Ips hauseri
(Kyrgyz mountain engraver)

I. hauseri is an endemic species of the Tien Shan mountains of China, Kyrgyzstan. Its distribution is limited by Picea schrenkiana forests of the Central and West Tien Shan, by the Dzhungarsky, Zailiisky, Kungei and Terskei Ala Tau, as well as of the Chatkalski and Ferganski mountain ranges. Its presence outside the habitat of Picea schrenkiana is questionable (Stark, 1952).

Beetles may be transported on the surface of trunks, young beetles may be under the bark. Eggs, larvae and pupae may be under the bark too.

During wood transporting, wood should be debarked and inspected for bore holes. Cut branches, plants for planting, including bonsai, should be inspected too.

I. hauseri is similar to I. typographus and I. duplicatus in its biology, ecology and appearance. The period of adult emergence of I. hauseri is very wide and varies according to altitude. In the lower altitude belt the first beetles appear in the first 10 days of May but their mass emergence occurs in the second or third week of May. Beetles invade impaired trees of different ages whose diameter is greater than 12 cm. On thin trees the galleries are situated in the butt of the trunk. On thick trees with diameters of around 140 cm the spread of an invaded area runs up to 25 m. In the understorey on green logs and wind-fallen trees the colonies of I. hauseri are situated on the upper stem while the lower stem remains unaffected. The mass reproduction of I. hauseri takes place on littered cutting areas.

I. hauseri is a polygamous species. Three to six female galleries 3-14 cm long (on average 7.8 cm) extend away from the nuptial chamber. To some extent their length is related to the density of the colonies, the stem diameter and the area of thick bark.

Newly emerged beetles feed under the bark. Sometimes they do not find enough nutrition here and leave the emergence sites for other parts of the stem or different trees.

In the lower altitude belt (1200-1500 m) the adults emerge in May. The completion of egg development and the larval emergence occurs in the first 10 days of June. The young beetles appear in the last ten days of July. Additional feeding on the bast lasts from 15 days to 1.5 months. The second generation of beetles invade trees in the first 10 days of August. The second-generation beetles emerge at the end of September. They find additional nutrition around the emergence area and then hibernate in the same place, under the bark.

In the middle altitude belt (1500-2000 m) the developmental stages of I. hauseri occur 2 weeks later than in the lower belt.

In the upper altitude belt (2000-2500 m) the development period of I. hauseri lasts 1 month longer on average. Due to this reason there is only one generation of I. hauseri.

The pest mainly invades the area of thick bark beginning at the base of the tree and extends to a height of 15-26 m.

The population of the parent generation of I. hauseri on a tree is related to its diameter. The highest density of invasion is for trees with a diameter of 40-50 cm.

The optimum density of the parent generation is five to six beetles per 10 cm² which provides for the largest emergence of the young generation. Colonies of I. hauseri which have a ratio of males to females of 1:4 or 1:5 are the most productive colonies. It should be mentioned that the highest colony density occurs very seldom.

The highest number of I. hauseri is observed in forests of the middle belt (about 58,800 ha), where the conditions are the most favourable for development. Also, the removal of invaded trees in these places is carried out more seldom than in the lower zone. It is warm enough for the development of two generations per year and it has the greatest number of trees damaged by stone-falls and avalanches.

19 species of entomophagans have been found in galleries of I. hauseri. Widespread European species proved to be the most active predators. The most predominant is Hypophloeus fraxini which is a typical predator of I. typhographus (Girits, 1974; Nikityuk, 1952, 1957). They actively feed on the larvae, pupae and young beetles of I. hauseri. Nudobius lentus is an active predator of I. hauseri eggs. Several Staphylinidae spp., such as Placusa complanata, Phloeonomus lapponicus were found in galleries of I. hauseri. These species are cited by Saalas (1923) as enemies of spruce bark beetles in Finland and were also found in galleries of I. hauseri: Epuraea pusilla, Lado jelskii, Hypophloeus sp., Medetera excelens, M. ambigua and Lonchaea seitneri.

The most widespread parasites are Dinotiscus eupterus and Rhopalicus tutela.

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Control efforts should be undertaken in the area of the present distribution of I. hauseri. Control measures include forestry and sanitary measures (improving the resistance of forests, cutting and elimination of all infested trees; cutting of "trapping trees" followed by their treatment), as well as treatments with chemical and biological preparations.

Entomophages may play an important role in the regulation of the pest population, but have not been used in biological control.