RSS Feed (xml)
Biological study of Locusta migratoria at East Samba,
East Nusa Tenggara, 1976
East Nusa Tenggara, 1976
by: Harsono Lanya
In Indonesia, a sensational explosion of migratory locust (Locusta migratoria) was happened at Sumba Island, the Province of East Nusa Tenggara. The plantation they destroyed was corn and rice. Along October to November of 1973, it was reported for the first time that they made a destroyed in farming area of the eastern of Waingapu, East Sumba. Then in the middle of 1974, it was reported that a whole area of East Sumba had been attacked. In the beginning of 1975, those locusts made a destroyed in Sumba Island, it means that it was included the Region of West Sumba (Soenardi, 1975).
Most of the species of these locusts which were in group of family of Acridiidae, known as polyphagous, it seems like no other plants they like. Something interesting of locust migratory in their characteristics, it is hat they like moving from one place to another in a huge amount, so, when they perch on plant area, they will destroy the plant until finish at a very short time (Dammerman, 1929). The following is the written research biological study at East Sumba from November 1975 until July 1976.
MATERIAL AND METHOD
Life Cycle
Egg pods were got in incubation, in a tube with sand media which had 14.29% of water degree of volume. In this research, we used 80 tubes of egg pods. The opening of tube was closed by plastics with small holes. The observation emphasized to the eggs stadium and they hatching percentage.
In a 30 cm x 30 cm x 40 cm wire netting, we kept 12 nymphs which had just hatched; we fed those 25-50 days old corn and rice. We attention observe to the growth of 120 nymphs in 10 cages till they became imago. Nymph stadium of instars 1, 2, 3, 4, and 5 known when they had skin molting.
The research of pre-copulation and pre-oviposition was done to 56 samples. For this need, we kept 8 males and 8 females which reached imago in same time; they were in 10 cages.
The influence of kind of food toward locust life
This research consisted of 6 treatment, they were (1) rice plant, (2) corn plant, (3) six kind of grass (Chrysopogon tenniculmis, Dichantum erectum, Heteropogon contortus, H. insignis, H. triticuss, and Themeda triandra, (4) rice and corn plant, (5) grass of H. triticuss, (6) rice and corn plant, grass of H. triticuss, and Themeda triandra. In this research, we used three replications and each cage of 40 cm x 40 cm x 50 cm was filled by 44 nymphs which had just emerged.
The design used was group random design. The test was BNJ. The research was done toward nymph stadium, nymph mortality, female’s weigh and length when it was becoming imago, number of eggs laid, and the age of female and male locust.
Preference to eaten plant
Base of tree of fresh eaten plant used was put into the water for 2.5 hours, then placed in a tube containing water then the tube was put in the 40 cm x 40 cm x 50 cm cage.
The experiment was done at night for 10 hours from 08.00 pm to 06.00 am. The index of the food was determined from the weight of each plant compared with the weight of corn eaten. Corn was used as standardization with the value of 100. The experiment eaten plant/ treatment which decreased were not because of being eaten was corrected with the blank/form of the same plant sample as follow:
In a 30 cm x 30 cm x 40 cm wire netting, we kept 12 nymphs which had just hatched; we fed those 25-50 days old corn and rice. We attention observe to the growth of 120 nymphs in 10 cages till they became imago. Nymph stadium of instars 1, 2, 3, 4, and 5 known when they had skin molting.
The research of pre-copulation and pre-oviposition was done to 56 samples. For this need, we kept 8 males and 8 females which reached imago in same time; they were in 10 cages.
The influence of kind of food toward locust life
This research consisted of 6 treatment, they were (1) rice plant, (2) corn plant, (3) six kind of grass (Chrysopogon tenniculmis, Dichantum erectum, Heteropogon contortus, H. insignis, H. triticuss, and Themeda triandra, (4) rice and corn plant, (5) grass of H. triticuss, (6) rice and corn plant, grass of H. triticuss, and Themeda triandra. In this research, we used three replications and each cage of 40 cm x 40 cm x 50 cm was filled by 44 nymphs which had just emerged.
The design used was group random design. The test was BNJ. The research was done toward nymph stadium, nymph mortality, female’s weigh and length when it was becoming imago, number of eggs laid, and the age of female and male locust.
Preference to eaten plant
Base of tree of fresh eaten plant used was put into the water for 2.5 hours, then placed in a tube containing water then the tube was put in the 40 cm x 40 cm x 50 cm cage.
The experiment was done at night for 10 hours from 08.00 pm to 06.00 am. The index of the food was determined from the weight of each plant compared with the weight of corn eaten. Corn was used as standardization with the value of 100. The experiment eaten plant/ treatment which decreased were not because of being eaten was corrected with the blank/form of the same plant sample as follow:
Part of the plant eaten was supposed as something wasn’t happened of weight decreasing, because the locust ate greedily only in the first two hours.The research was done in three serial, they are:
The first serial: The preference of imago toward 10 kinds of eaten plant, they are corn, sorghum, rice, sugarcane, coarse grass (Imperata cylindrica), wild sugarcane, groudnut, bamboo, wild sugarcane/elephant grass, and the grass of H. triticuss. Those ten eaten plants were put into a cage consisted of 100 imago. The research was done in four nights with three replications.
The second serial: The preference of imago toward 11 kinds of eaten plant, they are corn, cotton, long bean, small green bean, soybean, tomato, sawi/mustard green, cabbage, petsai, sweet potato, and cassava. Those ten eaten plants were put into a cage consisted 100 imago. This research was done in four nights with three replications.
The third serial: The preference of nymphs toward 12 kinds of eaten plant, they are corn, sorghum, sugarcane, coconut, coarse grass, wild sugarcane, the grass of C. tenniculmis, D. erectum, H. contortus, H. insignis, H. triticuss, and T. triandra. Those twelve eaten plants were put into a cage consisted of 150 instars nymph four and five. The research was done in three nights with three replications.
Behavior
The effect of light toward the locust behavior was seen at spraying at night with insecticide and it used patromax lamp. The reaction toward electric lamps along the street and the reaction toward patromax light were done in laboratory.
The features of life in group, migration, wind influence, the temperature, and humidity were watched closely in the field.
When the locusts lay the eggs and the depth are watched closely in the laboratory with media of sand and were also done in the field. The depth of laying their eggs in the sand media was watched to 40 samples individually at different time. 40 samples were watched in the field toward 4 places at different time. The way of copulation was watched in the laboratory with 3 kinds of different female’s body length toward males, they were 1:0.85; 1:1; 1:1.48. Watching toward the length of copulation was done in the laboratory at 68 samples.
The Influence of Weather toward Stadium of Nymphs
This experiment consisted of 3 behaviors; the first they were put in the sun directly on the day, and at night they were put into the laboratory, the second, they were put into laboratory, and the third, the cages put into the laboratory covered by wet bag. Each cage consisted of 50 nymphs with corn. This experiment was done twice. The watching was toward nymph stadium.
Sex Ratio
The watch of sex ratio was done by counting female and male adults. It was also done toward the last nymphs instar with insect net, the result of spraying and the result of keeping them were in the laboratory.
Natural Enemy
The locust predator was watched closely at population in the laboratory. The samples of eggs, nymph, and imago were in the laboratory to know whether there was parasitoid and disease on the surface locust body, we watched closely to know whether there was parasitoid or not, and to know endoparasitoid, we did surgical operation/dissection to the locust body. The died locust but the body were hard after they were got humidity to know whether there was mushroom. The operation was also done to the prothorax. The die ones because of bacteria could be known.
Morphology
Watching closely toward 50 samples of eggs from 10 egg pods was: color, form, length, and wide eggs. It was also done to 50 samples for the form and length of egg pods. The samples we watched were they watched in the laboratory of the locust we took from the field, and the eggs we kept in the laboratory to the rice and corn plant.
The watch of nymphs kept at rice and corn plant included color, body length, hind femur length, antenna length, and number of antenna joints, the form of wings and ovipositor; we needed to take 30 samples.
The watches of imago included color, body length, hind femur length, antenna length, number of antenna joints, and body’s others; we needed to take 30 samples. Those watching were done by stereo microscope.
RESULT AND DISCUSS
Life cycle
The result of experiment that the eggs incubation in 15 – 19 days or the stadium, average the nymph stadium were 16.7 days with cracking percentage 96.34 %, at 24 - 30.50C at the sand media. All of the cracking egg pods, and the numbers of eggs were 45±4 eggs with cracking eggs percentage was 96.34%.
At the eaten rice and corn plant in 23.6 - 31.50C room condition, humidity of 60 - 95%, the nymph locust got 5 instars: 1; 2; 3; 4; and 5 were 7.1; 6.7; 6.6; 7.5; and 10.7 days. Therefore the average nymph stadium was 38.5 days.
At 22.9 – 30.90C room condition, period of pra-copulation 11.5 days, and the average pra-oviposition was 21.4 days; the length of copulation was 1 - 21 hours but commonly 11 hours. The length of egg laying of sand media was 66 minutes.
The Influence of Kinds of Food toward Locust Life
The food given during nymph and imago, growth had the influence toward mortality of nymph, nymph stadium, weight and length of body when becoming imago and fecundity, but it didn’t influence toward the length of locusts life.
According to House (1961), the biology of an insect was influenced by nutrition value of food; it is because they had different protein, carbohydrate, fat, vitamin, mineral and water degree.
According to Wigglesworth (1953) the different of nutrition food will cause the speed of metabolism process in insect body. The bad nutrition food will give bad physiology process, so, it mal the growth of the insect get low.
The mixed food between rice, corn, and 2 kinds of grass had better nutrition than others. Those mixed food made low nymphs mortality that is 6.82%. The stadium of nymph is 39.0 days, the weight bigger was 965.7 mg. The length of the body longer, was 41.5 mm, and number of eggs given 267 eggs (6.65 egg pods, and each be 40 eggs) (Table 1).
The first instar nymphs are kept to the eaten plant of soybean, can not grow to be second instar, commonly it reached 5.8 days. Imago that kept in eaten food such as small green bean can stand for life was 7.8 days.
Therefore, the quality and quantity of food and also maybe they had chemistry of alkaloids or certain antibiosis is something determined the mortality of nymph and its stadium, but it didn’t influence toward the life length of locust, male and female. Preference of insect toward eaten plant determines quantity of consumption. the good food in optimum quantity will give the influence of the growth and development insect, so, therefore its imago had the length and a big weight of body diverse that kept at eaten food that had low nutrition’s.
The preference toward eaten food
The result of the preference of locust L. migratoria toward eaten plant can be seen from the food index, as seen as Table 2, 3, and 4.
At 22.9 – 30.90C room condition, period of pra-copulation 11.5 days, and the average pra-oviposition was 21.4 days; the length of copulation was 1 - 21 hours but commonly 11 hours. The length of egg laying of sand media was 66 minutes.
The Influence of Kinds of Food toward Locust Life
The food given during nymph and imago, growth had the influence toward mortality of nymph, nymph stadium, weight and length of body when becoming imago and fecundity, but it didn’t influence toward the length of locusts life.
According to House (1961), the biology of an insect was influenced by nutrition value of food; it is because they had different protein, carbohydrate, fat, vitamin, mineral and water degree.
According to Wigglesworth (1953) the different of nutrition food will cause the speed of metabolism process in insect body. The bad nutrition food will give bad physiology process, so, it mal the growth of the insect get low.
The mixed food between rice, corn, and 2 kinds of grass had better nutrition than others. Those mixed food made low nymphs mortality that is 6.82%. The stadium of nymph is 39.0 days, the weight bigger was 965.7 mg. The length of the body longer, was 41.5 mm, and number of eggs given 267 eggs (6.65 egg pods, and each be 40 eggs) (Table 1).
The first instar nymphs are kept to the eaten plant of soybean, can not grow to be second instar, commonly it reached 5.8 days. Imago that kept in eaten food such as small green bean can stand for life was 7.8 days.
Therefore, the quality and quantity of food and also maybe they had chemistry of alkaloids or certain antibiosis is something determined the mortality of nymph and its stadium, but it didn’t influence toward the life length of locust, male and female. Preference of insect toward eaten plant determines quantity of consumption. the good food in optimum quantity will give the influence of the growth and development insect, so, therefore its imago had the length and a big weight of body diverse that kept at eaten food that had low nutrition’s.
The preference toward eaten food
The result of the preference of locust L. migratoria toward eaten plant can be seen from the food index, as seen as Table 2, 3, and 4.
The experiment shows that not all kinds of food eaten, It had the value of low food index; it means that they aren’t liked although the plant had high nutrition. The locust chose they liked corn plant was the most, but small green bean, soybean, long bean, cotton, tomato, sweet potato, cassava, coconut leave aren’t liked. The food they don’t like so much as ground-nut could be eaten all when they were hungry. The food they don’t like but have height nutrition, like small green bean and soybean aren’t eaten although they were hungry. At the time of not so much food/ and so hungry, coconut leaf could be eaten.In fact, locust didn’t care about quality nutritious. It is suitable with Lipke and Fraenkel (1959) and Painter (1951) that is because of chemistry stimulation such as smell or certain alkaloids and taste and also mechanical stimulation from the structure and physical plant surface.
BehaviorLocust are interested in the night light, they like patromax light. We could find imago’s around the street light at night.
In the laboratory, the locusts which were in the cage gave positive phototropic reaction and they were always got gathering at the position where there was a light of sun directly. Nymphs did migration by hoping and walking. Imago could migrate in a huge amount moved to another area, they would destroy all the plant at a short time. The population when they perched on the land could be 6,045/25 m2 or 241,8/m2. Sumba’s Locusts had two style of flying, locally and moving. When the wind blew softly, they flew in the opposite direction and turn, but when the wind was strong, they flew following the wind direction.
The moving was not far, sometimes they just flew around the valleys in a local area. At night, they stopped flying, and at the raining did too.
Locusts ate on the day and at night. The adult ones usually ate when they perched in the afternoon till night and in the morning before flying. In the morning, they got the sun shine as much as possible. When they got 270C temperature, they started to fly.
The eggs were placed in a egg pods/packet on the land around 66 mm depth. At the time of laying their eggs, they made their abdomen twice longer. The holes of their eggs were covered by land using their kick. In the laboratory dry sand media was not so suitable for laying their eggs. They often cancelled laying their eggs.
In the laboratory, the copulation was happened at night, starting in the afternoon till morning. Out side, copulation was happened not only at night but also on the day.
The thick land was also not suitable for laying their eggs, but we found on it, perhaps, it was happened after raining when the land was soft.
The way of locust’s copulation was riding way. The length of female and male’s body didn’t influence their copulation. The research to the three kinds of them proved that they used the same way, it was riding way.
The beginning sex stimulation was shown by the male ones, they got on to females from the front side then turn their direction and stickled out their bodies to the left or right to get the females body.
Phase Theory
Uvarov (1921) stated a theory known as phase theory in locust’s life, they are solitaria/solitary phase, transient and gregaria/gregarious or migratory shown as follow:
In the laboratory, the locusts which were in the cage gave positive phototropic reaction and they were always got gathering at the position where there was a light of sun directly. Nymphs did migration by hoping and walking. Imago could migrate in a huge amount moved to another area, they would destroy all the plant at a short time. The population when they perched on the land could be 6,045/25 m2 or 241,8/m2. Sumba’s Locusts had two style of flying, locally and moving. When the wind blew softly, they flew in the opposite direction and turn, but when the wind was strong, they flew following the wind direction.
The moving was not far, sometimes they just flew around the valleys in a local area. At night, they stopped flying, and at the raining did too.
Locusts ate on the day and at night. The adult ones usually ate when they perched in the afternoon till night and in the morning before flying. In the morning, they got the sun shine as much as possible. When they got 270C temperature, they started to fly.
The eggs were placed in a egg pods/packet on the land around 66 mm depth. At the time of laying their eggs, they made their abdomen twice longer. The holes of their eggs were covered by land using their kick. In the laboratory dry sand media was not so suitable for laying their eggs. They often cancelled laying their eggs.
In the laboratory, the copulation was happened at night, starting in the afternoon till morning. Out side, copulation was happened not only at night but also on the day.
The thick land was also not suitable for laying their eggs, but we found on it, perhaps, it was happened after raining when the land was soft.
The way of locust’s copulation was riding way. The length of female and male’s body didn’t influence their copulation. The research to the three kinds of them proved that they used the same way, it was riding way.
The beginning sex stimulation was shown by the male ones, they got on to females from the front side then turn their direction and stickled out their bodies to the left or right to get the females body.
Phase Theory
Uvarov (1921) stated a theory known as phase theory in locust’s life, they are solitaria/solitary phase, transient and gregaria/gregarious or migratory shown as follow:
Nymph of Locusta in solitary phase was green, but in gregarious phase was orange to red and the dorsal part was black. Pronotum and hind femur of back kick in solitary phase was longer than gregarious phase.The features of imago form Locusta migratoria migratorioides solitaria and gregaria phase are: solitaria phase was bigger than gregaria phase of L. migratoria locust when we did the research in Sumba. The length of elitron to hind femur the back kick (E/F), the length of pronotum to the head width (P/C), and the height of pronotum to the head width (H/C) show that they were still in gregarious phase, was suitable with L. migratoria manilensis from the data of Uvarov (1921), shown in Table 5.
The Influence of Weather toward Nymph StadiumThe weather factor that could be described as a temperature factor, the humidity and the sun light could influence the nymph stadium. The result of the research is in Table 6.
Table of experiment result show at high temperature, low humidity, and got the sun light at nymph, stadium for 32.6 days, but a low temperature, high humidity, and didn’t get the sun light at nymph, stadium for 50.6 days.Sex Ratio
From 17,258 locusts in the research at 11 locations during the rainy season in November 1975 until February 1976 shows that there were 7,349 females and 9,909 males or 1:1.35. In the beginning of dry season in April, May, and June 1976 known that 1,896 locusts from 5 locations show that 906 females and 990 males or 1:1.09. In general, the comparison or sex ratio female to male was 1:1.32. The result of research in the laboratory shows that, when the locust got older, they males were more than the female ones. The males ones were had longer liver than the female ones (when they became adult female:males = 1:1.16 but when the age was 130 days =1: 1.77).
The Natural Enemy
From the field research, we met their natural enemies; they were predator, parasitoid, and diseases. Eagle was the predator, in the places, where imago’s stay, there would be eagles.
The nematode that was to be the locust’s parasite had 14 cm long and 0.5 in diameter mm. When we did the surgical, we found nematode, they also got out from the locusts anus. In the field, we often found nematode with the died body of locusts which have been sprayed by insecticide. In the eggs of locusts were, too, we often found larva of nematode.
Some larva Diptera was to be parasite of the locusts. There were 3 kinds of larva; the big one (Tachinidae) had 13 mm long and 4 mm wide, larva of fly Sarcophaga sp. (Sarcophagidae) had 8 mm long and 2.5 mm wide, small fly that had 3 mm long and 1.5 mm wide.
Those three larvae were found when we did surgical of locusts, and in the died ones that got out from tympanum and from degrades part. The small ones could be found in imago. The red mite larva was an external parasitoid from nymph and imago, we got it especially from imago thorax. The mite was Eurotrombidium sp. (Acarina, Trombidiidae).
In the field, the diseases we found were which attack the locust were bacteria and fungus. Bacteria made the locust body’s mushiness, they were inactive. Those symptoms were happened before the locusts died, they also lost appetite and from their mouth, there was a liquid. Before died, their bodies became broken down and the color was getting dark brown; it was because of the bacteria of Serratia marcescens. The symptoms of getting fungus couldn’t be seen clearly, but we could see them lost of appetite before the death. The body was still hard, when we cut in prothorax part, it will have fungus growth. We could find the fungus to the locusts which almost died.
Morphology
Eggs
The color of egg was whitish yellow, it is round and getting long, the middle part was bigger and it was like a banana. The length was 6.6 mm and the width was 1.2 mm. They laid 3 pieces and arranged in vertical line with a slide position in a packet. The packet was made from the foam which was easy to dry. The length was commonly 54 mm. The form was oval or curve.
Nymph
The result of the measurement to the length of body, length of hind femur back kick, the length antenna, the width of head and number of antenna to the locusts nymph which were kept in the laboratory to the corn plant and rice, shown in Table 7.
First Instar
The new cracked nymph was usually covered by an egg membrane, the color was pale, after one hour, it got to be dark, had black dots, then the color got to be dirty black grey. There were 3 specific black dots, the first was at the base of mandible, the second was at the front (between two antenna), and the third was at the front side of pronoun. The back of pronotum (Carina median) at the new cracked nymph was flat like a knife then it got to be unsharp. The limit of the bank of pronotum mesothorax and metetoraks were unsharp. The eng of wings were unsharp and went to the lower part, the bones in the wings were simple so that the limit of wings with thorax were unclear. The end of male and female body was not easy to the differentiated by normal sight. The end of flower valve of ovipositor was located at sternum abdomen to the front side and the end of male abdoment was still sunken.
Second Instar
After the first skin changing, the color of nymph was pale, whitish yellow and the color of pronotum back and thorax back were dark, the dorsal part was black and the ventral was the dirty grey, only pronotum side was yellow. The last periods of instar two grey yellow. At mandible base, they were black dots, and the dots between 2 antennas and the front of pronotum were no dots. At the front side of pronotum instar two until the last instar, there were white dots. The limit of pronotum back made an angle of 1900. The wings and the bones were simple and the end of it was not unsharp enough than instar one.
The end of flower valve of ovipositor until the tergum the ninth abdoment and the sternum of male’s abdoment end was almost flat.
Third Instar
The side of nymph instar three was yellow, the dorsal was black and the ventral was yellow. The black dots at mandible base were nothing. The wings got lower than instar two and it was blacker than mesothorax and metathorax. The limit of pronotum back got melengkung made an angle of 1400. The lower valve of ovipositor got longer until the limit of ninth and the tenth tergum and the end of male abdomen was unsharp. The female and the male abdomen were clearer to be seen, sighted by a dark (rugged black), at the female abdomen end ventral and the male.
Fourth Instar
After the third skin changing, those three wings turn up. The back wings covered the front wings, if we see them from side, and they covered thorax back, the end was until the front side of tergum the second abdomen.
The colour of instar 4 had brighter color than instar 3, the side part and and ventral were yellowish orange to red and the dorsal was black. The limit of pronotum back made a sharp angel than instar three (it was about1250). The diffrerence between male and female could be seen clearly, the ventral back of female’s abdomen was black but the male one was yellowish orange to red. The end of upper of ovipositor was longer and it was longer than sercus end and the lower valve was longer till sercus base. The end of sternum male’s abdomen was longer till the end of epiprox.
Fifth Instar
Nymph instar five was reddish orange to yellow, and the dorsal was black. Carina median had reddish orange to yellow strips and the base of wings was orange to yellow. The limit of pronotum back made 1150 angel. The wings were longer till the middle of the fourth tergum abdomen, the bones could be seen clearly. The upper and lower ovipositor were longer over than the end of epiprox and the end of male’s sternum abdomen was longer over than the end of epiprox and the end of male’s sternum abdomen was longer than the sternum the fourth nymph instar abdomen end.
Imago
When nymph put away its skin in the last skin changing, the wings are still folded and the end of them was rolled, then they spread out after 22 minutes. The whitish yellow integument was soft it’s harder after several days and the color was to be grey brown. When the female reached in doing time, the female was going to yellow, and the male one was to be the bright yellow after 2 months, the front wings were transparent (brownish yellow with black dots) and the back wings transparent but no dots. Carina median had yellow band between 2 black bands. When we saw it upper side, the middle part of pronotum got narrower. The limit of pronotum back was flat and it made 1200 angel. The end of female and male imago abdomen got more perfect, upper and lower values of female abdomen end was longer and the male abdomen end sternum was longer than instar five.
The form of head could be seen from the front side and the form of antenna could be seen at mouth, and also pronotom, thorax and wings.
The result of measurement to body, femur back kick, antenna, head, tergum and number of male and female antenna vertebrate when they were to be imago whose nymph was kept in laboratory at rice and corn plant could be seen in Table 8.
The Natural Enemy
From the field research, we met their natural enemies; they were predator, parasitoid, and diseases. Eagle was the predator, in the places, where imago’s stay, there would be eagles.
The nematode that was to be the locust’s parasite had 14 cm long and 0.5 in diameter mm. When we did the surgical, we found nematode, they also got out from the locusts anus. In the field, we often found nematode with the died body of locusts which have been sprayed by insecticide. In the eggs of locusts were, too, we often found larva of nematode.
Some larva Diptera was to be parasite of the locusts. There were 3 kinds of larva; the big one (Tachinidae) had 13 mm long and 4 mm wide, larva of fly Sarcophaga sp. (Sarcophagidae) had 8 mm long and 2.5 mm wide, small fly that had 3 mm long and 1.5 mm wide.
Those three larvae were found when we did surgical of locusts, and in the died ones that got out from tympanum and from degrades part. The small ones could be found in imago. The red mite larva was an external parasitoid from nymph and imago, we got it especially from imago thorax. The mite was Eurotrombidium sp. (Acarina, Trombidiidae).
In the field, the diseases we found were which attack the locust were bacteria and fungus. Bacteria made the locust body’s mushiness, they were inactive. Those symptoms were happened before the locusts died, they also lost appetite and from their mouth, there was a liquid. Before died, their bodies became broken down and the color was getting dark brown; it was because of the bacteria of Serratia marcescens. The symptoms of getting fungus couldn’t be seen clearly, but we could see them lost of appetite before the death. The body was still hard, when we cut in prothorax part, it will have fungus growth. We could find the fungus to the locusts which almost died.
Morphology
Eggs
The color of egg was whitish yellow, it is round and getting long, the middle part was bigger and it was like a banana. The length was 6.6 mm and the width was 1.2 mm. They laid 3 pieces and arranged in vertical line with a slide position in a packet. The packet was made from the foam which was easy to dry. The length was commonly 54 mm. The form was oval or curve.
Nymph
The result of the measurement to the length of body, length of hind femur back kick, the length antenna, the width of head and number of antenna to the locusts nymph which were kept in the laboratory to the corn plant and rice, shown in Table 7.
First InstarThe new cracked nymph was usually covered by an egg membrane, the color was pale, after one hour, it got to be dark, had black dots, then the color got to be dirty black grey. There were 3 specific black dots, the first was at the base of mandible, the second was at the front (between two antenna), and the third was at the front side of pronoun. The back of pronotum (Carina median) at the new cracked nymph was flat like a knife then it got to be unsharp. The limit of the bank of pronotum mesothorax and metetoraks were unsharp. The eng of wings were unsharp and went to the lower part, the bones in the wings were simple so that the limit of wings with thorax were unclear. The end of male and female body was not easy to the differentiated by normal sight. The end of flower valve of ovipositor was located at sternum abdomen to the front side and the end of male abdoment was still sunken.
Second Instar
After the first skin changing, the color of nymph was pale, whitish yellow and the color of pronotum back and thorax back were dark, the dorsal part was black and the ventral was the dirty grey, only pronotum side was yellow. The last periods of instar two grey yellow. At mandible base, they were black dots, and the dots between 2 antennas and the front of pronotum were no dots. At the front side of pronotum instar two until the last instar, there were white dots. The limit of pronotum back made an angle of 1900. The wings and the bones were simple and the end of it was not unsharp enough than instar one.
The end of flower valve of ovipositor until the tergum the ninth abdoment and the sternum of male’s abdoment end was almost flat.
Third Instar
The side of nymph instar three was yellow, the dorsal was black and the ventral was yellow. The black dots at mandible base were nothing. The wings got lower than instar two and it was blacker than mesothorax and metathorax. The limit of pronotum back got melengkung made an angle of 1400. The lower valve of ovipositor got longer until the limit of ninth and the tenth tergum and the end of male abdomen was unsharp. The female and the male abdomen were clearer to be seen, sighted by a dark (rugged black), at the female abdomen end ventral and the male.
Fourth Instar
After the third skin changing, those three wings turn up. The back wings covered the front wings, if we see them from side, and they covered thorax back, the end was until the front side of tergum the second abdomen.
The colour of instar 4 had brighter color than instar 3, the side part and and ventral were yellowish orange to red and the dorsal was black. The limit of pronotum back made a sharp angel than instar three (it was about1250). The diffrerence between male and female could be seen clearly, the ventral back of female’s abdomen was black but the male one was yellowish orange to red. The end of upper of ovipositor was longer and it was longer than sercus end and the lower valve was longer till sercus base. The end of sternum male’s abdomen was longer till the end of epiprox.
Fifth Instar
Nymph instar five was reddish orange to yellow, and the dorsal was black. Carina median had reddish orange to yellow strips and the base of wings was orange to yellow. The limit of pronotum back made 1150 angel. The wings were longer till the middle of the fourth tergum abdomen, the bones could be seen clearly. The upper and lower ovipositor were longer over than the end of epiprox and the end of male’s sternum abdomen was longer over than the end of epiprox and the end of male’s sternum abdomen was longer than the sternum the fourth nymph instar abdomen end.
Imago
When nymph put away its skin in the last skin changing, the wings are still folded and the end of them was rolled, then they spread out after 22 minutes. The whitish yellow integument was soft it’s harder after several days and the color was to be grey brown. When the female reached in doing time, the female was going to yellow, and the male one was to be the bright yellow after 2 months, the front wings were transparent (brownish yellow with black dots) and the back wings transparent but no dots. Carina median had yellow band between 2 black bands. When we saw it upper side, the middle part of pronotum got narrower. The limit of pronotum back was flat and it made 1200 angel. The end of female and male imago abdomen got more perfect, upper and lower values of female abdomen end was longer and the male abdomen end sternum was longer than instar five.
The form of head could be seen from the front side and the form of antenna could be seen at mouth, and also pronotom, thorax and wings.
The result of measurement to body, femur back kick, antenna, head, tergum and number of male and female antenna vertebrate when they were to be imago whose nymph was kept in laboratory at rice and corn plant could be seen in Table 8.
CLOSING
Life cycle of L. migratoria in eaten rice and corn in the laboratory was 76.7 days. The egg stadium was 16.7 days, nymph stadium 38.6 days and the period of pra-oviposisi was 21.4 days. The longest male age was 188 days, and the female one was 183 days. The average of male age was 119.8 days and the female one was 108.9 days. Sex ratio female to male was 1:1.32.
The difference of kinds or food influence the nymph stadium, nymph mortality, weight and length body of female and fecundity, but it didn’t influence to the age of locusts. At the mixture eaten plants which were liked by locusts, a female laid average 267 pieces.
Locusta migratoria chose graminae plant as their food. The plants they like were corn, sugarcane, sorghum, rice, and graminae grass. But they didn’t like cotton, sweet potato, small green bean, soybean, long bean and tomato, but some coconut leaves and groundnut could eaten all when they were hungry, but not for small green bean and soybean.
The natural enemies were flies, mite, and nematode, and also bacteria and fungus of insect pathogen. In the future, it needs an exploration about the locust’s enemy to get useful expansion.
Morphology and the characteristics instar nymph could be important biology information to know the age of insect, prediction/forecasting, and in relation to control strategy.
The difference of kinds or food influence the nymph stadium, nymph mortality, weight and length body of female and fecundity, but it didn’t influence to the age of locusts. At the mixture eaten plants which were liked by locusts, a female laid average 267 pieces.
Locusta migratoria chose graminae plant as their food. The plants they like were corn, sugarcane, sorghum, rice, and graminae grass. But they didn’t like cotton, sweet potato, small green bean, soybean, long bean and tomato, but some coconut leaves and groundnut could eaten all when they were hungry, but not for small green bean and soybean.
The natural enemies were flies, mite, and nematode, and also bacteria and fungus of insect pathogen. In the future, it needs an exploration about the locust’s enemy to get useful expansion.
Morphology and the characteristics instar nymph could be important biology information to know the age of insect, prediction/forecasting, and in relation to control strategy.
LIBRARY
- Dammerman, K. W. 1929. The Agricultural Zoologi of the Malay Archipelago. 473 p.
- House, H. L. 1961. Insect Nutrition. Ann. Rev. Entomol. 6: 13-24.
- Lipke, H. and A. Fraenkel. 1956. Insect Nutrition. Ann. Rev. Entomol. 1: 17-44
- Painter, H. H. 1951. Insect Resistance in Crop Plants. McMillan Book Co., New York. 520 p.
- Wigglesworth, V. B. 1953. The Principles of Insect Physiology. Muthuen and Co. Ltd. London. 546 p.
Read More......
- House, H. L. 1961. Insect Nutrition. Ann. Rev. Entomol. 6: 13-24.
- Lipke, H. and A. Fraenkel. 1956. Insect Nutrition. Ann. Rev. Entomol. 1: 17-44
- Painter, H. H. 1951. Insect Resistance in Crop Plants. McMillan Book Co., New York. 520 p.
- Soenardi. 1975. Keadaan Hama Belalang dan Pemberantasannya Dewasa ini di Sumba. Direktorat Perlindungan Tanaman Pangan, Jakarta. 7 p.
- Uvarov, B.P. 1921. Revision of the Genus Locusta (Pachytylus Fieb) with a New Theory as to Periodicity and Migration of Locust. Bull. Entomol. Res. 12: 135-163.- Wigglesworth, V. B. 1953. The Principles of Insect Physiology. Muthuen and Co. Ltd. London. 546 p.
