|HUNTING LONGHORN BEETLES
(Thanks to Gary Kurtz for correcting the translation, and for suggestions)
|Different species are found in different habitats, so the best way to get as many species as possible from a given area is to use more than a single hunting technique. In this page you will find a brief description of some of the most popular hunting methods, as well as a few simple tricks.|
|The beating sheet, or beating umbrella, is a favorite hunting tool for many collectors. Many species are rarely otherwise collected.
Position the beating sheet under a shrub, a branch or the foliage of a tree, and hit it with a pole. Most insects, responding to their natural instincts, will fall on the sheet. Most species will drop and momentarily play dead. Some species are extremely fast and have a tendency to fly as soon as they hit the sheet. Agitating the sheet with short side-to-side movements may keep some of these fast-fliers off their feet and will buy you a little time (those playing dead will continue playing dead). Collect from the sheet as your priorities dictate.
A simple transparent canister with a quick-pop lid that you can open with one hand is the fastest way to collect specimens from the sheet. Many collectors carry these in their shirt pocket, from where they can be quickly removed. Pop the lid, scoop the beetles up and re-close the canister. The contents can then be transferred to a proper killing-jar at leisure. **It is essential to quickly transfer Cerambycidae to the killing-jar, otherwise they will bite each other and you will end up with damaged specimens.
Simply walking through a dense forest and beating branches at random will give discouraging results. The best places to beat living trees and foliage are along forest paths (natural flyways), and around the periphery of open areas and fields that are in the sun. A study of species / host plant relationships will get even further results, allowing the capture of target species.
While beating living shrubs or foliage can give good results, as many nocturnal species are hiding there during the day, the Cerambycidae hunter will keep an eye open for recently dead or dying trees, as they will be most productive. Scanning the treetops is essential if you are to spot the most productive trees in a vast forest. The top of a tree is a good indication of the tree's health. Trees whose dead leaves are still attached are what to look for. As you head for your target trees, look down and around. On healthy trees, keep your eyes open for broken and dying branches and beat them, even those that look too tiny to harbor anything. Recently fallen or felled trees are a windfall.
Having located your target tree, start with a visual inspection of the trunk and main branches, taking care to not touch the branches because even a small knock-on-wood can result in many specimens falling to the ground. In the case of fallen trees, pay special attention to the underside of the trunk and branches, as this is where most species will be hiding during the day.
After your initial (as hands-off as possible) inspection and collection, put the beating sheet under some dead branches in such a way as to cover the most area possible, being careful not to shake anything in doing so.A hard hit (or double-hit) with your pole on top of those branches will do the job. All that remains to do is to collect the dislodged specimens from the sheet.
Before this first hit, however, the wise hunter would have already made a plan of attack in his mind, locating the branches that look the most promising, and beating them in order of priority. He knows that between two equally interesting spots close to each other, he will have to choose only one of them, because the shaking at the first spot will probably make nearby hidden specimens fall to the ground. Despite this, it is worthwhile to beat those already slightly shaken branches, as a few species won't fall when exposed to soft treatment. So, it is advisable to beat twice rather than just once. Before beating, a large, lightweight white sheet can be spread on the ground beneath the tree to considerably extend the falling surface...but this is not always practical. It is far simpler to just go with the beating sheet.
Some species are hiding in bark crevices of large trunks and branches and in many cases are undetectable to the eye without minute inspection. These can not be beaten in the same way. It is advisable to carry a small brush for the task of dislodging the beetles from those crevices. A small, soft-bristled dust broom is perfect for the task. With the beating sheet apposed against the trunk, brush the trunk from top to bottom, as you would do to dust it. For major branches, put the beating sheet under the surface to prospect, and gently brush this surface. For recently fallen trees, position the beating sheet under the trunk, and brush the underside of the trunk.
If you hunt in a particular area regularly, or are in a region for more than a single day, remember your most productive trees and return to them on a regular basis (day and NIGHT). Different species emerge and breed at different times of the year, so the fact that nothing is found on a tree that looks otherwise favourable is really not meaning that it will not be fruitful on a subsequent visit.
Regarding fallen trees, you may want to trim away some of the small branches which pose an obstacle to your access to the trunk and most productive branches. Leave these in a neat pile on the side. When you come back, you can always shake them over your beating sheet separately without the risk of disturbing your prime targets.
The beating sheet can also be useful for trees old enough so the bark is starting to fall off or can be easily peeled off, as many insects can hide under loose bark. As said before, appose the beating sheet on the trunk below the bark that will be removed. Peel off the bark. All hidden insects will either fall on the sheet or remain on the trunk or the inner surface of the bark, now more easily detectable.
Experienced hunters know very well how difficult it can be to find an insect that have been seen falling to the ground. Despite a meticulous research at the very spot where the specimen dropped, it often cannot be found among dead leaves, twigs, etc... The best way to rapidly recover those evanescent specimens is to throw on your beating sheet the forest floor material where the beetle dropped, on a surface roughly 30cm x 30cm. A quick inspection generally ends up into the capture of the fugitive specimen.
For collectors interested in other families as well, the beating sheet is also an invaluable tool. On it, you can throw and then closely examine anything from mushrooms to leaf-litter.
|A sawmill yard is where a company stores logs coming from primary cut sites. These trees, often still quite fresh, are usually stacked together and separated by species.
Before they get there, the trees are most of the time piled up directly on the spot where they have been cut, and left there for from a few days to one or two weeks at most. Timing is what's important here, for those spots are really temporary ones, and one has to be there during that short time span otherwise nothing is left. They are then transferred to sawmill yards, where the trees are to be found all year round, neatly stacked. This is the place where raw wood is stored before being sold for transformation.
So, all there is to do is to find a sawmill yard, and it is better to look for one in forested areas so insects attracted by this freshly cut wood will come in greater numbers. These attracted insects are coming there to mate and to lay their eggs. Longhorn beetles can often be seen in sawmill yards flying toward and around their recently cut host trees. A close inspection of the stacked wood will allow the discovery of immobile, cryptic specimens, hidden on the lower surface of the logs, while other specimens will be seen walking or running around well exposed in the sunshine.
With a net in hand during a hot and sunny day at the end of the afternoon or in the evening before sunset, a sawmill yard can yield interesting results. Earlier in the day can also allow the capture of nice species, while after sunset nocturnal species are waking up and getting out of their hiding places. A flashlight is then necessary to locate and capture these species that are generally not encountered during the day
Some sawmill yards are using insecticides that are sprayed all over on the logs. It is better to avoid them for health reasons, and also because they are practically deserted by insects. Other sawmill yards are only using plain water that is continually sprayed on the logs. This helps to prevent egg laying. How to recognise sawmill yards that are using insecticides from those that are not? This can easily be resolved by simply asking the owner or any employee on the spot. You have to contact them anyway if you are to hunt on their grounds, for it is always better to get permission first. They will be happy to allow you to collect insect pests that are eating away at their livelihood.
|The sweeping technique, although less productive than the previous method, allows the capture of species generally not taken with the beating tray, notably the species associated with herbaceous plants.
Equipped with a sweeping net stronger than the fragile butterfly nets, one must vigorously sweep various plants from the base up in open fields or elsewhere. Often, a few minutes sweeping session in a wild field where several plant species are occurring yields some Cerambycidae specimens, and undoubtedly many, even a dozen or more Coleoptera species belonging to other families.
|In temperate zone, at least for species of holarctic distribution, hunting by sight on flowers yields excellent results as far as Lepturinae are concerned. Some Cerambycinae are also found on flowers (Clytini, among others). The hunter will quickly learn to recognize the most productive flowers, keeping in mind that almost no type of flower should be overlooked, as some Cerambycidae species are very restrictive when it comes to the flowers they visit, sometimes being associated with only a single nectar feeding source.
It is recommended that you always have a net on hand. As you hand pick beetles from flowers, position your net under the flowers as a safeguard. If a flower cluster has an abundance of beetles, position your net under the cluster and shake it into the net (doing your best not to agitate the rest of the plant). You will have far fewer escapees this way, and can then collect your specimens from the net.
For hard to reach taller plants and bushes, position the net under the flower cluster and give the stem a sharp rap. As a prelude to flying the beetles will drop. Alternatively, for large enough clusters where many specimens are active, cover the flowers with your net and gently shake it a few times before withdrawal. Work your net.
For large flowering trees, a beating sheet is recommended. When Lepturinae and Cerambycinae hit the sheet, you have to think about your priorities and work FAST.
|This technique is the most productive of all when the right conditions present themselves, i.e. when the temperature is hot and humid and the moon is not visible or is hidden by thick clouds. During a drought, when there is a full moon, or when its very windy, night hunts can be quite a disappointment.
Generally, night hunt usually means a UV-light or mercury-vapour lamp passive hunt. You set your traps and wait.
Instead of simply sitting and waiting by your light traps, go and visit businesses or other building lights that are near interesting habitats close to your hunt site. A net with an extendable pole is highly recommended here, as the lights, and the beetles they attract, are often up high.
Go and hunt with a flashlight or headlight on tree trunks of recently dead or, still better, dying trees that you spotted during the day. These techniques fill time, and your collecting jar! On a bad night you may have almost nothing on your light trap sheet, but you can still go home with some remarkable catches from tree trunks and the sides of buildings.
UV or mercury-vapour? Good question, as each one has its own advantages. A UV-light neon is a really low energy consumer, so it can reliably be powered with a rechargeable battery, and this for the whole duration of a night hunt, and more. A mercury-vapour light bulb takes a lot of power, so forget about rechargeable batteries. What is needed here is an electrical outlet or a transportable generator.
Here in southern Quebec, Canada, I saw no difference between the two; UV-light traps attracted as many species in comparable quantities as mercury-vapour light traps did. But, having done the comparison only once, I do not have a definitive conclusion on this matter. For sure, a 250 or 500-watt mercury-vapour light can attract species from farther away than the standard 15-watt UV-light neon, but in a dense forest the difference is more in the proper placement of the traps than anything else. In open fields it might be another story. For practical reasons, I always use the UV-light neon, which gives excellent results.
The basic material for a night hunt may be as follows:
- A UV-light neon that can be plugged to a battery
- A rechargeable battery (motorcycle battery or other)
- Two large white sheets
- A long rope and clothes pins
- A headlight with spare light bulbs and batteries
- A killing jar and some ethyl acetate
- A beating sheet and / or net
In a forest or elsewhere, it is highly recommended to closely inspect the area during the day. This way, the best spot for the light trap can be chosen in advance and the location of nearby dead or dying trees can be noted for headlamp inspection later during the night, which can be very rewarding.
The location of the UV-light trap is of primary importance. A hilltop is always better than anywhere downhill, because the heat gathered during the day is going up, and insects have a strong tendency to follow those warm air currents. The trap should be set on a natural flyway, or in a place with the most visibility possible. It is also better if the area in front and back of the trap is free of shrubs or other low vegetation (less than 10 meters) otherwise many insects attracted by the trap will land and stay in the vegetation. Tip: Always use a beating sheet to beat the vegetation near and all around the light trap once the hunt is over. This often gives good results.
Installing a classic light trap:
Locate two grown trees at least 4 meters apart on top of a small hill in a wooded area, this is a good start. Tie the rope solidly to one of the trees, about two meters above ground. Then, take the loose end of the rope and pass it behind the second tree at the same height and come back to tie it on the first tree like you did at the beginning, trying to obtain as much tension as possible. You want to have two parallel lines running between the trees. Suspend the first sheet to one of the ropes using clothes pins. Leave at least 20 cm of the sheet hanging over top of the rope. This will give a hiding place for beetles that land on the sheet. They will crawl upwards and under this overhanging drape. Leave at least 20 cm of the sheet touching the ground. The other sheet is spread on the ground under the suspended sheet, right in the middle, covering the most ground surface possible. Place the rechargeable battery on the ground on the centre margin of the lower part of the suspended sheet. To prevent the shaking of the sheet by the wind, put addition heavy stones on each side on the centre margin. Your goal should be to create the flattest, wrinkle-free surface possible. Hang the UV neon on the rope passing in front of the one to which the sheet is suspended. It is best to hang the light 20-30 cm from the sheet. A front view looks like this. It is advisable to use a thin sheet that lets light permeate through, which will also attract insects from the opposite side of the light source.
Plug the neon to the battery half an hour before sunset or as soon as the day light is starting to wane, as some species are only flying just before dusk, while some diurnal species might be caught at their last flight of the day.
When inspecting the sheet, always begin with the very top of the sheet and the ropes, as the beetles found there will be the first to fly. Check the sheet on both sides and then inspect the trunks of surrounding trees. The last place to look is under the top-overhanging flap of the sheet. The beetles there are comfortably hidden and at no risk of flying.
From dusk to midnight sounds like a reasonable length when talking about an insect hunt, but when specimens are keeping coming to the sheet, it is easy to stay a few hours more; you can always uninstall and go home later. On the other hand, when the temperature is rapidly decreasing, sometimes nothing interesting will come in after eleven o'clock. Most of the time, when the temperature drops below twenty degrees Celsius, it is better to pack things up and go...unless you are after moths (which can be valuable for exchanges with other collectors).
Standard practice among many Coleopterists is that each collector installs 2 light traps in varying locations at a site. Make sure you set your traps so they don't compete with each other; in other words, so they are not visible from each other. Traps set in different locations on a given site will sometimes yield different results, especially regarding less common species. As you walk from one site to another, you have the opportunity to visit the various dead or dying trees you spotted previously.
Basic Schedule of a Night Hunt:
1- In driving to the site, take note of any MV or other bright lights on signs or businesses close to the site.
2- Two hours before sunset (if it's a new site), walk around (beat and/or sweep as you go), and visually locate the best locations to install your light traps. Memorize paths and the location of any dead and dying trees.
3- 45 minutes to sundown, install your traps, but don't plug them in.
4- Return to first trap and retrace your steps, plugging in each lamp so that everything is installed 30 minutes prior to sundown.
5- First careful inspection of the dead and dying trees spotted earlier. Nocturnal species are sometimes starting to wander around before the sun sets.
6- Shortly after sundown, make a visit of the traps for any early arrivals.
7- Tea time.
8- Revisit traps. In walking between light traps, closely inspect all dead and dying trees along the way. Make additional side trips, inspect trees not previously scheduled, whether they be dead or not.
9- At various times, depending on where you are hunting, hop into your car and go visit the lights of businesses and large signs you took note of previously.
A night hunt is far from passive. Instead of simply sitting by your sheet, waiting, there is a lot of hunting to do.
|Cerambycidae rearing is done from infested branches brought home and put in a cage or other container until the emergence of adults, or imagos.
The first step is to find infested branches, and this is not evident for the beginner. Branches from trees and shrubs that have been dead since a few weeks to a few months or for up to a year or two and from those that are dying will be of particular interest. A good initial sign of infestation is the frass the larvae are ejecting from tiny holes in the wood.
A look beneath the bark with an appropriate tool can reveal larvae galleries. The presence of those galleries beneath bark is only a sign of past activity and does not mean the larvae are still there. If the branch or log contains one or many exit holes, chances are that the cycle is over and it only contains empty galleries. But, don't jump to conclusions too quickly. Despite the exit holes there may still be other larvae or nymphs present, though not necessarily of the same species as the one having previously emerged. This can be particularly true if the branch is relatively fresh.
Having identified infested branches, cut them and put them in a container. The container can be a cage made for this purpose or a large aquarium topped with fine screen. In temperate zone, the gathered wood must be transferred outside before the cold season, because most species need to be exposed to cold for some time so they can properly develop (diapause). It is advised to not put them under cover, but to leave them exposed to rain and snow, just as they would naturally be. This will least disturb an often-fragile cycle that is not adapted to unforeseen events caused by human intervention.
Keep in mind that some species have a two-year (or more) life cycle, so bringing home infested branches does not necessarily mean you will get imagos in the following weeks or months. Species found in small branches or twigs often have a one-year cycle from egg to adult, but it all depends on so many factors (latitude, drought, etc...) that this is only a very general rule. For example, a given species can have a two-year life cycle in Canada and a one-year cycle in a more southern area like in Florida.
Some larvae produce a sound that is quite characteristic when they bore through wood. When easily heard, it comes from medium to big species, like Monochamini, which are well known for producing these loud sounds. This boring can be heard from quite far away on a calm, warm day; it means an infested tree is within reach, all is left to do is to find the sound source.
Species producing these sounds don't always belong to the Cerambycidae family - they can very well come from Buprestidae, which often infest the same trees as Cerambycidae do. Larvae from these two families are easily separated; Buprestidae larvae have the front of the body (right before the head) strongly flattened, rounded and much wider than the remaining, while for Cerambycidae this part is cylindrical and a natural continuation of preceding segments.
With an understanding of flight times and host plant relations of various species, you can also break or cut a few branches or vines of the host plant a few weeks before the optimal breeding time. Return later in the year and prune the dead branches to harvest the infested material. Early collecting of freshly infested wood helps to dramatically decrease or completely eliminates parasitism. Transfer the material to proper rearing cages. Many rarely collected species can be collected en masse using this technique.
As a final note: Cerambycidae rearing cages must be made with a good metallic mesh. Species of this family often have formidable jaws. They will chew through any soft-fiber mesh.
|FERMENTING BAIT TRAP
|An interesting method of passive hunting, the fermenting bait trap will attract species otherwise quite difficult to obtain.
A few over-ripened bananas left in the sun in a transparent and airtight container for a few days are a good start for a recipe that is as diversified as there are people preparing it. Wring the banana mixture through a sieve or cheesecloth to extract the most juice possible. From here you can improvise with organic substances at hand: Add a few beers, brown sugar, some molasses, yeast, a few ounces of rum, some wine, and other bits of rotting fruit. Let this mixture ferment a few more days under the sun, preferably in a transparent and closed container, and the recipe is ready to use.
Lepidoptera hunters who apply it with a paintbrush on tree trunks to attract moths call this mixture "sugar". For fermenting bait traps designed for Cerambycidae, the approach is different. The substance is poured into a plastic container already modified by cutting out a large opening on one side near the top. 4-litre (1 gallon) spring water containers with a handle are perfect. Beetles will enter the trap and be drowned in the liquid. Pass a rope through the handle and tie it to a branch that is both high enough and far enough away from the tree's trunk to avoid scavenging by wild animals. For best results, insure that the container is exposed to the sun for at least a few hours each day, preferably during the afternoon.
It is advised to gather the trapped species at least once every two or three days, otherwise those specimens may themselves become a part of the fermenting process.