FAQ Locust

Do different stages of locusts – early instars, later instars, adults – require a different dose of insecticide to kill them in the field?

Different stages certainly have different susceptibilities to insecticides – old fifth instar nymphs seem to be the most tolerant, possibly because it is difficult for the insecticide to penetrate their thick cuticles. However, it is not advisable to alter the dose depending on the stage of the locusts since this will complicate the control process because of the need to recalibrate for every different type of target encountered. This would also be difficult in practice due to their often being many different stages present in a target.

How many eggs does a Desert Locust female produce?

Desert Locust females lay eggs in an egg pod primarily in sandy soils at a depth of 10-15 centimetres below the surface. A solitary female lays about 95-158 eggs whereas a gregarious female lays usually less than 80 eggs in an egg pod. Females can lay at least three times in their lifetime usually at intervals of about 6-11 days. Up to 1,000 egg pods have been found in one square metre.

How long does a Desert Locust live?

A Desert Locust lives a total of about three to five months although this is extremely variable and depends mostly on weather and ecological conditions. The life cycle comprises three stages: egg, hopper and adult. Eggs hatch in about two weeks (the range is 10-65 days), hoppers develop in five to six stages over a period of about 30-40 days, and adults mature in about three weeks to nine months but more frequently from two to four months.

What is the role of FAO in locust control?

One of the mandates of the Food and Agriculture Organization (FAO) of the United Nations is to provide information on the general locust situation to all interested countries and to give timely warnings and forecasts to those countries in danger of invasion. Therefore, FAO operates a centralized Desert Locust information service within the Locust Group at FAO Headquarters, Rome, Italy. All locust affected countries transmit locust data to FAO who in turn analyze this information in conjunction with weather and habitat data and satellite imagery in order to assess the current locust situation, provide forecasts up to six weeks in advance and issue warnings on an ad-hoc basis. FAO prepares monthly bulletins and periodic updates summarizing the locust situation and forecasting migration and breeding on a country by country basis. These are distributed by email, fax, and post. All locust information is archived at FAO Headquarters and some of this is available on the Internet.

How do you monitoring the locust Population?

Assessment survey: This type of survey is undertaken in the field to monitor (1) the presence of locust and (2) ecological conditions and also undertaken to determine whether locust populations has crossed economic threshold level adults more than 10,000 ps km. and 5-6 hoppers per bush] that may require control.

Search survey:- This involves searching the hopper bands and swarms by following up a report from local people/ nomads/ BSF or any other agency. In this case ecological conditions available at the spot where hopper bands or swarms are found are fed into elocust2 unit and sent to Field Hqrs. This usually require hopper or swarm control. This also involves survey of the spot in the following years for checking any further locust infestation.

Survey Methodology:

Foot transect (FAO Method):- The locust surveyor walk about 300 meters into the wind and observes locust, vegetation, soil moisture etc. and feeds the information in e-locust2 and send the report to the headquarter.

Vehicle transect (FAO Method):- In this method the surveyor is in the vehicle and the vehicle is driven upwind for about one kilometer in the low gear and the locust adults are counted that fly up in front of the vehicle. The information on locust and ecological conditions are fed in e-locust3 unit and sent to headquarter.

What is the Present Scenario of LWO on locusts?

The scheme Locust Control and Research is being implemented through an Organisation known as Locust Warning Organisation (LWO) established during 1939 and later merged with directorate of PPQ&S in 1946. The Locust Warning Organisation (LWO) monitors locust development and its activities over an area of 2.05 lakh sq km of the Scheduled Desert Area (SDA) mainly in the states of Rajasthan and Gujarat and partly in Haryana.

The Scheme is being executed through ten Locust Circle Offices (LCOs) located at Bikaner, Jaisalmer, Barmer, Jalore, Phalodi, Nagaur, Suratgarh, Churu in Rajasthan and Palanpur & Bhuj in Gujarat, Locust Warning Organisation (LWO) Field Headquarters at Jodhpur and Locust Division at Central Headquarter Faridabad (Haryana). Besides, there is one Field Station for Investigation on Locust (FSIL) situated at Bikaner. To strengthen the locust monitoring and forecasting and as per the recommendations made during 28th Session of the FAO Commission for Controlling the Desert Locust in South-West Asia (SWAC), an advanced device named eLocust3 and software RAMSES V4 has been made functional in LWO from January, 2016 with the cooperation of FAO. LWO has wireless network for exchanging the information on locust survey and control between various field offices and

Hqrs. Faridabad. Satisfactory, locust control potential is being maintained in the form of pesticides, plant protection equipments, wireless sets, GPS, eLocust3 and trained manpower.

Can locusts be detected by satellites?

Weather satellites and other satellites used to monitor the environment cannot detect locust individuals or swarms. However, the highly sophisticated satellites used by the military can indeed detect locusts but these images are not available. Even if they were, it is unlikely that national and international locust organizations would have the ability to interpret the hundreds of images that would be produced on a daily basis.

Is it possible to find all locust infestations during a survey?

It is practically impossible to find every single locust or locust infestation during a survey, regardless if it is done by ground or air. This is because it is not possible to survey every square metre of locust habitat. Therefore, survey results should be considered as samples which are used to estimate the real situation. Experienced officers in locust-affected countries and other researchers suggest that perhaps about half of the locust infestations present in a given area are detected during surveys, depending on the habitat, accessibility and locust infestations in surrounding areas.

Define the following terms?

Solitarious: : Phase when individuals live mostly separate from each other.

Gregarious: Phase when large numbers of individuals gather together.

Transiens: : Intermediate phase when locusts are grouping and starting to act as a single mass and are either changing from solitarious to gregarious (gregarization) or from gregarious to solitarious (dissociation).

Congregans: Part of the transiens phase during which locusts are congregating and are in transition from the solitarious to the gregarious phase. Often used for nymphs.

Dissocians: Part of the transiens phase during which locusts are in transition from the gregarious to the solitarious phase. Often used for nymphs.

Solitaricolour: : Showing types of colour associated with solitarious behaviour.

Gregaricolour : Showing types of colour associated with gregarious behaviour.

Do Desert Locust plagues occur with any regularity?

The attack of the desert locust used to occur earlier in a phases of plague cycles. India witnessed several locust plagues, upsurges and incursions in the past. About 12 locust plagues were observed in India till 1962.Since than no locust plagues occurred. Similarly, 13 locust upsurges were recorded since 1964 till 1997. Small scale localized locust breeding have also been reported and controlled during the period 1998, 2002, 2005 , 2007 and 2010. Since 2010 till now, situation remained calm and no large scale breeding and swarms have been reported. However, solitary phase of Desert locust has been reported from time to time at some locations in the State of Rajasthan and Gujarat.