Biology of Sesamia calamistis Hampson (Lepidoptera: Noctuidae) at Metahara

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1 Proc. Ethiop. Sugar. Ind. Bienn. Conf., 1:35-44 (2009) RESEARCH PAPER Biology of Sesamia calamistis Hampson (Lepidoptera: Noctuidae) at Metahara Leul Mengistu 1, Tadele Tefera 2, Yoseph Assefa 2 and Firehun Yirefu 1 1 Ethiopian Sugar Development Agency, Research Directorate, P.O.Box 15, Wonji, Ethiopia 2 Haramaya University, P.O.Box 38, Dire Dawa, Ethiopia Abstract Study on biology of S. calamistis was conducted under field condition on pots grown three commercial sugarcane varieties during 2006/07 cropping season at Metahara Sugarcane Breeding Station. The result indicated that sugarcane varieties had no significant effect on egg hatching period of S. calamistis. The egg hatching period was ranged from 7.3 to 8.4 days at 19.8 o C temperature. On the other hand, larval development stage showed significant variation among the three sugarcane varieties. Among the varieties, the larvae required the shortest developmental period on N 14 and B52298 varieties. Moreover, the larvae took 50 to 71 days to complete their development stage irrespective of the varieties. However, sugarcane varieties had no significant effect on pupal development period. The study also showed that adult longevity of the pest ranged from 5.3 to 10.6 (mean = 9.1) and 6.7 to 12 (mean = 10.2) days for males and females, respectively. In addition, the shortest adult longevity period was recorded on NCo 334 variety. The result also indicated that there were significant differences between varieties in affecting fecundity. Besides, S. calamistis reared on B52298 laid 56 to 909 eggs (mean = 503), on N 14 laid 55 to 712 eggs (mean = 352) and on NCo 334 laid 34 to 584 eggs (mean = 308).Similarly, adult recovered from B52298 and N 14 has greater wingspan and body length as compared to the other variety. In general, S. calamistis completed its life cycle within 89.7 to 103 days irrespective of the varieties. Introduction Stalk boring Lepidopteran insect pests are among the major production constraints in the commercial sugarcane plantations of Ethiopia. The recent survey result indicated that Sesamia calamistis Hampson (Lepidoptera: Noctuidae) is the most widely distributed species and regarded as a potential pest in the sugarcane plantations of Ethiopia (Yoseph et al., 2006). In this regard, reports indicated that this pest occurs in Ethiopia regardless of specific elevation and/or temperature range (Assefa, 1985; Emana and Tsedeke, 1999). Moreover, ISSN print version,

2 Biology of S. calamistis 36 study on the biology of S. calamistis showed that it has five to six continuous and overlapping generations per year (Carnegie and Leslie, 1991). Damage caused by stalk borer larvae reduces yield by killing the growing point (deadheart), causing early leaf senescence and reduced translocation, and lodging due to weakened stems (Bosque-Perze and Mareck, 1990). Moreover, stalk borer infestation increases the incidence and severity of stalk rots (Bosque- Perze and Mareck, 1991). Recent study result indicated that sugarcane borer complex inflicted 19.25, and % cane weight losses in Wonji-Shoa, Metahara and Finchaa sugarcane plantations, respectively (Tesfay and Solomon, 2007). Similarly, shoot borer assessment study at Wonji-Shoa indicated that the pest inflicted up to 54 % dead-hearts during the first four months. Moreover, currently, borer complex damage tend to increase due to the prevailing factors like the poor cultural practices, climatic factors, type of variety grown, crop types and rendering little attention paid for borer control and others. Thus, understanding of the pest biology in the existing production system is the key factor for generating an overall knowledge and useful information that can be used for developing an appropriate pest management strategy. In this regard, no study has been carried out so far on the biology and performance of S. calamistis in the sugarcane production system of Ethiopia. As a result, this paper was initiated to study the field biology of the Pink Stem Borer, S. calamistis Hampson (Lepidoptera: Noctuidae). Materials and Methods Description of the Study Area The study was conducted in the sugarcane plantations fields of Wonji-Shoa (8 o 30' to 8 o 35' N; 39 o 20' E; 1540 m.a.s.l.), Metahara ( 8 o N; 39 o 52' E; 950 m.a.s.l.) and Finchaa (9 o 31' to 10 o N; 37 o 15' to 37 o 30' E; 1350 to 1650 m.a.s.l.). They receive an average of 831, 554 and 1280 mm rainfall, respectively. Planting Planting materials from ten months old seed cane of B52298, NCo 334 and N14 sugarcane varieties grown at Metahara were used for the study. Two double budded setts were planted in medium (20 cm height x 15 cm diameter having 20 liter water holding capacity) and large (50 cm height x 30 cm diameter having 30 liter water holding capacity) sized plastic pots filled with sterilized soil with sandy loam texture which were collected from the plantation field. Plants grown on medium sized pots (i.e. 96 pots) were used for oviposition and egg development experiments whereas those grown on large sized pots (i.e. 48 pots) were used for larval development experiment. The pots were arranged in a randomized complete block design with four replications in a total area of 14 square meters. Ammonium Sulphate Nitrate at 400 Kg ha -1 was applied at three

3 Leul et al. 37 months after planting and water was given at ten days interval using watering can. Insect Collection and Rearing The pink stalk borer, S. calamistis, larvae and/or pupae were collected from Metahara sugarcane fields. The collected larvae were given a fresh piece of sugarcane stalk and kept in a labeled plastic container (26 cm x 20 cm x 7 cm) covered with fine mesh. The larvae were transferred to 8-16 weeks old, three commercial sugarcane varieties grown in pots, and monitored until adult emergence. Soon after adult emergence, every paired adult (1:1 male to female ratio) was transferred into a cage and provided with young sugarcane shoots as an oviposition substrate. In addition, two cotton balls soaked with 20 % sugar water solution was placed in small vials (7 cm x 2.5 cm) at the corner of the cage to serve as food source for the emerging adult moths. The eggs were collected on daily basis and used as a starting material for the subsequent field experiments. Egg Stage The developmental period of S. calamistis was studied on the pot grown three commercial sugarcane varieties described above under field condition. Individual pots were strictly covered with fine white mosquito net until the end of the experiment. For this study, freshly laid eggs less than 24 hours were collected and transferred onto individual shoots of 4 months old following the procedures of Mihm (1985) and Davis et al (1989). Each shoot of sugarcane plant was infested with 10 eggs of S. calamistis and a total of 960 eggs were used for the whole experiment (i.e. for 48 pots). The experiment was laid in a randomized complete block design with four replications. Medium sized pots (having a volume of 20 liter) were used to grow the plants and spacing between pots and replications were 30 cm. Two vigorously grown shoots per pot were carefully selected and labeled before egg inoculation (ten eggs per shoot). The eggs were placed on the leaf sheath by detaching it slightly using a fine hair paintbrush (Ampofo and Saxena, 1989). All pots were examined four times a day at four hours interval (i.e. 6:30 AM, 10:30 AM, 2:30 PM and 6:30 PM) to record time of egg hatching. Larval Stage After egg hatching, the total period of the larval developmental stage was assessed. Four large sized pots were used for each treatment per replication and 30 cm spacing between pots and also replications. For this study, a total of 48 pots were used and covered with white mosquito net at the initial stage of the plant in a total of 8.82 square meter area. Two vigorously grown shoots per pots were selected and labeled for larval infestation. The leaf sheath of 5 months old plants were slightly detached and four neonate larvae were transferred with a

4 Biology of S. calamistis 38 camel s hair brush to each shoot (Ampofo and Saxena, 1989). Pots were covered with muslin cloth, in addition to the white mosquito net in order to minimize the effect of cold weather on larval developmental stages during the whole experimental period. The experiment was arranged in a randomized complete block design with four replications and a total of 384 neonates larvae were used on 96 shoots. Observations were made on daily basis until the commencement of the prepupal/pupal stage. This was confirmed by destructive sampling of the stalk from each treatment or variety starting from 3 rd to 10 th weeks after neonates larvae inoculation. Data on the total larval developmental period was recorded. Pupal Stage To determine pupal development period, the pre-pupal stage of S. calamistis was collected from sugarcane shoots of the three commercial varieties grown in medium sized pots which was already infested within the months of October, Pre-pupae collection was made through destructive sampling. The prepupa was separately kept in small transparent plastic box (15 cm x 6 cm x 10 cm) with moistened soil and were kept in cage made from white mosquito net under field condition in a shady place. Four plastic containers having 70 by 6 cm area and 20 cm spacing between plots as well as between replications were used. A total of 192 pre-pupae (16 pre-pupae per plot) were used. The experiment was laid-out in a randomized complete block design with four replications. Daily observations were made until adult emergence. Data on total number of days required for adult emergence (pupal period) were recorded. Adult Longevity A pair of newly emerged male and female adults (in a 1:1 ratio) of S. calamistis was released separately into a pot planted with the three commercial sugarcane varieties that was covered with cage made from white mosquito net. Two pots in a cage of size 50 cm x 50 cm x 50 cm were used; a total of 10 pairs of adults were released per plot. Spacing of 20 cm were left between pots and between replications and also kept in a shady place under field conditions. The experiment was laid in a randomized complete block design with four replications and a total of 120 pairs of newly emerging adults were used. Observations were made twice a day (at 9:00 am and 4:00 pm) to record adult longevity until the death of all adults. Realized Fecundity Pairs of newly emerged male and female adults of S. calamistis were released in a cage made from white mosquito net (50 cm x 25 cm x 25 cm). The three sugarcane varieties mentioned above were used as an oviposition substrate and were changed daily. Ten cages were used per treatment per replication and a

5 Leul et al. 39 total of 120 pairs of adults were used for this experiment. Adults were allowed to mate freely and were kept together until they die.the experiment was laid in a randomized complete block design with four replications. The pot grown plants were daily inspected for the newly laid eggs until the moths die. Data Analysis Total egg counts were log-transformed before subjecting them to the analysis of variance to ensure normality of the data. Number of days required for egg hatching, larval and pupal development, adult emergence and adult longevity were analyzed using two-way analysis of variance via a general linear model (PROC GLM, SAS Institute, ) computer package. Whenever the F- test was significant, least significant difference (LSD) was used for mean separation. The data were reported in the text using the back transformed values. Results and Discussion Biology of S. calamistis: Egg Stage Eggs of S. calamistis were white when first laid but changed to pale orange as they approach to hatching and had a flat top shape. The eggs were arranged in 2 to 4 contiguous rows and inserted between the lower leaf sheaths and stems. The field study result indicated that sugarcane varieties had no significant effect (P<0.05) on egg hatching period of S. calamistis (Table 1). The egg hatching period ranged from 7.3 to 8.4 (mean = 7.96) days at 19.8 o C temperature. The number of days reported here are high as compared to the reports of Shanower et al. (1993), which were 6.3 days at a temperature of 30 o C under field condition. The differences might be attributed to variation in temperature. It has been reported that temperature had a significant effect on egg hatching period of stalk borers (Foley, 1981; Ranga Rao et al., 1989; Shanower et al., 1993, Amanuel, 2006). Thus, the longer egg stage recorded in this study could be resulted from lower temperature during the study period (Annex Table 1). Larval Stage The number of days required for the development of larvae showed significant differences (P<0.05) among the three varieties (Table 1). Larvae entered to the prepupal stage within shorter period on the varieties N14 and B52298 as compared to NCo 334. The larva of S. calamistis is a yellowish pink colored caterpillar with more or less distinct black spot along the body representing the position of the spiracles. The larvae took 50 to 71 days to complete their developmental stage. This finding agrees with the works of Shanower et al (1993) that indicate larvae of S. calamistis took 50-99, and days to complete their developmental stage at a temperature of 20, 25 and 30 o C, respectively. Field observation on larval feeding habit showed that larva fed first within the tissues of the leaf sheath, and then entered the stem through a

6 Biology of S. calamistis 40 horizontal hole and moved downward, sometimes through several internodes. Moreover, the frass that fills the galleries was pushed out through the openings in the leaf sheath, which is in agreement with the reports of Heinrichs (1994) and Bosque-Perez and Schulthess (1998). Pupal Stage The newly formed pupa was pale brown and immobile but showed wiggling movement of the abdomen when touched. It could roll on its sides as well. The result revealed that sugarcane varieties had no significant effect (P<0.05) on pupal development period (Table 1). In addition, the study confirmed that S. calamistis had no diapausing stage, which agrees with the finding of Polaszek (1998) that indicated the S. calamistis has the capacity to breed throughout the year. Table 1. Developmental time of S. calamistis from egg to pupal stage on three sugarcane varieties Variety Egg hatching (days) Larval stage (days) Pupal stage (days) Mean ± SE Range Mean ± SE Range Mean ± SE Range B ± ± ± Nco ± ± ± N ± ± ± CV LSD Adult Longevity Adult longevity of S. calamistis ranged from 5.3 to 10.6 (mean = 9.1) and 6.7 to 12 (mean = 10.2) days for males and females, respectively (Table 2). Besides, the study revealed that there were significant differences (P<0.05) among varieties for males and females longevity (Table 2). The shortest adult longevity period was recorded on NCo 334. Many lepidopteran moths have non-feeding adults (Cook and Gage, 1995) and are therefore dependent on larval food quality and quantity that determine adult longevity, gamete production, fat reserves and muscle tissue (Gage and Cook, 1994; Gage, 1995). In this regard, Ryne et al (2004) reported that larval diet had a significant effect on adult longevity. Moreover, the latter authors indicated that high quality larval diet that contains inert material significantly affects adult longevity via its effect on moisture retention, which plays a key role in adult longevity. Thus, the difference in longevity period of S. calamistis among varieties could have resulted from the difference in feed quality

7 Leul et al. 41 Realized Fecundity There were significant difference (P<0.05) among varieties in affecting fecundity (Table 2). S. calamistis reared on B52298 laid 56 to 909 eggs (mean = 503), on N14 laid 55 to 712 eggs (mean = 352) and on NCo 334 laid 34 to 584 eggs (mean = 308) (Table 2). Different authors have reported that the number of egg laid per female could vary invariably depending on host plant preference, larval food quality and climatic conditions like temperature (Harris, 1962; Kaufmann, 1983; Bosque-Perez and Dabrowski, 1989; Shanower et al. 1993). The study on the effect of larval food on adult fecundity showed that larval food had a significant effect on adult fecundity (Shanower et al., 1993). Table 2. S. calamistis adult fecundity and longevity on three sugarcane variety Variety Number of eggs per female Longevity (days) Mean (± SE)) Range Male (Mean ± SE) Female(Mean ± SE) B ± ± ± 2.00 NCo ± ± ± 1.81 N ± ± ± 1.94 CV LSD Wingspan and Body Length of Adult S. calamistis The mean fully expanded wingspan (from the bottom tip to of one wing to the bottom tip of the opposite wing) and body length measurement of adult S. calamistis indicated that adults recovered on variety B52298 and N14 had greater length than on NCo 334 (Annex Table 2). Different authors also reported that feed quality has effect on adult body size, longevity and fecundity (Shanower et al. 1993; Gage, 1995) Conclusion The study indicated that sugarcane varieties had no effect on egg and pupal stages; but they affected larval developmental period, adult longevity and fecundity. Among the three varieties, shortest larval developmental period was recorded on N14 and B On the contrary, the shortest adult longevity period was recorded on NCo 334 variety. The larvae took 50 to 71 days to complete their development stage irrespective of the three varieties. The result also indicated that S. calamistis reared on B52298 laid the highest number of

8 Biology of S. calamistis 42 eggs compared to the other varieties. Moreover, adult recovered from B52298 and N 14 had greater wingspan and body length as compared to the other variety. Generally, the total days required to complete the life cycle of S. calamistis irrespective of the varieties ranges from 89.7 to 103. References Agrima Project and Engineering Consultancy Service (APECS) A report on the agricultural research services of the Ethiopian Sugar Corporation. Matha Private Ltd., Bombay India Amanuel Tamiru Study on the biology and some ecological aspects of Chilo partellus (Swinehoe) (Lepidoptera: Crambidae) in relation to its geographic expansion. M.Sc. Thesis, Addis Ababa University. Ampofo JKO and KN Saxena Screeening methodologies for maize resistance to Chilo Paretellus (Lepidoptera: Pyralidae). Proceedings of International Symposium Methodolgoies for Developing Host Plant Resistance to Maize Insects, 9-14 March, 1987, CIMMYT, Mexico; Bosque-Perez NA and ZT Dabrowski Mass rearing of the maize stemborers Sesasmia calamistis and Eldana sacccharina at IITA. pp , In; Toward insect resistant maize for the third world; Proceedings of the International Symposium on Methodolgies for Developing Host Plant Resistance to Maize Insects. Mexico, CIMMYT, DF. Boseque-Pereze NA and JH Mareck Distribution of lepidopterous borers in Southern Nigeria. Bulletin of Entomological Research, 80: Boseque-Pereze NA and JH Mareck Effect of the stem borer Eldana saccharina (Lepidoptera: Pyralidae) on the yield of maize. Bulletin of Entomological Research, 80: Bosque-Perez, NA and F Schulthess Maize: West and Central Africa. pp In: Polaszek A. (ed). African cereal stem borers: Economic importance, taxonomy, natural enemies and contro. CAB International, Wallingford. Carnegie AJM and GW Leslie Trends shown by light trap catches of some sugarcane pests. Proceedings of the South African Sugar Technologists Association, 65: Davis FM, WP Williams and PM Buckley Screening responses to South western corn borers (Lepidoptera: Crambidae) and fall army worm (Lepidoptera: Noctuidae) larval fed combinations of whorl leaf tissues from a resistance and susceptiblemaize hybrids. Journal of Economic Entomology, 91(5): Foley DH Pupal development rate of Heliothis armigera under constant and flactauting temperatures. Journal of Australian Entomological Society, 20: Gage MJG Continous variation in reproductive strategy as an adaptive response to population density in the moth Plodia interpunctella. Phiolosophical Transactions of the Royal Society of London, 261: Gage MJG and PA Cook Sperm size or numbers? Effects of nutritional stress upon eupyrene and apyrene sperm production strategies in the moth Plodia interpunctella (Lepidoptera: Pyralidae). Functional Ecology, 8: Harris KM Lepidopterous stem borers of cereals in Nigeria. Bulletin of Entomological Research, 53:

9 Leul et al. 43 Heinrichs EA(ed.) Biology and management of rice insects. Wiley Eastern, New Delhi. Holloway JD Noctuidae. pp In: Polaszek A. (ed). African cereal stem borers: Economic importance, taxonomy, natural enemies and control. Wallingford, UK: CABI. Kaufmann T The behavioural biology, feeding habits and ecology of three species of maize stem borers, Eldana saccharina, Sesamia calamistis and Busseola fussca in Ibadan, Nigeria, West Africa. Journal of the Entomological Society, 18: Mihm JA Breeding for host plant resistance to maize stem-borers. Insect Science and its Application, 6: Polaszek A An overview of parasitoids of African lepidopteran cereal stem borers (Hymenoptera: Chrysidoidea, Ceraphronoidea, Chalcioidea, Ichneumonoidea, Platygastroidea). Insect Science and its Application, 17: Ranga Roa GV, JA Wightmanand and DV Ranga Roa Threshold temperatures and thermal requirements for the development of Spodeptera litura (Lepidoptera: Noctuidae). Environmental Entomology, 18: Ryne CP, A Nilsson and MT Siva-Jothy Dietary glycerol and adult access to water: effects on fecundity and longevity in the almond moth, Journal of Insect Physiology, 50: Shanower TG, F Schulthess and NA Bosque-Perez The effect of larval diet on the growth and development of Sesamia calamistis Hampson (Lepidoptera: Noctuidae) and Eldana saccharina Walker (Lepidoptera: Pyralidae). Insect Science and its Application, 14: Tesfaye Haile-Micheal and Solomon Beyene Survey of insect-pests of sugarcane in Ethiopian Sugar Estates. Ethiopian Sugar Industry Support Center Share Company, Research and Training Service Division, Wonji. Yoseph Assefa, DE Conlong, A Mitchell First records of the stem borer complex (Lepidoptera: Noctuidae; Crambidae; Pyralidae) in commercial sugarcane estates of Ethiopia, their host plants and natural enemies. Proceeding of South African Sugarcane Technologist Association, 80:

10 Biology of S. calamistis 44 Annex Annex Table 1.Monthly average meteorology data (from June to January 2007) of the Metahara Sugarcane Breeding Station Meteorology Record. Months Rainfall (mm) Temperature ( o c)* Relative humidity (%) Min. Max. Min. Max. Jun Jul Aug Sept Oct Nov Dec *= The temperature data were collected at 1.5 m above ground Annex Table 2. Wing span and body length (cm) of adults of S. calamistis feed on three different sugarcane varieties No. B52298 N14 NCo 334 of Adult Wingspan Body Wingspan Body Wingspan Body (M/F) length (M/F) length (M/F) length (M/ (M/F) (M/F) F) Mean SD