Insecticidal Activity of Thai Botanical Extracts Against Development Stages of German Cockroach, Blattella Germanica (L.) (Orthoptera: Blattellidae)
Total Page：16
File Type：pdf, Size：1020Kb
SOUTHEAST ASIAN J TROP MED PUBLIC HEALTH INSECTICIDAL ACTIVITY OF THAI BOTANICAL EXTRACTS AGAINST DEVELOPMENT STAGES OF GERMAN COCKROACH, BLATTELLA GERMANICA (L.) (ORTHOPTERA: BLATTELLIDAE) Soraya Saenmanot1, Ammorn Insung2, Jarongsak Pumnuan2, Apiwat Tawatsin3 Usavadee Thavara3, Atchara Phumee4, Fréderick Gay5, Wanpen Tachaboonyakiat6 and Padet Siriyasatien7 1Medical Science Program, Faculty of Medicine, Chulalongkorn University, Bangkok; 2Department of Pest Management Technology, Faculty of Agricultural Technology, King Mongkut’s Institute of Technology Lat Krabang, Bangkok; 3National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Nonthaburi; 4Thai Red Cross Emerging Infectious Health Science Centre, King Chulalongkorn Memorial Hospital, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; 5Université Pierre et Marie Curie-Paris 6, CHU Pitié-Salpêtrière, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service Parasitologie-Mycologie, Paris, France; 6Department of Materials Science, Faculty of Science, 7Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand Abstract. The German cockroach, Blattella germanica, is considered an important medical and economic pest in Thailand. The insecticidal activities of hexane, acetone and ethanol extracts derived from six Thai botanicals, namely, Piper ret- rofractum Vahl, Stemona tuberosa Lour, Derris elliptica (Wall.) Benth., Rhinacanthus nasutus (L.), Butea superba Roxb., and Foeniculum vulgare Mill. were used to evaluate their toxicities against a variety of developmental stages of B. germanica including nymphs, adults and gravid females. All botanical extracts showed high insecticidal activity (up to 100%) after a 24-hour exposure at 200 µg/insect, using 2 µl/insect 1% Tween-20 in distilled water as negative control. Extracts from P. retrofractum gave the highest mortality to all B. germanica developmental stages, with the acetone µ extract showing maximal insecticidal activity against both gravid (LD50 = 39 g/ µ µ µ insect; LD90 = 52 g/insect) and adult (LD50 = 53 g/insect; LD90 = 104 g/insect) stages after a 6-hour exposure. Isolation and purification of the main components of P. retrofractum acetone extract by column chromatography led to a fraction with highest insecticidal activity against nymphs. Subsequent purification by thin layer chromatography led to identification of piperine as the major bioactive compound. This is the first report of insecticidal activity fromP. retrofractum extracts against B. germanica and holds promise as a potential biopesticide. Keywords: Blattella germanica, botanical extract, German cockroach, insecticidal activity Correspondence: Padet Siriyasatien, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand. E-mail: [email protected] 46 Vol 49 No. 1 January 2018 THAI BOTANICAL EXTRACTS AGAINST BLATTELLA GERMANICA INTRODUCTION are more environmental friendly and less toxic (Kamaraj et al, 2009; Koodalingam Cockroach is considered an important et al, 2009; Elango et al, 2010). Moreover, pest of concern to medical and public several Thai botanicals have long been health. Cockroaches are commonly found employed as insecticides or repellents in homes, hospitals, hotels and restaurants for pest and insect control (Promsiri et al, (Yeom et al, 2012). The insect is used as 2006; Tawatsin et al, 2006; Phasomkusolsil a key indicator of insanitary conditions and Soonwera, 2010). For example, Chang as they are able to carry various human and Ahn (2002) reported that methanol pathogens, including bacteria, viruses and extract of fruit from Illicium verum has protozoa, moreover, they contribute to the insecticidal activity against adults of B. cause of allergies and asthma (Slater et al, germanica when used as a fumigation 2007; Mindykowski et al, 2010). agent. Thavara et al (2007) demonstrated In Thailand, more than ten species of that essential oils of Citrus hystrix (Kaffir cockroaches have been described, includ- lime) exhibit complete repellency against ing the American cockroach (Periplaneta P. americana and B. germanica and also americana), Australian cockroach (P. aus- show a high repellency (87.5%) against tralasiae) and German cockroach (Blattella Neostylopyga rhombifolia under laboratory germanica) (Tawatsin et al, 2001; Sriwichai conditions. Ling et al (2009) stated that et al, 2002; Chompoosri et al, 2004). How- essential oils of Piper aduncum (spike pep- ever, B. germanica is considered as an per) can have insecticidal activity against important medical and economic pest adults and nymphs stage of P. americana. because it has a shorter generation time Tine et al (2011) revealed that azadirachtin and higher fecundity than the other cock- from kernel of neem tree (Azadirachta roaches, which makes it difficult to con- indica) has an insecticidal effect against trol. Conventional synthetic insecticides, newly emerged adults of Blatta orientalis such as pyrethroids, carbamates and or- under laboratory conditions. According to ganophosphates are very popularly used Sittichok et al (2013) essential oils derived compounds for controlling cockroaches from Thai plants Cymbopogon citatus (lem- (Lee et al, 1996; Syed et al, 2014). However, on grass), C. nardus (citronella grass) and these insecticides have several adverse ef- Syzygium aromaticum (clove) had highly fects including acute or chronic toxicity to repellent effects on adult P. americana. humans and animals. They can also have Thus Thai botanicals contain insecti- an adverse impact on the food chain of cidal or repellent substances and, impor- the ecosystem (Govindarajan et al, 2011; tantly, there has been no report, to the Amerasan et al, 2012; Muthukumaran best of our knowledge, of resistance by et al, 2015). Furthermore, cockroaches can pests and insects against Thai botanicals, develop resistance to these insecticides highlighting the attractiveness of Thai bo- (Pai et al, 2005). Due to these problems, tanicals as alternative substances for con- an alternative approach is to search for trolling German cockroaches. Hence, the effective botanical extracts, which are safe present study determined the insecticidal to humans and the environment. activity of organic solvent extracts derived Thailand has an abundance of plants, from six Thai botanicals, namely, Butea su- extracts of which are used in many ap- perba Roxb. (red ‘kwao krua’), Derris elliptica plications in place of chemicals as they (Wall.) Benth. (Derris), Foeniculum vulgare Vol 49 No. 1 January 2018 47 SOUTHEAST ASIAN J TROP MED PUBLIC HEALTH Mill. (Fennel), Piper retrofractum Vahl (Java prepared for a topical application bioassay long pepper), Rhinacanthus nasutus (L.) test (Rahman and Akter, 2006). (white crane flower), and Stemona tuberosa Cockroach Lour. (wild asparagus), against various B. germanica was obtained from the developmental stages of B. germanica in- Biology and Ecology Section, Medical cluding nymph, adult and gravid stages Entomology Group, National Institute of under laboratory conditions. In addition, the Health, Department of Medical Sci- the main component of Thai botanical ence, Ministry of Public Health, Thailand extracts with highest insecticidal effect and reared according to standard protocol against B. germanica was identified. (Thavara et al, 2007). Cockroaches were maintained in the insectary of the Labora- MATERIALS AND METHODS tory Animal Center, Faculty of Medicine, Chulalongkorn University, Bangkok un- Botanical material der ambient temperature (27-30ºC) and Thriving roots of B. superba, D. ellip- humidity (70-90%) and photoperiod of tica, R. nasutus and S. tuberosa, fruits of P. 12:12 hour light:dark cycle. Cockroaches retrofractum and seeds of F. vulgare (1 kg were fed dry dog food and water ad li- each) were purchased from a traditional bitum. The upper inside surfaces of the herbal medicine store, Bangkok, Thailand rearing container were smeared with pe- (Table 1). The plants were identified at troleum jelly to prevent cockroaches from the Plant Production Technology Section, escaping (Habes et al, 2006). B. germanica Faculty of Agricultural Technology, King final instar nymphs (3-4 weeks old), adult Mongkut’s Institute of Technology Lat males, non-gravid females (6-8 weeks Krabang, Bangkok, Thailand. old) and gravid females (with egg case) Preparation of botanical extract were employed for toxicity testing under The botanical materials were washed laboratory conditions. thoroughly with distilled water and cut Topical application bioassay into pieces (<2 cm in size), then left to A group of 10 each of unsexed nymph, dry in the shade and ground into fine gravid female and adult cockroaches (five powder using an electric blender. The males and five non-gravid females) were fine powders were extracted using a se- used in each experiment. Cockroaches quential extraction procedure with 1,000 were anesthetized briefly (<5 minutes) ml aliquots of three different solvents with carbon dioxide to facilitate handling with increasing polarity, namely, hexane, (Tunaz et al, 2009; Liu et al, 2011). Each bo- acetone and ethanol, by maceration at tanical extract of different concentrations room temperature (30 ± 2ºC) for three (2 µl/insect) were topically applied with a days with frequent agitation. The solvents micro applicator (Burkard Manufacturing, were removed by evaporation (AhbiRami Rickmansworth, United Kingdom) onto et al, 2014; Govindarajan and Sivakumar, the first abdominal