We are considering an optimal control problem for a type of hybrid system involving ordinary differential equations and a discrete time feature. One state variable has dynamics in only one season of the year and has a jump condition to obtain the initial condition for that corresponding season in the next year. The other state variable has continuous dynamics. Given a general objective function...

In the poultry industry, control of the red mite D. gallinae primarily relies worldwide on acaricides registered for use in agriculture or for livestock, and those most widely used are carbamates, followed by amidines, pyrethroids and organophosphates. Due to the repeated use of acaricides--sometimes in high concentrations--to control infestation, red mites may become resistant, and acaricides ...

Ticks and tick born diseases affect the economics of dairy farm animals. Continuous use acaricides leads to development acaricide resistance in population, order overcome resistance, newer alternatives like herbal extracts can be used as acaricides. The following study is designed evaluate acaricidal efficacy Azadirachta indica, Calotropis gigantea Ricinus communis against R. (Boophilus) microp...

Varroa destructor is the parasitic mite of honeybee, Apis mellifera. It presents a major threat to health bees and quality quantity honey. have increased their resistance acaricides; consequently, mites or vector viruses become more virulent. Infested colonies, commonly referred as ‘mite bombs’, facilitate dispersal transmission disease stronger healthier colonies. Acaricides are most used mean...

The levels of resistance to two organophosphate acaricides, coumaphos and diazinon, in several Mexican strains of Boophilus microplus (Canestrini) were evaluated using the FAO larval packet test. Regression analysis of LC50 data revealed a significant cross-resistance pattern between those two acaricides. Metabolic mechanisms of resistance were investigated with synergist bioassays. Piperonyl b...

BACKGROUND Honey bees (Apis mellifera) have recently experienced higher than normal overwintering colony losses. Many factors have been evoked to explain the losses, among which are the presence of residues of pesticides and veterinary products in hives. Multiple residues are present at the same time, though most often in low concentrations so that no single product has yet been associated with...

The control of the southern cattle tick, Boophilus microplus (Canestrini), in Mexico and many other countries relies on chemical acaricides. Boophilus microplus has developed resistance to all major classes of acaricides in recent years. To gain a better understanding of the resistance and to develop resistance management strategies that benefit both Mexican ranchers and USDA's cattle fever tic...