No abstract

The nicotinic acetylcholine receptor pharmacological profile of sulfoxaflor in aphids is consistent with that of imidacloprid. Additionally, the insecticidal activity of sulfoxaflor and the current commercialised neonicotinoids is affected by the point mutation in FRC Myzus persicae. Therefore, it is suggested that sulfoxalfor be considered a neonicotinoid, and that this be taken into account when recommending insecticide rotation partnering for effective resistance management programmes.

Host marking pheromones (HMPs) are used by insects to mark hosts (usually a fruit) where they have already laid eggs. The compounds serve as a deterrent to conspecifics avoiding over-infestation of hosts (i.e. repeated egg-laying into an already occupied/used host). If these HMPs are sprayed onto commercially valuable fruit they act as deterrents preventing attack by females interested in laying eggs into the valuable commodity. Having no insecticidal or toxic properties, and being natural products (or close derivatives thereof) they could be used as fruit sprays to replace insecticides, or in combination with other products to improve efficacy. This review discusses the isolation, and synthesis of the HMP of the Mexican fruit fly Anastrepha ludens a feared pest of citrus and mangos in Mexico and Central America. This compound is also recognized by females of other pestiferous species in the same genus Anastrepha distributed from the Southern USA to Northern Argentina, including many Caribbean Islands. The synthetic HMP was shown to exhibit strong electrophysiological activity against A. ludens and excellent interspecies cross recognition with other Anastrepha species. Behavioural tests confirmed the HMP deterring effect of the synthetic natural product. Further studies enabled us to drastically simplify the structure of the HMP and obtain a derivative, which we named Anastrephamide, which shows HMP deterring effects very similar to the natural product in laboratory and field tests. The potential use of such HMP derivatives in a crop protection scenario is briefly discussed.

We determined the efficacy of three potential oviposition deterrents in reducing fruit infestation by Anastrepha obliqua in tropical plum and mango orchards. These were: (1) Extracts of feces of Mexican fruit fly, Anastrepha ludens, known to contain the A. ludens host marking pheromone (HMP) and (2) two fully synthetic simplified analogues of the naturally occurring compound, which we have named desmethyl A. ludens HMP (DM-HMP) and Anastrephamide. Two applications of feces extracts 2 or 3 wk before fruit color break reduced A. obliqua infestation in plums by 94.1, 75.9, and 72% when measured 8, 14, and 25 d, respectively, after application. The natural A. ludens-HMP containing extract retained its effectiveness despite considerable rainfall (112.5 mm) and high A. obliqua populations. The synthetic desmethyl HMP derivative (DM-HMP) also reduced infestation in plums by 53.3 and 58.7% when measured, 18 and 26 d, respectively, after application. Finally, applications of Anastrephamide resulted in fruit loss cut by half and an 80% reduction in numbers of fly larvae per fruit. Our results confirm previous findings indicating that there is interspecific cross-recognition of the HMP in two of the most pestiferous Anastrepha species and open the door for the development of a highly selective, biorational Anastrepha management scheme.

Maduraferrin, a Novel Siderophore from Actinomadura madurae From a strain of Actinomadura madurae, a new siderophore was isolated. Maduraferrin is the Fe complex of an oligopeptide composed of salicylic acid, β‐alanine, glycine, L‐serine, Nδ‐hydroxy‐Nα‐methyl‐L‐ornithine, and L‐hexahydropyridazine‐3‐carboxylic acid. The complexing centers are a salicylamide moiety, a hydroxamic‐acid group and an acid hydrazide group.