List possible causes of the decline of european honey bee populations in the united states.

The following are the possible causes of the decline of the European honey bee populations in the United States:  

1. The increase in the use of herbicides and pesticides that honeybees ingest at the time of their daily pollination rounds are blamed largely, of this the main concern is the use of the class of pesticides known as neonicotinoids.  

2. The populations of bees may also be susceptible to other factors like the recent enhancement in the atmospheric electromagnetic radiation as a consequence of the growing numbers of wireless communication towers and cell phones.  

3. Another factor like global warming may be increasing the growth rates of pathogens like viruses, mites, and fungi, which are known to affect the bee colonies.  

a

explanation:

many plants naturally reproduce this way, but it can also be induced artificially. horticulturalists have developed asexual propagation techniques that use vegetative plant parts to replicate plants. success rates and difficulty of propagation vary greatly. monocotyledons typically lack a vascular cambium and therefore are harder to propagate.

"a.) well–developed vascular system."