Question

One of the major difficulties in the biological control of insect pests is that
A. The predator develops a preference to other diets and may itself becomes a pest
B. The predator does not always survive when transferred to a new environment
C. The method is less effective and compared with the use of insecticides
D. The practical difficulty of introducing the predator to specific areas

Answer 1

Hint: Biological control involves the mass-production and release of natural enemies like parasitoids and predators to manage pest insects in an environmentally sound manner. Radiation is employed to extend the applicability, cost-effectiveness and safety of rearing, shipping and deploying such natural enemies.

Complete answer:
Biological control is the use of living organisms to take care of pest populations below damaging levels. Natural enemies of arthropods comprise three major categories: predators, parasitoids, and pathogens.
Predators: Predators catch and eat their prey. Some common predatory arthropods include ladybird beetles, carabid beetles, staphylinid beetles, syrphid flies, lacewings, minute pirate bugs, nabid bugs, big-eyed bugs, and spiders.
Parasitoids: Parasitoids (also called parasites) don't usually eat their hosts directly. Adult parasitoids lay their eggs in, on, or near their host insect. When the eggs hatch, the immature parasitoids use the host as food. Many parasitoids are very small wasps and aren't easily noticed. Tachinid flies are another group of parasitoids. They give the impression of being like large house flies and deposit their white, oval eggs on the backs of caterpillars and other pests. The eggs hatch, enter the host, and kill it. Parasitoids often require a source of food additionally to their host insect, like nectar or pollen.
Pathogens are disease-causing organisms: The most groups of insect disease-causing organisms are insect-parasitic bacteria, fungi, protozoa, viruses, and nematodes. Biological control using pathogens is usually called microbial control. One very well-known microbial control agent that's available commercially is that the bacterium Bacillus thuringiensis (Bt).

Approaches to Biological Control Biological control are often natural: conservation of natural enemies or applied: inoculation or inundation.
Conservation of Natural Enemies: In many cases, purchasing natural enemies to supply biological control agents isn't necessary. Natural enemies are common and a grower can design production systems to draw in and keep the natural enemies within the system by providing environmental conditions conducive to the enemies' survival. Inoculation and Inundation: Inoculation and inundation involve the supplemental release of natural enemies to make populations of beneficial organisms. Many biological and microbial control agents are commercially available for purchase. An inoculative approach involves the discharge of natural enemies at a critical time of the season to enhance natural populations already present, but in numbers too low for effective pest management.
Microbial Control: Microbial control of insects is achieved through the inundative application of allowable formulations of insect-pathogenic bacteria, insect-pathogenic fungi or insect viruses.

Difficulties:
-Many of the foremost important pests are exotic, invasive species that severely impact agriculture, horticulture, forestry, and concrete environments. They have a tendency to arrive without their co-evolved parasites, pathogens and predators, and by escaping from these, populations may soar.
-Importing the natural enemies of those pests could appear a logical move but this might have unintended consequences; regulations could also be ineffective and there could also be unanticipated effects on biodiversity, and therefore the adoption of the techniques may prove challenging due to an absence of information among farmers and growers.
-Biological control can affect biodiversity through predation, parasitism, pathogenicity, competition, or other attacks on non-target species. An introduced control doesn't always target only the intended pest species; it also can target native species.
-Vertebrate animals tend to be generalist feeders, and rarely keep biological control agents.
-The predator develops a preference for other diets and should itself become a pest; is one amongst the most important difficulties within the biological control of insect pests.
-Biological control of weeds includes insects and pathogens. Predators, like lady beetles and lacewings, are mainly free-living species that consume an outsized number of prey during their lifetime and sometimes become a pest for one more predator.

Note: Biopesticide is employed for the modification of development of insect and behavior exerts a unique approach for management of insect population. The application of biopesticide is predicated on the principle that it produces safety to the human and environment. Wide research goes on, and it's required rather more in future to attain the advance.