The desert locust (Locusta migratoria), which is found throughout Africa and Asia, is a major pest. Its swarms are devastating and often result in plagues.
Locust swarms can vary from a few square kilometres to hundreds of square kilometres with 40 to 80 million individuals per square kilometre.
Desert Locus – Physical
The migratory locust (Locusta migratoria) is a large and common species in Africa, Asia and Australia. It is a graminivorous animal and prefers riparian environments with a cover of grasses. It is a strong disperser and often moves across large areas within a day.
The coloration of the migratory locust is variable depending on phase of development and age. Gregarious nymphs are covered in yellow to orange with black spots; solitary nymphs are green or brown.
Adults of the migratory locust are brown or green, with a variety of hues from light to dark. They are elongated, with long legs and short antennae. They are slightly shorter than gregarious nymphs.
In nymphs, topical application of a JH analog (JHA) caused a number of morphological characters to shift towards the solitary form, including wing morphology and relative wing size. These morphological characteristics were similar to those observed in juvenile locusts.
We analyzed the mRNA expression of LmigOrco in the antennae of the migratory locust Locusta migratoria and a desert locust Schistocerca gregaria by in situ hybridization (ISH). On L. migratoria, DIG-labeled antisense RNA probes of Orco were found in high numbers of cells located in sensilla basiconica and few in sensilla trichoida. However, no hybridization signals were obtained when we used a sense RNA probe for Orco.
To compare the antennal topography of these two locusts, we conducted ISH experiments with antennal sections from L. migratoria and S. gregaria, which were labeled with DIG-labeled Orco antisense or sense RNA probes. Fig. 5 shows the results. a) Hybridization signals in a segment of the antenna A, b) higher magnification of area boxed in A showing cluster of labeled cells, C). D), and e).
Food utilization efficiency was determined by comparing the average (mean +- SE) AD, ECI and ECD of the nymphs after being fed on four different food plants for 3 days. The results showed that the nymphs fed on maize, goosegrass, soybean and pakchoi had different levels of growth rate and overall performance compared to the control group. These differences were significant based on Turkey’s HSD analysis.
Habitat of Desert Locus
The migratory locust, Locusta migratoria (Linnaeus 1758) is distributed in most Old World countries, from sea-level to 4,000 m high in the mountains of Central Asia. It is a major pest in many tropical regions, and causes immense damage to crops.
These gregarious and mobile insects cause huge swarms that can spread over hundreds of kilometres of territory, which is why they are sometimes referred to as “locust plagues”. They are a threat to agriculture because they are graminivorous, and they can severely damage various kinds of agricultural crops.
Locusta migratoria is found in most of the Mediterranean, African, and Middle Eastern regions. It is most commonly found in wetlands or gravel bars, although it also occurs on cultivated fields and in dry grasslands.
It is also common in the steppes of western Kazakhstan and south-east Russia. The swarming locust populations of this species can reach over a large area, including the delta of rivers that flow into the Black, Caspian and Aral Seas and into Lake Balkash.
This species is a serious environmental problem in the desert regions of Algeria, especially the Central Sahara. This is caused by the expansion of irrigated cereal crops, especially those with pivoting sprayers, which have altered the habitat of these locusts in this region.
Several studies have shown that these locusts are most likely to occur in areas with a high amount of vegetation coverage (reed and weed), and a low level of soil moisture. These conditions are suitable for spawning and nymph growth, as well as for migration.
The vegetation cover is usually dominated by reeds and sedges. These plants provide plenty of food for locusts and are particularly suited to migratory locusts.
However, locusts are attracted to a wide range of other types of land covers, and in many cases, these habitats can be destroyed by human activities or global warming. Thus, it is important to be able to identify and assess the optimum locust habitat in order to reduce the occurrence of these pests.
To address this challenge, a Patch based – analytic hierarchy process (PB-AHP) model was developed to extract landscape structure and multiple habitat factors in Tianjin city, China. The results showed that the performance of this model was good, with an accuracy of 88%. In addition, it was able to generalize automatically the suitability of landscape and multiple habitat factors for the detection of locust.
Feeding
Locusta migratoria are insects that swarm in large numbers and devastate plants in fields. They are able to travel great distances, some species traveling 81 miles per day (Clark 1949).
As a result, they cause economic damage and have a negative impact on human health. They have been known to spread disease from one part of the world to another. They are also a major agricultural pest, which is why they are considered to be a serious problem in many parts of the world.
These insects are highly nutritious, with high protein and fat contents. Their low production requirements and their availability from the dead bodies of swarms have led to them being investigated as an alternative source of food for livestock and poultry.
There are a number of different methods for processing locusts into edible products. For example, freeze-drying whole locusts can produce locust meal (LM), which is a very high protein product. The LM can be further processed into defatted locust meal (DLM) and extracted locust fractions by using different processes.
The extraction process can improve the overall protein content and enhance the water and oil holding capacity of insoluble protein fractions. This is because protein is capable of retaining water, and insoluble proteins are often porous. The extraction process can also reduce the dark brown coloration of the locust meat, which is a beneficial characteristic for the production of locust meal.
A study was conducted to determine the effect of diet on the chemical composition of penultimate instar and adult locusts. Fresh and dry weight, as well as the content of lipid, protein, Ca, K, Mg, Na, P, Cu, Fe, Zn, retinol, lutein, zeaxanthine, cryptoxanthine, carotenes and gross energy were determined.
It was found that the concentration of dietary phosphorus (P) and carbohydrate (C) was affected by previous deprivation of these nutrients. The locusts were more sensitive to a prior deprivation of carbohydrate than to a prior deprivation of protein. When the locusts were offered a choice, they were more likely to choose the P diet, even after the conditioning period had been as short as 4 h.
Breeding
Locusts have a phase change during which they become gregarious (marching bands of hoppers and flying swarms of adult locusts). This behavior allows them to occupy and breed in a wide variety of habitats, which is why they can invade areas that are traditionally dominated by solitary species.
For this reason, they are very important pests, affecting more than one-fifth of the Earth’s land area and one-tenth of global populations. They are especially damaging to agriculture, where they consume a large number of crops and are devastating for forestry.
However, gregarious species can also be beneficial to humans by providing food for wildlife. In addition, they can be used as a source of protein in animal feeds.
These animals are well suited to this role as they can live in a variety of conditions and will feed on almost anything that can be found in nature or is grown commercially. They have a relatively long life cycle and do not require large amounts of feeding, so they can be very economical to breed.
To successfully breed these pests, it is crucial to have an enclosure that is big enough for the size of the swarms you intend to produce. It should be ventilated and closed appropriately to prevent escapes.
In addition, the temperature should be controlled to ensure optimal conditions. This will ensure the health and thriving of the breeding population. For this purpose, you can use a heating device or a regular light bulb. This will allow the animals to stay in the enclosure longer and thrive better.
It is best to keep these insects at a temperature of 30 – 38 degrees celsius during the day and 20 degrees during the night. This will ensure they are not overheated or suffer from dehydration.
Another important factor when it comes to breeding is the size of the vivarium. It needs to be large enough for the number of locusts you intend to breed, and it should have a sufficient amount of ventilation.
To make the best use of their natural characteristics, migratory locusts need to be kept in an enclosure that is warm and dark, but not too hot. This can be achieved with the use of a heat lamp or with a regular bulb that can be found in reptile-specialized stores.