Unless you grow plants commercially, you may very well not know what a thrips is. It is a tiny insect that can have a not-so-tiny effect on plants. Thrips pierce plant leaves and flowers and suck out their contents. And, not less important, many plant viruses are known to be transmitted by thrips . Needless to say, a lot of research is currently carried out on how to get rid of these creatures.
Sexual selection can lead to fascinating phenomena. We are all familiar with the fabulous color display of male peacocks to attract females. Less well known, but definitely not less interesting, are stalk-eyed flies. Due to the fact that the females strongly prefer males with wideset eyes, the males have developed eyes on stalks that can be larger than their bodies. And did you know that the Irish elk developed antlers through sexual selection that span over two-and-a-half meters? Some people believe that the males with antlers this large could hardly move through the forest, which may have led to the species’ extinction. It’s no wonder that sexual preference is so well-studied with so many hypotheses formulated in relation to it.
Aphids and their natural enemies
Leaf sucking creatures like plant aphids are common and can cause considerable damage to plants. Therefore, quite a lot of effort is made to control these tiny creatures. And because of environmental awareness, sustainable methods to control aphids are well developed. Aphids can be controlled successfully with ladybugs (Coccinella septempunctata) and also with lacewings (Chrysoperla carnea). Both species are natural enemies of aphids.
Image ladybug - By Gilles San Martin from Namur, Belgium (Coccinella magnifica) [CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons
We all know that the majority of plant species depends on pollinators, like bees and syrphid flies, for reproduction. What most of us do not know is that this process is far more complex than it looks at first sight. Think about it: pollinators do not visit flowers to transfer pollen, but to collect nectar. If the amount of nectar in the flowers is too large, the pollinators will not visit other flowers to collect more, so no pollen is transferred to other plants. Conversely, if the amount of nectar is too small, it will not pay for the pollinators to visit those flowers. So plants have to fine-tune the nectar production in their flowers to optimize pollination. And did you know that some plant species even add toxins to their nectar, which stimulates pollinators to move to other plants, bringing the pollen with them ?
However, it is not only body odor, but also body heat, CO2 from breathing and wind direction may also be important for the mosquitoes to find you. Furthermore, different mosquito species use different cues. For many mosquito species it is still not known exactly what they do to find their hosts.
Topics: EthoVision XT, Video tracking, insect behavior, exploratory behavior, Track3D, tracking, Automating behavioral observations, Tracking insects, Animal 3D tracking, 3D movement analysis, Mosquito
The importance of plant volatiles
Plant volatiles play an important role in the interaction between plants and insects that eat them. Insect damage very often induces plants to produce volatiles. These volatiles can improve the plant’s defense against insect herbivores. But they can also help the plants indirectly by attracting natural enemies of the plant eating insects.
Plants are sophisticated
Did you know that plants are not as passive as they appear to be at first sight? Although plants cannot run away when they are attacked by plant eating insects, they have several sophisticated ways to defend themselves. They can produce nasty substances upon attack. Or they can produce smells that attract natural enemies of their attackers . Now it also shown that the threat of being eaten can speed up seed production in plants and affect the behavior of pollinators.
In the past 20 years, populations of honeybees have declined all over the world. This is partly caused by the increased occurrence of parasites and pathogens. But the use of pesticides may also affect honeybee health. Pesticides accumulate in bees' food to such levels that the behavior of the bees is affected.
Flowers and pesticides
Ornamental flowers are among the main export products of The Netherlands. Thrips are one of the most important pests on ornamental flowers. Not only do thrips damage the flowers and the leaves, but they can also infest the plants with devastating plant viruses. Therefore, very strict export regulations apply for the presence of these pest insects and the damage they cause on the plants. This traditionally led to the use of a high amount of pesticides with ornamentals. But pest species become resistant to pesticides over time and, in addition to this, we do not want our flowers covered with pesticides.
Last year the news was hitting the internet: The Zwiebel lab (Vanderbilt University, Nashville, Tennessee, USA) may have found a new bug repellant that is stronger than DEET. They published a paper on it this year. It tells us how they used video tracking of insect larvae to test a range of possible variants of this new compound called VUAA1.