INSECTICIDAL AND RODENTICIDAL PLANTS
“This group includes plants that produce toxins for combating insects and other pests of agricultural crops, parasites of animals and humans, and finally, rodents” (Shalit M. S.).
In the flora of Kyrgyzstan, there are many insecticidal and rodenticidal plants. However, they are rarely used for combating insect pests, animal parasites, and rodents, with few exceptions.
The reasons for the weak use of insecticidal and rodenticidal plants are numerous. One of them is their insufficient study. The methods for applying insecticidal and rodenticidal agents are not well developed, etc.
Below we provide characteristics of the main insecticidal and rodenticidal plants.
Leafless Anabasis. Eight species of Anabasis are found in Kyrgyzstan. All of them contain toxic substances.
Leafless Anabasis, from the family Amaranthaceae, is a semi-shrub up to 75 cm tall. The root is woody with a caudex. The stems are succulent and branched. The leaves are scale-like, merging into short sheaths.
The flowers are small, membranous, inconspicuous, consisting of 5 petals, gathered in spike-like inflorescences. The fruit is berry-like and juicy.
It grows in valleys and foothills in the western part of the Chui Valley and in Talas — on saline clay soils.
Leafless Anabasis contains the alkaloid anabasine, which is an isomer of nicotine.
The toxin is present in all parts of the plant. In its fresh form, it has an unpleasant smell reminiscent of dog urine. In winter, when the toxins leach out, leafless Anabasis is eaten by camels.
The alkaloids of Anabasis are used to prepare anabasine sulfate, which is widely used to combat garden pests — apple moths, aphids, and other insects.
Scientists have discovered five alkaloids in leafless Anabasis, but the most important for use is anabasine, which is used to prepare anabasine sulfate. In structure and biological reaction, it is close to nicotine.
The highest concentration of anabasine (1.82%) is found in the terminal branches of the plant at the beginning of the growing season, with the amount of alkaloids varying significantly among different specimens. In some, the alkaloid content reaches 5-6%. Industrial harvesting of Anabasis is conducted in summer and early autumn. When harvesting the plant, it should be remembered that leafless Anabasis reproduces by seeds, so it is advisable to leave the best specimens for seeding.
It has been established that infusions and decoctions of Anabasis also yield good results in combating insect pests. Therefore, infusions and decoctions of Anabasis should be practiced more widely. They require less raw material, and this method of protecting cultivated plants is accessible to almost everyone.
Pelliota Anabasis. It grows in the Central Tien Shan and Alai on gravelly slopes. It can also be used as an insecticidal and rodenticidal plant.
Anabasis Tien Shan, Turkestan, Abolina, Fergana, woolly, and truncated, growing in different regions of Kyrgyzstan, should also be used more widely to combat insect pests.
Large thickets of Tien Shan Anabasis are found in the Kochkor region, in the valley of the Naryn River, on the slopes of the mountains surrounding Lake Issyk-Kul, and in other places. The widespread use of Tien Shan Anabasis to combat insect pests would positively affect the cleaning of pastures from toxic plants, as cases of poisoning of livestock by Anabasis have been observed in these areas.
Harmala, or graveyard plant. A widely distributed plant in valleys and foothills. Often found near settlements in fallow lands, in cemeteries, which is why it received the name graveyard plant.
It usually settles in places where the natural vegetation cover has been disturbed, on clay saline soils.
It acts as a pioneer plant on clay outcrops.
The stems of harmala reach 25 cm in height, are branched. The leaves are divided into lobes, up to 6 cm long. The flowers are white or pale yellow. The petals are somewhat thick, waxy. It blooms in July and bears fruit in July-August.
It is widespread in all regions of Kyrgyzstan in the agricultural zone.
Harmala contains the following alkaloids: harmine, harmaline, harmalol, peganine.
The highest concentration of alkaloids is found in the seeds, up to 4%; among the alkaloids, harmine predominates.
The amount of alkaloids varies significantly throughout the growing season. The highest concentration is found in mature fruits and seeds — 4.5% of absolutely dry matter. The leaves contain fewer alkaloids, and the stems contain even less. This should be taken into account when harvesting harmala.
Decoctions and infusions of harmala are used to combat insect pests of agricultural crops.
However, it is also widely used in medicine, as well as for dyeing wool and woolen products.
In the conditions of Kyrgyzstan, large areas of harmala are found in the Kochkor and Chui valleys, as well as in Talas, where its harvesting should be conducted.
Thick-fruited Sophora. A perennial, highly branched gray-green plant up to 45 cm tall with pinnate leaves. The entire plant is densely covered with silky hairs. The flowers are butterfly-shaped, gathered at the top of the stem in a loose raceme. The pods are 5.0-6 cm long, bead-like, indehiscent, with a long beak.
It blooms in April-May and bears fruit in June-July.
It grows in wormwood-ephemeral semi-deserts in the western part of the Chui Valley, on fallow lands and fallows, near irrigation ditches, in forest strips. It is a quarantine weed. It is not eaten by livestock. It increases in the grass cover year by year and clogs pastures. It readily settles where the natural grass cover is disturbed.
The entire plant contains toxic substances — alkaloids. The seeds are particularly toxic.
The maximum amount of alkaloids is found in the leaves and stems before flowering (up to 4.3%) and during flowering. Then the amount of alkaloids decreases; by the time of fruiting, it increases again and sharply decreases by the end of the growing season.
Infusions and decoctions of Sophora are used to combat apple moths and other insect pests.
At the same time, thick-fruited Sophora is also a medicinal plant.
Using it as an insecticidal plant would help clean pastures of this inedible weed.
Tail-leaved Sophora. A perennial gray-green plant up to 100 cm tall. The stem is finely hairy at the top. The leaves are pinnate.
It grows on fallow lands and fallows, in crops, on boundaries, and in wormwood-ephemeral deserts, where the natural vegetation cover is disturbed. In Kyrgyzstan, it is found everywhere in the agricultural zone. It is a notorious quarantine weed.
Due to its rapid vegetative reproduction and the fact that Sophora is not eaten by livestock, it increases its range year by year. The plant is toxic: it contains alkaloids.
It is used as infusions and decoctions together with green soap to destroy apple moths and other insect pests.
Thermopsis (mouse plant, in Kyrgyz: sarimya) lanceolate.
A perennial low plant (10-50 cm) with hairy stems. The rhizomes are long and branching. The leaves are trifoliate with stipules. The flowers are butterfly-shaped, bright yellow, arranged in pairs or whorls at the top of the stem. It blooms in May-June and bears fruit in July-August. The fruits are arcuately curved. It grows on saline clay soils, often in chive thickets. It can be found on fallow lands and fallows, and sometimes as a weed in crops.
The most characteristic thickets of Thermopsis are found in the Kochkor Valley, in the basin of Lake Issyk-Kul in the coastal strip, and on clay foothills in the eastern part of the Kyrgyz Ridge.
It settles everywhere in places where groundwater is found at a shallow depth.
The plant is toxic. It causes poisoning in livestock. It contains alkaloids, which are used in medicine as an expectorant. Infusions and decoctions with green soap are used to combat insect pests.
Sarsazan with cones. It is a small semi-shrub with a well-developed woody root. The stems branch well, are woody at the bottom. The flowers are bisexual. The perianth consists of three petals, with one stamen.
The flowers sit in the leaf axils. Sarsazan usually grows in circles, as its branches can root.
It is found on clay saline soils.
The most characteristic areas are found in the southeastern part of Central Tien Shan and in the valley of the Naryn River.
Sarsazan contains a large amount of potash (up to 29% in ash) and toxic substances.
Infusions and decoctions of it, together with green soap, are used to combat insect pests.
Beardless Livewort. A perennial herbaceous plant up to 40-50 cm tall. The leaves are repeatedly thrice-divided into thread-like lobes. The flowers are yellow. It blooms in May-June and bears fruit in July-August. It grows in semi-deserts and steppes, on the foothills of the Kyrgyz and Alai ranges and in Fergana on clay soils. In southern Kyrgyzstan, it is found in wheat and mixed grass steppes. Previously, yellow dye was obtained from its flowers, which was even a subject of trade with China.
Currently, livewort is used as an insecticidal plant. Decoctions and infusions together with green soap are used to combat insect pests.
Tomato. A well-known annual plant. The extract from the leaves has insecticidal properties.
However, it is rarely used to combat insect pests.
Mahorka Tobacco. Cultivated in Kyrgyzstan for a long time. The main tobacco-growing area is Talas. However, it is grown in gardens throughout the agricultural zone.
This annual herbaceous plant can reach up to 1 m in height with fleshy ovate-heart-shaped leaves. The entire plant is glandular-hairy. The flowers are whitish-green in a paniculate inflorescence. It blooms from June to August.
An infusion of the leaves is used to combat insect pests, especially apple moths.
Yarrow of Biberstein. A perennial plant up to 20-40 cm tall. There are several stems; they are slightly ribbed. The leaves are finely dissected. The flowers are yellow, gathered in inflorescences resembling baskets, which in turn form complex umbrellas. It blooms in May-June.
It grows in wormwood-ephemeral semi-deserts, in valleys and foothills in all regions of Kyrgyzstan except for high mountains. It is found on various soils — clay, stony, sandy, and others.
Infusions and decoctions together with green soap are used to combat insect pests.
Pink Wormwood, or Creeping Wormwood. A weed widely distributed in the foothills in wormwood-ephemeral deserts and semi-deserts.
A perennial plant with several stems up to 70 cm tall. The stems branch heavily and are significantly hairy.
The entire plant has a grayish-green appearance. The leaves are elongated and linear. At the tops of the stems are baskets of pink flowers. It blooms in June-July and bears fruit in August-September.
It is widespread in all regions of Kyrgyzstan in the agricultural zone. Decoctions and infusions are used to combat insect pests.
When using insecticidal and rodenticidal plants of Kyrgyzstan, priority should be given to such plants as pink wormwood, tail-leaved Sophora, thick-fruited Sophora, and beardless livewort. These species clog pastures and cause livestock poisoning. Reducing their numbers in the grass cover is very beneficial for improving pasture quality, and consequently, for increasing livestock production, which will positively reflect on the implementation of the Food Program.