damage amaranth as in Mexico. Its caterpillars consume leaves and seeds of different
plants, as well as browse galleries and feed in the stalks. If in Mexico they damage
amaranth leaves [23], then they developed inside the stalks in Brazil. The caterpillars
browsed galleries and fed inside stalks. Small holes, approximately 1.5 mm in diameter
were found in the thick part of amaranth stalk. It was supposed to be the exit holes,
which caterpillars of the last instar browse for further pupation in the soil.
In Argentina entomofauna of amaranth cultivars was studied [15, 16]. It was
found, that amaranth attracts many phytophagous insects, and their species
composition is richer in the native for the amaranth region than in the region of its
introduction. These authors also study agrotechnical methods, which limit the
injuriousness of intra-stalk pests, particularly crop density and sowing dates. They
show, that high crop density provides the more thin stalks, which are unsuitable for
oviposition. The stalks of the late crops are also yet thin in the period of oviposition,
which is unsuitable for oviposition. To regret, the authors did not mention the effect of
such agrotechnical methods to the crop of amaranth.
It was shown, that intra-stalk pests are the most spread and injurious in all regions
of amaranth growing. In the zones of introduction, new pests replace the pests of native
region. For example, in Argentina the longhorn beetle Aerenea quadriplagiata is one
of the most significant pests of stalks [20]. In South America, Xanthium cavanillesii
Schouw and Eucalyptus viminalis Labill are its hosts [13]. Besides these plants,
Aerenea quadriplagiata feeds with amaranth cultivars. Four amaranth cultivars had
different resistance to Aerenea quadriplagiata. Similar oviposition intensity was
registered, but larval survival was considerably different in these cultivars. Except
cultivar features, intensity of amaranth infestation by longhorn beetle depended on
stalk diameter. Like other intra-stalk pests, Aerenea quadriplagiata oviposites into the
stalks with diameter 5.53–7.29 mm. As a result of two-year research, scientists
proposed a variety of amaranth, the least infested and damaged by this longhorn beetle.
A detailed study of insects associated with Amaranthus retroflexus L. was carried
out by Carl Edward Stegmaier (Carl Edward Stegmaier, 1950) in Kansas. He listed 210
species of insects, including the pests, their predators and parasitoids. The most
injurious species were larvae of mordellid beetle Mordelistona sp., which fed inside
stalks, and larvae of weevil Conotrachelus seniculus, which browsed roots and often
caused plant mortality.
In one of the papers, published in 1998, it is stated, that amaranth is of potential
for India. A list of 20 pests is presented there, including polyphagous noctuids,
polyphagous sucking insects – Cicadellidae, Thysanoptera, Hemiptera, the weevil
Hypolixus truncatulus. This weevil and noctuids are listed as the most harmful
pests [28]. Thus, the weevil Hypolixus truncatulus is the main pest of amaranth stalks
both in India and in Mexico. It is widely spread in the subtropics of India [22], and the
data on its biology and harm to cultivated plants were published in India as early as the
beginning of the 20th century. Later J. Tara (2009) describes in detail the morphology
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