If we want to talk about biodiversity then where better to look than at the insect world where there are more species than any other kind of animal or plant on Earth.
The recently released annual bulletin (volume 7) of the Entomological Society of Malta has opened a window on the fascinating world of insects in the Mediterranean region, especially Malta. The society’s interest extends to all arthopods, which makes up 70 per cent of the animal kingdom, and includes the study of crustaceans as well as spiders, scorpions, millipedes and centipedes in addition to over a million described insect species. Many more are waiting to be discovered and formally described.
The 2015 bulletin is a result of scientific work by 12 Maltese nationals, another 10 authors from Europe and a contributor from Iran. This year, there is open access to the contents of this peer-reviewed scientific journal with illustrated papers from the current and previous years now available online.
Society president David Mifsud gave credit wherever due to all those who contributed to the bulletin. Contributors range in age from 15 to 82, proving that the study of arthopods can be a source of keen interest for people of all ages.
Newcomers to the world of insects and its terminology will turn immediately to the helpful section at the back of the book intended “for the young entomologist”.
Here, in layman’s terms and beautiful full colour plates, we are able to look into the secret lives of a rare moth, defensive beetle, tadpole shrimp, jumping spider and a pygmy ‘moth’ that is really a butterfly. This year, seven new butterflies were recorded in Malta.
Unchanged since the Triassic period over 200 million years ago, the tadpole shrimp is a living fossil. Rare and elusive, it inhabits freshwater rock pools.
The rest of the book is a valuable mine of information on 309 different species of arthropods found in the Maltese islands. Of these, 112 species have been recorded here for the first time ever.
On the cover of the 160-page bulletin, a delicate moth dances below six similar looking moths overhead – all recorded for the first time in Malta. It takes a good eye and expert knowledge to be able to identify them as separate species. Both photographer and graphic designer together have put together a striking cover image. The moths appear to be leaping and pirouetting across the cover in a blithe form of dance.
Some of these moths are active by day while others are more likely to be seen at night as they are attracted to artificial lighting. The moth (Coleophora arenicola – first discovered in North Africa in 1952) was found in Malta on seed pods of red clover at Dingli.
The larva spins a case from silk, attaching it to the side of the seed pod, and then drills through to eat the unripe seed. After feeding contentedly until the end of May, it then finds a sheltered location on the sides of rocks and attaches the case securely. This is the first time the moth, first seen in Algeria, has been recorded in Europe.
Another member of this moth family favours the buttercup for laying of its eggs in March. Unusually, the females of this particular species are unable to fly. As a defence they may jump up to 30cm when disturbed.
Insects help to keep pests, such as the potato aphid, naturally under control without the use of chemicals which may damage the environment
Not all insects are bugs. Some members of the Hemiptera order of insects are known as ‘true bugs’, recognised by the way their mouths are designed to take fluid from plants. In this category, 21 species from the sub-order Heteroptera, recognisable by their wing type, have revealed themselves for the first time ever in the Maltese islands.
Insect hunters scoured valleys, peering under the bark of trees and looking in decayed vegetation in a variety of habitats. One of the new bugs to come to light is of a type very partial to cultivated ornamental plants. Another is known to be a voracious predator of whitefly.
A freshly discovered type of wasp from the Brachonid family is new to science and provides the first knowledge of this species, which Malta has now shared with the international community of insect enthusiasts and scientists. The wasp, Dolichogenidea zerafai, named after the entomologist who came across it, Michael Zerafa, has so far only been reported in Malta and nowhere else in the world.
Wasps from this family are known to be parasitoid as they lay their eggs on other insects or inject them into live caterpillars. Estimates about the number of parasitoids in the world vary widely. Most of them are very small in size, so it is believed that there are many undiscovered species out there, still waiting to be found. Some can be as tiny as the full stop at the end of this sentence, as their host and egg-depository is itself the egg of a particular insect.
When an adult parasitoid wasp is looking for a suitable host, it first identifies its preferred habitat, which has a distinct look and smell. Once the egg hatches, the larvae eat the host alive before emerging as an adult. The various different species specialise in attacking one host species, usually during a particular stage of its life cycle. This specialisation has given rise to a huge diversity within this family.
These insects have an important role to play in all terrestrial ecosystems, including garden habitats, as they control the population of caterpillars which can quickly devastate vegetation and crops.
In spite of this critical role, few people are familiar with them, unaware that they kill enormous numbers of garden pests. They are produced on an industrial scale and help to keep pests, such as the potato aphid, naturally under control without the use of chemicals which may damage the environment.
Here is another point to consider when pondering the insect world. Not all flying insects are ‘true flies’ (Diptera). A range of small fly-like winged insects happen to fall under a separate order (Strepsiptera). Of the true flies, a crane fly and two species of the tiny sun fly attracted to warm, semi-arid habitats have been found for the first time in Malta, adding a whole new family of flies called Trixocelidae to the Maltese repertoire.
Go to lakes and mountains in northern Europe at a certain time of year and you are likely to meet midges. With a name thought to come from the Gaelic – Meanbh-Chiuleag – biting midges are a family of small flies found in almost any aquatic or semiaquatic habitat throughout the world, including Malta.
Little is known about them as they have hardly been investigated, yet 13 new records of midge have been uncovered in Malta over the past year, adding to eight already known since at least 1804. The earliest recorded was from Rabat, and was identified by the eminent German entomologist Meigen, known for his pioneering work on flies.
Biting midges are a family of small flies, also in the order of Diptera. Most females are adapted to suck blood from some kind of host animal.
The early stages of life for most biting midges need moisture in order to survive. Some are totally dependent on ponds, streams and salt marshes for their development. Others are semi-aquatic, developing in mud, wet meadows, leaf litter, moss, tree holes, under bark and in farm animal dung.
Adults may feed on flowers or prey on other insects. A few of the blood-sucking species can be carriers of disease, such as bluetongue in sheep and cattle and African horse sickness. Other types of midges found in tropical regions are important pollinators of commercial crops such as cocoa.
A soldier beetle, widespread in Europe, Asia and North Africa was collected in spring 2014 and confirmed as a new record for Malta. This type of orange-red beetle whose larvae are sometimes observed feeding on slugs and snails, can be found on flowers where they often eat both the flower and any pollinators that alight on it.
A certain group of the ‘picture-winged’ fly family plays a useful role. The larvae of some of these flies develop in carrion that has reached an advanced stage of decay after several months. Because they develop at constant rates, their size and stage of development provide clues to the time and conditions of death.
The economic, veterinary, forensic and ecological importance of insects is clear from the wealth of information supplied in this publication. Their usefulness as occasional climate change indicators is also evident.
Some specifics of how cameras have been used in combination with microscopes to capture the fine, detailed images, are also given.
All papers are peer-reviewed and assessed by foreign scientists, making the journal a platform for further studies. Thirty-two Maltese scientists have contributed to the bulletin since 2008, with almost double that number of foreign scientists from as far apart as Serbia and the US. So far, 1,278 different species have been described, with 416 new records for Malta and three completely new to science.
http://insected.arizona.edu/arthroinfo.htm
www.entomologicalsocietymalta.org/publications/esm-bulletins