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Jfuas No.1 June 2013

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Biology and Food Preference of Zonocerus variegates

(L.) On Different Types of Food Plant Species

المزركشوبيول الجراد جيةف لها المفضلة النباتات التغذيةيوأنواع

By:1-Ibrahim Abdel-Rahman Ibrahim Abdel/Fattah, Faculty of Environmental Sciences and Natural

Resources, Department of Plant Protection, University of El fasher, Sudan

2-Elwasila Guddoura Mohammed, Faculty of Agriculture, Department of Crop Protection,

University of Khartoum, Sudan.

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الفارش م2013يونيو–األولالعدد–التطبيقيةالعلوممجلة–جامعة

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Abstract

This study was carried out in Darfur Region, during the period

(1999-2000). The objective was to study the feeding rate and food

preference of Zonocerus variegatus L. on different types of food

plant species and its possible distribution through the

seasonal water courses. The present study indicated that the

highest live weight was gained by the nymphs and adults when

fed on cassava, okra , caster and millets, whereas the lowest live

weight gaining’s were obtained when these stages were fed

on Ipomoea fistulas , Psidiumgua java, Calotropis procera and

Sorghum bicolor . The study also confirmed that I.fistulosa is not

suitable food for instars and adults growth and development. Though,

the dense concentration of mature adults on I.fistulosa for breeding

activities would provide appropriate conditions for applying suitable

control measures. Western Sudan was known since long ago as

drought victimized area, and that the menace of variegated

grasshopper is high in the potential Wades will complicate the

agricultural situation especially during scarce food production.

.Key words: Zonocerus variegate s(L.),Wade, pharmacophagous,

chemo-ecological.

Introduction

Mohammadain (1996) stated the first appearance of Zonocerus

variegates (L.) in Western Darfur State where an area of about

75190 hectare was infested by this serious insect pest. Since that time

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the grasshopper was continuously endangering the whole agricultural

sector in Darfur region and migrating inward to infest new areas. The

pest is strictly polyphagous grasshopper with a wide range of food

acceptance. It does seem that the species alone can cause massive

losses on different crops grown along the wades. Although this

grasshopper has reached pest status very recently, yet its significant

damaging levels on the economically important cereal and

horticultural crops ranked it as one of most serious insect pest

currently existing in the whole region. Crops damaged included okra,

onion, Jews mallow, banana, lucerne, maize ,millet , sorghum,

mango, guava, lemon, cassava etc., besides other wild plant

species, along the banks of the major seasonal water courses (Wades)

and their tributaries in West Darfur (P.P.D.,1996).

The quite rich food ecology enabled the pest to become

established despite of the P.P.D. notable efforts to contain the

problem. In season (2001) the infested area was estimated to be 17800

hectare in Kebkabayia along Wade - Bari towards the East. Thus the

species was able to cover 89 klms. in length making its way deeper

into the Province (P.P.D.,2001).This work is aiming to study the

quantitative and qualitative effects of some food types on growth,

development and longevity of a selected stages of the exotic

grasshopper to specify its essential, non-essential and

pharmacophagous food plants. Expected results are assumed to

assess the behavioral factors that interact with nutritional factors to

affect pest population size .These in turn would have to ensure that

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how could, the conventional classification of agricultural pests i.e.

minor , national, absence of vigilance and lack of knowledge would

have on the agricultural situation in the Sudan.

MATERIALS AND METHODS

To investigate the feeding rate and food preference of

Zonocerus variegates(L.), selected stages, the 4th,5

th,6

th, instars and

new adults were tested under the laboratory conditions, season 2001.

Nymphs and adults each approximately in the same age after molting

and after fledging were collected randomly from the stock-culture

established from eggs brought from the field Figs. (1). These were

divided into four groups each of (10) individuals kept in a separate

plastic jars, plate ( 1 ).The tested groups were then starved for 24hrs,

following the method adopted by Mohammadain (1997) (when reared

tree locust nymphs).The tested groups were allowed next to feed on

specific host plants such as Manihot esculenta plates (2+3), Hibiscus

esculents, Psidium guajava, Ipomoea fistulas, Ricinus communis

,Calotropis procera ,pennisetum typhoideum and Sorghum bicolor .

Each group was replicated five (5) times on every tested host plant.

The following tests were carried out:

Faecal pellet test

The faecal pellets voided by the different stages during (24)

hours were collected carefully, dried up under shade on air dry-basis

and weighed by a sensitive electric balance i.e. Sartorius research.

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Live weight test

Tested nymphs and new adults were weighed before and after

feeding by using a sensitive balance to calculate the live weight gained or

lost when fed on different food plants for (24)hours .

Dry matter tests

Fresh food plants were weighed before and after consumption by

different tested nymphs and new adults. Unconsumed fresh food

plants were collected, dried up under shade (to avoid thermal

decomposition), on air dry – basis and weighed by a sensitive balance.

Dry matter weights obtained after consumption were subtracted from

the dry matter weights of food before consumption. This test was

aimed to calculate the real amount of food consumed by the different

stages of Zonocerus variegates (L.) on the dry matter basis.

The above three tests were compiled to study the effects of food

plants on live weight, food efficiency, preference and non preference

and feeding rates. The stages from the 4th

stage onwards were

selected, because, they are manageable and easy to deal with

compared to the restless early stages specially when using the

sensitive balance. Also practicable and reliable data can be obtained

from small but effective group which serves the purpose of the test.

Effects of Ipomoea fistulosa on nymphs development

To test the effects of Ipomoea fistulosa on the survival

percentages and development periods of Zonocerus variegates (L.)

nymphs; the following experiment was carried out:

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In season 2001,twenty (20) 2-days old 4th

instars were selected for

rearing to avoid the risk of dying because 1st-3

rdinstars , sometimes

do not thrive, when fed on certain food plants i.e. Cassava until its

nymphs has reached the 4th

instars and accordingly the period spent

for growth and development was measured. (Pans Manual, 1986,

Steedman, 1990 and Owueme1994). Instars were divided into (5)

groups each containing (4) nymphs was kept in a separate rearing jar,

Plate (1) and was reared under the laboratory conditions on pure

leaves of Ipomoea fistulosa. The jars set - up, rearing and

observations were made all through.

RESULTS

The feeding rate and food preference of Zononcerus variegates

(L) nymphs and new adults were examined on (8) different food plants

under the laboratory conditions. These plants were abbreviated as

shown below:

1- Manihot exculenta (M. e.)

2- Hibiscus exculentus (H. e.)

3- Psidium guajava (P. g.)

4- Ipomoea fistulosa (I. f.)

5- Ricinus communis (R. c.)

6- Calotropis procera (C. p.)

7- Pennnisetum typhoideum (P. t.)

8- Sorghum bicolor (S. b.)

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Results showed that some food plants i.e., M. e., H. e. and P. t.

were preferred and were suitable for development where high live

weights were gained. On the other hand some other food plants were

not or less preferred i.e. P. g., I. f., CP and S. b. where less live

weights gained or lost.

Results obtained comprised mean dry weights of different food

plants consumed, mean dry weight of faecal pellets voided and the

live weights gained or lost by the different stages fed on the tested

food plants listed above. Data was compiled to calculate the food

which was obtained by the formula:-

Food efficiency % = Net food x100

Initial food consumed

Net food = Dry food consumed - Dry faecal pellets

Results obtained were presented as follows:

On the food plant (M. e.), the mean dry weight of food

consumed was: 28.414+ 6.127, 37.322+16.540, 79.420+ 25.768 and

106.24.217, the mean dry weight of faecal pellet voided

was:7.992+1.592, 18.422+3.689,34.428+9.754 and 43.962+11.297,

the mean live weight gained or lost was:16.860+ 5.670, 54.944+

13.218, 110.124+ 29.643 and 150.632+29.088 mgs food efficiency

was: 71.94, 56.65 and 58.53% for the 4th

, 5th

, instars and the new adult

respectively.

On the food plant( H. e.),the mean dry weight of food consumed

was:30.914+27.305, 51.316+25.9, 113.410+33.345 and

140.518+27.584,the mean dry weight of faecal pellets voided

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was:6.438+1.089,16.968+2.431,46.068+4.686 and 39.190+8.818,the

mean live weight gained or lost was; 14.566+5.809, 35.014+15.333,

109.342+ 20.354 and 78.694+17.082 mg, food efficiency was:

79.174+66.934, 59.379 and 72.110 for the 4th

, 5th

, 6th

instars and the

new adult, respectively.

On the food plant (I. f.), the mean dry weight of food consumed

was: 5.072 ± o.109, 1o.344 ± 1.643 , 17.662 ± 1.191and 35.564 ±

4.396 the mean dry weight of faecal pellets voided was: 2.952 ±

1.195, 7.414 ± 3.322, 14.114 ± 4.860 and 17.916 ± 8.882, the mean

live weight gained or lost was: 7.566 ± 11.133, 1.568 ± 14.620, 1.465

± 17.905, and 20.008 ± 40.074 mg, food efficiency was: 41.798,

28.325, 20.088 and 49.623% for the 4th

, 5th

, 6th

, and the new adult

respectively.

On the food plant (C. p.), the mean dry weight of food consumed was:

16.452 ± 8.791, 31.964 ± 3.689 and 41.566 ± 13.820, the mean dry

weight of faecal pellet voided was: 6.264 ± 2.605, 12.622 ± 2.179 and

17.344 ± 6.175, the mean live weight or lost was: 1.75 ± 7.419, 5.776

± 30.111 and 4.048 ± 31.623 mg, food efficiency was: 61.925, 60.511

and 58.273% for the 4th

, 5th

, 6th

, and the new adult respectively.

On the food plant (P. t.), the mean dry weight of food consumed

was: 29.098 ± 12.965, 43.652 ± 14.853 and 56.084 ± 11.335, the mean

dry weight of faecal pellet voided was: 14.738 ± 4.483, 24.514 ± 3.67

and 29.498 ± 3.560, the mean live weight gained or lost was: 18.984 ±

15.529, 30.064 ± 9.749 and 4.504 ± 18.187 mg, food efficiency was:

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50.840, 43.842 and 47.403% for the 4th

, 5th

, 6th

, and the new adult

respectively.

On the food plant (S. b.), the mean dry weight of food consumed was:

16.724 ± 3.487, 22.388 ± 9.989 and 34.566 ± 8.175, the mean dry

weight of faecal pellet voided was: 11.994 ± 1.403, 16.294 ± 4.526

and 23.23 ± 7.231, the mean live weight gained or lost was: 14.632 ±

15.223, 27.014 ± 14.563 and 14.458 ± 19.014 mg, food efficiency

was: 28.282, 27.219 and 32.795% for the 4th

, 5th

, 6th

, and the new

adult respectively.

Effects of Ipomoea fistulosa on nymphs development

The effects of Impoea fistulosa on the survival percentage and

developmental period of different nymph instars from 4th

instars to

adult emergence were presented in Figs. (3) and (4).

Results obtained showed that the prolonged feeding periods of

nymphs on Ipomoea fistulosa resulted in adverse effects on their

biology. The percent mortality of nymph instars was: 15 %, 15%

and10% for the 4th

, 5th

and 6th

nymph stages respectively. The 83.33%

survival instars molted into adult stage after having passed through

(5) nymph instars and the rest (16.67%) after having passed

through(6) nymph instars Fig.(5).

The developmental periods of the 4th

, 5th

and 6th

instars were

34.76 ± 16.98, 42.8 ± 10.67 and 4.5 ± .071 days respectively. Adult

longevity was ranged from1 - 14 days were all of them died before

reaching maturity. Growth up normality were not seen but, the

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colours of both instars and the new adults were changed into pale

yellow, small in size and the growth was retarded or delayed.

%su

rviv

al

Figure.1 Survival percentage of the different instars of Z.variegates (L)

reared on I. fistulosa under the laboratory conditions

Figure.2.Mean duration of the different instars of the Z.variegatus (L)

reared on Ipomea fistulosa under the laboratory conditions.

Mea

nd

ura

tion

(days)

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Jfuas No.1 June 2013

115

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Figure 3.fledging percentage of Z .variegatus completed development

through 5-6 instars when reared on Ipomoea fistulas under the

laboratory conditions.

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Plate (1) Rearing jars

Plate (2)

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117

Plate (3)

plates 2+3 show two species of Cassava used for rearing Z. Variegatus

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Discussion

Results indicated that, Manihot esculenta (M. e.), Hibiscus

esculentus (H. e.), Ricinus communis (R. c.) and Pennisetumty

phoideum (P. t.) are the Preferred food plants and suitable for

development. The highest live weight gained after 24 hours among all

tested food plants is obtained from cassava (M. e.). This finding

agrees with Hill (1981), Boppre and Fischer (1994). This finding also

strongly supports the results obtained under the laboratory

conditions, when nymphs from the 4th

, instars onwards have

successfully completed their development up to fledging, maturity and

reproduction purely on cassava. Okra (H. e.) ranked second in terms

of live weight gaining and it was proved to be suitable as nutritional

food during instars rearing and field observations. Caster (R. c.)

ranked third in terms of live weight gaining, though Hill (1981)

reported this plant as an alternative food for this pest. However,

millet (P. t.),although a fourth in terms of live weight gaining ,

yet it was proved to be a suitable food plant enabling development

of instars when used as a mixed food. This evidence confirms Hill

(1981) who reported that, the finger millets is essential food for Z.

varigates (L.).

On the other hand tested food plants, I. fistulosa, P. guajava, C.

procera and S. bicolor proved to be less or not preferred food plants

where the lowest live weights were gained or lost when stages fed

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on. The negative results indicate that tested stages have lost their live

weights probably due to adverse effects of the plant constituents.

Generally this result is comparable with Tamu and Modder

(1996), although they used other different plant species except

cassava. Linking the results of this study with that obtained from the

field, apparently, the occurrence of certain plant species in the pest

habitats would eventually have effect on its survival and abundance.

In this sense, cassava the main food plant which is highly required by

the pest is currently grown at different wadies i.e. Wadi-Rati south of

El Ginenia. Okra the popular food plant is grown at a wide scale in all

wadies of Darfur, can form a second choice for the pest in the absence

of cassava. Even in the absence of the two essential food plants

coexist, the chance of its survival, development, reproduction is high

due to its polyphagus behavior. Accordingly their harmful effects to

farmers are great.

Effects of I. fistuolosa on nymphs development

Results of this test indicated that I. fistulosa is not suitable food

plant for rearing Z.variegatus (L.) nymphs .The percent mortality of

nymph instars was 15%, 15% and 10%for the 4th

, 5th

and 6th

nymph

stages respectively. The developmental period of the 4th

, 5th

and 6th

,

instars was 34.76 ± 16.98, 42.8 ± 10.67 and 4.5 ± o.71 days

respectively. Generally growth is retarded and adult longevity was

ranged 1-14 days where all of them died before maturity. Like

certain other noxious plants, I.fistulosa is known to cause incidence

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of poisoning in domestic animals (Goats), Abdel-Hadi (1987). Z

.variegatus (L.) was the unique grasshopper feeds on I. fistulosa along

the Wa�I. fistulosa Wadi.

I. fistulosa was considered to be not a suitable food plant for

grasshoppers (Chapman et al, 1986) due to its toxicity. Generally,

when rearing instars of Z. variegates (L.), the need for essential food

is considered to be an important factor for successful development.

However, a complete diet containing all required nutrients is rarely

found in one plant species. Apparently very few plants including

citrus and cassava fulfill the nutritional requirements for good survival

of the grasshopper (Boppre and Fischer 1994). As the pest exhibits

polyphagous feeding habits, a complete diet is usually secured from

several food sources in nature. Hence, instars appear to have a mixed

food for proper development. Abdel-Hadi (1987) identified the

alkaloid Ergometrine from I. fistuolosa extracts which probably plays

a similar role as the Payrolidizin alkaloids (PAs) that extracted from

Chromolema odorata. Therefore the improper nymph development

on I. fistulosa appears to be due to the effect of toxic alkaloids and the

fact that nymphs were fed on a single food source.

The ability of some instars to complete development on I.

fistulosa can be explained by the fact that, nymphs would have

benefited from the nutrients when those were fed on a mixed food

plant initially and stored in their bodies during the early stages of

development (1st -

3rd instars

) . This was then supported by nutrients

Jfuas No.1 June 2013

121

found in I. fistulosa leaves. However, poor performance was obtained

when Z. variegates (L.) nymphs fed on C. odorata.

Continuous feeding increased the dose of toxins to become lethal,

although tolerance appeared among stages (i.e.4th

stage).

Results of this test confirmed that 4th

instars have got a high

survival abilities to thrive and complete development on I. fistulosa,

although it is not a suitable food. In the absence of essential food

sources, this bush can temporary serve this grasshopper until booming

food situations prevails. As this noxious plant remain unconsumed by

many animals, thus it would constitute a potential food source for the

pest in fallow lands during the dry conditions. Further investigation is

needed on the chemo-ecological relationship between Z. variegatus

(L.) and the bush plant, I .fistulosa.

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References

Abdel-Hadi, A. A. (1987).Pharmacological and Phytochemical

investigation of Ipomoea carnea subsp. fistulosa .Ph.D. Thesis,

University of Khartoum.

Ali, B. A. (1997). Studies on the biology and seasonal occurrence and

control of the Sahelian tree locust, Anacridium melanorhodon

(Walkor) (Orthoptera: Acrididae) M.Sc. Thesis, University of

Khartoum.

Boppre, M. and Fischer, O.W.(1984) Zonocerus and Chromolaena

in West Africa. New Trends in locust Control. Deutsche Gesellschaft

fur Technische Zusammennarbeit (G.T.Z.), GmbH, Tech. Coope.

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Chapman R. E., W.W. Pageand A. R. MacCaffery (1986)

Bionomics of the variegated grasshopper (Zonocerus variegates (L.)

in West Africa. Ann. Rev.Entomol.31: 479-505.

Hill, D. S. (1981). Agricultural insects pests of the tropics and their

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edn.). Hyda house, Saxby Avenue, SKegeness, Lincs.,

England.746.

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plants on the variegated grasshopper, Zonocerus variegates

(Linnaeus) (Orthoptera: Pyrgomorphidae). African Entomology 4(2),

189-196.

Mohammadain, A. (1996). An outbreak of Zonocerus variegates (L.)

in Western Darfur State, Plant Protection Directorate ( Khartoum

North), Ministry of Agriculture, Sudan.

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P.P.D.(1996). Zonocerus variegates (L.) Annual campaign report, El

Geneina, West Darfur State, Sudan.

P.P.D. (2001).Zonocerus variegates(L.)Annual campaign report, El

fasher, North Darfur State, Sudan.

Pans Manual, (1986). Pest Control In Tropical Root Crops No (4)

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Steedman, A. (ED)(1990). Locust handbook. (3rd

end.), London,

Overseas Development Administration, Natural Research Institute,

204pp.

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