Еколошки и економски значај фауне надфамилије Chalcidoidea Србије (Insecta: Hymenoptera)

Abstract

Надфамилија Chalcidoidea (Hymenoptera: Apocrita, Parasitica) је међу опнокрилцима једна од најбројнијих врстама. До сада је описано око 22.000 врста, а процене су да их можда има и до 500.000. У Европској фауни је присут- но 5.121 врста. На подручју Србије требало би очекивати најмање око 2000 врста, док их је до сада познато свега 366, што указује да је ова група инсеката слабо истражена. У питању су ситни инсекти, чија је величина тела у просеку 1,5 мм. Највећи број врста су зоофагни (паразитоиди), али има и фитофага. У еколошком и економском смислу, многи представници имају изузетно велики значај. Готово да нема врсте инсеката, која међу представницима надфамилије Chalcidoidea нема своје природне непријатеље, који у различитим екосистемима веома успешно кон- тролишу бројност својих домаћина. Зато су многе врсте Chalcidoidea постали кан- дидати за агенсе биолошке контроле разних штетних организама. До сада је преко 800 таквих врста употребљено са мањим, али често великим успехом у класичној биолошкој контроли разних штетних организама, међу којима доминирају штетни инсекти у пољопривреди и шумарству. Поред штетних инсеката, биолошка кон- трола је веома успешна и против крпеља (Acari: Ixodidae), као и неких инвазивних коровских биљака. Биолошка контрола је вршена интродукцијом агенаса или њи- ховим масовним гајењем у лабораторијама (тзв. биофабрикама). Поред изузетно корисне улоге многих представника надфамилије Chalcidoidea у регулацији или ре- дукцији бројности штеточина, односно њихових домаћина, неке фитофагне врсте су опасне штеточине гајених биљака у пољопривреди и шумарству. Да би се боље сагледао еколошки и економски значај ове групе инсеката, у раду су дати примери властитих истраживања на подручју Србије. То су паразитоиди чији су домаћини: Tortrix viridana L.(Lepidoptera: Tortricidae), Ips typographus (L.) и Magdalis armigera (Geoffr.)(Coleoptera, Curculionidae), Stictocephala bisonia Kopp &Yonke ( Hemiptera: Membracidae), Dryocosmus kuriphilus Yasu.(Hymenoptera: Cynipidae) и хиперпарази- тоид на домаћину Megachile rotundata (F.)(Hymenoptera: Apidae).

Superfamilia Chalcidoidea belongs to order Hymenoptera, and suborder Apocrita parasitica. Body length of these insects is average about 1,5 mm. Due to small size and criptic way of living, they were and are not even today attractive for enthomologists, so relatively small number of scientists investigates this group. According to latest classification, superfamilia Chalcidoidea comprises 22 families, out of which 18 live in Europe, while 4 families live on other continents. There is still no consensus about taxonomical order of families within the superfamilia Chalcidoidea. For this reason most of authorts use alphabetical order. The largest number of species of the superfamilia Chalcidoidea are parasitoids of hyperparasitoids. There are almost no insect orders whose representatives have no natural enemies among the members of superfamily Chalcidoidea. Also, parasitoids from other insect orders, and even species from the same superfamily or families have hyperparasitoids (of first, second or even third order) from the superfamily Chalcidoidea. However, some families of superfamily Chalcidoidea have phytophagous species. In environmental sense, species of superfamily Chalcidoidea who live as parasitoids have highly important role in maintaining biological equilibrium in nature. There are no self-sustainable ecosystems in Europe any more because man affected them in higher or lesser degree. However, they still survive and are sustained thanks to existence of natural enemies of certain members of ecosystems. Among natural enemies of many phytophags, members of superfamily Chalcidoidea have important role. Regarding economical significance, species of superfamily Chalcidoidea prevail among other parasitoid species. To this day, more than 800 species of this superfamily have been used in classical biological control of various pests. Beside harmful insects in agriculture and forestry, some species of Chalcidoidea have been used in control of tiks (Acari: Ixodidae), as well as in control of some invasive plant species. Most of the species of Chalcidoidea used in biological control of pests were utilized by method of introduction (most commonly from Europe to North America or reversly) or by by mass breeding in laboratory conditions - in so called biofactories. Especially convenient for mass breeding are the species of geneza Trichogramma (Fam. Trichogrammatidae), Encarsia (Fam. Aphelinidae), Diglyphus (Fam. Eulophidae) etc. Larvae of some phytophagous species of the superfamilia Chalcidoidea live in seed and gales of various plants. To this day there were 80 species registered who cause more or less damage in agriculture and forestry. Pest insectsin our fauna belong to families Erytomidae and Torymidae. Some species from the genus Bruchophagus and Systole are notorious pests in agriculture, while some species from the genus Megastigmus and Bruchophagus are important pests in forestry. In order to prevent damage from phytophagous Chalcidoidea, it is necessary to use chemical protection measures which are rather costly, so this could also be contributed to economical significance. If all the above mentioned is taken into account, it is not easy to establish with precision the economical significance of fauna of superfamily Chalcidoidea. The most common method of control of harmful insect species in agriculture and forestry, and control of tiks and plant pests is chemical treatment by insecticides, acaricides and herbicides. It is well known that pesticides are among the most dangerous environemntal polluters. Their use causes common acute but also even more frequent cronical poisoning of people and animals. They also cause drastical disturbance of ecosystems in which they are used. They do it by reduction or elimination of predators and parasitoids, pollinators and many other organisms which are common and essencial members of those ecosystems (forests, grasslands, aquatic ecosystems etc.). The alternative solution that is available is biological means of control of harmful organisms by using their natural enemies, and most dominant among those are species from the superfamily Chalcidoidea. There is a trend worldwide nowdays to reduce quantity or even eliminate use of pesticides. Production of organic food is promoted, and such food can not be imagined without biological control of pests by use of natural enemies, most commonly belonging to superfamilia Chalcidoidea. There are 21.982 described species from the superfamilia Chalcidoidea, and it is estimated that there 100.000, even 500.000 not describet yet. Estimated numbers of species are most probably realistic because each year hundreds of new species are being described, new for the science. Also, many regions on Earth are insufficiently or not at all explored, and there is likely to expect to discover many new species. If it is estimated that there are about 100.000 species, this would mean that only 22% species are known and if there are 500.000, the percentage of known species is even less, and amounts about 5%. It is evident that superfamilia Chalcidoidea is globally not investigated enough. There are 5.121 European species and in Serbia only 366. Number of known Chalcidoidea species in Serbia is low, indicating that their fauna is not researched enough. Small number of entomologists investigated this group. Some of the enthomologists were studying other insect groups and by breeding them in laboratories, they obtained parasitoids of those insects. On territory of former Yugoslavia and later Serbia, there were no specialists for this group of insects and the enthomologists were sending those parasitoids abroad for determination, most often to Dr Zdenek Bouček in British Museum of Natural History in London. Dr Bouček was on several ocastions in former Yugoslavia (including Serbia) collecting Chalcidoidea. He determined and published all material collected by local investigators and by himself. The number of species thus identified on territory of former Yugoslavia was 949. According to estimate of this author, this is 1/3 of the number of species which could be expected in this area. He claimed that based on personal experience on area of Chekoslovakia and Great Britain. If from this number we deduct mediteraniean species, it could be estimated that on theritory of Serbia there are about 2000 species. This would indicate that 366 described species respresent only about 20% of the expected number of srecies of Chalcidoidea in fauna of Serbia. More intense faunsitic investigation of Chalcidoidea in Serbia started in 1976, and in the last forty years aboundant material was collected which is only partially processed, while the largest proportion of speciemns is yet to be determined. It is estimated that after the determination of this material the percentage of known species from 20% of the expected 2000 species will reach 50%. Тhis points to the need to intensify research of fauna of Chalcidoidea in the future through inclusion of younger entomologists.