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Globe Thistle Weevil - for RADEK #1 (82)
boreocypriensis
![Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 3334 W: 139 N: 3744]](http://i1.treknature.com/misc/g-g-g.gif) (9862) | Larinus onopordi (Globe Thistle Capitulum Weevil) (A Male) #1
Dear Friends, as you are known my main subject in TN is herpetology (amphibians & reptiles). However, all organisms are showing many interactions between them in nature and thus we have to take into consideration all organisms which may be related with their environments. Therefore, when we make study on our main subject, we have to collect additional information on their biotic (other organisms) and abiotic factors (chemical, topographical structures, temperature, humidity etc.) which exist in the sharing environment to make good scientific evaluations. On this way, I concentrate to other organisms, such as plants, insects, etc. and share these observations with my friends in TN as I made now.
Today I would like to dedicate these captures (see also WS to see the female ) of this interesting Globe Thistle Weevil to one of my beloved and heartfelt friends in TN, Radek (Radomir Jaskula) (cicindela) who is an expert on insects and photographing them to thanks to him for his valuable contributions to TN . I hope you can like this Radek :)! I wish you all the best my friend and thanks once more for your significant contributions!
Since I have got limited information on the identifying the insects, Dr. Levent Gültekin (Ataturk Univ., Erzurum) identified this interesting curculionid for me. Therefore, I indebted to him for his kind helping! I photographed this Globe Thistle Capitulum Weevil on a Echinops capitulum around the Yılankale Castle (Ceyhan) in Adana province during our herpetological trip to SE Anatolia.
Hoping that you like these shots!
Cheers,
Bayram
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Phytophagous insects represent a major part of world’s biodiversity. Most hypotheses explaining this extraordinary diversity refer to small body size, specialization on many different microhabitats, short generation time, ability to open up new resources and host plant shifting. Use of the rostrum for excavating an oviposition site in a plant structure can be seen clearly as a key point in explaining diversity within Curculionoidea (Order: Coleoptera). The development of a long rostrum in females of Curculionoidea allowed invasion of a new adaptive zone through excavation of oviposition sites in plant parts otherwise not previously available as food sources for immature stages. The evolution of host choice and knowledge of how this might affect the speciation process is important for an understanding of this diversity. Considerable attention has been paid to the formation of host races, generally concentrating on host shifts occurring in sympatry.
Echinops are perennial or biennial spiny herbs with erect ridged stems. Leaves simple to three-pinnatisect, petiolate or sessile. Capitula single-flowered, congested into globose heads subtended by small reflexed bracts. The genus Echinops has sixteen species in all Turkey. Of these, Echinops sphaerocephalus L. is distributed mainly in northeastern Anatolia. This plant is on the weed list in Turkey in common pastures, meadows, environs of airport, highways and railways , maize, cotton fields, field margins and other crops (citrus, okra, grape, soybean, wheat, tomato, sesame, groundnut and bean). Also, E. sphaerocephalus is on the invasive weed list of North America and it is commonly found in Nebraska. Even though informed about the weed characteristics of E. sphaerocephalus in current literature, this plant also has medicinal uses. E. sphaerocephalus contains the non-poisonous alkaloid, echinopsin, which gives sufficiently recovery in chronic radiation sickness. Polysaccharides isolated from E. sphaerocephalus have been used in traditional Chinese medicine as drugs with anti-inflammatory effect and anti-tumor promoting action in the osseous system. Except for its useful peculiarities writen above and though E. sphaerocephalus may become a weed in some areas, it is used as a honey plant: E. sphaerocephalus and E. ritro were planted in Michigan, USA. Values of honey efficiency and attraction for bees were found highest among those recommended for gardens as investigated in ten plants in Poland :).
The weewil genus Larinus comprising ca. 180 species is represented by approximately 140 species in the Palaearctic. Larinus is species-richest in the Mediterranean where about 100 species occur. The main host plant of Larinus onopordi is E. sphaerocephalus in Northeast Anatolia, but rarely prefers E. orientalis to complete their generation in this plant. Overwintered adults associated with host plants from mid May (According to Dr. Gultekin, “we detected that this event in early April”). After feeding several days on leaves, they mate [I will upload an additional capture soon:) ] and laid their eggs in flowerheads using rostrum by excavation of the oviposition hole. In addition, the adults damage the stem below flowerhead opening vertical holes. Adult activity period lasted approximately 44 days. Adult population rise to a peak level in the last week of May. Mating activity duration lasts approximately the adult activity period which is 37 days. After depositing eggs, females close on eggs a pale green secretion then this secretion dried, hardened and turned black. The eggs are laid superficially and it is easy to see the eggs when opening this dry secretion. Eggs occurrence span is 33 days. Hatching and feeding in flowerhead larvae continue to grow untill mid September. Larval period duration is 79 days. From the third week of July, pupae is seen in Flowerhead. In one flowerhead, four larvae can grow, also mature larva made up the pupal cell by using mouth secretion and plant remnant where 4 pupal cells occur. If there are more than one larva or pupa in one flowerhead, this flowerhead abnormally shaped. Pupa duration is 51 days. Upon reaching the new generation adult stage, they wait in the flowerhead 7-10 days and emerge from here for find a suitable hibernating site such as under stones. This weevil shows an aggregation behavior which is possibly seen in 1-3 specimens together hiding under a stone for hibernation. In this way, L. onopordi produced one generation per year.
References:
1. Gültekin, L. (2006). Host plants of Larinus latus (Herbst 1784) in eastern Turkey (Coleoptera: Curculionidae). - Weevil News, No. 40: 7 pp.
2. Gültekin, L. (2008). Seasonal Occurrence and Biology of Globe Thistle Capitulum Weevil Larinus onopordi (F.) (Coleoptera: Curculionidae) in Northeastern Turkey. Mun. Ent. Zool., 1 (2): 191-198. |
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