Desert Locust population dynamics
Pakistan is an important front-line country for Desert Locust because it has summer and spring breeding areas. Summer breeding normal occurs along the Indian border in the deserts of Tharparkar, Khipro and Cholistan (Sindh and southern Punjab provinces).
The timing of summer breeding coincides with the southwest monsoon rains which normally arrive during the second half of June or first half of July and end in September or October. The scale and location of breeding differs every year, depending on the duration and nature of monsoon rains. The locusts tend to stay out of the irrigated agricultural areas of the Indus Valley except during periods of increased locust activity. Locust populations from adjacent areas in Rajasthan, India can cross back and forth along the common border during the summer. Once the monsoon rains end and vegetation dries out, locust adults will move from both countries towards the spring breeding areas in western Pakistan.
Spring breeding normally occurs every year in Baluchistan, first commencing in coastal areas from west of Karachi to the Iranian border in about February or March. As temperatures warm up, locust adults will appear in the interior of Baluchistan from Turbat to Dalbandin and Nushki, including Panjgur and Kharan valleys. Locusts may also reach the remote Great Sandy Desert west of Kharan. Desert Locusts rarely move north of the Chagai Hills and Quetta except when swarms form. Cold weather in the interior can delay locust maturation by several weeks or more. The breeding areas continue into adjacent coastal and interior areas of southwest Iran (Sistan-Baluchistan province). Breeding in Baluchistan differs from year to year depending on the timing, location and duration of the seasonal rains. In most years, spring rains will end in about April but ecological conditions may remain favourable until June. In other years, insufficient rains fall to allow breeding.
The Lasbela / Uthal area west of Karachi is considered as a transition zone where locusts may be present nearly any time of year.
National Locust Programme
The Department of Plant Protection (DPP) at the Ministry of National Food Security & Research is responsible for Desert Locust survey and control operations in Pakistan. DPP is located in Karachi. Ground surveys are carried out regularly in the summer and spring breeding areas from about June to November and February to May, respectively. Surveys are usually organized from permanent locust outposts (district offices) in the summer (Bahawalpur, R. Khan, Sukkur, Mirpurkhas) and spring (Pasni, Turbat, Panjgur, Kharan, Nushki) areas. During emergencies, seasonal outposts are established. During the summer, a monthly meeting is held on the Indo-Pakistan border for locust officers from India and Pakistan to exchange information on the current locust situation. Since 1995, a joint Iran/Pakistan team undertakes a ground survey every April for two weeks in Baluchistan, Pakistan and two weeks in southwest Iran. Pakistan is the only Desert Locust country that maintains its own fleet of aircraft dedicated for locust survey and control operations. Pakistan also hosts the oldest continually operating locust outpost in the recession area on the Baluchistan coast in Pasni. Both of these date from the pre-partition British colonial period.
