Analytical observation Upsurge and Current Situation of Desert Locust ( Schistocerca gregaria) in Sindh, Pakistan

: Schistocerca gregaria (Forskl, 1775), one of the most notorious insects in the world, significantly harms the economy and agriculture each year. It was reputedly the biggest infestation to hit Pakistan since the 1990s, destroying wheat, rice, sugarcane, cotton, and vegetable crops, and it was also the cause of the worst disaster of 2019–2020. Increases in Desert Locust swarms have had a devastating impact on Pakistan's agricultural sector, causing widespread crop failures. Financial losses throughout the two agricultural seasons in 2020 and 2021 are estimated to be between $3.4 billion and $10.21 billion. The result was a significant rise in the cost of everyday goods on the market. In addition, an increase in locust activity has been seen in some of the worst hit regions. Correct species identification is crucial for efficient management and control measures. This research aims to provide light on the reasons behind this vital management focus .


Introduction
Throughout history, locusts have both been feared and respected.These insects, which are related to grasshoppers, congregate into gigantic swarms that travel across continents, destroying crops and causing significant agricultural harm in their wake.Since the Pharaohs ruled ancient Egypt, locust plagues have wreaked devastation on cultures and they continue to do so now.The greatest locust infestation in the past three decades has hit Pakistan.In West and North Africa, the Middle East, and Southwest Asia, the desert locust Schistocerca gregaria (Forskl, 1775) is regarded as a serious agricultural pest (Cressman, 2021;Lecoq, 2001;Steedman, 1990).Recurrent invasions of this insect pose a serious threat to agricultural production and have disastrous effects on food security in more than 50 countries (Brader et al., 2006;Lecoq, 2005Lecoq, , 2004Lecoq, , 2003Lecoq, , 2001;;Samejo et al., 2021).Pakistan has a questionable history, with occasional swarm invasions.Moreover, the country has "outbreak zones," or areas where locusts are more likely to swarm, reproduce, and multiply rapidly, making them more likely to cause outbreaks and plagues when the conditions are right.Outbreaks of desert locusts threaten the livelihood of 10% of the population.Fewer than half a square mile can hold 40-80 million desert locusts in a swarm that covers 460 square miles.If each locust consumes its weight in plants per day, then a swarm of this size would eat 423,000,000 pounds of vegetation every day.In more than 60 districts of Sindh, Baluchistan, Punjab, and Khyber Pakhtunkhwa provinces, a recent swarm (2019-2020) destroyed important crops like wheat, cotton, rice, sugarcane, tobacco, corn, watermelon, chilies, eggplant (brinjal), okra (lady finger), mango, citrus, apple, grapes, strawberry, peaches, banana, and guava (Riffat et al., 2021).Losses for "rabi crops" (sown in winter and harvested in spring) might total 353 billion Pakistani rupees (2.19 billion US dollars), while losses for "kharif crops" (sown in summer) could total 464 billion Pakistani rupees (2.88 billion US dollars) (FAO 2020).These infestations have destroyed harvests incalculably, sometimes resulting in terrible famines (Dowlatchahi et al., 2020).The FAO has advised a preventative control strategy based on the monitoring of epidemic regions and ecological circumstances since the 1960s (Lecoq, 2004(Lecoq, , 2003;;Showler, 2019).If necessary, early intervention and consequently restricted use of pesticides are then suggested.However, continuing instability in several desert locust distribution zones, together with continued political and financial turbulence, keep the threat alive, and some outbreaks cannot be suppressed at an early stage, as was recently noticed once more (Meynard et al., 2020;Showler et al., 2021;Showler and Lecoq, 2021).

Material and Methods
Selection of sites, Killing and Preservation: All specimens were gathered from several Sindh districts agricultural fields and rocky abandoned areas (Fig. 3) Materials were delivered to the Department of Zoology, Entomology and Biocontrol Research Laboratory (EBCRL), University of Sindh, Jamshoro.The technique for euthanasia was modified somewhat from (Riffat et al., 2021;Riffat and Wagan, 2015) and involved killing the specimens in conventional entomological death bottles for 5-10 minutes with potassium cyanide or chloroform.Because samples colors may vary, they were not kept around for very long.Then, after killing, samples were swiftly pinched.On the pronotum, just to the right of the median carina and posterior to the transverse sulcus, an insect pin was placed.On the stretching board, the head was slightly lowered.The long axis of the body was virtually at a right angle to the pin when the left wings were placed.The back legs were bent under the body to take up less room and lessen the chance of breaking.The wings and the hind legs were not hidden by the open belly.Fully dried specimens were stored in bug cabinets with labels that included the date, habitat, location, and collector's name.In order to keep ants and other insects away, boxes were filled with naphthalene balls.The specimens were identified using the Orthoptera Species File (OSF) (Cigliano et al., 2018) and the bibliographies offered by Riffat and Wagan, 2015.An Ernst Leitz Wetzlar Germany 545187 camera lucida mounted on a microscope was used to make line drawings, which were subsequently improved using the Adobe Illustrator CC-2015 and Adobe Photoshop CS software.Measurements of different body parts were calculated in millimeters using the microscope (Oculas), 10 10 graph, compass, divider, and ruler (mm).The distributions of the species that reached were mapped using GPS coordinates.These specimens are deposited in the Sindh Entomological Museum Jamshoro, Department of Zoology, University of Sindh, Jamshoro (TN: 938 SEM) (SEMJ).Pakistan.

Systematic account Cyrtacanthacridinae Cyrtacanthaciridini
Schistocerca Stål, 1873 Schistocerca gregaria (Forskal, 1775) Diagnostic features (Figs.1-2 a-k): Body large in size with yellowish brown in color but slightly smaller than female.Filiform antennae that a little bit longer than the pronotum and head combined.Longer pronotum than head, Fastigium of vertex trapezoidal extends from the vertex over the pronotum.Pronotum has with a low median carina in prozona.Prosternal process has cylindrical, slightly inclined.Lower basal lobe of the hind femur is shorter than the upper.The hind tibia's external top spines are absent.Tegmina and wings fully developed.Tegmina covered with plenty of brownish spots.Tegmina have slightly larger than wings.Abdomen is smaller than tegmina.Body has yellowish brown in color.Head has yellowish, eyes brownish.Fastigium of vertex show yellowish median band runs from the vertex over the pronotum.Lateral sides of pronotum are brown and dorsal side slightly dark brown.Femur yellowish with light dark shaded pattern noticed from the lateral side.Median carina present on pronotum is slightly white in color.Femur is dark brown inside and light brown outside.Tibia has yellowish with multiple dark pointed spines.Tegmina have with numerous brownish spots.Wings show pale color from the base up to the center of the wing while remaining area hyaline.2, Fig. 3).
Recent emergence of desert locust: Both in Baluchistan and many areas of Sindh, a thorough study was planned.In June 2022, the situation with the Desert Locust remained stable.In several parts of Sindh and Balochistan where no control operation was carried out, only small numbers of solitarious hoppers and adults continued to exist (Table 3).
With the exception of a few districts, Sanghar Tharparkar, Ghotki, and Kashmor, i.e., 31, 26, 23, and 21 correspondingly, where hoppers have emerged, the situation is generally excellent and the present locust emergence is peaceful in visited places.Small-scale breeding will take place in the deserts of Nara, Thar, and Cholistan over the projected period.Due to this, locust populations will marginally rise but will still be quite low.If there is rainfall throughout the expected timeframe, limited breeding may also take place in Balochistan and the interior of Punjab.

Discussion
Africa, the region north of the equator, the Middle East, the Arabian and Indo-Pakistani peninsulas, and occasionally Mediterranean Europe make up the habitat of the desert locust.Over 20% of the world's land area is covered by the 57 countries.The locusts retire to the driest regions of their typical habitat between two successive invasions, where they might go undiscovered for several years (Lecoq 2004).This insect is not merely a problem of the past, and spectacular incidents still happen occasionally (Belayneh, 2005;Latchininsky et al., 2011;Latchininsky, 2013).For a variety of reasons, some outbreaks cannot be stopped at an early stage (Lecoq, 2005(Lecoq, , 2001)), the swarms spread quickly over an expanding area, the control measures become more and more expensive and difficult to organize, the villagers are typically powerless in the face of the swarms' sudden and massive arrival, and crop damage can be significant (Brader et al., 2006;Lecoq, 2005) According to DDP, across the provinces of Baluchistan, Khyber Pakhtunkhwa, Punjab, and Sindh, a total of 300,595 ha was sprayed after an estimated 932,580 ha area was inspected for desert locust activity (Ahmed 2019).14 districts in Punjab Province were impacted, while the most heavily infested districts in Baluchistan were Kaachi and Kharan, Laki Marwat, and Tank districts of Khyber Pakhtunkhwa Province, while the most heavily infested districts in Sindh Province were Khairpur, Kashmoor and Benazir Abad, National Locust Control Center, 2021.Due to the extensive use of chemicals and pesticides during locust control activities, there may be adverse environmental repercussions (Lazar et al., 2016).The ecosystems inevitably suffer collateral damage as it is difficult to distinguish between locust swarms and other benign animals and plants.Intoxication from the utilized chemical pesticides may also occur in humans, in addition to the direct effects on the surrounding ecology (Brader et al., 2006;Riffat, 2020).Experts on climate change also anticipate an increase in temperature.The rate of locust growth and swarm migration is governed by temperature.Thus, the protracted maturation and incubation periods during the spring may be shortened as a result of climate change, allowing an additional generation of breeding to take place in North-West Africa, the Arabian Peninsula, and South-West Asia.This might raise the annual locust production rate in certain areas and the danger of plague in general.Any modifications to wind circulation, speed, or direction are anticipated to have an impact on Desert Locust migration and may open up new travel opportunities for adults and swarms at various periods of the year.The ecological, habitat, and meteorological circumstances will determine if they can survive, reproduce, and establish themselves in these new locations (WMO & FAO, 2016).According to (Sharma, 2014) the arrival of the rainy season in March is projected to cause the locust epidemic to spread even further, as well as food shortages and humanitarian concerns.Considering the current situation, this study supports (Sharma, 2014).

Conclusion
Due to the impact of a significant desert locust swarm in 2019-2020, Pakistan's economic situation has declined.Increased regional collaboration between nations is crucial for management programs since locust outbreaks are frequently of an international nature and transboundary migration is frequent.Strong procedures must be put in place to provide ongoing financial assistance at the national and international levels so that treatment programs may be implemented quickly as a component of effective sustainable preventative management strategies.Furthermore, functional genome sequencing may reveal a variety of molecular targets that might aid in management.Author Contributions: field surveys N.S & methodology R.S Conceptualization, analysis and drafting S. K analysis & methodology, S.S. field surveys Conceptualization, S.M.The manuscript's published form was approved by all authors once they had read it.Funding: This study was funded by the HEC/GCF-290.Acknowledgments: The authors are highly thankful to villagers who helped in the field searching & collection of samples.

Table 3 . Current status of locust emergence in Sindh (Solitary Phase) during 2022
Bermuda grass (Cynodon dactylon).The damage was incalculable due to the enormous swarm that was seen during the current study, which consumed all vegetation in its grgareous phase.The farmers were extremely concerned since they had witnessed the destruction of their crops firsthand.Both crops and non-crop plants were largely consumed.Global distribution: India, Iran, Yemen, Iraq, Egypt, Kenya, Ethiopia, Eriteria, Somalia, Sudan, Kuwait, Saudi Arabia and Pakistan.Its presence in Sanghar, Badin, Nangarparkar, Umerkot, Chachro, Diplo and Mithi, Khairpur, Thar and Nara, Sindh, Pakistan (Table