the rates versus temperature for the immature stages. Indian Ocean as well as in Cape Verde (Ekesi and Lower developmental thresholds that were estimated Billah 2007; De Meyer et al, 2007; De Meyer et al., from linear regression equations for the egg, larva and 2010). The putative aboriginal home of B. invadens is pupal stages were 8.8, 9.4 and 8.7 respectively. Total believed to be Sri Lanka and first specimens in this degree-day accumulation was estimated at 376 DD for country dates to 1993 (Drew et al., 2005). The species development from egg to adult emergence. The has also been reported from southern India highest adult survival given as the mean of emergence (Sithanantham et al., 2006) and Bhutan (Drew et al., from a cohort of 50 eggs occurred at 20-300C. At the 2007). De Meyer et al. (2010) used 2 correlative egg stage, survivorship was highest at 20-300C and at approaches of ecological niche models (ENMs) larva and pupa stages at 250C. namely genetic algorithm (GARP) and maximum entropy (MAXNET) to estimate the potential global

TEAM Newsletter No. 8 (July 2010) 4 distribution of B. invadens based on associations invadens such as mango, avocado and cucurbits from between known occurrence records and a set of Kenya, Tanzania and Uganda are already banned in environmental predictor variables. The projections of Seychelles, Mauritius and South Africa. Trade of the two ENMs for the native range were similar; both several horticultural produce between Africa and the indicating the species prefer hot and humid US has been severely hampered by recently issued environment and Sri Lanka and southern India as Federal Order by US banning importation of several highly suitable. Projecting niche models to Africa and cultivated fruits and vegetables from African countries Madagascar also yielded similar predictions between where B. invadens has been reported (USDA-APHIS, the two methods although with MAXNET appearing 2008). EU interception of African mangoes due to more conservative and both models predicted high phytosanitary regulations on non-European suitability in the Equatorial rain forest belt and the East Tephritidae is tightening. Interception of mangoes due African coastal regions. Global projections also to fruit flies was at 21 rejections in 2008 increasing to showed the same tendencies as with the above with 38 by August 2009 (Guichard, 2009). The direct and GARP predicting somewhat broader potential indirect damage continue to have wide reaching distributional areas in tropical South America and social-economic implications for millions of rural and Southeast Asia (particularly Thailand, Cambodia and urban populations involved in the mango value chain Vietnam). across Africa.

There are six barriers that a species has to overcome Exposure of B. invadens eggs to native Psytallia and to become invasive in a new region (Richardson and Tetrasticus species using sentinel fruit domes in the van Wilgen, 2004). The analysis for B. invadens was field and subsequent dissection of host eggs shows only able to assess one of them, that is, the likelihood heavy encapsulation of the eggs of the native of the species surviving in the new region (De Meyer parasitoid species (Mohamed 2006; S. Mohamed, et al., 2010). In Africa, for example, most of West unpublished). This shows that in addition to the direct Africa, Central Africa and Madagascar, and parts of and indirect damage described above, B. invadens East Africa, are indicated as highly suitable by the could also be contributing to significant ecological sink models. Large regions of the Neotropics are also of native parasitoid species due to the strong immune indicated as being suitable, as is most of Southeast system of the invader. Asia. The authors cautioned that a comprehensive assessment of invasion risk for this species for various g. Host plants parts of the world will require that other barriers be assessed, which will require better knowledge of the Bactrocera invadens possess some characteristics of species’ basic biology and natural history. The authors both k-strategy (i.e. very aggressive, adaptation to concluded that as the assessment did not explore all new environments, strong competitor) (Rwomushana, of the invasion challenges that non-native species 2008) and some traits of r-strategy of being highly face, the maps that were generated in the study fecund (Ekesi et al. 2006) contributing to the should not be interpreted as maps of invasion risk or polyphagous nature of the pest. For example in likelihood of establishment. However, a region Kenya, Rwomushana et al. (2008b), reported fourteen presenting suitable climatic conditions for the species cultivated and wild fruit species as hosts of B. is likely more vulnerable than one presenting invadens. Among the cultivated fruit that were found to unsuitable conditions. be heavily infested were mango, Mangifera indica L. (Anacardiaceae); banana Musa sp. (Musaceae); and f. Economic and ecological impact citrus (Citrus limon, Citrus reticulata, and Citrus sinensis) (all Rutaceae). Marula Sclerocarya birrea The invasion of alien species can cause extensive (Anacardiaceae) and Terminalia catappa economic and ecological damage, with unpredictable (Combretaceae) were the most preferred among the negative effects on crops, ecosystem function, wild host plant. In Tanzania, Mwatawala et al. (2006) resource distribution and environment. Since the who carried out host range study along attitudinal arrival of B. invadens, direct yield loss on mango gradients, added several host plant species to the list, across Africa have been estimated to vary from 30- most important of which is avocado Persea americana 80% (Ekesi et al., 2006; Vayssieres et al., 2009; (Lauraceae). Other plants found to be infested with B. Rwomushana, 2008) depending on locale, cultivar invadens in Tanzania were in the family Cucurbitaceae and season. On citrus species, B. invadens was by far (e.g. watermelon, Citrulius lanatus; cucumber, the dominant fruit fly species accounting for 1-13% Cucumis sativus; Pumpkin, Cucurbita sp.; Kumquat, infestation in the surveys, and overall means of 20- Fortunella margarita; Pomelo, Citrus grandis; Grape 32% in orchards (Hanna et al., 2009). fruit, Citrus paradis (Rutaceae); Peach, Prunus persica; Loquat, Eriobotra japonica (Rosaceae); In addition to these direct loses, indirect losses Robusta coffee, Coffea canephora ( Rubiaceae) and attributed to quarantine restrictions imposed by Governor’s plum, Flacourtia indica (Flacourtiaceae) importing countries to prevent entry and establishment (Mwatawala et al., 2006). of B. invadens have been enormous. In 2008, farmers in Malindi, Coast province of Kenya lost a total of US$ In a followed up study, Mwatawala et al. (2009), added 1 million to B. invadens export market restrictions on several new host species including Solanum mangoes resulting in loss of income to hundreds of aethiopicum, Solanum melongena, Solanum nigrum smallholder mango growers. In the case of avocado, (all Solanaceae), Spondias cytherea Sonn Kenya lost US$ 2 million in 2008 due to B. invadens (Anacardiaceae), Syzigium cumini (Myrtaceae), quarantine restriction imposed by South Africa (Otieno Theobroma cacao (Sterculiaceae), Lucky nut Thevetia et al., 2010). Export of potential host species of B. peruviana,(Apocynaceae), Grape, Vitis vinifera

TEAM Newsletter No. 8 (July 2010) 5

(Vitaceae) as well as S. birrea and T. catappa. The end of April to reach a peak at the end of June during authors also confirm the earlier finding that mango and the rainy season. Regression analyses indicated that guava are the most preferred among the cultivated minimum–maximum temperature, relative humidity host. and rainfall were the major climatic factors influencing fly populations. Daily rainfall was the factor showing In West Africa, the pest has also been reared from the strongest positive correlation with B. invadens citrus, mango, cashew, papaya, guava, pepper, and populations. A consistent population increase of B. several wild host plants (R. Hanna, unpublished data; invadens in the early rainy season caused G. Goergen et al. IITA, unpublished data). considerable damage to mid season and late season mango cultivars and seasonal increase of the B. h. Population dynamics and altitudinal distribution invadens population coincided with the fruiting period of the main mango cultivars in the Northern Guinean Mwatawala et al. (2006) studied the temporal savannah. Mean damage on mangoes for the 2 occurrence of B. invadens in three agro-ecological seasons and 2 studied orchards increased from 17% areas of Morogoro Region, Tanzania, during 2004– in early April to 73% at mid June. 2005. Weekly and monthly trappings were carried out with modified McPhail traps baited with methyl The distribution and abundance across altitudinal eugenol, protein bait or BioLure. The authors report gradients (300 to 2200 meters above sea level) along permanent presence of B. invadens at low and mid- the Voi-Mwatate-Ngerenyi-Wuria Peak on the Taita altitudes (380–520 meter above sea level [masl]) with Hills of Kenya since 2005 to date using methyl peak periods coinciding with the fruiting season of eugenol baited Lynfield traps shows that the average mango and guava. At high altitude (1650 masl) its number of flies is highest (34-142 flies/trap/day) at incidence was only temporal and thought to be as a lower elevations (< 400 masl) and the lowest number result of dispersal from lower altitudes after the end of of flies (< 4 flies/trap/day) at high elevations (>2000 the mango fruiting season. masl). At intermediate elevations (400-1000 masl), fly catches ranged between 12-121 flies/trap/day). Peak Rwomushana (2008) studied the annual and seasonal capture coincided with fruiting of available host fruits population dynamics of B. invadens and native such as mango, guava, citrus, marula and tropical Ceratitis species from 2005-2007 using Multilure traps almond. baited with 2% NuLure on mango in combination with regular fruit collections. The relative abundance index i. Competitive displacement (RAI) in infested fruit ranged from 0.70-1.00 for B. invadens, 0.04-0.30 for C. cosyra while that for C. Before 2003, the mango fruit fly, C. cosyra has long capitata was negligible. Temporal pattern of trap been recognized as the most dominant and damaging captures was closely associated with mango fruit tephritid fruit fly pest of mango in Africa (Lux et al. abundance and seasonal maturation. Generally, adult 2003a). In 2004, a shift in dominance between C. population was low at the onset of fruit maturity in cosyra and B. invadens was observed in mango October, peaked in December when fruit ripening orchards at Nguruman in the Rift Valley Province of occurred and began to decline in January after harvest Kenya, just one year after its detection in the country, was complete. Indices of B. invadens adult population and Ekesi et al. (2006) in assessing the level of ranged from14 flies/trap/day to 30 flies/trap/day. Fruit damage of the new invasive species on mango collections during the 2005/2006 season showed that speculated that competitive displacement appeared to the density of B. invadens in fruits collected from the be in progress (Ekesi et al., 2009). From available ground and tree increased gradually at the onset of data it was shown that in the 2000 to 2002 season, the fruit maturity in October from 2 flies/kg fruit and 0 indigenous fruit fly C. cosyra was the principal pest flies/kg fruit, respectively. This peaked in November at detected in monitoring traps and reared from mango 14 flies/kg for ground fruits and 10 flies/kg fruit for tree fruits apparently because B. invadens had not invaded collected fruits. Later in the mango season, higher the study area. During the October 2003 to January density of adults was recovered from fruits on the tree 2004 growing season, out of 2,916 fruit flies collected (9 flies/kg fruit) than from the ground (8 flies/kg fruit) from monitoring traps, 72% of the population was C. during the December sampling. In the 2006/2007 cosyra, 27% was B. invadens, while other flies fruiting season, peak infestation in fruits occurred in consisting mainly of C. rosa, C. fasciventris, C. November in fruits from the ground (35 flies/kg fruit) as capitata and Dacus spp. made up 1% of the well as those from the tree (21 flies/kg fruit). Similarly, population. In the same year, fruit infestation data higher density of adults was recovered from tree fruits showed that C. cosyra consisted 82% of flies reared (6 flies/kg fruit) than from ground fruits (2 flies/kg fruit) from mango fruit while B. invadens was 18% of the in fruit samples collected in December. population (Ekesi et al., 2009). By November 2004, B. invadens rapidly increased its share of the fly Vayssieres et al. (2009) monitored different fruit flies population reaching 75% in monitoring traps. On including B. invadens that are associated with mango mango fruits, the invader had occupied 80% of the trees in two orchards in Benin using traps baited with population. By October 2007 to January 2008, a methyl eugenol, terpinyl acetate and Torula yeast complete reversal of the 2003 figure was observed during 2005–2006 mango season and analysed with 98% and 88% of the fly population consisting of population fluctuations with respect to environmental B. invadens in traps and fruits, respectively (Ekesi et factors including air temperature, relative humidity and al., 2009). Indeed by 2003 to 2004 season, the density rainfall and different mango cultivars. The authors of C. cosyra on mango fruits was 4.5 flies/kg fruits but showed that B. invadens populations were scarce decreased to 0.7 flies/kg fruit in the 2007/2008 during the dry season, but increased steadily from the season, while the level of infestation by B. invadens

TEAM Newsletter No. 8 (July 2010) 6 has showed an increase from 4.1 flies/kg in the 2004/ invadens (7.6-11.0 flies) under interspecific 2005 season to 5.6 flies/kg fruits in the 2007/2008 competition. The authors concluded that the season (Ekesi et al., 2009). mechanisms contributing to the displacement of C. cosyra by B. invadens may be associated with intricate The authors tested two possible mechanisms interactions between resource pre-emption and responsible for the displacement namely; resource fluctuations in temperature in mango agroecosystems competition by larvae within mango fruits and (Rwomushana et al., 2009). aggression between adult flies. Under interspecific competition, larval duration in B. invadens was j. Mating behaviour significantly shorter (6.8 to 7.3 d) compared with C. cosyra (8.0-9.4 d). Pupal mass in C. cosyra was When B. invadens were released on field cages affected by competition and was significantly reduced containing fruiting mango trees, mating behavior (7.4-9.6 mg) under competitive interaction compared started and continued 1-2 hr period immediately with the controls (12.1-12.8 mg). Interspecific preceding sunset. Prior to 17 00 h, males formed competition also had a significant adverse effect on C. aggregation of 1-2 flies per observational count. At cosyra eclosion, with fewer adults emerging under co- 1800 h, the number of males increased to 5-9 and infestation compared with the controls. Interference leking was exclusively on leaves. Calling which competition through aggressive behaviour showed that consisted of males fanning their wings rapidly and fewer C. cosyra (3.1) landed on mango dome rubbing their abdomen with their legs started at 1800 h compared with the controls (14.2) when adults were and 48% (24/51) of fanning took place at 1830 h and mixed with B. invadens adults in Plexiglas cages. later increased to 64% (41/64) at 1900 h as compared to only 21% (6/28) of males observed after 1900 h Similarly the number of times C. cosyra was observed (Ekesi and Mohamed, unpublished data). Calling ovipositing was significantly lower (0.2) under among groups of 7-9 flies created a buzzing sound competitive interaction compared to the controls (6.1). with small white clouds (possibly dispersing Aggressive encounters in the form of lunging/head- pheromones). Calling males frequently changed butting and chasing off other species from the mango perches on leaves than non-calling males. A male dome was higher for B. invadens compared with C. under observation called for up to 3.9 min during cosyra. It was concluded that exploitative competition which females landed at 2-3 cm in the front of the through larval scrambling for resources and male. Thereafter, the male stops wing-fanning and interference competition through aggressive mount on the female and copulation occurred. At 1830 behaviours of the invader are important mechanisms h, 30% of total mating was observed and at 1900, 54% contributing to the displacement of C. cosyra by B. of the total mating was recorded. Pairing mates invadens in mango agroecosystems (Ekesi et al., remained on the leaves for 5.1 min and then flew 2009). away. No wing-fanning occurred during mating and no obvious courtship behaviors were observed (Ekesi and Rwomushana et al. (2009) further investigated the Mohamed, unpublished data). interspecific interaction of B. invadens and C. cosyra at 4 constant temperatures of 15, 20, 25 and 300C and k. Response to food attractant 50 ± 8% r.h. using manipulative larval co-infestations on mango fruits to assess the mechanisms Rwomushana (2008) evaluated the efficacy of Nulure, contributing to the extirpation of the indigenous Torula yeast, Corn steepwater and a local yeast-based species in mango agroecosystems. Temperature attractant in Multilure, Easy and Lynfield traps for two played a significant role in mediating both the consecutive mango fruiting seasons: October to competitive response and competitive effect of both December 2006 and November 2007 to January 2008 species. At 150C, larvae of C. cosyra could not in attracting B. invadens on mango in Kenya. Multilure complete development to pupal stage under trap baited with torula yeast and Nulure were the most interspecific competition with B. invadens and the low attractive bait and trap combinations with total temperature prolonged development of the invasive captures of 18-30 B. invadens/trap/day and 11- 23 species and reduced adult emergence. When the flies/trap/day, respectively. The Easy trap was the larvae were held at 200C, C. cosyra was driven to least effective trap with all the food attractants tested. extinction (no adult emergence) when B. invadens All attractants caught more females than males except infested mango fruits 1-3 days earlier. However at the for corn steepwater and the highest proportion of same temperature, although larval duration was not females captured was 61% with the Torula yeast affected by interspecific competition in both species, /Lynfield trap combinations. significantly higher number of C. cosyra (13.0-15.0 flies) emerged from mango fruits when the native Ekesi et al. (2007b) conducted 2 field trials on mango species was given 1-3 day head start compared with orchards at Nguruman, Kenya to compare catches of the invasive species (2.5-9.8 flies). At 25-300C, the B. invadens in Multilure trap baited with female larval developmental time of both species was not selective food-based attractants in mango orchards. In affected by interspecific competition. However, apart both trials, the treatments included Multilure trap from the infestation sequence in which C. cosyra was baited with Nulure/borax solution, putrescine infested at 1 day earlier (14.2 flies), adult emergence (PT)/trimethylamine (TMA)/ammonium acetate (AA), 2 of the native species was drastically reduced (1.0-8.6 patches of AA, 2 patches of AA/TMA, 2 patches of flies) under interspecific competition compared with AA/PT and TMA/AA all as wet traps. At Nguruman, the invasive species (11.2-16.6 flies) at 250C. treatment PT/TMA/AA captured significantly more Similarly, at 300C, significantly fewer C. cosyra adults females and males of B. invadens compared with the were recovered (1.0-3.8 flies) compared with B. other treatments while at Muhaka, the Nulure

TEAM Newsletter No. 8 (July 2010) 7 treatment caught more males and females of B. octanoate and ethyl cis-4-octenoate. On both marula invadens although catches were not significantly and Indian almond, prenyl acetate was identified. different from the PT/TMA/AA treatment. The Additional compound identified from Indian almond treatment consisting of 2 patches of AA caught the were citronellyl acetate, geranyl acetate and elemicin lowest number of females and males of B. invadens in but geranyl acetate was the major active compound. both experiments. Total (male and female) catches Apart from the 8 key compounds identified from the 3 also differ significantly among treatments with host plants, several other volatiles mixture found PT/TMA/AA and Nulure treatments recording the include some terpenes esters, hydrocarbons and highest number of male and female flies of B. acids. Individual compounds and their blends are invadens. Percent female catches ranged from 45- being tested using GC-EAD and wind tunnel 50% at Nguruman and 58-68% at Mukaha. behavioural assay (Ekesi, 2010).

Field trials conducted at Nguruman, Kenya during the l. Sexual maturation and response to methyl 2007/2008 and 2008/2009 mango season compared 6 eugenol commercial food attractants (Biolure, Torula yeast, Mazoferm, Nulure, Hymlure) and 2 locally developed Assessment of sexual development and mating attractants from waste brewer’s yeast (Kenya and response of laboratory reared flies shows that females Ugandan Yeast). In both seasons Mazoferm, torula population began mating at 4 days of age with more yeast and the food lures based on local (Kenya and than 50% mated at day 8 after eclosion and 100% of Uganda) waste brewer’s yeast captured significantly the females were mated at day 12 after emergence. more female flies (32-62 females/trap/day) than However females of wild population had longer sexual Biolure, GF-120, Nulure and Hymlure (5-19 maturation time with mating starting at 12 days after females/trap/day) (Ekesi and Mohamed, unpublished eclosion with 50% mating at 18 days after eclosion data). Percent female catches was however highest in and 86% mating occurring at 23 days after emergence the Nulure (73%) and ranged from 52-66% in the other (Ekesi et al., unpublished data). Assessment of the baits (Ekesi, 2010). In Benin, 3 baits (Torula yeast, relationship between sexual maturation rate and Nulure and Biolure) were tested for attraction to B. response to methyl eugenol in field cages revealed invadens. Catches were 3-4 fold-higher in torula yeast that response of laboratory reared male flies increased (92-241 flies/2 weeks) than in Nulure (30-90 flies/2 with age with 30% laboratory reared flies responding weeks). Biolure was the least effective (Ekesi, 2010). to methyl eugenol when 2 days and 90% when they were 10 days old. In wild population of male B. Using the Modified McPhail traps baited with different invadens, 24% responded to methyl eugenol when 8 types of lures (Trimedlure, Methyl eugenol, Cue Lure, days old and 92% when 21 days old (Ekesi et al., protein bait and single matrix BioLure containing unpublished data). Males of both laboratory and wild putrescine,ammonium acetate and trimethylamine) to populations of B. invadens therefore responded document the diversity of fruit flies in four main agro- strongly to methyl eugenol prior to sexual maturity and ecological zones in the Morogoro region of Tanzania, this probably contributes to the success of male Mwatawala et al. (2006) caught the following number annihilation in management of B. invadens (Hanna et of B. invadens in the different attractant types: methyl al., 2009). eugenol (180269 flies), protein baits (4944 flies), BioLure (324 flies), Trimed lure (62 flies), Cue Lure (15 3. MANAGEMENT flies). Mwatawala et al. (2006) also used the same lure types (methyl eugenol, protein bait and Biolure) to a. Suppression through baiting technique assess the seasonality and host utilization pattern of B. invadens across the same region. Fruit fly suppression is mainly based on the use of food baits (hydrolyzed proteins or their ammonium Kimbokota (2010) assessed the bahavioural response mimics) mixed with a killing agent and this method has of B. invadens to three major host fruits (mango, been tested for the management of B. invadens. Ekesi Terminalia catappa and Sclerocarya birrea) at 3 et al. (2007c) assessed the efficacy of Nulure bait maturity stages (fruitlet, mature and ripe) using a flight mixed with spinosad in suppressing the population of glass dual choice flatbed wind tunnel in the laboratory. B. invadens and other native fruit fly pests on mango In all mango cultivars tested (Apple, Sensation and during the November/December 2005 mango season Kent), flies were able to respond to fruit volatiles at all in Malindi, Kenya. Results showed that application of maturity stages but at varying degrees. More flies the Nulure/spinosad bait spray reduced fruit fly were attracted to ripe mango fruits than fruitflets and population by 58%, relative to the control. Mean fruit mature fruits. In T. cattapa, significantly more female infestation was 34% and 73% in untreated control flies were attracted to mature fruits than fruitlets and plots. ripe fruits. In marula, significantly higher number of flies was attracted to mature and ripe fruits than fruits Effectiveness of GF-120 spinosad fruit fly bait in at fruitlet stage. The study provides important baseline suppressing B. invadens and other mango infesting information to identification of volatiles from these fruit flies was assessed by comparing treated orchards fruits that could be utilized for detection, monitoring with untreated mango orchards in Benin (Vayssieres and management of B. invadens. The authors trapped et al., 2009). In 2006 and 2007, the larval infestation volatiles from ripe fruits of the 3 major host plants by B. invadens and other native fruit fly species was above and GC-EAD analysis detected a total of eight significantly lower in plots treated with GF-120 than in active compounds from the host fruits and the untreated control plots. GF-120 provided an 81% compounds were identified with the aid of GC-MS reduction in the number of pupae/kg of mango fruit analysis. On mango, active compounds included ethyl after weekly applications for 7 wk in 2006 and an 89%

TEAM Newsletter No. 8 (July 2010) 8 reduction after 10 wk of weekly applications in 2007 Being an alien pest and seemly lacking resident (Vayssieres et al., 2009). parasitoid species in Africa, B. invadens represents a typical target for classical biological control. Therefore, Field trials conducted for 2 seasons on mango a search for a co-evolved parasitoid species was orchards at Nthagaiya, Kenya, showed that application initiated. The first approach undertaken with regard to of GF-120 led to a significant reduction in fruit damage classical biological control was exploration for by B. invadens and indigenous Ceratitis species parasitoids in the pest’s putative aboriginal home. compared to the control: 30% fruit damage in treated Three exploration missions were undertaken by plots against 59% damage in control plots (2006-2007 icipe/IITA scientists. Result of the survey proved the mango season); and 28% fruit damage in treated plots anticipated high richness of Sri Lanka in various compared with 52 mango damage in control plots parasitoid guilds as well as predators. Among the (2007-2008 mango season) (Ekesi., 2010). parasitoid species recovered during the explorations were four Braconids, D. longicaudata, Psyttalia incisi, b. Potential for male annihilation technique Fopius arisanus, Fopius sp.; one Eulophid; Tetrastichus sp; one Pteromalid; Spalangia sp; and Male annihilation techniques (MAT) aims at reducing one Diapriid, Trichopria sp (S. Mohamed et al., male fruit fly populations to low levels that mating does unpublished data; M. Billah et al., unpublished data). not occur (in the case of eradication) or reduced to low Three predator species were also recovered during levels (in the case of suppression). Hanna et al. (2008) the same exploration including one Staphylinid assessed the potential of male annihilation technique species, one unidentified beetle and another (MAT) in suppressing the population of B. invadens on unidentified mite (M. Billah, unpublished data). mango in Benin in 2008. During the first 2 weeks of However, due to extreme difficulties in obtaining trapping, it was reported that B. invadens populations import permits from the Sri Lankan government, the were very low during March and April, but were more natural enemies have not been imported to Africa. abundant in MAT orchards compared with control orchards. The trend was reversed by early May when The second approach employed by icipe was B. invadens populations increased steeply in the importation of promising parasitoids from laboratories control orchards, while B. invadens populations in the with established colony of fruit fly parasitoid that are MAT orchards remained relatively flat and at levels of closely related to the target pest species (i.e. B. less than 10% of those in the control orchards. invadens). In this regard, two parasitoid species, Percentages of fruits infested was similar for mid- Fopius arisanus (Hymenoptera: Braconidae), and season varieties in the control orchards (43-53%), but Diachasmimorpha longicaudata (Hymenoptera: significantly lower in MAT orchards where fruit fly Braconidae) were imported in 2006 from the University infestations were reduced by 39.8% for Eldon and of Hawaii at Manoa, Honolulu, Hawaii, where they 46.8% for Kent varieties, and with up to 60% reduction were being reared and released for the control of the in pupae/kg fruit. Average fruit infestation of the early oriental fruit fly, Bactrocera dorsalis (a closely related season variety Gouverneur was less than 1% in all species to B. invadens) (Zwaluwenberg, 1947). At orchards. icipe, basic bioassays pertaining to preference, acceptability and physiological suitability for the c. Parasitoids immature development of B. invadens to the two introduced parasitoid species were carried out under Shortly after B. invadens was detected in Kenya, restrict quarantine condition. Results of these tests attempts were made to identify a native parasitoid proved that the egg parasitoid F. arisanus is a very species that would successfully develop in this host promising candidate (>70% parasitism) for and able to establish what is known as new management of B. invades (Mohamed et al., 2010), association. Two solitary parasitoids, Psyttalia cosyrae and when used in a holistic IPM approach should and P. phaeostigma (Hymenoptera: Braconidae) and contribute substantially to the suppression of the one gregarious parasitoid, Tetrastichus giffardii exploding population of B. invadens. (Hymenoptera: Eulophidae) were tested. Bactrocera invadens was readily accepted by T. giffardii and to a On the other hand D. longicaudata perform poorly lesser extent by the two Psyttalia species. However all (14% parasitism) on the target host as almost one eggs of the two Psyttalia species and nearly all eggs third of this parasitoid eggs that ovipoisited in B. of T. giffardii were encapsulated in larvae of B. invadens larvae were encapsulated (Mohamed et al., invadens (Mohamed et al., 2006; S. A. Mohamed, 2008). The encapsulation of D. longicaudata by B. unpublished data). None of the few individuals of T. invadens is somewhat intriguing given the fact that this giffardii progeny that escaped encapsulation was able parasitoid is known to introduce a symbiotic to complete development to the adult stage. This level entomopoxvirus (DlEPV),that suppresses the immune of parasitoid encapsulation by B. invadens as system of its host during oviposition (Lawrence and indicated earlier suggests that in addition to the very Akin 1990; Lawrence 2002; Lawrence 2005). The virus destructive nature of this pest, it also has a potential replicates in hemocytes of the host and disrupts the for serving as a reproductive sink for some of the encapsulation process by making the hemocytes to indigenous parasitoid fauna such as T. giffardii. Also, lose their adhesive property (Lawrence 2005). collection of 34,430 kg of various host fruit of B. However, interestingly after 36 generations of rearing invadens (wild and cultivated host) sampled from East D. longicudata on B. invadens, more virulent offsprings and West Africa yielded no single parasitoid (S. Ekesi, are emerging and have been able to counteract the unpublished; R. Hanna, unpublished) immune response of the pest.

TEAM Newsletter No. 8 (July 2010) 9

Based on the encouraging performance of Fopius in mango production system showed that 60% of the arisanus, coupled with the innate traits of this growers attributed better mango quality in terms of parasitoid species such as effective searching appearance, shelf-life and sweetness to the presence behavior and high foraging efficiency (Wang and of O. longinoda (Sinzogan et al., 2008). Nevertheless, Messing (2003), field releases of the parasitoid are 40% of the pickers still considered weaver ants a underway in Kenya, Tanzania, Mozambique and Benin nuisance pest during harvest and methods for following the approval of the respective government minimizing ant aggression and irritation need to be authorities. Preliminary results showed over 40% developed to gain wider acceptance of the technology parasitism in the field on mango and guava. by mango growers (Sinzogan et al., 2008). d. Use of fungal entomopathogens f. Orchard sanitation

Compared with other methods for suppressing fruit Poorly managed or abandoned orchards and a variety flies, the concept of using entomopathogenic fungi for of wild host can results in high population build up of fruit fly suppression is relatively new (Ekesi et al., fruit flies. Rwomushana (2008) was able to 2007c). In recent studies, several potent isolates have demonstrate that the density of B. invadens was been identified against B. invadens both for soil significantly higher in fallen mango on the ground inoculation targeting pupariating larvae and adult using compared with that sampled from the tree signifying autodissemination devices (Ekesi et al., 2007c; Ouna, the important role of orchard sanitation in the 2010). The ultimate goal is to reduce oviposition by management of the insects. The collection and gravid female fruit flies and the overall effect of fungal deposition of fallen, damaged and unwanted fruits in infection on adult fecundity and fertility has been an Augmentorium (Klungness et al., 2005) is being shown to be very high. Ouna (2010) demonstrated strongly advocated among fruit and vegetable growers over 70% reduction in B. invadens egg fertility due to across Africa. Removal of infested can contribute fungal infection. In field suppression trials, Ekesi et al. significantly to reduction of fruit fly population (2007c) applied granular formulations of Metarhizium (Rwomushana, 2008). anisopliae at the rate of 60 kg/ha (one gram of spore consisted of 3 x 108 conidia) once at the onset of g. IPM mango fruiting to assess the impact of the treatment on the population of B. invadens and mango fruit Previous experience with exotic and native fruit fly infestation. Results showed that application of the species in Africa and with other species in similar fungus reduced fruit fly population by 64% relative to agroecologies in Latin America and the South Pacific the control. Mean fruit infestation was 46% in the has shown that management of fruit fly species in fungus treatment and 73% in untreated control plots. general is unlikely to be successful if based on a Granular formulation of fungal biopesticides as used in single management technique (Aluja et al., 1996; this study has the advantage of increasing the Allwood and Drew, 1997; Lux et al., 2003a). An concentration of inoculum in the soil through integrated pest management (IPM) approach offers sporulation in and/or on the granular substrate, and the best method to improve the economies of the microcyclic conidiation. While soil inoculation with M. production system by reducing yield losses and anisopliae cannot be considered as a stand-alone enabling growers to comply with stringent quality strategy, the fungus has a significant role to play when standard of the export market (Aluja et al., 1996; combined with other IPM component for B. invadens Allwood and Drew, 1997; Lux et al., 2003a). The suppression (see section on IPM). approach that is being promoted across Africa by the icipe-led African Fruit Fly Program (AFFP) is to use a e. Use of the weaver ant combination of management techniques that is based on at least 2 or all the components listed in this mini- Van Mele et al. (2007) used field exclusion review. For example, Ekesi et al. (2007c) was able to experiments in mango orchards to demonstrate the demonstrate that application of a combination of efficacy of the weaver ant Oecophylla longinoda in the Nulure/spinosad bait spray with soil inoculation of M. protection of mango infestation by B. invadens and anisopliae reduced B. invadens population by 79% native Ceratitis species. Fruit fly damage was as low relative to the control. Mean mango fruit infestation as 3.3% in Eldon and Kent and 0% in Gouverneur in was 10% in the combined treatment of bait and fungus trees with ant. However, mangoes from trees where and 73% in untreated control plots. Similarly, in field ants were excluded yielded as much as 44, 79, and trials conducted during the 2006-2007 mango season, 108 fruit fly pupae for Eldon, Gouverneur, and Kent, combined application of M. anisopliae and GF-120 respectively. Deterrence and disturbance by ants spinosad bait spray achieved the highest reduction of during fruit fly oviposition are believed to be B. invadens (92.1%) relative to the control at the last responsible for the protection of the fruits from fruit fly date of sampling (Ekesi, 2010). Application of M. damage. In a follow up studies, Van Mele et al. (2009) anisopliae and GF-120 either alone or in combination showed that B. invadens oviposition is affected by ant led to significant reduction in mango damage by fruit secretions. When offered ant-exposed and unexposed flies: % fruit infestation was 46%, 30%, 16% and 59% mangoes in the absence of the ants, B. invadens were in the M. anisopliae alone, GF-120 alone, M. reluctant to land on ant-exposed fruits and, when they anisopliae plus GF-120 and control plots, respectively. do land they often take off quickly and fail to oviposit. In the 2007-2008 mango season, % reduction of fruit The number of puparia collected from unexposed flies relative to control was also highest in the M. mangoes was approximately eight-fold higher than anisopliae plus GF-120 treatment achieving 77.3% from ant-exposed ones. Studies based on local reduction in B. invadens. The respective % fruit knowledge of growers on the benefits of weaver ants infestation was 38, 28, 11 and 52% in M. anisopliae

TEAM Newsletter No. 8 (July 2010) 10 alone, GF-120 alone, M. anisopliae plus GF-120 and often cited as possible impediment for application of control plots. An integrated approach to the area-wide management but potential exists for this management of B. invadens therefore offers better management approach in targeted agroecological prospects for the horticulture industry than zones and this should be pursued. Similarly, the use of management options that are based on single bullet. sterile insect technique (SIT) should be possible in All the listed management techniques are currently isolated ecologies and thus worth exploring. Post available across Africa although grower education will harvest treatment research should be vigorously be crucial to adoption of the IPM strategies for B. pursued and the need for a standardized or generic invadens. post harvest treatment regimes acceptable for all countries across SSA negotiated and agreed with h. Post harvest importing countries will become necessary in the future. Finally, the protection of the African horticulture The level of control measures documented above at against alien invasive pest fruit flies should be in the the pre-harvest management levels is not sufficient for long-term as important as the creation of short-term quarantine sensitive markets and without post harvest export opportunities through suppression of fruit flies treatment to provide quarantine security, export of that are already in the continent. The need to fruits and vegetables to lucrative markets abroad will strengthen the quarantine security in SSA as a whole be limited by quarantine restrictions. Cold (citrus and can therefore not be overemphasized. avocado) and heat (mango) treatments activities have commenced at icipe in close collaboration with the References Citrus Research International (CRI), South Africa and South African Avocado Growers Association (SAAGA) Allwood A. J. and Drew R. A. I. (1997) Control strategies for fruit flies (family Tephritidae) in the South Pacific, pp. 171– to develop post harvest treatment parameters for B. 178. In Management of Fruit Flies in the Pacific (Edited by invadens. Once completed and implemented, this A. J. Allwood and R. A. I. Drew). ACIAR Proceedings No. should increase export potential for these fruits from 76. Africa. Aluja M., Celedonio-Hurtado H., Liedo P., Cabrera M., Castillo F., Guillen J. and Rios E. (1996) Seasonal 4. CONCLUSIONS AND PERSPECTIVES population fluctuations and ecological implications for management of Anastrepha fruit flies (Diptera: Tephritidae) Since the detection of B. invadens there has been a in commercial mango orchards in southern Mexico. Journal of Economic Entomology 89: 654–667. steady increase in the volume of research activities Chang CL. (2009). Fruit fly liquid larval diet technology aimed at understanding the taxonomy, biology, transfer and update. Journal of Applied Entomology 133, ecology and management of the pest. Potentials 164-173 abound to improve upon this existing knowledge in the Clarke, A. R., Armstrong, K. F., Carmichael, A. E., Milne, J. various facets to guide implementation of R., Raghu, S., Roderick, G. K and. Yeates, D. K (2005). management methods. Molecular relationships, Invasive phytophagous pests arising through a recent mating compatibility test and crosses with closely tropical evolutionary radiation: the Bactrocera dorsalis related species should open up new opportunities to complex of fruit flies. Annual Review of Entomology 50 293- 319. unravel the taxonomic mystery of this pest. Our Copeland RS, Wharton RA, Luke Q, De Meyer M, Lux SA, understanding of off-season survival, altitudinal limit Zenz N, Machera P, Okumu, M, (2006). Geographic and factors that regulate population abundance in the distribution, host fruits, and parasitoids of African fruit fly field is still very marginal. There is substantial gap in pests Ceratitis anonae, Ceratitis cosyra, Ceratitis knowledge with regard to the behavioural studies and fasciventris, and Ceratitis rosa (Diptera: Tephritidae) in dispersal ability of the pest. There is also scope to Kenya. Annals of the Entomological Society of America 99: expand knowledge on the chemical ecology of the 261-278. pest that could lead to the development of new De Meyer, M. Copeland, R. S., Lux, S. A., Mansell, M., Quilici, S., Wharton, R., White, I. M. and Zenz, N. J. (2002). attractants. In this regard, additional studies are Annotated checklist of host plants for Afrotropical fruit flies warranted on bait development including those based (Diptera: Tephritidae) of the genus Ceratitis. Musée Royal on locally available raw materials such as waste de l’Afrique Centrale Tervuren, Belgique 27: 1-91. brewer’s yeast. Torula yeast and Moazoferm are by far De Meyer, M., Mohamed, S. & White, I.M. (2007) Invasive the most efficient food baits for B. invadens currently, fruit fly pests in Africa. http://www.africamuseum.be/fruitfly/ and opportunities exist to research into possibilities of AfroAsia.htm (Accessed 20 May 2010). converting the 2 food baits into solid or dry baiting De Meyer, M., Robertson, M.P., Mansell, M.W., Ekesi, S., stations. While the use of spinosad bait spray, soil Tsuruta, K., Mwaiko, W., Vayssières J.-F. and Peterson A.T. (2010). Ecological niche and potential geographic treatment with M. anisopliae and the weaver ant distribution of the Invasive Fruit Fly Bactrocera invadens technology has proven effective in Benin and Kenya, (Diptera, Tephritidae). Bulletin of Entomological Research this is based on few trials under smallholder settings. , 100: 35-48. Large-scale field testing across different Drew, R.A.I., Tsuruta, K. and White, I.M. (2005) A new agroecological zones in Africa is warranted. Foreign species of pest fruit fly (Diptera: Tephritidae: Dacinae) from exploration needs to be expanded and efficient Sri Lanka and Africa. African Entomology 13: 149-154. biological-control agents that target different Drew, R. A. I., M. C. Romig, and C. Dorji. (2007). Records of developmental stages of B. invadens need to be Dacine fruit flies and new species of Dacus (Diptera: Tephritidae) in Bhutan. The Raffles Bulletin of Zoology, introduced. Although no native parasitoid species have 55:1-21. been observed attacking B. invadens, attention should Drew, R.A.I., Raghu, S. and Halcoop, P. (2008) Bridging the be given to the possibility of new associations in other morphological and biological species concepts: studies on African genera such as Diachasmimorpha and Fopius the Bactrocera dorsalis (Hendel) complex (Diptera: as well as exploring for efficient indigenous pupal Tephritidae: Dacinae) in South-east Asia. Biological Journal parasitoid. The fragmented production structure is of the Linnean Society 93, 217–226.

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Ekesi S., Nderitu P. W. and Rwomushana I. (2006) Field entomopoxvirus in host haemocytes. Journal of Insect infestation, life history and demographic parameters of Physiology, 51:221-233. Bactrocera invadens Drew, Tsuruta & White, a new Lawrence, P.O, Akin DB, (1990). Virus-like particles from the invasive fruit fly species in Africa. Bulletin of Entomological poison glands of the parasitic wasp Biosteres Research, .96: 279-386. longicaudatus (Hymenoptera: Braconidae). Canadian Ekesi, S., and Billah, M.K. (2007). A field guide to the Journal of Zoology 68, 539–546. management of economically important tephritid fruit flies in Lux, S. A., Copeland, R. S., White, I. M., Manrakhan, A., and Africa. ICIPE, Nairobi, Kenya Billah, M. K. (2003a). A New Invasive Fruit Fly Species Ekesi, S;Nderitu, P. W; and Chang, Chiou Ling(2007a). from the Bactrocera dorsalis (Hendel) Group Detected in Adaptation to and Small-Scale Rearing of Invasive Fruit Fly East Africa. Insect Science and Its Application 23: 355– Bactrocera invadens (Diptera: Tephritidae) on Artificial Diet. 361. Annals of the Entomological Society of America, 100: 562- Lux, S.A., Ekesi, S., Dimbi, S., Mohamed, S. and Billah, M. 567. (2003b) Mango infesting fruit flies in Africa-Perspectives Ekesi S., Lux S. A. and Billah M. K. (2007b) Field and limitations of biological approaches to their comparisons of food-based synthetic attractants and traps management. pp. 277-293 in Neuenschwander, P., for African fruit flies. IAEA Technical Bulletin 1574: 205-222 Borgemeister, C., and Langewald, J. (Eds.), Biological Ekesi, S., Dimbi, S. and Maniania, N.K. (2007c) The role of Control in Integrated Pest Management Systems in Africa. entomopathogenic fungi in the integrated management of CABI, Wallingford. tephritid fruit flies (Diptera: Tephritidae) with emphasis on Lux, S.A. (2005) Project Report: FAO-TCP on Bactrocera species occurring in Africa. In: Use of Entomopathogenic invadens. FAO, Rome Fungi in Biological Pest Management (S. Ekesi & N.K. Mohamed, S.A., Wharton, R.A, von Mérey, G., and Maniania, Eds.), pp. 239-274. Research SignPost, Kerala Schulthess, F (2006). Acceptance and suitability of Ekesi, S., Billah, M.K., Nderitu, P.W., Lux, S.A. and different host stages of Ceratitis capitata (Wiedemann) Rwomushana, I (2009). Evidence for competitive (Diptera: Tephritidae) and seven other tephritid fruit fly displacement of the mango fruit fly, Ceratitis cosyra by the species to Tetrastichus giffardii Silvestri (Hymenoptera: invasive fruit fly, Bactrocera invadens (Diptera: Tephritidae) Eulophidae). Biological Control 39: 262-271. on mango and mechanisms contributing to the Mohamed S.A., Ekesi S. and Hanna R. (2008) Evaluation of displacement. Journal of Economic Entomology 102: 981- the impact of Diachasmimorpha longicaudata on 991. Bactrocera invadens and five African fruit fly species. Ekesi, S. (2010) Progress Report: Development and Journal of Applied Entomology 132, 789–797. Implementation of a Sustainable IPM Program for Major Mohamed, S.A., Ekesi, S., and Hanna, R. (2010) Old and Mango Pests and Opportunity for Improving Market and new host-parasitoid associations: parasitization of the Processing Information in sub-Saharan Africa. Gesellschaft invasive fruit fly Bactrocera invadens (Diptera: Tephritidae) für Technische Zusammenarbeit (GTZ) GmbH, Eschborn, and five other African fruit fly species by Fopius arisanus, Germany an Asian opiine parasitoid. Biocontrol Science and Guichard, C. (2009). EU Interceptions rising in 2009. In Technology 10: 183-196. Fighting Fruit Flies Regionally in sub-Saaharan Africa. Mwatawala, M., De Meyer, M., White, I. M., Maerere, M., and COLEACP/CIRAD, Information Letter 4, 4. Makundi, R.H., (2007). Detection of the solanum fruit fly, Hanna, R., Gnanvossou, D., and Grout, T., (2008). Male Bactrocera latifrons (Hendel) in Tanzania (Dipt., annihilation technique (MAT) in eliminating B. invadens in Tephritidae). Journal of Applied Entomology 131, 501-503. northern Benin. In Fighting Fruit and Vegetable Flies Mwatawala, M.W., De Meyer, M., Makundi, R.H., Maerere, Regionally in Western Africa. COLEACP/CIRAD, A.P. (2009). Host range and distribution of fruit-infesting Information Letter 7,3. pestiferous fruit flies (Diptera, Tephritidae) in selected Hanna, R., Gnanvossou, D., and Grout, T., (2009). Citrus areas of Central Tanzania. Bulletin of Entomological infestations by tephritid fruit flies in sub-Saharan Africa: first Research 99: 629-641 results from Benin show substantial infestations largely by Mwatawala, M.W., De Meyer, M., Makundi, R.H., and the Sri Lanka fruit fly Bactrocera. In Fighting Fruit and Maerere, A.P., (2006). Seasonality and host utilization of Vegetable Flies Regionally in Western Africa. the invasive fruit fly, Bactrocera invadens (Dipt., COLEACP/CIRAD, Information Letter 2, 3. Tephritidae) in central Tanzania. Journal of Applied Khamis F, Karam N, Guglielmino CR, Ekesi S, Masiga D, De Entomology 130, 530-537. Meyer M, Kenya EU and Malacrida A.R (2008) Isolation Mwatawala, M.W., White, I.M., Maerere, A.P., Senkondo, F.J. and characterization of microsatellite markers in the newly and DE Meyer, M. (2004). A new invasive Bactrocera discovered invasive fruit fly pest in Africa, Bactrocera species (Diptera: Tephritidae) in Tanzania. African inavadens (Diptera: Tephritidae). Molecular Ecology Entomology 12: 154–156. Resources 8, 1509 – 1511. Otieno,W S., Mucheni, S, Waiganjo, M., Chepkwony, N,. and Khamis FM, Karam N, Ekesi S, De Meyer M, Bonomi A, Arim, O. J. (2010). Fruit flies Threats and fighting Gomulski LM, Scolari F, Gabrieli P, Siciliano P, Masiga D, perspective in KENYA Country Report. World Bank Video Kenya EU, Gasperi G, Malacrida A.R, and Guglielmino C.R Conference on Fighting Fruit flies in East and Southern (2009) Uncovering the tracks of a recent and rapid Africa. invasion: the case of the fruit fly pest Bactrocera invadens http://www.globalhort.org/media/uploads/File/Fruit%20Fly/F (Diptera: Tephritidae) in Africa. Molecular Ecology 18: ruit%20fly%20threat%20to%20Kenya.pdf. (Accessed 2nd 4798-4810. June, 2010). Kimbokota, F (2010). Behavioural and chemical ecology of Ouna, E.A (2010). Entomopathogenicity of Hyphomycte fungi oviposition by the mango-infesting fruit fly, Bactrocera to fruit fly Bactrocera invadens (Diptera: tephiritidae) and invadens, a new invasive species of Asian origin. Ph. D. their potential for biological control on mango. M.Sc. thesis, Thesis, University of Dar Es-salaam, Dar Es-salaam, Kenyatta University, Nairobi, Kenya. Tanzania. Richardson, D.M. and van Wilgen, B.M. (2004) Invasive alien Klungness, L.M., Jang, E.B., Mau, F.L., Vargas, R.I., Sugano, plants in South Africa: how well do we understand the J.S., and Fujitani, E. (2005) New sanitation techniques for ecological impacts? South African Journal of Science 100, controlling Tephritid fruit flies (Diptera: Tephritidae) in 45–52. Hawaii. J. Appl. Sci. Environ. Manage. 9: 5 – 14 Rwomushana, I. (2008) Bioecology of the invasive fruit fly Lawrence, P.O, (2002). Purification and partial Bactrocera invadens (Diptera: Tephritidae) and its characterization of an entomopoxvirus (DlEPV) from a interaction with indigenous mango infesting fruit fly species. parasitic wasp of tephritid fruit flies. Journal of Insect PhD thesis, Kenyatta University, Kenya. Science 2, 1–12. Rwomushana, I., Ekesi, S., Ogol, K.P.O C. and Gordon, I. Lawrence, P.O, (2005). Morphogenesis and cytopathic (2008a) Effect of temperature on development and survival effects of the Diachasmimorpha longicaudata

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of immature stages of Bactrocera invadens (Diptera: asociados al mango : inventario y fluctuacion de las Tephritidae). Journal of Applied Entomology 132: 832-839. capturas en la Guinea maritime. Fruits, 55: 259-270. Rwomushana, I., Ekesi, S., Gordon, I, and Ogol, C. K.P.O Vayssières J.F., Wharton R., Delvare G., Sanogo F. (2004). (2008b) Host Plants and Host Plant Preference Studies for Diversity and pest control potential of hymenopteran Bactrocera invadens (Diptera: Tephritidae) in Kenya, a New parasitoids of Ceratitis spp. on mangos in Mali. In: Barnes Invasive Fruit Fly Species in Africa. Annals of the Brian N. (ed.). Proceedings of the 6th International Entomological Society of America 101(2): 331-340. Symposium on Fruit Flies of Economic Importance, 6-10 Rwomushana, I., Ekesi, S., Ogol, C.K.P.O. and Gordon, I. May 2002, Stellenbosch, South Africa. Irene Isteg Scientific (2009) Mechanisms contributing to the competitive success Publications, p. 461-464. International Symposium on Fruit of the invasive fruit fly Bactrocera invadens over the Flies of Economic Importance. 6, 2002-05-06/2002-05-10, indigenous mango fruit fly, Ceratitis cosyra: the role of Stellenbosch, South Africa. temperature and resource pre-emption. Entomologia Vayssières, J.F., Sinzogan A.A.C., Korie, S., Experimentalis et Applicata 133: 27-37. Ouagoussounon, I., Thomas-Odjo,A. (2009). Effectiveness Sinzogan A.A.C., Van Mele, P., and. Vayssieres, J.-F of spinosad bait sprays (GF-120) in controlling mango- (2008); Implications of on-farm research for local infesting fruit flies (Diptera: Tephritidae) in Benin. Journal of knowledge related to fruit flies and the weaver ant Economic Entomology 102:515-21. Oecophylla longinoda in mango production. International Wang, Xin-geng and Messing, R.H. (2003). Foraging Journal of Pest Management, 54: 241-246. behavior and patch time allocation by Fopius arisanus Sithanantham S, Selvaraj P, and Boopathi T (2006) The fruit (Hymenoptera: Braconidae), an egg-larval parasitoid of fly Bactrocera invadens (Tephritidae: Diptera) – new to tephritid fruit flies. Journal of Insect Behavior, 16:593-612. India. Pestology 30, 36–37. USDA-APHIS (2008) Federal import quarantine order for host White, I.M. and Elson-Harris, M.M. (1992) Fruit Flies of materials of Bactrocera invadens (Diptera: Tephritidae), Economic Importance: Their identification and bionomics. invasive fruit fly species. USDA-APHIS. 3pp. 601 pp. CAB International, Wallingford. Van Mele P., Vayssières J.F., Van Tellingen E. and Vrolijks J. White, I. M (2010). Identification of peach fruit fly, Bactrocera (2007) Effects of the African weaver ant Oecophylla zonata (Saunders), in the Eastern Mediterranean. longinoda in controlling mango fruit flies (Diptera Diagnosis Bactrocera (Bactrocera) zonata (Saunders). Tephritidae) in Benin. Journal of Economic Entomology http://www.iaea.org/programmes/.nafa/d4/public/zonata.ht 100, 695–701. ml#efflatoun (accessed, 2nd June 2010). Van Mele, P., Vayssières, J.F., Adandonon, A. and Sinzogan, Zwaluwenberg, R. H. van, (1947). Notes and exhibitions. A. (2009). Ant cues affect the oviposition behaviour of fruit Proceedings of the Hawaiian Entomological Society 13: flies (Diptera: Tephritidae) in Africa. Physiological 8. Entomology, 34, 256-261. Vayssières J.F. and Kalabane S.. (2000). Inventory and fluctuations of the catches of Diptera Tephritidae Sunday Ekesi and Samira A. Mohamed associated with mangoes in Coastal Guinea = Diptères International Centre of Insect Physiology and Ecology Tephritidae associés au manguier : inventaire et fluctuation des captrues en Guinée maritime= Dipteros tephritidae (icipe), Nairobi, Kenya [email protected]

PHOTOS FROM TRAINING COURSE

Group training course on Fruit Fly Detection and Monitoring for quarantine personnel and agricultural extension officers of Mozambique.

TEAM Newsletter No. 8 (July 2010) 13

Group training course on Fruit Fly Taxonomy and management for quarantine personnel and agricultural extension officers from West African countries.

STUDIES ON THE REPRODUCTIVE BIOLOGY OF THE HIGHLY INVASIVE INSECT PEST SPECIES CERATITIS CAPITATA (WIEDEMANN; DIPTERA: TEPHRITIDAE) USING NEUTRAL MARKERS AND NEW TRANSGENIC TOOLS

Dissertation of FRANCESCA SCOLARI The research activity of this phD thesis was directed to for a PhD in CELLULAR BIOLOGY implement the basic knowledge of the biology of the species, with the final aim of improving the current University of Pavia, Italy control methods based on SIT. The studies took Tutor: Prof. Giuliano Gasperi advantage of the markers already available, i.e. neutral microsatellite markers, but also developed SUMMARY appropriate new transgenic tools.

The Mediterranean fruit fly (medfly) Ceratitis capitata Once it had been assessed that medfly females mate was the first true fruit fly species to extend its home several times in the wild and that the frequency of range and gradually became a global invader remating can be influenced by environmental factors (Malacrida et al., 2007 for a review). For this reason, it and population size (Bonizzoni et al., 2006), it was has been subject of numerous genetic studies over the important to study how the sperm from different males last two decades and has become a model for the are used after their storage in the female study of invasive processes and for the development spermathecae and fertilization chamber. Therefore, and refinement of control methods, such as the Sterile attention was focused on verifying the presence and Insect Technique (SIT). The wide range of biochemical level of differential sperm use by twice mated females. and molecular markers available for the medfly This study confirmed the presence of a strong allowed a thorough investigation of its reproductive precedence of the last male over the first in siring the behavior, which plays an important role in the progeny, opening the field to considerations about the colonization success of the species (Malacrida et al., possible consequences of this phenomenon on the 1998; Haymer and McInnis 1994; McPheron et al. size and genetic structure of populations. Secondly, 1994; Baruffi et al. 1995; Gasparich et al. 1995; male sperm precedence was shown not to be related Gomulski et al. 1998; Villablanca et al. 1998; Davies et to a differential amount of sperm transferred by the al. 1999; He and Haymer 1999). two males or to a differential sperm mortality effect. Moreover, the paternity data showed that the last male

TEAM Newsletter No. 8 (July 2010) 14 precedence declines as oviposition progresses over to wild type strains in different preliminary laboratory the female’s reproductive period, implying a competitiveness tests; several lines showed reduced progressive use of sperm retained by the female from fitness indicating that the genetic bottleneck during the the first male (Figure 1). Therefore, among the establishment of the lines, the presence of the possible mechanisms underlying such a sperm use transgene, or its particular insertion into the genome pattern, the sperm stratification model might can cause fitness costs. In spite of this, in some lines adequately support the experimental observations. In the transgenes were demonstrated not to dramatically conclusion, it appears that the observed pattern of impair fitness, indicating the advantage of creating sperm use in remated females is mostly controlled by many independent transgenic lines to choose those differential retention and the mechanical movement of that are competitive. sperm in the female’s storage organs, rather than by the effects of rival male seminal fluids.

Figure 2. Fluorescence in female spermatheca. Green fluorescent sperm in a mechanically opened spermatheca from a wild type female mated to a transgenic male.

The availability of transgenes specifically expressed at the sperm level, may also provide the basis to set up a sperm quantification protocol by quantitative PCR Figure 1. Changes in the proportion of offspring assays. This highly sensitive molecular technique may sired by the first male (P1) over time from twice- allow us to precisely determine the number of sperm mated females. transferred by each male in the reproductive tract of Within 36 twice-mated females, 32, 30, 36, 35 and 34 multiple mated females. The analysis might provide individuals laid eggs on the first, second, third, fourth more unbiased results, which would be able to and fifth oviposition day, respectively. An average of reinforce the data actually obtained by sperm eight progeny per female was scored on each day. counting. Vertical bars indicate standard errors. Moreover, the constructs introduced by microinjection into medfly embryos, besides the spermatogenesis- This study opens the way to further investigations specific marker, also carry attP sequences, which aimed at clarifying the events occurring during the makes it possible to use the site-specific integrase mating and fertilization processes. Studies carried out system from phage phiC31 to add additional functional on other species, especially Drosophila spp., suggest transgenes into competitive transgenic lines at the that, besides sperm viability and abundance, other same genomic position. Recent results showed that sperm quality traits play an important role in post- this kind of site-specific recombination works in medfly copulatory sexual selection, such as sperm size and and different ‘integrated’ lines were molecularly motility, which have therefore to be explored. characterized (Schetelig et al., 2009). This study made Moreover, it would be interesting to identify biologically post-integration manipulations possible, allowing also active medfly accessory gland proteins (Acps) and test the stabilization of transgenes by removing a how they modify female behavior after mating. transposon inverted terminal repeat, which represent a threat for the stability of the line and for the safe In order to better understand the sperm usage potential use of transgenic insects in the field. mechanisms in medfly, a fluorescent sperm-marking system which permits direct sperm visualization and The safety issue linked to the use of transgenic insects thus aids the analysis of the mating physiology of the in the field was thus analyzed focusing attention on the species was developed (Scolari et al., 2008). This second main aim of this phD thesis: the practical study showed that the endogenous β2t promoter could application of these new tools for improving the control be used in the medfly to generate fluorescently labeled methods against medfly. In fact, the knowledge sperm, which are clearly visible also in the sperm acquired with these studies has also an impact on the storage organs of wild type females mated to implementation of pest control methods, as the transgenic males (Figure 2). The transgenic strains effectiveness of the SIT applications strongly depends carrying fluorescent sperm were molecularly on medfly sexual behavior (Scolari et al., 2008a). The characterized, brought to homozygosity and compared

TEAM Newsletter No. 8 (July 2010) 15 results of these studies which may have an effect on appropriate. Owing to the sterility, exposure of the SIT can be summarized as follows: environment to the transgenes will be limited to the lifespan of the released individuals. Transgene 1. Last male sperm precedence: a central issue in constructs containing only fluorescent protein SIT is producing sterile males as sexually markers will be most suitable to transfer transgenic competitive as wild males. However, it is known technology from the laboratory to the field, since that the sterile males have lower mating they will improve SIT applications by simplifying competitiveness than wild males and are less the monitoring, should not provide an advantage to successful in preventing female remating (Vera et the carrier organism and should allow the al., 2003; Kraaijeveld and Chapman, 2004). identification of carriers at later stages. Such initial Consequently, within a SIT-treated area, the transgenic SIT programs could then provide the female tendency to mate more than once may be first ecological insights into the fitness of enhanced if its first mate is sterile. In turn, the transgenic insects and their distribution. increased level of polyandry may augment the chances of mating between wild females and wild Finally, the research on medfly sexual behavior could fertile males, favouring viable offspring production, take great advantage from an ongoing gene discovery especially considering the occurrence of last male program (Gomulski et al., 2008). Using a functional sperm precedence. In order to avoid this peculiar genetics approach, based on Expressed Sequence situation, it is important that the improvement of Tags (ESTs) and microarray technologies, this SIT effectiveness is addressed to try to limit research project aims to identify genes involved in multiple matings with fertile males. In this biologically important processes such as development, perspective, an increase in the sexual sex determination and mate and host recognition in C. competitiveness of sterile males and their release capitata. In particular, the genes identified from male so that they vastly outnumber the wild males in the testes and accessory glands mRNA and the analyses target population are the two main objectives that of their expression patterns will lead to an increase in have to be taken into account. the basic knowledge of the components involved in spermatogenesis, male fertility and female fecundity 2. Availability of a fluorescent sperm marking system: processes. The screening of the library derived from this allows the separation of males from females male testes will represent a starting point to and clearly identify the testes as well as single characterize sex specific promoters that could be used sperm in adult stages. A simple distinction between for medfly genetic sexing. Besides the characterization wild type sperm and sperm from released sterile of genes differentially expressed in the two sexes, it is males will greatly improve monitoring SIT also important to identify genes coding for odorant programs, which is a key component to run this binding proteins, which have a key role for studying, at environment-friendly pest management in a molecular level, medfly behavior to different chemical successful and cost effective manner. The attractants and pheromones. An enhanced knowledge combination of the fluorescent markers developed of these basic biological processes will provide in this study could be excellent for this purpose. additional means to further improve environmentally Owing to the stability of the fluorescent proteins, safe, biological pest management approaches. both the red fluorescence (DsRed) in the body as well as the green fluorescence in the testes (tGFP) References are visible several months after death. Therefore, even dead flies captured in traps within the SIT Baruffi L, Damiani G, Guglielmino GR, Bandi C, Malacrida AR release area could be scored to calculate the ratio and Gasperi G 1995. Polymorphism within and between of released to wild insects. In addition, sperm populations of Ceratitis capitata: comparison between marking would make it possible to more easily RAPD and multilocus enzyme electrophoresis data. Heredity, 74: 425-437. assess the mating status of trapped females, which Bonizzoni M, Gomulski LM, Mossinson S, Guglielmino CR, would permit the monitoring of the mating Malacrida AR, Yuval B and Gasperi G 2006. Is polyandry a efficiency of the released sterile males. common event among wild populations of the pest Ceratitis capitata? Journal of Economic Entomology, 99: 1420-1429. 3. Development of fit and safe transgenic lines: the Davies N, Villablanca F and Roderick GK 1999. Bioinvasions creation of several transgenic lines, already tested of the medfly Ceratitis capitata. Source estimation using for fitness in preliminary laboratory tests, permitted DNA sequence at multiple intron loci. Genetics, 153: 351- the identification of potential candidates to be used 360. Gasparich GE, Sheppard WS, Han HY, McPheron BA and in future field release campaigns. The high quality Steck GJ 1995. Analysis of mitochondrial DNA and control during the production of sterile insects for development of PCR-based diagnostic molecular markers SIT as well as the fact that sterilized insects are for Mediterranean fruit fly (Ceratitis capitata) populations. incapable of transmitting their genes on to the next Insect Molecular Biology, 4: 61-67. generations provide ideal initial conditions for first Gomulski LM, Bourtzis K, Brogna S, Morandi PA, Bonvicini C, releases of genetically engineered insects into the Sebastiani F, Torti C, Guglielmino CR, Savakis C, Gasperi field. Before fertile transgenic insects can be G and Malacrida AR 1998. Intron size polymorphism of the released in economic and medical field Adh1 gene parallels the worldwide colonization history of the Mediterranean fruit fly, Ceratitis capitata. Molecular applications, ecological risk assessments are Ecology, 7: 1729-1741. necessary. Nevertheless, to assess such potential Gomulski LM, Dimopoulos G, Xi Z, Soares MB, Bonaldo MF, risks, at some point transgenic insects will have to Malacrida AR, Gasperi G 2008. Gene discovery in an be released. For this purpose, SIT programs that invasive tephritid model pest species, the Mediterranean use sterilized transgenic insects carrying harmless, fruit fly, Ceratitis capitata. BMC Genomics, 9:243. fluorescent-protein-based markers will be most Haymer DS and McInnis DO 1994. Resolution of populations of the Mediterranean fruit fly, Ceratitis capitata, at the DNA

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level using random primers for the polymerase chain Scolari F, Schetelig MF, Gabrieli P, Siciliano P, Gomulski LM, reaction. Genome, 37: 244-248. Karam N, Wimmer EA, Malacrida AR and Gasperi G He M and Haymer DS 1999. Genetic relationships of (2008a) Insect transgenesis applied to tephritid pest populations and the origins of the new infestations of the control. Journal of Applied Entomology, 132: 820-831. Mediterranean fruit fly. Molecular Ecology, 8: 1247-1257. Vera MT, Cladera JL, Calcagno G, Vilardi JC, McInnis DO, Kraaijeveld K and Chapman T 2004. Effects of male sterility Stolar E, and Field Working Group, 2003. Remating of wild on female remating in the Mediterranean fruitfly, Ceratitis Ceratitis capitata (Diptera: Tephritidae) females in field capitata. Proceedings. Biological sciences/The Royal cages. Annals of the Entomological Society of America 96, Society (Suppl.) 271, S209-S211. 563-570. Malacrida AR, Gomulski LM, Bonizzoni M, Bertin S, Gasperi Villablanca FX, Roderick GK and Palumbi SR 1998. Invasion G and Guglielmino CR 2007. Globalization and fruitfly genetics of the Mediterranean fruit fly: variation in multiple invasion and expansion: the medfly paradigm. Genetica, nuclear introns. Molecular Ecology, 7: 547-560. 131: 1-9. Malacrida AR, Marinoni F, Torti C, Gomulski LM, Sebastiani Contact: F, Bonvicini C, Gasperi G and Guglielmino CR 1998. Francesca Scolari, PhD Genetic aspects of the worldwide colonization process of Dept. of Animal Biology Ceratitis capitata. Journal of Heredity, 89: 501-507. McPheron BA, Gasparich GE, Han H and Steck GJ 1994. Laboratory of Insect Evolutionary Molecular Biology – Mitochondrial DNA restriction map for the Mediterranean Medfly Group fruit fly, Ceratitis capitata. Biochemical Genetics, 32: 25-33. University of Pavia Schetelig MF, Scolari F, Handler AM, Kittelmann S, Gasperi Via Ferrata 1 G and Wimmer EA 2009. Site-specific recombination for I-27100 Pavia, Italy the modification of transgenic strains of the Mediterranean tel: xx39 (0382) 986302 fruit fly Ceratitis capitata. Proceedings of the National email: [email protected] Academy of Science of the USA, 106:18171-18176. http://www.unipv.it/webbio/labweb/bamedfly.htm Scolari F, Schetelig MF, Bertin S, Malacrida AR, Gasperi G and Wimmer EA 2008. Fluorescent sperm marking to improve the fight against the pest insect Ceratitis capitata (Wiedemann; Diptera: Tephritidae). New Biotechnology, 25: 76-84.

THE NELSON MANDELA AFRICAN INSTITUTE OF SCIENCE AND TECHNOLOGY

The Nelson Mandela African Institute of Science and related fields, and with sufficient doses of relevant Technology in Arusha (NM AIST-Arusha) is one of the social sciences ingredients. Life sciences (Bio- four institutions in the Pan-African Network of African Sciences and Bio-Engineering) will be developed to Institutes of Science and Technology located across become one of the niche-areas of AIST-Arusha, taking the continent. These institutes are the proud brainchild advantage of the immense bio-diversity in countries of the Nelson Mandela Institution (NMI Inc.) which forming its catchment area. envisions to train and develop the next generation of African Scientists and Engineers and impact AIST-Arusha wil seek to stimulate and catalyze profoundly on the continent’s development through intensification of agricultural production, and value science and technology applications. addition to the various natural products (agricultural, mineral, etc) produced in the region. Other main NM AIST-Arusha, a Tanzania Commission for thematic areas to be covered by AIST-Arusha will Universities accredited institution of higher learning, is include Energy, ICT, Mining, Environment and Water. a world class research oriented institution whose final Emphasis shall be on linkage to society and the local objectives are engraved in the well versed vision and industry, and scientific and technological response to mission with the ultimate goal to contribute local needs. Hence the training curricula will significantly to the economic development of Africa incorporate strong innovation and entrepreneurship through the much needed input in Science and programmes, viz. strong academia-industry relations Technology. NM AIST-Arusha is an institution with a will be part of AIST-Arusha's development agenda. transparent governance system. It is part of the parent AIST-Arusha's curriculum will also seek to Nelson Mandela Institution Inc. which is a private accommodate, enable, stimulate and catalyze the charity organization incorporated in the USA. innovativeness and entrepreneurship qualities inherent in the Y-generaton for the benefit of SSA's sustainable Mission of the NM AIST-Arusha is to deliver and development. promote high quality and internationally competitive teaching and learning, research and innovation, and LOCATION public service in science, engineering and technology The start-up campus of NM AIST-Arusha is at the for enhanced value addition to people and natural fomer CAMARTEC premises in Tengeru, 16 km East resources, and entrepreneurship to stimulate and of Arusha City centre. The main campus is being catalyse economic growth and sustainable developed in a sprawling 3.285 acres land at development in Africa. Karangai, 20 km south of Tengeru CONTACT INFORMATION NM AIST-Awsha is to become a research intensive P.O. Box 447, Arusha, TANZANIA training institution mainly for postgraduates and post- [email protected]; website www.nm-aist.ac.tz; docs in Science, Engineering and Technology (SET) Tel.:255 272 555070; Fax 255 272 555071

TEAM Newsletter No. 8 (July 2010) 17

PEOPLE: FRANCESCA SCOLARI Potential Invasive Pests Workshop October 10-14, 2010, Mayfair Hotel. Miami (Coconut Grove), Florida USA Francesca Scolari started her PhD studies in October (http://www.conference.ifas.ufl.edu/TSTAR). 2005 in the Laboratory of Insect Evolutionary Molecular Biology at the University of Pavia (Italy) 12th Workshop of the IOBC Global Working Group on under the supervision of Professor Giuliano Gasperi. Arthropod Mass Rearing & Quality Control (AMRQC). On February 13th, 2009 she successfully defended 19-22 October 2010, Vienna, Austria. her PhD thesis entitled ‘Studies on the reproductive (http://www.tinyurl.com/amrqcreg) biology of the highly invasive insect pest species Ceratitis capitata (Wiedemann; Diptera: Tephritidae) Standards Committee Meeting, International Plant using neutral markers and new transgenic tools. Protection Convention, FAO. 1-5 November 2010, Rome, Italy. Her PhD research activity was centered on medfly mating behavior, especially focusing on the sexual International Congress on Biological Invasions. 2-6 behavior in the wild, the sperm use mechanisms within November 2010, Fuzhou, China. the sperm storage organs of twice mated females in laboratory conditions, and the development of a sperm VI Curso Internacional de Capacitação em Moscas marking system through a transgenic approach. das Frutas de Importância Económica e Quarentenária, 3-12 November 2010, Juazeiro (Bahia) Her PhD thesis has been performed within the and Petrolina (Pernambuco), Brazil. framework of the Vigoni project, a research exchange programme between Italian and German universities FAO/IAEA Workshop on Evaluation of Field Cages for and thanks to several grants obtained from the Lepidoptera SIT Behavioural Assessments. 21-22 University of Pavia and the Collegio Nuovo, one of the November 2010, Stellenbosch, South Africa. founder members of the University School of Advanced Studies in Pavia (IUSS). FAO/IAEA Regional Training Course on Surveillance At present, she is a post-doc in Pavia and she Strategies for and Diagnosis of Tephritid Fruit Fly Pest continues her collaboration with Professor Gasperi’s Species in the Asian and the Pacific Regions (under group, working on topics related to medfly TC Project RAS5052). 22-26 November 2010, reproductive behaviour, such as transgenic sperm Brisbane, Australia. use, seminal fluid proteins and olfaction.

THIS NEWSLETTER News

This newsletter is intended for the publication of Dear colleagues, subjects of interest to the members of TEAM. All Together with growers, we wrote a french 4-pages content is solicited from the membership and should practical leaflet devoted to field advisors and olive be addressed to the members of the editorial board. growers, to teach them about conservation biocontrol, and necessity to maintain flora inside the orchard. We EDITORIAL BOARD focused on the case of Dittrichia viscosa, a Compositae that hosts a parasitoid of the olive fruit fly, Nikos Kouloussis and we teach the growers how to recognize and Aristotle University of Thessaloniki propagate this species in the olive groves. School of Agriculture 54124 Thessaloniki, Greece We will be editing this leaflet (5000 copies) and will be [email protected] able to spread it in the Mediterranean basin to who may be interested. Please notify yourself (with your Sunday Ekesi mail address and number of copies desired) if you're International Centre of Insect Physiology and Ecology interested to learn more about conservation biocontrol (icipe), Nairobi, Kenya applied for olive fruit fly. [email protected]

Best regards, Francesca Scolari Francois Warlop University of Pavia GRAB Avignon, ITAB, France Dept. of Animal Biology, [email protected] Via Ferrata 1, I-27100 Pavia, Italy [email protected]

FORTHCOMING MEETINGS Nikos Papadopoulos University of Thessaly, School of Agriculture 8th International Symposium on Fruit Flies of 38442 N. Ionia (Volos) Magnisias, Greece Economic Importance. 26 September - 1 October [email protected] 2010, Valencia, Spain. (http://www.fruitflyvalencia2010.org).

FAO/IAEA National Coordinators Meeting / Workshop on Standardised Entomological Monitoring of Old World Screwworm (OWS) Flies (Chrysomya bezziana), 27-29 September 2010, Muscat, Oman.

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TEAM STEERING COMMITTEE Nikos Papadopoulos ([email protected]), Greece Abdeljalil Bakri ([email protected]), Morocco Yoav Gazit ([email protected]), Israel Brian Barnes ([email protected]), South Africa Mariangela Bonizzoni ([email protected]), Italy Massimo Cristofaro ([email protected]), Italy Slawomir Lux ([email protected]), Poland David Nestel ([email protected]), Israel Rui Pereira ([email protected]), Portugal Serge Quilici ([email protected]), France EDITORIAL BOARD Nikos Kouloussis ([email protected]) Sunday Ekesi ([email protected]) Francesca Scolari ([email protected]) Nikos Papadopoulos ([email protected])

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