Proceedings of 6th International Fruit Symposium 6–10 May 2002, Stellenbosch, South Africa pp. 461–464

Diversity and pest control potential of hymenopteran parasitoids of Ceratitis spp. on mangos in Mali

Jean-François Vayssières1*, Robert Wharton2, Gérard Delvare3 & Fatogoma Sanogo4 1Laboratoire d’Entomologie de Kourou - Cirad-Flhor, B.P. 701, 97387 Kourou, Cedex, France 2Department of Entomology, Biological Control Facility, Texas A&M University, College Station, Texas 77843, U.S.A. 3CIRAD TA 40 / L Campus International de Baillarguet, CSIRO – 34398, Montpellier, Cedex 5, France 4Institut d’Economie Rurale, Département Fruits et Légumes, B.P. 858, Sikasso, Mali

In Mali, 1205 mangos (Mangifera indica L.) were sampled between April and September 2000 and placed under observation. We recovered 7518 adults of six species of Ceratitis, namely C. cosyra (Walker), C. silvestrii Bezzi, C. quinaria (Bezzi), C. fasciventris (Bezzi), C. anonae Graham and C. ditissima (Munro). A total of 436 hymenopteran parasitoids belonging to eight species were recovered from the fruit : Psyttalia perproximus (Silvestri), P. cosyrae (Wilkinson), Fopius caudatus (Szépligeti), fullawayi (Silvestri) (all , ); sp. (Braconidae, ); Tetrastichus giffardianus Silvestri (Eulophidae, Tetrastichinae); Spalangia simplex Perkins, Pachycrepoideus vindemiae (Rondani) (Pteromalidae, Pteromalinae). The most abundant parasitoid species were P. cosyrae, F. caudatus and P. vindemiae. The opiines (koinobionts) are the most abundant group of tephritid parasitoids and are more frequently used in integrated pest management programmes. Other families of parasitoids, such as Eulophidae (koinobionts) and Pteromalidae (idiobionts), are infrequently used for tephritid biological control as very little is known about the role of these micro-hymenopterans in controlling tephritid larvae. Data on their life cycle and host specificity will therefore be valuable in determining their role in comple- menting the impact of the opiines on the biological control of tephritid larvae. This paper presents the first results of such a study.

INTRODUCTION This study formed part of a six-month programme Mango production is rapidly expanding in West to establish an integrated pest management (IPM) Africa. Developing countries such as Mali, Sene- system in Mali using spot treatments of a mixture gal, Burkina Faso and Guinea are beginning to of insecticide and protein hydrolysate applied to increase their export of mango fruits (Mangifera the foliage of mango trees. indica L.) (Anacardiaceae). Annual mango produc- tion in Mali is estimated at 100 000 tons but MATERIALS AND METHODS only rarely more than 1% of this is exported. The Three sites were chosen in three different mango principal reasons for the low level of exports is production areas in Mali for the current study: related to both structural and phytosanitary Sikasso, Bougouni and Bamako. The large size of problems, specifically those stemming from fruit the orchards and the low use of chemical treat- infestation by fruit flies, resulting in losses esti- ments in the southern areas of Sikasso and mated at more than 50% of production. Bougouni allowed us to collect a great deal of Chemical control, first used as the only manage- information on the mango crops and its fruit fly ment tool, has been questioned because of parasitoids. resistance, high cost and contamination of fruits To determine the species involved in damaging and the environment. For this reason, the biologi- mango fruits, all the varieties encountered (15) cal control of pests with parasitoids is receiving were sampled during the fruiting season. The greater attention. mango varieties were Alfonse de Goa (four sam- No survey has been yet undertaken of the ples), Amélie (116), Bewerly (one), Brooks (164), parasitoids of fruit flies occurring in the large areas Davis Haden (four), Edwards (seven), Eldon (two), of mango production in Mali.The objectives of this Haden (24), Julie (eight), Keitt (528), Kent (222), study were: 1) to make an inventory of fruit fly Miami Late (19), Palmer (38), Smith (60) and Zill parasitoids in areas of mango production in Mali; (eight). and 2) to determine the overall parasitism rate and In the southern region, mangos were sampled the pest control potential of these hymenopteran from April to September 2000. Fruits collected parasitoids. were placed in bowls with wet sand on a wire

*To whom correspondence should be addressed. netting. The bowls were covered with a fine E-mail: [email protected] gauze mesh. Twice a week the sand was washed 462 Proceedings of the 6th International Fruit Fly Symposium

Table 1. Ceratitis species and associated parasitoids recovered from different mango varieties in Mali.

Mango varieties Number of fruits Number of pupae/ Parasitism Fruit fly species Parasitoid species collected kg fruit rate (%) recovered

Alfonse de Goa 4 70 8.19 Ceratitis cosyra Psyttalia perproximus; Spalangia simplex; Pachycrepoideus vindemiae Amélie 116 15 1.19 C. cosyra; C. silvestrii; Pachycrepoideus vindemiae; Spalangia C. quinaria simplex Bewerly 1 29 0 C. fasciventris; C. anonae None

Brooks 164 45 6.77 C. cosyra; C. silvestrii; Diachasmimorpha fullawayi; Psyttalia C. quinaria; C. fasciventris perproximus; P. cosyrae; Fopius caudatus; Spalangia simplex; Asobara sp.; Tetrastichus giffardianus; Pachycrepoideus vindemiae Davis Haden 4 11 14.28 C. cosyra Psyttalia sp. Edwards 7 39 6.25 C. cosyra Psyttalia sp. Eldon 2 149 0 C. cosyra None Haden 24 8 18.33 C. cosyra; C. fasciventris Psyttalia perproximus; P. cosyrae; Diachasmimorpha fullawayi Julie 8 8 0 C. cosyra None Keitt 528 16 6.36 C. cosyra; C. silvestrii; Fopius caudatus; Psyttalia perproximus; C. quinaria; C. fasciventris; P. cosyrae; Spalangia simplex; C. anonae; C. ditissima Diachasmimorpha fullawayi; Pachycrepoideus vindemiae Kent 222 18 7.12 C. cosyra; C. silvestrii; Fopius caudatus; Psyttalia sp; Psyttalia C. quinaria; C. fasciventris; perproximus; Spalangia simplex; C. anonae Pachycrepoideus vindemiae Miami Late 19 27 10.34 C. cosyra Pachycrepoideus vindemiae Palmer 38 8 6.17 C. cosyra Smith 60 57 5.6 C. cosyra; C. silvestrii; Fopius caudatus; Diachasmimorpha C. fasciventris fullawayi; Psyttalia perproximus; P. cosyrae; Asobara sp.; Spalangia simplex; Pachycrepoideus vindemiae Zill 8 123 2.4 C. cosyra Psyttalia sp. to collect pupae, which were then stored in plas- C. cosyra (Walker), C. silvestrii Bezzi, C. quinaria tic boxes with their reference numbers until the (Bezzi), C. fasciventris (Bezzi), C. anonae Graham fruit flies had emerged. and C. ditissima (Munro), which are the main Fruit fly identifications made in Sikasso were con- pests of mangos in these areas. The Ceratitis firmed by a taxonomist. Parasitoid identifications species recovered from each mango variety is were made in the laboratories of Texas A&M Uni- listed in Table 1. versity and CIRAD Montpellier. The recovery rate of fruit flies per kg is also shown in Table 1. The highest recovery rates were from RESULTS varieties Eldon, Zill, Alphonse de Goa, Smith and Between April and September 2000, 1205 Brooks. mangos, with a total weight of 602 kg, were From the six Ceratitis species we obtained eight placed under observation. Most mangos be- parasitoid species:Psyttalia perproxi- longed to four varieties – Amélie, Kent, Keitt and mus (Silvestri) (Braconidae: Opiinae), P. cosyrae Brooks. (Wilkinson) (Braconidae: Opiinae), Fopius caudatus We recovered 7518 adult fruit flies (Ceratitis (Szépligeti) (Braconidae: Opiinae), Diachasmi- spp.) from these mangos, which yielded 436 morpha fullawayi (Silvestri) (Braconidae: Opiinae), hymenopteran parasitoids. These parasitoids are Asobara sp. (Braconidae: Alysiinae), Tetrastichus associated with six species of Ceratitis, namely giffardianus Silvestri (Eulophidae: Tetrastichinae), Vayssières et al.: Control potential of hymenopteran parasitoids of Ceratitis spp. on mangos in Mali 463

Table 2. Abundance of parasitoids recovered from Ceratitis species in Mali.

Parasitoid genus Family Number of parasitized %/genus %/family pupae

Psyttalia Braconidae 110 26 57 Fopius sp. Braconidae 106 24 Diachasmimorpha Braconidae 25 6 Asobara Braconidae 6 1 Tetrastichus Eulophidae 39 9 9 Spalangia Pteromalidae 58 13 34 Pachycrepoideus Pteromalidae 92 21 Total 436 100 100

Spalangia simplex Perkins (Pteromalidae: Ptero- DISCUSSION malinae) and Pachycrepoideus vindemiae Rondani We obtained a great many hymenopteran (Pteromalidae: Pteromalinae). parasitoids from these samples of infested mango The fruit fly hosts of these parasitoids are listed in fruits. Among these eight species recovered, Table 1. P. perproximus, F. caudatus and D. fullawayi were Table 2 shows that the most abundant parasitoid previously found in West Africa from fruits infested genus in the three harvesting areas was Psyttalia by fruit flies (Steck et al. 1986) but P. cosyrae, spp. The majority of the parasitoids (57%) were S. simplex and P. vindemiae have not previously braconids (Table 2), followed by the pteromalids been recorded from West Africa. (34%). Figure 1 shows that the highest parasitism rate The highest rate of parasitism (Fig. 1) was 10.7% (10.7%) was recorded in the area with the lowest in the Bougouni area for the three-month period fruit infestation rate (Bougouni). This may be May to July 2000, which corresponds with the explained by the fact that the Bougouni area is period of lowest fruit infestation. still covered with wooded savanna together with Late mango varieties in this area (Keitt, parasit- many other wild host-plants of Ceratitis spp. ism rate = 6.36%; Haden, 18.33%; Davis Haden, (Annona senegalensis, Saba senegalensis, Landol- 14.28%) and semi-late mango varieties (Kent, phia heudolotii, Nauclea latifolia). These are a 7.12%; Miami Late, 10.34%) showed the highest potential source of fruit fly infestation and there- parasitism rate (Table 1). fore also of the development of the parasitoids Host specificity was not studied in detail, but throughout the year. The presence of wild host- the fruit fly species most parasitized was C. cosyra. plants such as these are of great importance for

Fig. 1. Mango infestations and parasitism rates of Ceratitis spp. in three main mango-production areas in Mali (2000). 464 Proceedings of the 6th International Fruit Fly Symposium

Fig. 2. Infestation and parasitism rates of Ceratitis spp. for the five most common varieties of mango in Mali (2000).

IPM in general, and especially for biological characteristics of this subfamily, seeking when- control.m ever possible to determine their role in comple- With respect to the differential infestation rate menting the impact of the opiines. of mango varieties, two reasons could explain The Fopius species (opiines) are able to attack the low parasitism rate of fruit flies on the Amélie eggs and early instar fruit fly larvae in the fruits. mango variety (Fig. 2). In the first place this Because their hosts are usually located near variety matures at the end of March and begin- the surface of the fruits and are thus especially vul- ning of April at the end of the dry season when nerable, these biological control agents are poten- the density of parasitoids is very low. Second, tially of great value. insecticide treatments against oecophyl ants This study is only the first step in a quest for a were applied in about 50% of the Amélie better knowledge of African parasitoids of Cera- orchards studied, which could have negatively titis species. Much work remains to be done. impacted on parasitoids. The opiines (koinobionts) are the most abundant ACKNOWLEDGEMENTS group of tephritid parasitoids and are more We would like to thank all Malian farmers for their frequently used in IPM programmes than other cooperation and their kindness towards us.Thanks groups. Other families of parasitoids such as also due to to Marc De Meyer (R.M.C.A., Belgium), Eulophidae (koinobionts) and Pteromalidae to the staff of I.E.R (Institut d’Economie Rurale) (idiobionts) are rarely used for tephritid biological and CAE (Comité Agro Entreprise) at Bamako and control. Consequently very little is known about Sikasso, and to USAID for allowing us to publish the importance of these chalcidoids in the bio- these results. logical control of tephritid larvae. In our study, members of the subfamily of Pteromalinae repre- REFERENCE STECK, G.J., GILSTRAP, F.E., WHARTON, R.A. & HART, W.G. sented 34% of the total number of parasitoids 1986. Braconid parasitoids of infest- recovered. It will therefore be informative to ing coffee and other fruits in West-Central Africa. study the life cycles, host specificity, and other Entomophaga 31(1): 59–67.