Invasive Stink Bugs and Related Species (Pentatomoidea)

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342 Invasive Stink Bugs and Related Species (Pentatomoidea)


6.5.1.8 W. H. White and L. W. Brannon


The last paper we have selected for our brief survey of the early control practices for Murgantia histri-
onica is that of White and Brannon (1939). These authors discussed “Methods of Control,” in which they
began with the following statement, “For the best results in the treatment of the harlequin bug, preventive
measures are necessary, as this insect is exceedingly difficult to combat after it has become numerous on
its host plants.” Following, they divided these measures into cultural methods and contact insecticides
and included information on natural enemies.


6.5.1.8.1 Cultural Methods


Under cultural methods, they discussed clean culture, trap crops, handpicking, and the hand torch. These
methods, by now, were standard procedure, including the use of a hand torch.


6.5.1.8.2 Contact Insecticides


Under contact insecticides, they repeated what earlier investigators has said about the difficulty in kill-
ing this bug with these insecticides because these chemicals had to come in contact with sucking insects
to be effective. This was difficult because “the plants upon which the insects feed usually attain such a
dense growth that it is practically impossible to reach the insects on all parts of the plant.” They noted
that several insecticides had been tested and that derris extract spray and derris dust was recommended
for control of this bug. They also noted that more recent work by Walker and Anderson (1939) had shown
that “derris or cube root powder (containing 5 or 6 percent of rotenone and used at the rate of 4 pounds
in 50 gallons of water with wetting agent) is effective for control of the harlequin bug.” In conclusion,
they stated “It should be borne in mind that only those insects actually hit by the insecticide are killed.
Thoroughness of application is therefore of prime importance.”


6.5.1.8.3 Natural Enemies


White and Brannon (1939) discussed natural enemies of Murgantia histrionica but noted that the bug
“is remarkably free from parasites and predacious insects. No internal parasite of the insect has been
recorded.” They stated that there were three known egg parasites, namely Trissolcus brochymenae (as
Trissolcus murgantiae), Trissolcus euschisti (as Trissolcus podisi), and Ooencyrtus johnsoni, “but, so
far as has been observed, they have never become abundant enough throughout the infested territory to
serve as a natural means of control of this pest.” However, they noted that O. johnsoni “appeared to be
of considerable value in eastern Virginia during the unusually severe harlequin-bug outbreak of 1932.”
“During the latter part of August, approximately 50 percent of the eggs in some fields were parasitized,”
suggesting that “under favorable conditions this parasite may prove to be highly beneficial in some parts
of the South.” They also noted that “the wheel bug [Arilus cristatus (L.)], has been recorded as feed-
ing on young harlequin-bug nymphs, and another, the leaf-foot bug [Leptoglossus phyllopus (L.)], is
recorded as destroying the adult, but these are of slight importance as a means of natural control.”


6.5.2 Age of Synthetic Insecticides


An “Age of Pesticides” began in the 1940s with Paul Müller’s discovery of the insecticidal properties of
DDT (Metcalf 1980) and, since that time, chemical control has persisted as the predominant tactic used
for pest management in most agricultural systems including control of Murgantia histrionica on bras-
sica vegetables. However, there have been major shifts in the classes of insecticides used over the years.


6.5.2.1 Chlorinated Hydrocarbons


In the 1940s, effective control of Murgantia histrionica was achieved with dust applications of DDT or
other chlorinated hydrocarbons including chlorinated camphene (toxaphene), chlordane, and benzene
hexachloride (BHC) (Brooks and Anderson 1947, Gaines and Deane 1948). The latter, in particular, was
considered very toxic to this bug even at concentrations as low as 0.5% active γ isomer; chlordane and
toxaphene were more toxic than DDT (Gaines and Dean 1948). Later, lindane (almost pure γ BHC) also

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