Schistocerca gregaria

The cotton leafworm, Spodoptera littoralis (Boisd.),isaninsect that causes serious damages to more than 112 plant species belonging to 44 different families.Botanical extractsof Ipomoea  carneawere very  efficient againstfourthinstar  larvae of Spodoptera  littoralis. Based  on  LC50and  LC90values, Ipomoea  carneaacetone extracts  were  recorded  24.622  and 164.947 ppm, respectively.  Whilehexaneextracts were 232.677 and 15,377.590 ppm, respectively. Also,the treatment of fourth instar  larva  of S.  littoraliswith chlorpyrifos  insecticide  caused  9.497  and  91.126  ppm,  respectively.  The  chemical constituents  of  acetoneextract  of I.  carneaby  using  GC–MS  analysis  resulted in the  most  active  compoundsthat were palmatic (iso propyl-hexadecanoate),silane, [[(3.alpha.,5.alpha.,20R)-pregnane-3,20-diyl]bis(oxy)] bis (trimethyl-(cas)5.and pederone that recorded (44.025%, 11.455%and 9.325%, respectively).Ipomoea carneaextracts were produced with different deformation abnormalities of all S. littoralisstages.

Abstract: Locusts show density-dependent continuous phase polyphenism; they appear in two forms or phases, gregari-ous and solitary, and there is a continuous range of intermediates between the extreme phases. The endocrine control of phase polyphenism has been the most intensively studied in desert locusts, Schistocerca gregaria, Indeed, results of inves-tigations over the past 15 years, provide some of the most detailed information on the endocrine mechanisms that poten-tially regulate desert locust phase polyphenism. In addition, recent studies on the juvenile hormone titres, ecdysteroid ti-tres, the discovery of [His7]-corazonin as dark-colour-inducing neuropeptide (DCIN) and the involvement of serotonin pulse in the metathoracic ganglion that triggers behavioural gregarization in the desert locust have yielded not only a good progress in our understanding the endocrine control of phase polyphenism but also unexpected results which indicate that the endocrine control of desert l...

The recent upsurge of the desert locust Schistocerca gregaria (Forskål, 1775) has had an impact on East Africa and the Middle East as far as India. It has affected and slowed down many aspects of the Pakistani economy. Swarms of locusts have infested many areas and caused immense damage to all types of crops. Both farmers and economists are concerned and are trying to get the most up-to-date information on the best strategy to manage this pest. This paper is an attempt to (i) provide insight into the dynamics of this upsurge internationally as well as in the various regions of Pakistan, (ii) briefly assess its local impact and locust control measures, and (iii) clarify the role of the various stakeholders in the management, both nationally and internationally, suggesting various improvements for the future.

The ecology of phase polyphenism plays a major role in locust swarm formation. We describe how recent advances in the understanding of phase polyphenism can be combined with existing management approaches as part of a preventative Desert locust management strategy. We start with a brief overview of phase polyphenism with particular emphasis on the role that resource distribution patterns play in the process of locust phase change. We then review current perspective on preventative locust management, and conclude by proposing a framework for quantitatively assessing the risk that phase change will occur in local locust populations. Importantly, the data required to implement this framework can be readily collected with little additional effort or cost just by slightly modifying locust habitat survey protocols that are already in operation. Incorporating gregarization risk assessment into existing preventative management strategies stands to make a considerable contribution toward rea...

Two isolates of Metarhizium spp. were studied for propagule production, because of their pathogenic activity towards locusts and grasshoppers (Mf189 = M. flavoviride (or M. anisopliae var. acridum) strain IMI 330189, and Mf324 = M. flavoviride strain ARSEF324). Both isolates were grown in seven different liquid media, which have been developed for mass production of various Hyphomycetes, considered as candidates for microbial control of noxious insects. Shake-flask experiments were carried out at 28 degress C in the dark. Production was quantified for 72 h and the effects of the tested media were evaluated on propagule concentration, morphology and pathogenicity. Based on preliminary experiments, all tested media were supplemented with 0.4% Tween 80 to avoid the formation of pellets and to produce unicellular propagules. Submerged propagule yields were higher with Mf189 than with Mf324 in all seven media. While high concentrations of propagules (1.4 to 2.4 x 10(8) propagules ml(-1) ...

This paper reviews data on the localization of octopaminergic neurons revealed by immunocytochemistry in insects, primarily the locusts Schistocerca gregaria and Locusta migratoria, cricket Gryllus bimaculatus, and cockroach Periplaneta americana. Supporting evidence for their octopaminergic nature is mentioned where available. In orthopteran ventral ganglia, the major classes of octopamine-like immunoreactive (-LI) neurones include: (1) efferent dorsal and ventral unpaired median (DUM, VUM) neurones; (2) several intersegmentally projecting DUM interneurones in the suboesophageal ganglion; other DUM interneurones are probably GABAergic; (3) a pair of anterior median cells in the prothoracic ganglion; (4) a single pair of ventral cells in most thoracic and some other ganglia; these appear to be plurisegmentally projecting interneurones. Eight categories of octopamine-LI neurones occur in the orthopteran brain. The basic projections of three types are described here: one class project...