Egypt. J. Plant Prot. Res. Inst. (2021), 4 (1): 36 –41

Egyptian Journal of Plant Protection Research Institute www.ejppri.eg.net

Potential of scalaris (Diptera: ), as biocontrol agent of Eobania vermiculata under semi field conditions Karima, Mahmoud Azzam and Nema, M. El-Abd Plant Protection Research Institute, Agricultural Research Center, Dokki, Giza, Egypt. ARTICLE INFO Abstract: Article History Received: 7 / 1 /2021 Terrestrial gastropods are economic important pests that Accepted: 29 / 3 /2021 distributed in many Governments in Egypt causing severe damage to different important plants. The overuse of molluscicides against these destructive pests leads to more Keywords environmental pollution. So, searching for biological control Gastropods, Eobania agent became necessary to avoid the hazard of molluscicides. vermiculata (Lowe) ( Diptera: Phoridae) has a potential ,malcophagous , to become a biocontrol agent of terrestrial snail Bradybaena Megaselia scalaris, similaris (Ferussac) . This study aimed to shed light on the role biological control and of malacophagous M. scalaris in controlling terrestrial semi field . snails Eobania vermiculata (Müller) ( Gastropoda: Helicidae) under semi field conditions. Results of releasing M. Scalaris within E.vermiculata plots indicate an extrusive relation between time and mortality rates either of juvenile or mature snails and time needed for total mortality was reported significantly longer period in mature snails than juvenile snails. It could be concluded that M. scalaris may play an important role in controlling terrestrial gastropods.

Introduction Phorid were also reported. Zaki et al. Terrestrial gastropods are (2019) carried out a survey of aquatic economic important pests that and terrestrial malacophagous insects distributed in many Governments in associated with snails during 2016- Egypt causing severe damage to 2018 in Sharquia Governorate. The different important plants (Desoky, survey revealed the existence of four 2018; Azzam and Abd El-Hady, 2018). terrestrial and three aquatic snail The overuse of molluscicides against associated with three aquatic these destructive pests leads to more and three terrestrial malacophagous environmental pollution (Godan, 1983). insect species including Megaselia So, searching for biological control scalaris (Loew) and Petrostecus agent became necessary. Azzam and barbarous. Phorids are amongst the Tawfik (2005) recorded the existence of most biologically diverse families of 16 species of terrestrial malacophagous insects (Brown, 2018). Many phorid insects, including four sarcophagid are of injured hosts, species of which Wohlfartia sp. was (Brown, 2000 and Hash, 2014 ). reported only on slugs. Two drosophilid The definition of a scavenger is species and two sphaerocerid and four an organism that consumes dead or

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Azzam and El-Abd, 2021 decaying organic material (Lincoln et malacophagous insects in semi field al., 1998), whereas a is one conditions. that feeds on a single host, ultimately Therefore, this study aimed to causing its death (As opposed to shed light on the role of predators that feed on more than one malacophagous insect M. scalaris in host or true parasites that feed on a host, controlling terrestrial snails Eobania but do not kill it (Godfray, 1994). vermiculata (Müller) under semi field Females of the phorid Megaselia conditions to reduce the overuse of steptoeae Hartop et al. (Diptera: pesticides which increase the Phoridae) were found to be quickly environmental pollution . attracted to crushed glass snails of the Materials and methods species Oxychilus draparnaudi (Beck) 1. Samples collection: (Gastropoda: Oxychilidae) ( Brown and Samples of terrestrial snails Vendetti, 2020). M. scalaris was were collected from infested plants by recorded to parasitize only certain hand picking from Great Cairo, Egypt species of adult insect or larvae and during 2016 -2019 .Snails and slugs snails (Ahmad and Ho, 1980; Robinson, were identified according to Godan 1975 and Idris and Abdullah, 1997). (1983); Cowie (2002); Auffenberg and Idris and Abdullah (1997) found in Stange (2009 ) and Baker (2009) . laboratory studies that M. scalaris has a 2. Rearing of predator: potential to become a biocontrol agent Rearing of M. scalaris started of Bradybaena similaris (Ferussac). with collecting the larvae attacking They reported that 55% of B. similaris snails from natural habitats. When the ,exposed to M. scalaris was parasitized. larvae pupated, the pupae were However, percent of the transferred individually into test tubes snail in the field is ranged between10 covered with piece of cotton. Emerged and 35%. Lower parasitism rate was flies were confined as coupled in probably due to low parasitoid similar test tubes .Small ribbon of rice population in the field as a result of paper soaked with sucrose solution was heavy use of pesticides. The larval hanging down in the tube as a source of developmental time was significantly sucrose ,one small crushed snail was longer (p<0.05) when larvae were fed added to each tube as a source of on live B. similaris than on its tissue protein. extract (Idris et al., 2001). Disney 3. Rearing of gastropods: (1994) reported that the development of After collecting and M. scalaris and its parasitism rate identification gastropods, they washed is quite dependent on host species, thoroughly in fine metallic net under temperature and nutrient provided by strong stream of tape water then washed the host. Bohart and Gressit (1951) by distilled water, take some recorded nine species of Megaselia individuals in petri-dish with distilled including M. scalaris as a snail water and examined it under research predator in larval stage. Tawfik et al. microscope to check the presence of (1999) studied the biology of M. microorganisms . This process repeated scalaris by feeding on three terrestrial several times until look remove all snail species ,as malacophagous insects external associated organisms. through its larval stages which predate Rearing of E. vermiculata snail many snails through each larval was carried out by placing the examined in gregarious behavior . Rare individuals in plastic cages after investigation in the role of sterilizing it by ethanol alcohol and substrates with sterilized clay and

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Egypt. J. Plant Prot. Res. Inst. (2021), 4 (1): 36 –41 irrigated with distilled water. After egg After five days mini plots began laying, the eggs were washed gently by examined daily and number of dead distilled water and transfers to sterilize snails was recorded and collected at the petri dishes contained sterilized clay. corner of plots without removing it The petri dishes were then placed in from the cages to excuse propagation of dark place until hatching. The newly the flies and gave chance to larvae to hatched snails were transferred gently attack another snails. Escaping flies to new sterilized cages as mentioned during cages examination was above and supplied with some lettuce neglected to imitate that was occur in leaves after washing it thoroughly by nature . strong stream of tape water to remove 5. Statistical Analysis: associated organisms then wash with Differences between mortality distilled water and introduced to the rates for mature and juvenile snails newly hatching snails. were analyzed by ANOVA and T test 4. Experimental test: value using PSPP program and time Twelve transparence plastic needed for mortality analyzed by Qui boxes, each measured (50 x25x20 cm) square test using Ldp line program . were used as mini plot experiments. Results and discussion Each box was sterilized by ethanol Mortality of both juvenile and alcohol 70% and substrates with mature stages of E. vermiculata snail sterilized clay (5cm height), moisten was summarized in Table (1). As seen with dechlorinated water. Six of these in this table, high extrusive relation boxes were provided with 100 mature between time and mortality rates either snails of E. vermiculata for each, while of juvenile or mature snails. It was the other six boxes provide with 100 noticed that the first three and four days juvenile snails per box from the same for juvenile or mature snails species. Some lettuce leaves were respectively, have no mortality this was added to every plot as a source of food maybe due to lacking larvae which .Every plot was covered with perlon predate the snails where pre oviposition gauze and confirmed by rubber band. period and incubation period of eggs 100 couples (Male and female) of M. take from 1-4 days (Tawfik et al., 1999) scalaris flies were confined in ten . Table (1) showed also that time needed plastic test tubes( 10 males and females for total mortality was reported longer /tube ) ,partially covered with piece of period in mature snails than juvenile cotton and contained mall ribbon of rice snails. This is because larvae consumed paper soaked with sucrose solution as a greater number of small snails than source of food for flies .One tube was large or mature snails. Tawfik et al. added to every cage from five plots for (1999) reported high consumption rate both mature and juvenile snails. The of M .scalaris on E. vermiculata sixth box from mature and juvenile immature snails than mature snails and snails was left without adding the tube also on other snails that were smallest contained flies, as a control treatment. in size than E. vermiculata snail . Through the first five days the mini Disney (1994) reported that the plots were observed from the development of M. scalaris larva and its transparence wall boxes to avoid parasitism rate is quite dependent on escaping of the flies before mating and host species, and nutrient provided by oviposition which take 1-4 days ( the host. It was noticed also that daily Tawfik et al.,1999), and dead snails mortality rate increase day after day due were recorded. to progress of larval development that predate a greater number of snails

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Azzam and El-Abd, 2021 through late than early instars . r=0.9and 0.72 for both juvenile and Tawfik et al. (1999), mentioned that mature snails respectively. Lt 25, 50, daily consumption of different larval 75,and 99 were significantly longer in instars of M .scalaris E. vermiculata mature snails than in juvenile snails. increase as the larval predator develops Sallam and El-Wakeil (2012) to reach the maximum in the mature mentioned that juvenile snail stages larva. Idris and Abdullah, 1997, found were more vulnerable for predator in laboratory studies that M. scalaris attacking, than adults . has a potential to become a biocontrol agent of Bradybaena similaris (Fer.). Table (2) showed high correlation between time and mortality Table (1): Daily and accumulation mortality rate of Eobania predating by Megaselia scalaris under semi field conditions . Mortality of Eobania vermiculata Time Juvenile snail Mature snails /day Rate % of dead Rate % of Rate %of Rate % of Accumulated dead snails in day accumulated dead snails snails Consumption dead snails in in day in day day

1 0 0 0 0 2 0 0 0 0 3 0 0 0 0 4 5.67 5.67 0 0 5 6.5 12.165 3 3 6 11.335 23.5 4.165 7.165 7 15.835 39.335 5.665 12.835 8 21.67 61 7.165 19,99 9 22.5 83.5 9 28.995 10 16,5 100 10.835 39.835 11 13.335 53.165 12 15.335 68.5 13 17.5 86 14 11 97 15 3 100 Table (2): Time mortality relationship of Eobania vermiculata snail predating by Megaselia scalaris under semi field conditions . Mortality ratios Probity linear of time in days needed for Eobania snail mortality of % Juvenile snails Mature snails 25 5,8677 8.3104 50 7.0361 11.6415 75 8.4371 16.3079 99 13.1619 37.2295 Slope 8.5530 4.6077 P 0.0008 00000 Calculated Tabulated Calculated Tabulated X2 26.7837 15.5 3203223 22.35 R 0.8969 (0.09) 0.632 0.7174 (0.72) 0.514

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Egypt. J. Plant Prot. Res. Inst. (2021), 4 (1): 36 –41

It could be concluded that M Brown, B.V. (2018): A second .scalaris may play an important role in contender for “world’s smallest controlling terrestrial gastropods. fly” (Diptera: However, further study needs to be Phoridae).Biodiversity Data carried out before any decision can be Journal 6: e22396. made regarding for using in field https://doi.org/10.3897/BDJ.6.e application of gastropod control .Such 22396. studies may probably on the safety for Brown, B.V. (2000): Revision of the useful organisms .These studies should "Apocephalus miricauda- be done in laboratory before field- group" of ant-parasitizing flies testing is conducted in fields . (Diptera: Phoridae). References Contributions in Science, 482: 1 Ahmad, Y. and Ho, T.H. (1980): List ‑62. of economic pests, host plants, Cowie, R.H. (2002): Invertebrate parasites and predators in West invasions on Pacific islands and Malaysia (1920-1978). Ministry the replacement of unique of Agriculture, Malaysia, native faunas: a synthesis of the Bulletin No. 153, pp: 538. land and freshwater snails. Auffenberg, K. and Stange, Biological Invasions, 3(3): 119- L.A.(2009): Samoan land snails 136. identification guide. http// Desoky, A. E. A. S. S. (2018): www.samoasnails/idguide.asp. Identification of terrestrial Azzam, K. M. and Abd El-Hady, E. gastropods species in Sohag A. (2018): Survey on terrestrial Governorate, Egypt. Arch. molluscs and parasitic Agric. Environ. Sci., 3: 4548. nematodes as bio control agents Disney, R.H.L. (1994): Scuttle Flies: in some Governorates. The Phoridae. Chapman and Menoufia J. Plant. Prot., 3: 45- Hall,London, pp: 467. 52. Godan, D. (1983): Pest slugs and Azzam, K. M. and Tawfik, M. F. S. snails, biology and control. (2005): Survey of terrestrial and Verlage, Berlin, pp. 422. aquatic malacophagous insects Godfray, H.C. (1994): Parasitoids: in certain Governorates in behavioral and evolutionary Egypt. Egypt. J. Biol. P. ecology. Princeton University Control, 15: 89-92. Press, Princeton, New Jersey, ix Baker, S. P. (2009): North East Florida + 473 pp. https://doi.org/ Terrestrial Mollusks. 10.1515/9780691207025. http/www.jaxshells.org. Hash, J. (2014): Species of Megaselia Bohart, G.E. and Gressit, rondani (Diptera: Phoridae) J.L.(1951):Filth inhabiting attracted to defensive flies of Guam. Bull. Bemica, P. compounds of cyanogenic Bishop Mus., 204:1-152. millipedes (Diplopoda: Brown, B.V. and Vendetti, J.E. Polydesmida). Proceedings of (2020): Megaselia steptoeae the Entomological Society of (Diptera: Phoridae): specialists Washington 116 (3): 273-282. on smashed snails. Biodiversity https://doi.org/ 10.4289/0013- Data Journal 8: e50943. 8797.116.3.273 https://doi.org/10.3897/BDJ.8.e Idris, A.B. and Abdullah, M. (1997): 50943 The phorid fly, Megaselia scalaris (Loew), as a candidate

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