734 Invasive Stink Bugs and Related Species (Pentatomoidea)
apple maggot [Rhagoletis pomonella (Walsh)], and various soil insects (Flint and van den Bosch 1981,
Singh 2012). It was used primarily in orchards until the 1940s (Ware 1994) and resulted in some of the
first concerns about the safety of its residue on fruits. Today, there still are orchard soils contaminated
with lead and arsenic (Lah 2011).
During this same period (1800s–early 1900s), biological control received little attention even though it
had been utilized as far back as 324 B.C. by the Chinese (see above), and its underutilization continued
into the mid-1900s. However, there was one early success of biological control that was an extremely
effective tactic in North America. The invasive cottony cushion scale (Icerya purchasi Maskell) was
causing severe losses to the citrus industry in California by the 1880s. In an example of classical bio-
logical control, the United States sent an entomologist, Albert Koebele, to the scale’s native Australia
to search for natural enemies. One of the two beneficials he brought to California, the vedalia beetle
[Rodolia cardinalis (Mulsant)] was extremely successful in controlling the scale, and California’s citrus
industry was protected by the early 1890s (Flint and van den Bosch 1981).
16.2.1.5 Influence of Farming Practices on Control
The increased emphasis on methods of insect control in North America was greatly influenced by
the changing demographics of the human population and changes in farming practices that were
occurring at about the same time. During this period, there was an increase in the United States
population, with many immigrants having an agricultural background (Reinhardt and Ganzel 2003).
Most farmers supported themselves by growing crops for their own consumption rather than selling
to urban inhabitants. In fact, in 1790, 96.7% of the American population lived on farms, the remain-
ing 3,3% in cities. Farmers, not unexpectedly, raised a wide variety of crops and livestock (Reinhardt
and Ganzel 2003).
Between the late 1700s and early 1930s, catastrophic insect infestations often were isolated and, thus,
pest problems generally were not severe because the plantings of various crops were smaller and inter-
spersed (Reinhardt and Ganzel 2003). There were exceptions, of course (e.g., boll weevil, Anthonomus
grandis grandis Boheman; Colorado potato beetle), but, for most farmers, handpicking (physical con-
trol) and several cultural control methods were recommended including clean culture, burning of weeds
and rubbish piles in winter, and trap crops. Insecticides were not particularly effective and could be
dangerous. Some of the most dangerous were arsenical compounds (i.e., Paris Green, Scheele’s Green,
London Purple). In fact, in 1925, a family of four in London became ill from arsenic poisoning after
consuming apples from the western United States that had not been washed properly by the grower after
spraying (Reinhardt and Ganzel 2003). Petroleum products, including kerosene, were not particularly
appealing because, according to several entomologists at the time (e.g., Smith 1897; Paddock 1915, 1918;
Jones 1918, Watson 1918), a solution strong enough to kill the insects also would injure or kill the plants.
Nicotine sulfate generally was ineffective (Drake 1920). However, Riley (1884) did have good results
using pyrethrum in a liquid solution.
As noted above, most farmers raised several crops annually on their farms from the late 1700s to the
early 1930s. But, there were exceptions. Some farmers specialized in single crops (i.e., monoculture).
An excellent example was cotton, which was grown in large plantations beginning in the 1800s, typi-
cally ranging from 500 to 1,000 acres (Vejnar 2011). Insect damage to cotton, particularly from the
boll weevil, was of primary importance because of the high cash value of the crop. Not surprisingly,
the damage caused by sucking insects was not appreciated fully until Morrill (1910) reported that these
insects were capable of causing severe damage to the bolls. Cultural methods were the primary recom-
mendations for control including timing, clean culture, handpicking (mechanical control), and spraying
with kerosene.
A second example of the effects of monoculture on insect populations was that of potato and its pri-
mary pest, the Colorado potato beetle. This beetle first was noted as a major pest of this crop during
an outbreak that occurred in 1859 in fields about 100 miles west of Omaha, Nebraska (Jacques 1988),
undoubtedly encouraged by the cultivation of “considerable acreages” of this crop.
During the 1930s, several changes occurred in farming practices that had a significant effect on agri-
cultural production (Reinhardt and Ganzel 2003). In 1930, farmers made up only 21% of the labor force.