Printer Friendly

Response of the parasitoid, Aphidius matricariae Haliday (Hymenoptera: Aphidiidae) mummy to cold storage.

ABSTRACT

The green peach aphid and its parasitoid Aphidius matricariae were reared on sweet pepper plants. Several experiments were conducted to find the response of the parasitoid to cold storage. Successful cold storage of late instar parasitoid within mummy at 3.5[+ or -] 0.3 C of different acclimation periods of 6, 12, 18, 24 and 36 hours at 8 [+ or -] 1 C were achieved for at least 2 weeks with great emergence and survival percentages and few effects on longevity. Adults emergence, survival and longevity from mummies stored for 3 weeks were better than from mummies stored for 3 weeks although increasing the acclimation periods from 6 to 12, 18, 24 and 36 hours had no observable trends on the above test parameters. It was concluded that the acclimation itself is very important factor for successful storage to a lesser degree. The process of cold storage was failed without acclimatization. In addition, cold storage of late instar A. matricariae within mummified M. persicae for 1, 2 and 3 weeks at 3.5 [+ or -] 0.3 C after an acclimation periods of 6, 12, 18, 24 and 36 hours at 8 [+ or -] 1 C leads to the following conclusions.

1. In general, adults emergence, survival and longevity from mummies stored for 1 and 2 weeks were better than from mummies stored for 3 weeks.

2. Although increasing the acclimation periods from 6 to 12, 18, 24 and 36 hours had no observable trends on the above tested parameters, acclimation itself is a very important factor for successful cold storage.

KEYWORDS: Cold temperature, Aphidius matricariae, Acclimation periods, Life cycle parameters, Aphid mummies

INTRODUCTION

Aphids are economic insects. They attack many cultivated and wild plants infesting leaves and stems producing honeydew which encourages sooty mold to grow and transmitting viral diseases to plants. The green peach aphid, Myzus persicae Sulzer (Homoptera: Aphididae) is considered to be with wide host range. In Jordan, Mustafa [15, 16, 17] reported M. persicae on several plants including peppers. Virus disease transmitted by this aphid in Jordan caused significant production problems to peppers [7]

In Jordan, most members of solanacious and cucurbits are important host for M. persicae [3]. The degree of infestation varies from one vegetable crop to another. Sweat pepper which forms about 3% of the total area planted to vegetable crops is the most vulnerable one. This aphid transmits potato virus Y (PVY) which is one of the most important yield- reducing factors as a result of severe mottling, stunning, flower abortion and local lesion followed by systemic necrosis. In addition, to direct damage by sucking plant sap and honeydew exudation on which a black sooty mold develops [3]. However, more than 72% of pepper in Jordan was exported to different countries. Future encouragement of continuous exportation will face the high market standard demands in the form of quality control especially for residues of chemical control [4]. Implicit in IPM is the maximum utilization of natural enemies; supplemented with selective use pesticides when necessary is the major step to meet these demands [14].

Successful integration of biological and chemical control in insect pest control program is a major challenge facing applied entomologists [6,23]. One major step in integration these two management techniques is to understand the impact of various pesticides on the pest [4, 5] and its natural enemies. In aphid parasitoids, the late larval and pupal stages within mummified bodies of their aphid hosts seems to be less susceptible to pesticides which offers an opportunity for selective application of pesticides[2,13,18]. The cold storage of aphid parasitoids being inside mummified aphid has a great economic importance in relation to application of IPM or biological control programs locally, regionally and globally. It is a simple method to keep mass-reared parasitoids alive when they are of no use. In this way, it is easily to be shipped and the cost of mass rearing may be lowered [20,21].

In Jordan, Aphidius matricariae was reported to be the most effective parasitoid attacking the green peach aphid. The parasitism percentage under plastic house conditions on pepper plants at Baqa' area reached 77-99% when the plants were infested with different ration of the aphid and the parasitoid[1]. However, the aim of this investigation was to study the effect of cold storage of mummy on emergence, survival, longevity and fecundity of the parasitoid. This would be the first step in the possibility of integration of biological and chemical control for the green peach aphid and its parasitoid, A.matricariae under greenhouse, and field conditions.

MATERIALS AND METHODS

Sweet pepper plant production:

Seeds of sweet pepper "Super lamuyo F1" from Vilmorin-France were regularly planted in seed trays to get seedling of 6-7 leaves. The seedlings were transplanted in plastic pots containing 50% soil and 50% peat moss. Irrigation and fertilization were done as usual until the seedlings become 25-30 cm in length.

Green peach aphid culture:

The aphids were collected from pepper plants grown in Madaba area, 20 km from Amman, the capital. Infested leaves were collected and transferred to the insectary lab at the National Center for Agricultural Research and Extension (NCARE) in Baqa'. Glass slides mounting were prepared for identification according to Blackmann and Eastop [10]). Taxonomical confirmation was carried out by Dr. Tawfiq M. Al Antary of the University of Jordan. About 100 first and second instar nymphs were isolated from the infested leaves. In greenhouse, a wooden cage containing 5 pepper plants were infested with isolated nymphs using a small moistened brush and monitored daily.

Green house Aphid culture:

In the greenhouse at NCARE, a separated cabin containing 300-400 pepper seedlings were used for the aphid culturing. Infested leaves from the wooden cage were taken after 3 weeks, distributed in plants, and monitored daily. The plants and the aphid culture were renewed after 4-5 months from aphid infestation.

Lab aphid stock culture:

In insectary lab at NCARE, 7 wooden cages, each containing 9 sweet pepper plants were infested with the aphid collected from the greenhouse culture. The plants were renewed gradually and when necessary, and from time infested leaves from the greenhouse culture were distributed on the plants. This culture was kept during the whole period of study and used for re-infestation of the newly established culture in greenhouse.

The aphid parasitoid culture:

Leaves of sweet pepper plants containing mummies of parasitized green peach aphid were collected from Madaba area and transferred to the insectary lab at NCARE. The mummies were taken with a small moist end brush and placed in test tubes covered with moist piece of cotton containing droplets of honey. Ten test tubes, each containing 5 mummies, were used and left under lab conditions with daily inspection for emergence. The emerged parasitoids were checked under the binocular microscope to be sure that they were of the same species and then collected by mouth aspirator into two separated vials. Slides mounting were prepared for taxonomical identification according to Pike et al. [10]). Identification gives the genus only (Aphidius) was carried out with the help of Prof. Tawfiq M. Al-Antary. One of the tow vials was sent to Prof. Giovanni Minio-Istituo di Entomologica Agaria, University of Palermo- Italy for taxonomical identification. The specimen was identified as Aphidius matricariae. The second vial was used for parasitoid culturing in the greenhouse.

Greenhouse parasitoid culture:

In the greenhouse, another separated cabin containing 100 sweet pepper plants were used at the beginning of the culture. Infested leaves from the greenhouse aphid culture were collected and distributed on the plants. Two weeks later, 5 females and 5 males in a test tube were released on the plants. The plants used for culturing were renewed after 4-5 months from aphid infestation, and the number of plants was increased to 300 on the second and third circulation of parasitoid culturing. Green sticky traps were hanged above the plants to reduce the number of the adult parasitoids [12]. In addition, the culture was checked twice a week to collect mummies for studies or to destroy excess ones.

Lab parasitoids stock culture:

In a separated insectary lab at NCARE, 7 wooden cages each containing 9 sweet pepper plants were infested with the aphid and the parasitoids. The plants were renewed gradually and when necessary and from time to time infested leaves and mummies from greenhouse aphid and parasitoids cultures were introduced to the plants. Green sticky traps were fixed inside the cage to reduce the number of parasitoid adults. In addition, the culture was checked two times weekly to destroy access mummies. This culture was kept during the whole period of study and used for re-infestation of the newly established cultures in the greenhouse.

Cold storage of late instar A. mataricariae within the mummy:

Late instar parasitoid within mummies, 2-4 days before emergence were collected from greenhouse parasitoids culture by a small moistened brush and transferred to the lab in a while plastic dishes. The mummies checked under the dissecting binocular microscope to be sure that they were healthy and at the right stage. Ten mummies were introduced in a black camera film box (replicate), and kept in the dark at the following contrast temperatures: acclimation periods were for 6, 12, 18, 24 and 36 hours at 8 [+ or -] 1 C using Isotemp Laboratory Refrigerator (Fisher Scientific). After the acclimation periods, storage periods were for 1,2 and 3 weeks at 3.5 [+ or -] 0.3 R.H. 95% using Controlled Environment Chamber (Conviron) Canada.

Storage at the same temperature without acclimation was carried out; at the end of the storage period, the mummies were transferred to vials covered with moistened pieces of cotton containing droplets of honey under lab conditions ([8,1121]. The layout of the experiments was factorial arrangement in CRD with 5 replicates and 15 treatments (without acclimation not included).

Effect of cold storage on emergence:

Number of emerged parasitoid adults was taken two times daily for 5 days. In addition, treated mummies were dissected under the binocular microscope at the end of the study to count emerged and non-emerged ones.

Effect of cold storage on survival and longevity:

Emerged adults of the same age were collected two times daily by mouth aspirator. The same vial was covered with a moistened piece of cotton contained droplets of honey, and monitored two times daily. Survival for each treatment was based on percentage emerged adults that survived 2 days after emergence. To estimate adult longevity, one survived adult from the previous replicate was collected randomly and placed on a separated vial covered with moistened piece of cotton contained droplet of honey. Five replicates (adults) were used for each treatment and checked daily until death.

Statistical analysis:

Data was analyzed by analysis of Variance with mean separation at 5% level of significance using Duncan's multiple range test.

Lab conditions:

Rearing of the aphid and its parasitoid were conducted under the following conditions: Temperature 24 [+ or -] 3 C, R.H. 60 + 10%, L: D 14:10 and light intensity from 4000-7000 Lux.

Results:

Effect of cold storage on emergence, survival, and longevity of the parasitoid:

Table 1 shows emergence, survival and longevity of A. matricariae adults from mummified M. persicae stored for 1,2 and 3 weeks at 3.5 [+ or -]0.3 C after acclimation periods 6, 12, 18, 24 and 36 hours at 8 [+ or -]1 C.

Effect of cold storage on emergence:

Number of emerged adults per 10 mummies (Table 1 and Fig 1) stored for one week at 3.5 [+ or -]0.3 C ranged from 8.6- 9.4 for all acclimation periods. These numbers of emerged adults were not significantly different. Emerged adults from mummies stored for 2 weeks (Table 1 and Fig. 1) for different acclimation periods ranged from 7.6- 8.8. emergence from the treatment 2 weeks storage- 6 hours acclimation (7.6) adults was significantly lower than emergence from the treatment 2 weeks storage--24 hours acclimation (8.8) adults. While emergence from the treatments 2 weeks storage--12, 18 and 36 hours acclimation (8.0, 8.6 and 8.6) adults, respectively, was not significantly different from emergence of the treatment 2 weeks storage- 24 hours acclimation (8.8)adults.

Emergence from the treatment 3 weeks storage (Table 1 and Fig 1) for different acclimation periods ranged from 5.6-7.6. emerged adults from the treatments 3 weeks storage -6 and 12 hours acclimation (5.6 and 6.2 ) were significantly lower from emergence of the treatments 3 weeks storage--18, 24 and 36 hours acclimation (7.6, 7.2 and 7.6) adults respectively.

Emerged adults from mummies stored for one week for all acclimation periods in arrangement (8.8, 8.6, 8.8, 9.0 and 9.4) were not significantly different from emergence of the treatments 2 weeks storage- 18, 24 and 36 hours acclimation (8.6, 8.8 and 8.6) adults respectively.

Number of emerged adults (Table 1 and Fig 1) from treatment 1 week storage--36 hours acclimation (9.4) was significantly higher from emergence of the treatment, 2 weeks storage--6 and 12 hours acclimation (7.6 and 8.0) adults, and 3 weeks storage--6, 12, 18, 24 and 36 hours acclimation (5.6, 6.2, 7.6, 7.2 and 7.6) adults respectively.

Effect of cold storage on survival:

Survived emerged adults from treatments 1 and 2 weeks storage at 3.5 [+ or -] 0.3 C for all acclimation periods (Table 1 and Fig. 1) ranged from 89.6 -100%. These survival percentages were not significantly different. Whereas survival from treatment 3 weeks storage -24 hours acclimation (88.6%) was not significantly different from the treatments, 1 week storage- 6, 12, 18, 24 and 36 hours acclimation (96, 97.8, 97.8, 100, and 100%), respectively, 2 weeks storage-6, 12, 18, 24 and 36 hours acclimation (92.4, 89.6, 100, 100 and 97.8%), respectively, and 3 weeks storage--6, 12 and 36 hours acclimation (82.6, 80.6 and 84%), respectively, but its significantly higher from treatment 3 weeks storage--18 hours acclimation (73.6%). In addition survival from the treatments 3 weeks storage--6 and 36 hours acclimation (82.6 and 84%) were not significantly different from survival of the treatment 2 weeks storage 12 hours acclimation (89.6%).

Effect of cold storage on longevity:

Longevity of survival adults from mummies at 3.5 [+ or -] 0.3 C for 1 week after acclimation periods of 6, 12, 18, 24 and 36 hours (Table 1 and Fig. 1) ranged from 5.6- 6.4 days. These longevity periods were not significantly different. Whereas longevity from treatment 2 weeks storage 18 and 24 hours acclimation (6.2 and 5.8) days were not significantly different from longevity of the treatments 1 week storage -6, 12, 18, 24 and 36 hours acclimation (5.8, 5.6, 5.8, 6.4 and 6.0) days, respectively. Longevity from treatment 2 weeks storage--6, 12, and 36 hours acclimation (4.8, 5.2 and 5.0) days, respectively, were not significantly different from the treatments 1 week storage--6, 12 and 18 hours acclimation (5.8, 5.6 and 5.8) days, respectively.

Longevity of survived adults from the treatment 3 weeks storage- 6, 12, 18, 24 and 36 hours acclimation ranged from 4.4-4.8 days (Table 1 and Fig 1). These longevity periods were significantly different. However, longevity from the treatment 1 week storage- 24 hours acclimation (6.4) days was significantly higher longevity from the treatments, 2 weeks storage--6, 12 and 36 hours acclimation (4.8, 5.2 and 5.0) days, respectively and 3 weeks storage--6, 12, 18, 24 and 36 hours acclimation (4.4, 4.6, 4.4, 4.6 and 4.8) days, respectively. However, adults longevity from treatment 1 week storage- 6 hours acclimation (5.0) days was not significantly different from treatments, 2 weeks storage- 6, 12, 18, 24 and 36 hours acclimation (4.8, 5.0, 5.6, 5.4 and 5.8) days, respectively, and 3 weeks storage--18, 24 and 36 hours acclimation (4.8, 4.4 and 4.6) days, respectively. Whereas longevity of survived adults from the treatments 3 weeks storage--6 and 12 hours acclimation (4 and 4) days was not significantly different from the treatments, 3 weeks storage -18, 24 and 36 hours acclimation (4.8, 4.4 and 4.6) days, respectively, and 2 weeks storage--6 hours acclimation (4.8) days, but it was significantly lower than other treatments.

The cold storage treatments for 1, 2 and 3 weeks at 3.5 [+ or -]0.3 C without acclimation periods were not included in the results analysis. Number of emerged adults were very low (0-3) for the treatment 1 week storage, and zero for the treatments 2 and 3 weeks storage.

Discussion:

The development of low cost, effective storage methods constitutes one of the most challenging problems in the efficient rearing of parasitoids and predators. It is especially important for the production of high- quality biological control agents to be used in inoculative, augmentative, or inundative release. Progress in this area would aid public and commercial insectaries because effective storage methods would translate into reduced investment in rearing facilities, and increase ability to meet peak demands for production and distribution. Aspects of the proposed storage procedure could be enhanced further.

For storage to be value in mass production of A. matricariae, it must fulfill several requirements. High emergence rate of parasitoid within the mummy after storage, high incidence of survival and longevity for emerged adults, synchronous and predictable initiation of reproduction after storage, and sustained high fecundity. The experiment (Table 1) illustrated that late instar A. matricariae within mummified M. persicae could be stored for at least 2 weeks and generally met these requirements.

The present results could be compared with the literature data about the time at which 80% or more emergences still occur at the best acclimation/storage condition tested. Only 2 weeks for 2 polyphagous species that was distributed in subtropical areas, Lysiphlebus testaceipes [9] and A. colemani [21]). Three weeks were for A. uzbekistanicus [21]). Different results about A. matricariae were obtained. These were 2 weeks in southern France and 4 weeks in England [21]. However, the successful storage of A. matricariae within mummified aphid took place in hibernal quiescence for one month only [20]). The present work agreed with the work conducted by Al Antary and Abdel-Wali [6]. Storage generally lowered fecundity and fertility below that unstored adults. Archer et al. ([8] indicated that adults of A. asychis stored for 15 days reproduced at the same level of unstored adults, but reproduction declined as the length of storage increased, while Tauber et al. [22]) stated that despite some reproduction in fertility, the level of fertile egg production by females Ch. carnea after storage was compatible with the objectives of mass production. However, in case of using the parasitoid might be not convencing, it is worth applying integration between this biological agent with chemical control of the green peach aphid (Al Antary and Abdel Wali, 2016 )

Conclusions:

Cold storage of late instar A. matricariae within mummified M. persicae for 1, 2 and 3 weeks at 3.5 [+ or -] 0.3 C after an acclimation periods of 6, 12, 18, 24 and 36 hours at 8 [+ or -] 1 C leads to the following conclusions:

3. In general, adults emergence, survival and longevity from mummies stored for 1 and 2 weeks were better than from mummies stored for 3 weeks.

4. Although increasing the acclimation periods from 6 to 12, 18, 24 and 36 hours had no observable trends on the above tested parameters, acclimation itself is a very important factor for successful cold storage.

ACKNOWLEDGMENT

We would like to thank the University of Jordan and National Center for Agricultural Research and Extension (NCARE) for help and financing this research.

The authors declare that there is no conflict of interest

REFERENCES

[I] Abdel-Wali, M., M. Salem and M. Qaryouti, 1999. Biological control of whitefly and other important pests. NCARTT, Financed research projects by GTZ and Higher Council for Science and Technology.

[2] Abo Al-Ghar, G. and A. El-Sayed, 1992. Long-term effect of insecticides on Diaeretiella rapae (M'lntosh), a parasitoid of cabbage aphid. Pestic. Sci., 36: 109-114.

[3] Al Antary, T.M. and A. Al Mommany, 1990. Pests of Garden and Home, 1st edition. Dar Al Arabiah for publication and Distribution, Cario., pp: 390.

[4] Al Antary, T.M. and B. Khader, 2013a. Toxicity of four insecticides on longevity and fecundity of three populations of the green peach aphid Myzus persicae (Aphididae: Homeptera) for three generations. Jordan J. Agric. Sci., 9(1): 52-62.

[5] Al Antary, T.M. and B. Khader, 2013b. Residual effect of certain insecticides against different strains of green peach aphid on pepper. Jordan J. Agric. Sci., 9(3): 311-320.

[6] Al Antary, T.M. and M.I. Abdel-Wali, 2015. Effeect of cold storage on biological parameters of the aphid parasitoids Aphidius matricariae Haliday (Hymenoptera: Aphidiidae). Egyptian Journal of Biological Pests Control., 25(3): 697-702.

[7] Al Mommany, A. and T.M. Al Antary, 2008. Pests of Garden and Home, 2nd edition. Publications of the University of Jordan, Amman, pp: 518.

[8] Archer, T., R. Bogart and R. Eikenbary, 1976. The influence of cold storage on the survival and reproduction by Aphelinus asychis adults. Environ. Entomol., 5(4): 623-625.

[9] Archer, T., C. Murray, R. Eikenbary, K. Starks, R. Morrison, 1973. Cold storage of Lysiphlebus testaceipes mummies. Environ. Entomol., 2: 1104-1108.

[10] Blackmann, R.L., and V.F. Eastop, 1994. Aphids on the world's trees. An Identification and information guide. Cab international in associated with the Natural history Museum.

[11] Gilkeson, L., 1990. Cold storage of the predatory midge Aphidoletes aphidimyza (Diptera: Cecidomyiidae). J. Econ. Entomol., 83(3): 965-970.

[12] Goff, A., and L. Nault, 1984. Response of the pea aphid parasite Aphidius ervi Haliday (Hymenoptera: Aphidiidae) to transmitted light. Environ. Entomol., 13: 595-598.

[13] Hsieh, C., and W. Allen, 1986. Effects of insecticides on emergence, survival, longevity, and fecundity of parasitoid Diaeretiella rapae (Hymenoptera: Aphidiidae) from mummified Myzus persicae (Homoptera: Aphididae). J. Econ. Entomol., 79: 1599-1602.

[14] Metcalf, R., and W. Luckmann, 1974. Introduction to Insect Pest management. John Willey and Sons Inc. Newyork.

[15] Mustafa, T., 1985. The aphids of Jordan, I. A preliminary list. Dirasat. XII. 161-166.

[16] Mustafa, T., 1986a. The aphids of Jordan, II. A second list. Dirasat. XIII. 209-213.

[17] Mustafa, T., 1986b. The aphids of Jordan, III (Homoptera). A third list. Entomologica Basiliensia (12): 77-82.

[18] Patel, I., B. Prajapati, G. Patel and A. Pathak, 1996. Relative toxicity of insecticides to Diaeretiella rapae, a hymenopterous parasite of mustard aphid (Lipaphis erysimi). Indian Journal of Agricultural Sciences, 66(8): 507-508.

[19] Pike, K., P. Stary, T. Miller, D. Allison, L. Boydston, G. Graf and R. Gillespie, 1997. Small-grain aphid parasitoids (Hymenoptera: Aphlenidae and Aphidiidae) of Washington: distribution, relative abundance, seasonal occurrence, and key to known North American species. Environ. Entomol., 26(6): 1299-1311.

[20] Polgar, L., 1987. Induced diapauses for a long term storage of Aphidius matricariae. OILB. pp: 152-153.

[21] Rabasse, J. and A. Ibrahim, 1987. Conservation of Aphidius uzbekistanicus Luz. (Hym.: Aphidiidae) parasite on Sitobion avenae F. (Hom.: Aphididae). OILB. pp: 54-56.

[22] Tauber, M., C. Tauber and S. Gardescu, 1993. Prolonged storage of Chrysoperla carnea (Neuroptera: Chrysopidae). Environ. Entomol., 22(4): 843-848.

[23] Al Antary, T. and M. Abdel-Wali, 2016. Integration of biological and chemical control of Myzus persicae Sulzer (Hemiptera: Aphididae ) under green house conditions. Egyption Journal Of Pest Control., 26(3): 533-537.

Address For Correspondence:

Tawfiq M. Al-Antary, Plant Protection Department, School of Agriculture, The University of Jordan, Amman- Jordan

Tawfiq M. Al-Antary and Marwan I. Abdel-Wali

Plant Protection Department, School of Agriculture, The University of Jordan, Amman- Jordan

This work is licensed under the Creative Commons Attribution International License (CC BY).

http://creativecommons.org/licenses/by/4.0/

Received 23 August 2016; Accepted 1 November 2016; Published 20 November 2016

Table 1: Emergence, survival, and longevity of Aphidius matricariae
adults from mummified Muzys persicae stored for 1, 2 and 3 weeks at 3.5
[+ or -] 0.3 C after an acclimation periods of 6, 12, 18, 24, and 36
hours at 8 [+ or -] 1 C.

Treatment          Emergence (mummies/10)
                   Mean [+ or -] SE

6 hrs. x 1 week    8.80 [+ or -] [0.37.sup.ab]
12 hrs. x 1 week   8.60 [+ or -] [0.40.sup.abc]
18 hrs. x 1 week   8.80 [+ or -] [0.20.sup.ab]
24 hrs. x 1 week   9.0 [+ or -] [0.32.sup.ab]
36 hrs. x 1 week   9.40 [+ or -] [0.25.sup.a]
6 hrs. x 2 weeks   7.60 [+ or -] [0.25.sup.cd]
12 hrs. x 2 weeks  8.0 [+ or -] [0.32.sup.bcd]
18 hrs. x 2 weeks  8.60 [+ or -] [0.40.sup.abc]
24 hrs. x 2 weeks  8.80 [+ or -] [0.20.sup.ab]
36 hrs. x 2 weeks  8.60 [+ or -] [0.25.sup.abc]
6 hrs. x 3 weeks   5.60 [+ or -] [0.25.sup.e]
12 hrs. x 3 weeks  6.20 [+ or -] [0.37.sup.ab]
18 hrs. x 3 weeks  7.60 [+ or -] [0.25.sup.cd]
24 hrs. x 3 weeks  7.20 + [0.49.sup.d]
36 hrs. x 3 weeks  7.60 + [0.25.sup.cd]

Treatment          Survival%
                   Mean[+ or -] SE

6 hrs. x 1 week    96.0 [+ or -] [2.45.sup.a]
12 hrs. x 1 week   97.8 [+ or -] [2.20.sup.a]
18 hrs. x 1 week   97.8 [+ or -] [2.20.sup.a]
24 hrs. x 1 week   100.0 [+ or -] [0.0.sup.a]
36 hrs. x 1 week   100.0 [+ or -] [0.0.sup.a]
6 hrs. x 2 weeks   92.4 [+ or -] [3.12.sup.ab]
12 hrs. x 2 weeks  89.6 [+ or -] [5.32.sup.abc]
18 hrs. x 2 weeks  100.0 [+ or -] [0.0.sup.a]
24 hrs. x 2 weeks  100.0 [+ or -] [0.0.sup.a]
36 hrs. x 2 weeks  97.8 [+ or -] [2.20.sup.a]
6 hrs. x 3 weeks   82.6 [+ or -] [5.26.sup.bcd]
12 hrs. x 3 weeks  80.6 [+ or -] [2.58.sup.cd]
18 hrs. x 3 weeks  73.6 [+ or -] [4.10.sup.d]
24 hrs. x 3 weeks  88.6 + [6.03.sup.abc]
36 hrs. x 3 weeks  84.0 + [5.13.sup.bcd]

Treatment          Longevity (days)
                   Mean[+ or -] SE

6 hrs. x 1 week    5.80 [+ or -] [0.37.sup.abcd]
12 hrs. x 1 week   5.60 [+ or -] [0.25.sup.abcde]
18 hrs. x 1 week   5.80 [+ or -] [0.37.sup.abcd]
24 hrs. x 1 week   6.40 [+ or -] [0.25.sup.a]
36 hrs. x 1 week   6.0 [+ or -] [0.45.sup.abc]
6 hrs. x 2 weeks   4.80 [+ or -] [0.37.sup.def]
12 hrs. x 2 weeks  5.20 [+ or -] [0.20.sup.bcdef]
18 hrs. x 2 weeks  6.20 [+ or -] [0.49.sup.ab]
24 hrs. x 2 weeks  5.80 [+ or -] [0.37.sup.abcd]
36 hrs. x 2 weeks  5. 0 [+ or -] [0.32.sup.cdef]
6 hrs. x 3 weeks   4.40 [+ or -] [0.25.sup.f]
12 hrs. x 3 weeks  4.60 [+ or -] [0.25.sup.ef]
18 hrs. x 3 weeks  4.40 + [0.25.sup.f]
24 hrs. x 3 weeks  4.60 + [0.25.sup.ef]
36 hrs. x 3 weeks  4.80 + [0.37 def]

Means in each column followed by the same letter are not significantly
different (P
COPYRIGHT 2016 American-Eurasian Network for Scientific Information
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2016 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Al-Antary, Tawfiq M.; Abdel-Wali, Marwan I.
Publication:Advances in Environmental Biology
Article Type:Report
Date:Nov 1, 2016
Words:4595
Previous Article:Causes and prevention of fruit drop of syzygium samarangense (wax apple): A review.
Next Article:An automatic pattern matching approach for oil spill detection in SAR images.
Topics:

Terms of use | Privacy policy | Copyright © 2021 Farlex, Inc. | Feedback | For webmasters