A FEW WORDS ABOUT WEEVILS (CURCULIONIDAE)

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(Edited)

Among many small wonders from the varied and colorful insect world around me, this group of beetles - the weevils, hold one of the more prominent places in my private insect fan list of sort, with their often exaggerated, cartoonish looking rostrums and a nice variety of shapes, iridescence and colors.
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For the opening picture, I chose the Rhynchites bacchus. This small irridescent beauty is considered a pest because, among other woody rosaceae plants, it feeds and reproduces on some important cultivated species like plums, peaches, almonds and apricots.
The adult beetles feed in the spring on buds, flowers and young fruits. When comes the time for reproduction, after the mating, females deposit eggs in young fruits, one egg per fruit, then sever the fruit stalks by chewing them. The larva develops in the fallen fruit while the fruit is rotting. Once full-grown it enters the soil.
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Because of their lifestyle connected with life cycles of fruit-bearing shrubs and trees, many weevils regularly come in conflict with the human interests.
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This incredible character with extremely long beak is the Curculio nucum, a species that feeds and reproduces using hazel plants and their delicious hazelnuts.
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On these photographs you can see the female. Their beaks are as long as the rest of the body and look quite spectacular, while those of the males are by one third shorter.
Development takes place mostly within a two-year life cycle. Adult beetles emerge in the spring from the soil where they have been overwintering as adult. They feed on hazel buds and leaves. The adults can be found from May to the end of August. Females deposit eggs within maturing hazelnuts, laying a single egg per nut, around the end of July/beginning of August. One female can lay up to twenty - thirty eggs. One week after egg deposition the larvae hatch, and start to feed inside a nut. They spend around one month there, eating most of the nut content. By the end of the summer, mature larvae leave the nuts through round holes and then burrow into the ground, where they build individual cells. After overwintering, most larvae pause for the whole season and undergo metamorphosis in the next summer. Newly formed adults then mainly overwinter in their pupal cases before emerging in the spring of the following year.
As you surely noticed, the reproductive procedure and the usage of fruits are very similar to those of the precedent weevil species.
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At this point ... I'm very unhappy to announce ... that after a long & exhausting search through the meandering flow of information on Internet ... I didn't found anything about this interesting species. It's a weevil, that's for sure ... but what else can I tell you about it? Well, not much. It is interestingly shaped and is not very common here where I live. I saw it only a few times in my life. Here you can see the beetle in pose that assumes when threatened. It looked much better on photograph in this horizontal composition, but the situation was actually vertical. Since I'm a more artsy than science oriented guy by my profession and vocation, I chose this good-looking layout that can lead you to some inexact conclusions. The weevil is holding to a small wild orchid, where I put it to have a good, clear view with dark background while using the flash. In reality, I always encounter this species in different circumstances ... as you'll see on the following photograph.
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Here you can see this species camouflaged on the stony terrain, the same habitat where the wild orchids grow. Although is the same species, this is not the same individual ... and you can see some additional camouflage on this one. While walking through the carpet of lichens and moss, in between rocks, on a shrub - covered area near the sea, you'll notice some small lichen patches on the insect's body. It's an amazing species, hope I'll find more about it soon.
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These small weevils mating on the thistle flower, are the male and the female of the Rhinocyllus conicus.
They don't look very interesting, special or attractive confronted with other, more exuberant species you saw in the post ... but there is one interesting and peculiar detail about them ... among many weevils considered as pests, this one was occasionally used as a weed control for invasive, aggressive thistle growth.
The female lays over hundred eggs on ... or near ... the bracts of the thistle flower head. She covers the eggs with masticated plant tissue to protect them from predators. When the white larva emerges from its egg it burrows into the flower head and feeds on the flower parts and developing seeds. As it grows it deposits excrement and chewed plant tissue on the walls of its chamber, producing a rigid protective shell in which it will pupate. Pupation takes up to two weeks and when the weevil emerges as an adult it remains inside the chamber for a few more weeks before tunneling out of the plant.
Damage to the plant occurs mainly from larval destruction of the flower head, which prevents seed production. Adults feed on foliage, but that doesn't do much damage to the resilient thistle plant.
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Here is another mating shot of this species ... where you can see, if you confront it with the precedent photograph, how the colors of these weevils may vary, how they can be more or less yellow.
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The weevil on this photograph is one of the Lixus species. The genus Lixus is present with quite a few very same - looking insects, so I can't tell you which exactly is this one. Looks a lot like Lixus bardanae, but I'm not sure.
Lixus weevils feed and reproduce on herbaceous plants like Thistles, Irises, Curly Dock and others.
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Here is another similar Lixus ...
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... and this one ...
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... is ready to fly.
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This brown species, with the characteristic yellowish line, is the Lixus juncii ... that uses various Chenopodium as host plants.
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Here you can see the Otiorhynchus sulcatus ... the Black vine weevil ... slowly crawling across the small dusty road that leads to the coast.
The adult weevils of this species have fused wing covers, and are unable to fly. They feed at night on the outer edges of leaves, causing the leaves to have a notched margin. They attack a wide range of different garden plants.
The larvae attack the base of the plant and the roots.
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Here is another pretty generic looking weevil. I don't know the exact species. Looks a lot like a part of the Otiorhynchus genus, but I'm not sure.
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On this photograph you can see one clear example of the Otiorhynchus type of weevil - The Otiorhynchus sensitivus ... so maybe you can figure it out if the species on one photograph before is somehow related and part of the Otiorhynchus bunch.
I couldn't find any information about this species (The Otiorhynchus sensitivus ) besides its scientific name ... and all that I can tell you from my experience is that I always encounter these beetles on Ivy and blackberry shrubs.
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Species on this photograph is the Coniocleonus nigrosuturatus.
These weevils avoid places with compact and overgrown vegetation, and as I found out in some articles, that's maybe because the soil in such places is not sufficiently warm for larval development, the formulation " we suppose " was used in those texts.
I find them, not very often but regularly every summer, on the meadows with short grass and on the dusty roads along the coastline. They use some Geraniaceae plants as hosts.
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Tiny weevil on this photograph is the Polydrusus formosus.
The adults are eaters of young leaves and open blossoms of a wide variety of woodland trees and shrubs. The larvae live and grow in the soil, feeding on roots. On the following picture ...
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... you can see this weevil among some interesting fungal formations. I took these shots deep into the dense coastal forest.
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here you can take a look at the mating of the Attelabus nitens - The Oak leaf roller. The female of this species lays a single egg near the edge of the leaf and then cuts and rolls up part of the leaf to protect the egg and the developing larvae. Very colorful and interesting species. And now ...
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... with this Lixus weevil on the palm on my hand ... is time to end this weevil collection - THE END.
Yap, the collection abruptly ends here ... but the post continues ... because I would like to say a few more things.
While uploading the enlargeable photographs here on STEMsocial, I noticed that they are not visible in the preview ... so I decided to put only smaller versions in the story.
But now, after everything is said and shown I'll upload those larger version of some of these photographs ... in hope that they'll be visible ... and you can somehow enlarge them.
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Curculio nucum
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Strange unidentified weevil on wild orchid.
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Strange unidentified weevil camouflaged in the lichens and moss.
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Lixus bardanae?
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Polydrusus formosus
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Lixus on the palm of my hand.
I would like to say one more thing ... regarding the drafts save here on STEMsocial ... I think there's no way to save my progress while preparing the post, or I can't understand how to do it, making the publishing here pretty tense and stressful. Usually I copy my progress in word document ... but sometimes I forget ... and then occasionally some accidents happen, things get lost and I get crazy. If someone has some good idea to help me with this issue I'll be grateful to hear it.
As always in these posts on HIVE, all the photographs are my work.



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18 comments
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Ohhhhh Wevils! Terrible pests but so photogenic and kind of cute looking :D

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Manually curated by EwkaW from the Qurator Team. Keep up the good work!

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I have seen the Rhinocyllus conicus and Polydrusus formosus over here but none of the other strange weevils you have found. That really long nosed one is hilarious.

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:D Looks like some space invader that is hard to take seriously. I like the variety of weevils around, almost every year I come across some that I have never seen before.

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This post was chosen to be voted by THEUNION.
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Waoo you are an expert with the camera, the way you focus on the creature and capture the image accurately is great

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Thanks. :)A lot of practice, I spend most of my free time with insects, tiny flowers and similar stuff.

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