SAT OG 2016 Reading - Test 3 reading 5

Questions 42-52 are based on the following

This passage is adapted from Richard J.Sharpe and Lisa Heyden,“ Honey Bee Colony Collapse Disorder is Possibly
Caused by a Dietary Pyrethrum Deficiency.” ©2009 by Elsevier Ltd.Colony collapse disorder is characterized by the disappearance of adult worker bees from hives.

Honey bees are hosts to the pathogenic large

ectoparasitic mite Varroa destructor(Varroa mites).

These mites feed on bee hemolymph (blood) and can
kill bees directly or by increasing their susceptibility
5 to secondary infection with fungi, bacteria or viruses.

Little is known about the natural defenses that keep

the mite infections under control.
Pyrethrums are a group of flowering plants which

include Chrysanthemum coccineum, Chrysanthemum
10 cinerariifolium, Chrysanthemum marschalli, and

related species. These plants produce potent

insecticides with anti-mite activity.The naturally

occurring insecticides are known as pyrethrums.

A synonym for the naturally occurring pyrethrums is
15 pyrethrin and synthetic analogues of pyrethrums are

known as pyrethroids. In fact, the human mite

infestation known as scabies(Sarcoptes scabiei) is

treated with a topical pyrethrum cream.
We suspect that the bees of commercial bee
20 colonies which are fed mono-crops are nutritionally

deficient. In particular, we postulate that the problem

is a diet deficient in anti-mitetoxins:pyrethrums,

and possibly other nutrients which are inherent in

such plants. Without, at least, intermittent feeding on
25 the pyrethrum producing plants, bee colonies are

susceptible to mite infestations which can become

fatal either directly or due to a secondary infection of

immunocompromised or nutritionally deficient bees

This secondary infection can be viral, bacterial or
30 fungal and may be due to one or more pathogens.

In addition, immunocompromised or nutritionally

deficient bees may befurther weakened when

commercially produced insecticides are introduced

into their hives by bee keepers in an effort to fight
35 mite infestation. We further postulate that the proper

dosage necessary to prevent mite infestation may be

better left to the bees, who may seek out or avoid

pyrethrum containing plants depending on the

amount necessary to defend against mites and the
40 amount already consumed by the bees, which in

higher doses could be potentially toxic to them.
This hypothesis can best be tested by a trial

wherein a small number of commercial honey bee

colonies are offered a number of pyrethrum
45 producing plants, as well as a typical bee food source

such as clover,while controls are offered only the

clover.Mites could then be introduced to each hive

with note made as to the choice of the bees,and the

effects of the mite parasites on the experimental
50 colonies versus control colonies.
It might be beneficial to test wild-type honey bee

colonies in this manner as well,in case there could be

some genetic difference between them that affects the

bees’ preferences for pyrethrum producing flowers.

Question 42 How do the words“ can ,” “ may, ” and “ could ”in the third paragraph(lines 19-41)help establish the tone of the paragraph?