65 Biological Parameters of Trichogramma
Total Page：16
File Type：pdf, Size：1020Kb
Pakistan J. Agric. Res. Vol. 26 No.1, 2013 BIOLOGICAL PARAMETERS OF TRICHOGRAMMA CHILONIS ISHII (TRICHOGRAMMATIDAE: HYMENOPTERA) FEEDING ON SITOTROGA CEREALELLA EGGS AT THREE CONSTANT TEMPERATURES Rizwana Sultan*, Javed Khan, Ehsan ul Haq, Tariq Mehmood**, Roshan Zada Khattak***, and Naheed Akhtar** ABSTRACT:-The study was conducted on the biological parameters of Trichogramma chilonis Ishii (Trichogrammatidae: Hymenoptera) feeding on grain moth, Sitotroga cereallela eggs at three constant temperatures and five different ages of host eggs at Insect Pest Management Programme, National Agricultural Research Centre, (NARC) Islamabad. The results revealed that maximum rate of parasitism was 95.70 ± 1.94 at 28 ± 1 °C while minimum was 61.30 ± 1.70 at 32 ± 1 °C. Maximum adult emergence and female ratio from parasitized eggs were 96.30% with 59.2± 5.83 female ratio at 28 ±1 °C while minimum was 51.10% with female ratio of 58.1 at 32±1 °C. The maximum developmental duration (9.6 ± 0.32 days) and adult longevity (4.3 ± 0.38 days) was at 24 ±1 °C while minimum was 7.4 ±0.36 and 2.0 ±0.56 days at 32 ± 1 °C. The results indicate that temperature has a significant effect on the biological parameters of Trichogramma and with increasing temperature developmental duration decreased. Similarly effect of host eggs age indicates that maximum parasitism and adult emergence were 97.40 ± 0.84% and 98.20 ± 0.94% on 2h old eggs while minimum parasitism was 24.6 ± 4.92% and adult emergence was 21.5 ± 1.33% from 72h old eggs. Adult longevity and female ratio was not significantly different at different ages of host eggs. Thus out of three tested temperatures, 28 ±1 °C was more suitable for mass rearing of Tricho- gramma and feeding 2-12h old eggs for maximum parasitism and adult emergence from parasitized eggs under laboratory condition of 28 ±1 °C. Key Words: Trichogramma chilonis; Sitotroga cereallela; Feeding; Temperature; Host Egg Age; Biological Parameters; Pakistan. INTRODUCTION then copulates with the opposite sex and starts searching for fresh Trichogramma parasitizes eggs Lepidoptera eggs for further egg- of Lepidoptera by laying one or laying (Smith, 1996). more eggs inside the eggs of the Trichogramma can easily be host insects. The eggs hatch into reared on moth eggs under laboratory small larvae, which feed on the condition. Rearing of Trichogramma embryo of the moth eggs, there by requires first rearing of an insect killing it. After 8-10 days of feeding typically specie of moth to produce and growth, an adult wasp chews out eggs in which the wasp will develop. through the shell of the moth egg. It The most common lepidopterous * Department of Zoology, Hazara University Garden Campus Mansehra, Pakistan. ** Insect Pest Management Program, National Agricultural Research Centre, Islamabad, Pakistan *** National Insect Pest Management Program, National Agricultural Research Centre, Islamabad, Pakistan. Corresponding author: [email protected] 65 RIZWAN SULTAN ET AL. insect hosts used for mass rearing of conditions and to explore its potential Trichogramma are the Angoumois as a bio control agent against lepido- grain moth (Sitotroga cereallela pterous insect pests of agricultural Olivier), Rice meal moth (Corcyra importance. cephalonica Stain) and Mediterr- anean flour moth (Ephestia kueh- MATERIALS AND METHOD niella Zetler). All these three moths are easily and inexpensively reared on The present study was condu- wheat or other grains and are comm- cted on the biological parameters of only used to rear Trichogramma but Trichogramma chilonis feeding on Sitotroga is more practical for large Sitotroga cerealella eggs at Institute of scale production (Hassan et al., Plant and Environmental Protection, 1988). NARC, Islamabad, during 2010. Several factors affect the mass rearing of Trichogramma i.e., tempe- Effects of Constant Temperatures rature, relative humidity, photo- on the Biological Parameters of period and host eggs quality. The size Trichogramma chilonis Feeding of the host eggs could alter the size of on Sitotroga cerealella eggs the emerged wasp, which could have The biological observations of T. effects on wasp attributes such as chilonis were studied at three target host acceptance and fecundity constant temperatures (24, 28 and 32 (Greenberg et al., 1998). ± 1ºC), 50-60% R.H. and 16hL:8hD Rearing conditions such as food, period in a growth chamber. Two temperature, light etc. may effect the hours fresh eggs of S. cereallela were performance of Trichogramma obtained from culture stock. A total of (Hoffmann et al., 2001). Fluctuating 100 eggs of S. cerealella were stuck to temperatures from upper and lower white hard card (1.5x3.0cm) with glue extreme limits are prevailing in and placed in transparent glass jars natural environment of insects for (3.5 cm in diameter x 12 cm in length) which they have to develop adap- for 24h. Each jar contained 20 mated tation at certain limits against these one-day old female parasitoids. The temperatures. (Hassan, 1994). Simi- experiment was replicated 10 times. larly the age of host eggs involve in After 5 days, the parasitized eggs Trichogramma production in at least which turn black were counted under two ways. Firstly the oviposition a microscope. Adult emergence from preference of the parasitoid females parasitized eggs was recorded after 8- and secondly as an indicators of the 12 days. Total developmental period resource quality available for the from parasitism to adult emergence developing parasitoid larvae (Farid et and female ratio were also recorded in al., 2001). each treatment. After adult emer- The present study on the bio- gence 100 males and females were logical parameters of Trichogramma kept separately in a gelatin capsules chilonis Ishii at varying temperature provided with honey solution. The and host ages was conducted, which adults were critically observed daily could be usefully employed for mass till their death in capsules and the and quality production of the duration in days were calculated for parasitoid under local environmental all male and female wasps separately. 66 BIOLOGICAL PARAMETERS OF TRICHOGRAMMA CHILONIS Effect of Host Egg Age on the observed at 28 ±1°C followed by 24 Biological Parameters of ±1°C (92.3%) and minimum rate of Trichogramma chilonis parasitism were 61.3% on 32 ±1°C. The experiments were cond- The rate of parasitism by T. chilonis ucted on the effect of S. cerealella eggs were not significantly different to of different ages (2h, 12h, 24h, 48h each other at 24°C and 28°C, while it and 72h) Eggs were glued separately was significantly different at 32 ±1°C. on paper card at 100 eggs per each The result further indicates that at card. Each card (with age of one age high temperature, rate of parasitism only) was placed singly in 12cm x 4 by Trichogramma decreased signi- cm glass jars containing 20 pairs of ficantly (Table 1). male and female parasitoid under Some earlier studies by different laboratory conditions of 28 ±1 °C with authors also indicate significant 50-60% R.H. The cards were removed effect of temperature on the biological after 24h. The following parameters parameters of T. chilonis. Singh et al. were recorded daily: percent para- (2002) reported that some strains of sitism, adult emergence from para- T. chilonis could tolerate up to sitized eggs, total developmental 37±1°C. Calvin et al. (1984) reported period from parasitism to adult emer- 30°C was the most suitable tempe- gence, female ratio from emerged rature for T. chilonis. Miura and Koba- adults. yashi (1993) demonstrated that 28°C The data were statistically ana- was the optimum temperature for T. lyzed by using analysis of variance chilonis developing on eggs of (ANOVA). Then LSD test at P<0.05 Diamond back moth which are in probability was used for the compa- agreement with our present study rison of means of significant results. that 28°C was the optimum tempe- rature for T. chilonis feeding on eggs of RESULTS AND DISCUSSION S. cereallela. The results further indicate that Effects of Constant Temperatures maximum adult Trichogramma emer- on the Biological Parameters of gence from parasitized eggs were Trichogramma chilonis Feeding 96.3% at 28°C followed by 89.4% at on Sitotroga cerealella Eggs 24°C and 51.1% at 32 ±1°C which The study revealed that maxi- indicates that adult emergence from mum rate of parasitism (95.7%) was parasitized eggs were significantly Table 1. Effect of temperatures on biological parameters of Trichogramma chilonis feeding on Sitotroga cerealella eggs Treatment Percent Percent adult Developmental Female Adult parasitism emergence duration ratio longevity ±SD ±SD ±SD ±SD ±SD 24 ±1°C 92.30±4.92a 89.40±5.33b 9.6±0.32a 51.0±2.39b 4.3±0.38a 28 ±1°C 95.70±1.94a 96.30±3.45a 8.2±1.08b 59.2±5.83a 3.6±0.41b 32 ±1°C 61.30±1.70b 51.10±1.41c 7.4±0.36c 58.1±4.13c 2.0±0.56c Means followed by the same letters do not differ significantly at P< 0.05 (LSD test) 67 RIZWAN SULTAN ET AL. different at different temperature 28 ±1°C and lowest (51%) at 24 ±1°C. levels. The results indicate, that the female Nadeem et al. (2009) reported ratios were non-significant to each highest emergence (98.0%) of T. other. Female longevity was maxi- chilonis adults from host eggs at mum (4.8 days) followed by 3.6 and 28°C, while lowest emergence (33.7%) 2.7 days at three constant tempe- was at 35°C. The result of the present ratures, respectively. The result study also indicates that 28 ±1 °C was indicates that T. chilonis longevity the suitable temperature due to maxi- were significantly different at mum adult emergence from the para- different temperatures.